22 May 2013
Parallel Session: Musculoskeletal and Mammo23
Parallel Session: Education and Management37
Parallel Session: Technical issues and Miscellaneous79
23 May 2013
Parallel Session: Pediatric912
Parallel Session: Genitourinary-Gastro1214
Poster Abstracts1416
Mehdi Behzadi, Chief, Section for Musculoskeletal Radiology, Department of Radiology, Stavanger University Hospital, Norway. Christian Stersdal, Consulting Orthopedic Surgeon, Department of Orthopedic Surgery, Haukeland University Hospital, Norway
Introduction: Entrapment of the quadratus femoris muscle between the trochanter minor of the femur and the ischium-hamstring tendon, ischiofemoral impingement, is an uncommon and controversial cause of hip and groin pain. Most patients reported with this condition so far have been women in their 40s.
Case description: A 14-year-old girl was referred to the Department of Radiology in 2010 because of persistent pain in the groin. Despite being comprehensively examined with radiography, ultrasonography, and magnetic resonance imaging, the correct diagnosis was not made before 2012. She did not respond well to conservative treatment and eventually underwent surgery the same year in May 2012.
Discussion: To our knowledge, this patient is the second youngest reported with ischiofemoral impingement and the first one surgically treated in Norway. There was an unfortunate delay of diagnosis in our case, the possible reasons for which will be discussed, underscores the need to raise the awareness of both musculoskeletal radiologists and orthopedic surgeons about this condition.
Long-standing symphyseal and adductor-related groin pain is a common problem for many athletes, and requires a multidisciplinary approach. Radiological evaluation of symptomatic individuals is a cornerstone in the diagnostic work-up, and should be based on precise and reliable diagnostic terms and imaging techniques.
The authors performed a review of the existing original evidence-based radiological literature involving radiography, ultrasonography, and magnetic resonance imaging (MRI) in athletes with long-standing symphyseal and adductor-related groin pain. Our search yielded 17 original articles, of which 12 are dedicated to MRI, four to radiography, and one to ultrasonography. Four main radiological findings seem to consistently appear: degenerative changes at the pubic symphyseal joint, pathology at the adductor muscle insertions, pubic bone marrow edema, and the secondary cleft sign. However, the existing diagnostic terminology is confusing, and the interpretation of radiological findings would benefit from imaging studies using a more systematic approach.
Purpose: To assess the diagnostic accuracy of weight bearing fluoroscopy with 3D multi planar reconstructed (MPR) images when diagnosing the presence and the extent of bone cysts in patients with a Scandinavian total ankle replacement (STAR) as compared to plain digital radiographs, hypothesizing that 3D MPR show more and larger cysts.
Methods and Materials: All STAR patients visiting the outpatient department for routine follow-up were asked to enroll in this independent study approved by the local ethical board. Forty-two consecutive patients were included. All 3D MPR images were reviewed independently by two blinded musculoskeletal radiologists in regards to size and location of cysts. Cysts were measured in three planes when possible.
Results: Significantly more cysts were detected on 3D MPR (74 vs. 55), P 0.03 (McNemar's test). The average size of cysts on 3D MPR were 1653 mm3/57 mm2 vs. 813 mm3/62 mm2 on plain digital radiographs with a significant difference in size, p < 0.0001 (Wilcoxon signed rank test). These findings support the hypothesis that 3D MPR show more and larger periprosthetic cysts in STAR patients as compared to plain digital radiographs. An inter-observer agreement of 0.24 (p 0.1), 95 CI (0.08, 0.41) and an intra-observer agreement of the senior radiologist at 0.20 (p 0.3), 95 CI (0.23, 0.62) highlight the importance of experience when interpreting 3D MPR images.
Conclusion: Data imply that cysts are better detected and more accurately measured with 3D fluoroscopic MPR imaging as compared to plain digital radiographs, which underestimate not only the presence but also the extent of cysts.
The lecture intend to show how MRI can assist the surgeon in making the right decisions by thorough imaging and interpretation of hip morphology and pathology.
We will present imaging heavily reliant on high resolution 3D MRI to back up clinical and X-ray investigation on FAI and other hip dysmorphology, and a non-contrast image protocol developed over a 5-year period as the result of FAI investigation in collaboration with announced speaker of the programme, Jone Segadal.
The lecture will show main FAI findings such as the pathology of the cam lesion and how to reliably investigate the alfa-angle, how to asses pincer related morphology and pathology, and MRI primarily focused on detecting subtle FAI-related pathology of the young patient.
The imaging techniques presented are made on commonly available 1.5 Tesla equipment and intended possible to incorporate in routine FAI investigation of most diagnostic centers.
Purpose/Objective: Our purpose was to find a practical approach for quality assurance of chest radiographs, to reduce the number of rejected chest images and provide individual feedback to radiographers.
Materials and Methods: We adapted the well-known PGMI system for quality assurance in the Norwegian Breast Cancer Screening Program, to fit positioning and image criteria for chest radiographs given in the radiographic guidelines at the hospital. The PGMI system is a quality-review model that classifies images into following categories; Perfect, Good, Moderate and Inadequate. These categories were used to evaluate the images according to positioning of patient and X-ray tube, collimation, rotation, breathing, movement, artifacts and exposure. Each category has different codes that depict reasons why the image has fallen into this particular category. The aim of the department was to reach an average percentage of above 75 on images categorized as perfect and good. 20 radiographers were selected and a total of 1620 images were evaluated. Two radiographers put each individual image into one of the four categories based on the codes representing the different image criteria. The 20 radiographers were evaluated twice. The first evaluation was made without the knowledge of the radiographers. The second took place after weekly lessons focusing on anatomy, pathology and positioning technique during 4 months. Lessons about the thorax region were preformed for radiologist and radiographers. Our department has an ongoing reject analysis which was used to complete the results of the PGMI evaluation.
Results: First evaluation: AP/lateral projections(): P:34/33, G:4/20, M:3/14, I:58/33 and P G:38/53.
Common codes for moderate and inadequate AP: Scapula and chin in thorax (69), missed visualization of the lung (6), and rotation of the sternoclavicular joint (12).
Lateral: Superimposition of the posterior lung border (48), missed visualization of the lung (14) and arms not raised clear of the thorax (2).
Second evaluation:
AP/lateral projections(): P:54/35, G:9/27, M:3/14, I:34/25 and P G:62/61.
Common codes for moderate and inadequate AP: Scapula and chin in thorax (64), missed visualization of the lung (5) and rotation of the sternoclavicular joint (3).
Lateral: Superimposition of the posterior lung border (38), missed visualization of the lung (14) and arms not raised clear of the thorax (9).
Reject-analysis:
First evaluation AP/lateral():4,8/6,6
Second evaluation AP/lateral():5,6/12,4
Discussion/conclusion: The implementation of the PGMI evaluation of chest radiographs gave us the opportunity to register image quality. After continuous focus on thorax we were able to increase the number of perfect and good images by 24. On the other hand the reject analysis showed a doubling in rejected lateral images. PGMI is a good tool to register image quality and enables us to give individual feedback to radiographers. PGMI can also be successfully implemented to evaluate image quality of other anatomical regions.
Purpose/Objective: Radiography education and profession in Europe are facing changes for reasons stemming from the standardization of education by the Bologna process and also because of rapid changes in the healthcare environment and client demands. Because of this, radiography education should be competence- and evidence-based. The aim of the present paper is to present a review of articles presenting radiographer's generic and specific competencies and explain how these competencies are described.
Materials and Methods: The following databases were searched: Cinahl and Medline in English language, SweMed Scandinavian database, and Medic Finnish language electronic database. Also volumes of some peer-reviewed journals were searched by these main keywords: radiographer/radiologists/technologist/X-ray nurse/radiotherapist and their Finnish and Norwegian synonyms. These were combined to keywords competency, competence, radiography, radiotherapy, radionuclear, and 'nuclear medicin. The time limit was set from 2000 up to the date of search in order to have a view about radiographers' competencies nowadays.
Results: Three generic and five specific competencies for radiographer work were formed on the basis of theoretical framework and data. Generic competencies found were communication competence, professional competence, and innovation competence. The profession specific competencies were patient care, leadership and management, diagnostic imaging, radiotherapy and radiation safety, and quality assurance competencies.
Discussion: This presentation gives ideas on how to implement evidence-based method in radiography education: constructing curriculums and using evidence-based pedagogy. The authors also suggest creating professional evidence-based competence criteria for radiographers both for the education and clinical practice of different levels.
Purpose/Objective: Project purpose in details is to develop evidence-based digital imaging and quality assurance for dental X-ray equipment and viewing conditions in order to reduce the radiation dose to the population. Specific aims are to develop: curriculum, evidence and web-based pedagogy, e-based learning materials for digital dental imaging and viewing conditions, X-ray equipment quality assurance and dose optimization education for adult and juvenile education and an implementation plan of internal evaluation of quality control for dental equipment and viewing conditions.
Materials and methods: This project benefits and implements the evidence-based method of developing curriculums produced in previous project by the project members.
Results: Expected outcomes are an educational package for evidence-based digital imaging and quality assurance for dental X-ray equipment and viewing conditions. This includes curriculum with evaluation criteria, as well as e-based learning materials for Bachelors and Masters level juvenile and life-long education for dental hygienists and dentists.
Discussion: Although doses incurred during dental examinations are in general relatively low, dental radiography accounts for nearly one third of the total number of radiological examinations in the European Union. Digital imaging gives opportunities to get the doses lower with the same image quality, but there is also possibility for dose increase because it is easy and quick to take more X-rays. Therefore special attention with regard to radiation protection and follow-up of doses and image quality is needed also in a form of education to the healthcare staff taking dental X-rays.
Purpose: The purpose of the project was to insure that the necessary practical and theoretical knowledge was given to each student so that at the end of their internship they could perform radiological examinations independently and correctly.
Materials and Methods: We designed evaluation sheets for practical and theoretical tests that included anatomy, pathology, technical parameters, patient care, use of contrast media, and radiation knowledge.
Ten days were used for planning of the project. Enough time was allocated on the test day for students to conduct the two tests.
For the first student evaluation we were two head radiographers (1 examiner 1 observer), plus a representative from the radiographer school in Drammen to evaluate the examiner, seeing that it was the first time. In the future it will only be one examiner.
Results: Students completed two radiological examinations independently. They were also given the opportunity to justify the choices they made during the test and verify for themselves the technical expertise they have gained throughout their internship.
The teaching we planned was sufficient for the theoretical test, but in future we will choose to increase the scope of teaching in terms of content and teaching sessions. The requirements we posed to the students could be perceived as high, but since we saw that previous students knowledge including anatomy, pathology and radiation physics was something lacking, we chose to maintain the standards we believe are needed to conduct a radiological survey in a satisfactory and acceptable manner.
We observed later that the time we spent on the theoretical review of the CT test may be shortened to only 1 h and not 1.5 h. We used 30 min on a general radiography and 40 min on a CT examination which provided students ample time in the lab. The students learned that the practice should end with a test and we believe that this contributed to a more active and responsible attitude among students in relation to their own learning. They were given specific goals to strive for and proven the expectations we had for them. We therefore believe that they received maximum learning from their internship.
Discussion/Conclusion: After monitoring the students and feedback from them, we believe that we have achieved our project goal which was that students would have a tool to verify for themselves whether they have achieved their goal in their internship. We could document that students did not just participate in an internship, but that they successfully completed their internship in the implementation of the practical and the theoretical tests. It was a positive experience for both student and for us.
Purpose: Children are of special concern in radiation protection because radiation exposure during childhood causes larger additional cancer risk than a corresponding exposure in adulthood. Furthermore, children have special characteristics which must be taken into account in radiological practice.
Pediatric radiologists in Finland all work in the five university hospitals of the country, but most pediatric radiography examinations are done in health centers and smaller hospitals where even a general radiologist might not be available every day. That is why Radiation and Nuclear Safety Authority STUK and pediatric radiologists started their joint effort to establish national guidelines of pediatric imaging in 2004.
Materials and Methods: The initial meeting to establish the guideline included several representatives of both radiation protection authority and radiology professionals including pediatric radiologists, radiographers and medical physicists familiar with pediatric imaging. The process of writing the guideline was divided between the pediatric radiologists who worked together with the other professionals in their organization. Each publication had one to two editors who collected, edited, and shared the text for review to all pediatric radiologists and selected clinical experts. Electronic communication by e-mail facilitated quick communication and only a few problems needed a face-to-face meeting.
Results: The first guideline was published in 2005 and included mainly detailed practical technical advice for the most common radiography, fluoroscopy, and CT examinations. The next supplementing guideline was published in 2008 including advice in justification and quality criteria for good imaging practices. The third one focused on pediatric CT because of its significantly higher radiation dose and complex technique which make optimization more challenging. The guidelines are freely available on the STUK Radiation and Nuclear Safety Authority website, and have actively been quoted in all radiological education and training.
The implementation of the guidelines and change in practice has been proven in regular clinical audits, internal audits and self-evaluations. During 20052010 the audits focused especially to pediatric imaging.
Discussion: The process of initial meeting to establish the focus, dividing work load to several practitioners, active cooperation of different professionals, reviews by different professionals and meetings only to resolve the most difficult details was proved to be both effective and reasonably fast. The editors' familiarity with the subject and connections with different professionals are essential for smooth process.
Collaborative effort by all professionals involved in practice, including radiologists, radiographers, medical physicists, and the radiation protection authority can produce instructions that can be widely accepted and utilized.
Objective: In 2012 Odense University Hospital organized the treatment of non-elective patients in a new way. Most of the non-elective patients are examined, diagnosed, and treated in the Emergency Department (ED). The Department of Radiology moved all examinations related to trauma and emergency radiology to the ED. Planning and executing the integration of a satellite Radiology Department in an ED, however, resulted in challenges. Especially did the task of changing the mindset of a large group of radiographers, to meet the strict timeframe from the new workflow in the ED.
One of the primary workflow-related challenges was the demand from the ED that all radiological examinations must be performed within 1 h of the patient arriving. This was to be accomplished without any additional workforce resources.
Methods: The management aspects were solved by hiring an experienced radiographer 6 months prior to the starting date of the new ED. The approach to the task was to identify the needs of the new ED and then prepare the workforce for their new task by promptly giving them as much information as possible. It was also very important for the head radiographer of the ED to remain visible and communicate as much as possible with the colleagues.
Results: After 1 year of operation the challenge of one hour examination time is still promising. The workforce related challenges are still present, but most are solved.
The experiences prior to starting the new ED and the continued accumulated experiences, are presently used by other hospitals in Denmark and Norway (Bergen/Trondheim).
Discussion: What method is the best for a paradigm shift in operational workflow in a new ED. Is a theoretical or practical approach the best?
For us a practical approach turned out to be the best solution, primarily because this method was much more visual and concrete for the majority of the workforce. It gave them a more palpable management. We also used lead the way management, where the head radiographer of the ED was the same person from 6 months prior to the opening of the ED. This same head radiographer was an integral part of the operational aspect and continues to be so.
Introduction: Nurses and medical doctors are allowed to use the mobile C-arm in operating theaters and emergency rooms in Finland. According to Finnish legislation nurses working in operating theaters have a 40-h (1,5 ECTS) course in radiation protection in their bachelor degree. Training includes fundamentals of radiation physics and radiation biology, radiation protection provisions, radiation safety measures at the workplace, and medical use of radiation in the area of mobile C-arm.
The purpose of this study was to find what the critical points in education are and how well the key factors affecting to the radiation protection and safe use of mobile C-arm in operating theaters and emergency are learned during the course.
Methods and Materials: The course consists of five areas given in EU legislation. There are 16 h of lectures and 2 h of demonstration, 2 h of written exam and 20 h of independent work (reading legislation and articles). Features and technical parameters of C-arm are demonstrated step by step in practice. A written exam has to be passed. More than 1600 answers have been analyzed.
Results: About 80 of the participants passed the test the first time and only 1 needed a third exam. Most participants were nurses. The most difficult areas were the basic concepts: radiation and its features, effects of radiation at the molecular, cellular and tissue levels, deterministic and stochastic effects of radiation, dose motoring and categories A and B, controlled and supervised areas and monitoring of radiation exposure of workers. The operational radiation protection was quite well known but dose optimizing methods are not understood very well.
Conclusion: Radiation and Nuclear Safety Authority (STUK) performed in 2010 a study to the radiation safety officers in duty in hospitals. According to the results there is a lack of training. Only some nurses have radiation protection education during their bachelor degree because all universities of applied sciences do not offer course in radiation protection.
The nursing staff is very willing to evolve into good safety culture but the use of equipment and all properties in radiation dose optimization are difficult to understand. More hands-on training is needed. During the courses there has been discussion about factors influencing to the interpretation of fluoroscopic procedures and expose of children and pregnant women.
Purpose: Radiation is commonly used in operating theaters by nurses and medical doctors. The purpose of this study was to find out how much radiation is used, in which procedures, how the radiation protection is realized and who are responsible of radiation safety in operating theaters in Finland.
Materials and Methods: The questionnaire was made for this study in cooperation with the Radiation and Nuclear Safety Authority in Finland (STUK). The research data were collected in Spring 2012 by an electronic questionnaire. Research data consist of 31 answers given by the operating theaters. There were seven sections in the questionnaire: radiation user's organization, use of radiation, C-arm techniques, radiation dose monitoring of the staff, use of radiation shields, radiation protection during pregnancy (patient or the staff member), and safe use of radiation.
Results: As an essential result was lack of training. Updated training in radiation protection varies among operating theater units. Approximately 17,600 procedures were done in operating theaters in 2011. About 1350 (8) of them were children procedures. Orthopedic and traumatological procedures were the most common. Responsibilities in radiation user's organization were divided. Physicist or radiologist was mostly as a radiation safety officer. Physicist was responsible of quality assurance. The charge of C-arm belongs to nurse or practical nurse. Nurse, surgeon, or practical nurse was in charge of using C-arm during procedures. 84 of the respondents had personal dose monitoring and the dosimeter was placed on thyroid shield, apron, or left arm. Nearly every operating theater unit records patient doses regularly. Both aprons and thyroid shields were available every operating theater. Nevertheless, all the staff members do not wear protective shields during procedure (19). Lead shields for all patients were used in 58 of cases. Staff members without shields exit the room during use of radiation. Pregnant staff members were transferred to other duties (61).
Conclusion: The use of radiation is an integral part of the work in operating theaters considering the number of procedures. Nevertheless, there was a lack of training. The right way to use of radiation dosimeter is not clearly understood. Surgeon is often in a hurry which bothers the staff member in charge of C-arm. In many theaters staff were aware of the problems related to the use of radiation, but there seems to be an indifference attitude to radiation protection.
Purpose: The purpose of this study was to find out radiographer students' opinion about learning in a project. The students made material for ortopantomogramic imaging of the teeth in the area of dose optimizing with a head phantom.
Materials and Methods: The students made five different PowerPoint materials with texts and images as well as photos taken by themselves. The presentations are from the equipment and its use, positioning including positioning criteria and errors, image quality and dose with different programs and quality assurance. Also a guidebook for children made earlier as a bachelor thesis was translated to English. All materials are in English. Four students wrote their own experiences about the benefits and learning outcomes.
Results: The students were very satisfied with the results they reached. It was interesting to plan the whole project in a small group quite independently. The literature of dental imaging is now familiar for them. They learned a lot of panoramic equipment and quality assurance of dental imaging. The head phantom was useful for positioning and it was instructive to take a photo of the position and then analyze the radiograph. Also the dose optimization and measuring of scattered radiation was illustrative.
The students learned also team work, honoring each other's opinions and making common time schedules. They usually worked after school hours in the evening and that's why they sometimes were stressed and tired. The material was made in English and that was very demanding but also useful for future purposes.
Conclusions: The students made materials for three ECTS course in panoramic imaging. The materials will be available in educational package for evidence based digital imaging and quality assurance for dental X-ray equipment and viewing conditions made by Metropolia University of Applied Sciences (Finland), Oulu University of Applied Sciences (Finland), Radiation and Nuclear Safety Authority (Finland), Helsinki University institute of dentistry (Finland), Oslo and Akershus University College of Applied Sciences (Norway) and Tartu School of Health Care (Estonia).
Objective: Dynamic contrast-enhanced MRI can be used for the assessment of renal glomerular filtration rate (GFR), which is the most used parameter for kidney function in the clinics. Due to patient movements, mainly from breathing, the image time series must be motion corrected in order to be properly analyzed. Moreover, the kidney cortex must be automatically located to estimate the GFR.
Traditionally, these two tasks are accomplished sequentially, registration followed by segmentation. As an alternative, we propose a method to perform simultaneous registration and segmentation, with an iterative feedback mechanism between those two steps.
Material and Methods: We used four data-sets from healthy volunteers. A breath-hold T1-weighted 3D single gradient recall echo (GRE) pulse sequence implemented on a 1.5 Tesla MR scanner (Avanto, Siemens) was used to acquire signal-intensity time curves after administration of a small dose (2 mL) of a gadolinium-based contrast agent intravenously.
Given a data term D and regularization term R we propose to solve the registration problem
for user defined settings a, > 0. The function q is a level set function defining the cortex, x are the spatial coordinates and u is the deformation field.
The distance measure di, i 1,2 from the foreground and background data to a training set depends on the deformation field u, which turns the method into a segmentation-driven registration. We propose to use the Mahalanobis distance for di, where the distance is projected from a sphere onto an ellipsoid.
Evaluation and results: Our model: (i) produces a good 3D segmentation of cortex; (ii) has larger deformation fields than the traditional model; (iii) resulted in reduced kidney volume compared to the sequential model in three out of four experiments; (iv) has smoother time curves in three of four experiments; and (v) has a better fit to the underlying data in terms of a compartment model.
Discussion and Conclusions: Our evaluation revealed that the proposed model had the ability to produce a 3D segmentation of the kidney cortex. Although the small number of subjects in our study, these results indicate that our method potentially has advantages compared to the traditional, sequential model, possibly due to the internal feedback loop between the segmentation and registration. The improvements in the analysis of these data can be important for the further development of DCE-MRI into a clinical tool for quantitative kidney diagnostics.
Objective: The recommended approach of analyzing uniformity in CT images is to scan a uniform phantom and measure the mean HU value in a region of interest (ROI) placed centrally in the image, as well as ROIs in the top, bottom, left, and right position of the image. The difference in HU value between the center and the peripheral ROI should be 4 HU (1). Using this method, only a small area of the image is analyzed and any potential artifacts outside these ROIs are not found. Inspired by work done at Karolinska University Hospital (2, 3) we propose a method to analyze the uniformity of an entire CT volume in both x-y and z-direction in order to detect any inhomogeneity in the CT image volume.
Method: Images of the uniform CTP486 module in the Catphan 600 phantom (The Phantom Laboratory, Salem, USA) were analyzed by using an in-house made program developed in Python programming language (Python Software Foundation). A grid consisting of small quadratic ROIs is fitted into the central part of the image, avoiding any edges. The mean pixel value is calculated for each quadratic ROI and the difference between the ROI with the maximum mean value and the ROI with the minimum mean value is noted. If there are heterogeneities in the image this difference will be detected. The difference between the maximum and the minimum mean value is plotted for every image in the z-direction, showing the uniformity of the entire CT image volume and pointing out images with any discernible artifacts and heterogeneities.
Result: Both clearly visible artifacts and even imperceptible heterogeneities were easily identified for different CT systems from all CT vendors.
Conclusions: This method utilizes the entire CTP486 module of the Catphan 600 phantom for uniformity analysis, and graphically displays the result for every slice in the phantom, yielding information of the uniformity in x-y and z direction. Any artifacts and other heterogeneities are easily identified by slice and position. This sensitive, quick and robust analysis may be worthwhile to implement in quality assurance software.
Purpose: To evaluate the role of contrast-enhanced whole-body MR as a part of FDG PET/MR examinations in cancer patients.
Materials and Methods: Twenty-one patients (7 F, 14 M, age range, 4077 years, mean age, 61 years) with malignant disease who underwent PET/MR (positron emission tomography/magnetic resonance imaging) with FDG (18F-fluorodeoxyglucose) were included in this retrospective study. Diagnoses included sarcoma (n 10), carcinoma of unknown primary (n 4), melanoma (n 2), plasmocytoma (n 1), rectum carcinoma (n 1), seminoma (n 1), and lymphoma (n 1). FDG PET/MR was performed on a 3.0T PET/MR system. The PET/MR examination included non-enhanced T1-weighted gradient echo images used for attenuation correction (atMR) and contrast-enhanced (CE) THRIVE (T1 High Resolution Isotropic Volume Examination) images of the whole body. 4.5 MBq 18F-FDG/kg body weight was applied intravenously in all patients (275317 MBq 18F-FDG). Average time between tracer injection and start of the PET scan was 72 min.
MR images were evaluated by two board-certified radiologists. In cases of differing findings the final decision was met in consensus. A four-point scale was used to evaluate lesion detectability. Cohen's kappa was used to analyze the inter-rater agreement.
Lesion conspicuity on atMR and CE MR scans were compared using the Wilcoxon rank sum test.
Results: Sixty-seven lesions suspected for malignancy were detected by PET. Forty-five of those lesions were detected using contrast-enhanced MR and 33 lesions using atMR. CE MR also identified two cerebral metastases not detected by PET. Thus CE MR detected 14 lesions missed by atMT. Lesion conspicuity was significantly better with CE MR in comparison to atMR (p < 0.0001). Inter-rater agreement was excellent for both the enhanced ( 0.92) and non-enhanced MR images ( 0.9).
Conclusion: The addition of contrast-enhanced whole-body MR to oncologic FDG PET/MR scan protocols improves lesion detection and conspicuity in comparison to FDG PET/MR without MR contrast media. Thus the use of MR contrast media is recommended in PET/MR scans performed for tumor staging. Further studies are necessary to decide which diagnostic MR sequences are needed in PET/MR depending on the indication.
Purpose: Justification of radiological examinations should include informed consent of the patient. There are recommendations for the information, but we lack knowledge of the attitudes and expectations of the patients themselves. The aim of this study was to find out the wishes of the patients regarding the contents of this information.
Materials and Methods: The study was performed in the department of diagnostic radiology of a university hospital. A questionnaire was developed concerning expectations for information on a radiological examination and the dose and risks of radiation. A table demonstrating six different ways to inform about the dose and another table demonstrating four ways to tell about the risks were also prepared. Altogether 147 randomly selected voluntary patients were interviewed after radiological examinations by a radiographer using the questionnaire and showing the tables. The patients had gone through various examinations with different levels of radiation prior to the interview. The patients were between 1885 years of age (average 52.8 years); 60 were women and 40 men.
Results: Altogether 99 of the patients asked to take part in the survey accepted the invitation. According to an open question, patients would like to get information on the risks, the examination process, the dose, the options and the purpose of the examination; only 60 (15/251) of the comments revealed no need for information. A wish to receive information about the dose and risks of radiation in connection with all examinations or any examination causing at least a medium dose of radiation (generally speaking) was expressed by 94 of the patients (n 143). When patients were shown the table demonstrating different ways of indicating the dose, patients preferred the symbols and the scale of minimal-low-medium. When asked about the risks shown in the table, they preferred the scale of almost zero-minimal-very low risk of fatal cancer and the corresponding data shown by numbers. The patients would mostly like to receive the information from the referring practitioner (3.9 on a scale of 15) and the radiographer (3.3), and from the information letter sent from the hospital prior to the examination (3.9).
Conclusion: Most patients expect to receive diverse information on radiation in connection with an examination using ionizing radiation. These expectations should be taken into consideration when planning patient information.
The three essential elements in a radiological examination are a technically correct examination, a competent interpretation, and relevant communication of the results to the clinicians. Interpreting a trauma scan can be a difficult task because a myriad of pathologies is often found where life-threatening injuries must be identified and an accurate and immediate report is required. A proposal is made to solve this problem in the form of a checklist. The CT Trauma Checklist can improve the interpretation of the scan and make communication to all the members of the trauma team effective.
Purpose: Primary purpose was to make a presentation of an interesting case at Rntgenveckan Ume 2011.
Abstract: I started my radiology residency at Sahlgrenska University Hospital in May 2011 and won the first price at Ung Forums case presentation, Rntgenveckan 2011 Ume. This case presentation is about a healthy young man who injured himself during a rollerblade trip resulting in neck pain with neurogenic upper arm symptoms. Initially the patient did not seek medical help because he was young and healthy, and who seeks medical help for a little neck pain? Prolonged and accentuating health problems led the patient to seek medical help. Following radiologic examinations revealed a serious underlying pathology, not expected regarding the patients history. This case is one of many showing that radiology is the clinician's eyes on reality. The underlying pathology will be revealed at the case presentation in Bergen 2013 making the case more interesting.
Purpose: The increasing number of pediatric CT examinations is a challenge for both justification and optimization processes, especially for those institutions where the number of pediatric patients is small and thus experience is limited.
The Finnish Radiation and Nuclear Safety Authority (STUK) has already published several guidelines of pediatric imaging in cooperation with pediatric radiologists. We describe the recently published national guideline for pediatric CT.
Materials and Methods: The guideline consists of two parts: technical and clinical. The differences between different scanners are a big challenge for optimization. The technical part therefore includes both technical principles and parameters common to all equipment as well as vendor-specific chapters. The development of rapid multislice techniques has changed the procedure of pediatric CT, especially in body and trauma imaging. At the same time the development of MRI has affected the justification of CT.
Results: The technical chapters include practical advice for optimizing tube voltage, tube current, slice thickness and their effect to image quality. It also explains the basic terminology like SFOV/DFOV, AEC and dose indices in practical terms. The vendor-specific chapters include additional detailed information of special features like the use of RefmAs, NI, AEC, iterative reconstruction.
The clinical part is divided anatomically but includes also own chapters for trauma CT and PET-CT covering CT examinations performed in most institutions. Every chapter includes list of indications based on both literature and national practices, practical advice for the whole procedure like the need of breath hold, use of i.v. and p.o. contrast or the need of multiple phases.
The chapter for head CT discusses the differences in routine imaging of the brain vs. the imaging the ventricular size in patients with ventriculo-peritoneal shunt. The ENT chapter shortly discusses both facial trauma and preoperative imaging. The chapter for chest imaging includes also HRTT, and abdominal CT is also discussed though ultrasound and MRI are much more common in pediatrics. CT of articular trauma and the use of CT topogram/scanogram in leg length discrepancy arevs included in Orthopedic chapter. Chapter for trauma CT includes rules for indications based on literature.
Conclusion: The rapid development of CT equipment and the differences in technical details make guidelines challenging to develop. We will present our national guidelines that include both very practical technical knowledge and advice for justification and performance of common pediatric CT examinations.
The reported incidence rates of injury-related bone fracture in children below 16 years lies between 1.2 and 5. The incidence varies with age, gender, social and environmental factors and typically peaks at 1112 years in girls and 1314 years in boys, with a male-to-female incidence ratio of 1.5. The distal forearm is the most affected site, and often caused by a fall. We here present the incidence and fracture pattern in a population based cohort of otherwise healthy children, aged 02 years. This age group is particularly vulnerable to intentional injuries.
Material and Method: During the period 20102012 all children between 0 and 2 years, seen at the A&E department in Bergen (Bergen Legevakt) due to an injury, and who had radiographs taken, were included. Data on previous injury, age, sex and injury mechanism were drawn from the prehospital and hospital notes and PACS archive. All radiographs were reviewed by a pediatric radiologist, registering the following: site and type of fracture, callous formation (yes, no), bone structure (normal, pathological) and metaphyseal appearances (shape (normal, metaphyseal collar, metaphyseal irregularity), injury). The study was approved by the Regional Ethics Comitte (REK-Vest).
Results: 200 children (94 girls) between 2 and 24 months of age were included, of whom 68 had a definite fracture (68 per 10,000 children less than 2 years). 21 (30.8) of the fractures involved the radius. Most were horizontal or greenstick-fractures, and none involved the metaphysis. A fall was noted as the most common mechanism, although an unclear history was reported in 36 children (18). 25 of the children without a fracture had a so-called pulled-elbow. 429 metaphysis were analyzed, of which 10.9 were defined as either irregular (8.6) or demonstrating a metaphyseal collar (2.3). No injury to the metaphysis was seen.
Conclusion: The incidence of fractures in children under the age of 2 years was 68 per 10,000, of which the distal forearm was most commonly involved. Notably, none of the fractures involved the metaphysis, indicating that this type of fracture probably has a more atypical injury mechanism. A wide spectre of normal metaphyseal irregularities exists in this age group. These findings are important to know about in order to avoid misinterpretation as a sign of child abuse.
Purpose/Objective: Radiologic imaging of child abuse demands high image quality because the consequences of misdiagnosis are serious. In the region of Southern Denmark approximately 40 children per year are examined in four different radiology departments. Until recently different guidelines were used. This proposed difficulties, since all images are subject to second opinion statements. In addition crucial interdisciplinary efforts between the radiological and pediatric departments were organized differently.
Child abuse imaging differs from other radiological investigations due to the fact that the images are directly involved in a legal process. The child and the family face major consequences if the images are not adequate from a legal point of view. If head trauma or fractures are overlooked, or if there is radiological uncertainty of the diagnosis, the child may be sent back to violent parents or caregivers. This is obviously the worst-case scenario, because the mortality rate of battered child syndrome is between 15 and 38. In the certain type of abuse called shaken baby syndrome less than 35 of the survivors have no physical or mental consequences of abuse.
If no abuse has taken place, and the certainty of the diagnosis is questionable, it may result in prolonged hospitalization of an innocent family. Re-examination could also be called for, which may result in unnecessary excess radiation dose.
Materials and Methods: A literature review was performed and the results were presented and discussed at a meeting in Odense University Hospital.
Results: The reviewed literature agrees that child abuse imaging should be performed by two experienced radiographers with special skills in the field. Images should be acquired at low noise levels in order to produce images that clearly distinguishes between cortical and cancellous bone and soft tissue. A speed class of 100 against normally 200 or 400 will be sufficient, but this demands somewhat higher radiation dose compared to common pediatric bone examinations.
For children below the age of 2 years, images must be acquired systematically and consequently. In this age group cranial CT scanning is performed as a standard procedure since 6080 of the deaths in child abuse are related to intracranial lesions. Cranial CT does not replace conventional head X-ray.
The children should be followed by a pediatric nurse who decides whether parents or caregivers can attend the examination.
Discussion/conclusion: Common evidence-based guidelines for child abuse imaging are implemented in the Region of Southern Denmark and annual meetings are arranged. Both pediatric radiologists and special radiographers attend. In the meetings legal aspects, best practice and best evidence in imaging and cooperation with pediatric departments is discussed, and guidelines may be adjusted subsequently.
Purpose: To describe the use and feasibility of MR compatible incubator in routine MR examination of term and preterm infants.
Material and Methods: From June 2012 a MR compatible incubator was introduced into regular use in consecutive 3T brain/spine and body examinations performed in neonates using dedicated pediatric head, body and spine coils. Body weight, postmenstrual age (PMA) at time of examination, exam time, the use of anesthesia, hemodynamic changes during the MR exam, clinical indication and results including image quality were registered.
Results: Registered results until 31.12.2012 include a total of 24 patients of which 18 brain and 9 body/spine examinations. Mean patient weight was 3478 g (15004400 g) and PMA 38 (3044) weeks. General anesthesia using the built in ventilator was used in 15 patients, whereas the remaining were pacified using feed and wrap or light sedation during the procedure. No significant hemodynamic changes were registered during the examinations and the changes in body temperature were 1 degree in all patients. The image quality was good or acceptable in all exams. Motion artifacts were registered in five patients. The main indication for brain imaging was asphyxia and for neck/cardiac and abdominal imaging, tumor and anomalies. The imaging time in the scanner was 11.5 h.
Discussion/conclusion: MR compatible incubators provide new possibilities to examine critically ill neonates in a safe environment with good or acceptable image quality of the brain and body. Logistic adaptations and close multidisciplinary collaboration is necessary.
Purpose: To optimize the filtration used for pelvic radiographs in patients with Perthes disease.
Materials and Methods: Twelve exposures of a Leeds phantom were performed using an Opera Swing D4000RF(2010). The numbers of line pair groups and low contrast circles for Kv 65, 68 and 70 using mAs 2, 5 and 10 were counted and the DoseAreaProduct (DAP) was registered. Measurements with filter settings: no filter, 2 mmAl, 0.1 mmCu 1 mmAl and 0.2 mmCu 1 mmAl. All measurements were performed with and without a grid.
Results: At both 68 and 70 Kv, the dose was reduced by approximately 70 when using the 0.2 mmCu 1 mmAl filter, with and without a grid. Image quality decreased for both settings by 10.
At Kv 65 without grid and a filtration of 0.2 mmCu 1 mmAl, the dose was reduced by 77, with 20 reduction of image quality. Using a filtration of 2 mmAl, the dose was reduced by 61 with 10 increase in image quality. When using a grid, the dose was reduced by 75, with 30 reduction in image quality using a filtration of 0.2 mmCu 1 mmAl. Using a filtration of 2 mmAl, the dose was reduced by 41, and the image quality increased by 10.
Discussion: In children with Perthes disease, the following exposure techniques have been implemented in our department: 70 Kv using 0.2 mmCu 1 mm Al filter, with and without grid; 68 Kv using 0.2 mmCu 1 mm Al filter, without grid and 2 mm AL filter, with grid; 65 Kv using 2 mm AL filter with and without grid.
Children and young adolescents suffering from diffuse heel pain are frequently referred for radiological assessment at Section of Pediatric radiology, Haukeland University Hospital. When the calcaneus grows faster than the leg muscles and tendons, overstretching occurs thus making the heel less flexible and putting pressure on the growth plate. This may cause inflammation of the growth plate, Sever's disease (i.e. calcaneal apophysitis).
Objective: To examine for underlying pathology in children with persistent heel pain.
Material and Method: During Dec 2011Jan 2013, 21 children were invited to participate in the study. Both heels were examined in all but two cases. Radiological procedures included ultrasound, X-ray and for six patients, MRI (Sagittal SE T1- and STIR weighted images only). All patients were clinically evaluated by a radiologist on the same day of imaging.
Results: 21 children (6 girls, 15 boys) were included, mean age 10, 7 years. 14 patients did actively participate in soccer and/or handball, 4 participated in other forms of sport, whereas 3 patients indicated no physical exercise other than sports at school. No underlying pathology was seen in 19 of 21 cases. One of 21 patients was described with irregular calcanei, but did not show up for MRI. One of 21 was recommended a follow-up MRI to check for a synnovial cyst or ganglion. The MRI was normal.
Conclusion: In 19 of 21 patients referred for persisting heel pain, no underlying pathology was found, including markers for Sever's disease. It may be argued that young adolescents and children with these symptoms should be given a lateral heel X-ray of both feet to exclude fracture or malignancies.
Purpose: To examine the value of CT urography using split-bonus technique to distinguish carcinoma from adenomas in the upper urinary tract.
Materials and Methods: Patients, who between 2006 and 2011 underwent nephroureterectomy and who had split bolus CT urography prior to surgery, were included. The images should be available electronically. The attenuation values before and after administration of iodine based contrast was measured. The radiology, patient, and pathology records were reviewed.
Results: A total of 159 patients had nephrophrectomy. Of these 69 patients fulfilled the inclusion criteria. In 31 patients histopathologic examination revealed a benign diagnosis and in 39 a malignant diagnose. Neither absolute nor change in attenuation values obtained at CT urography could distinguish between benign and malignant lesions. No patient had a CT urography within the last year before the examination that lead to surgery.
Conclusion: A split bolus CT urography cannot distinguish between benign and malignant tumors in the upper urinary tract, but the examination is useful to diagnose a tumor in the renal pelvis and ureter.
Objectives: Study the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for assessment of tumor microvasculature in endometrial carcinoma patients, and explore possible correlations to clinical phenotype and microstructural characteristics based on diffusion-weighted imaging (DWI).
Methods: Three-dimensional DCE-MRI data with high temporal resolution (2.49s) were acquired preoperatively in 55 patients using 1.5T. Subsequent quantitative modeling allowed calculation of four independent parameters describing the microvasculature: blood flow (Fb), extraction fraction (E), capillary transit time (Tc) and transfer from extravascular extracellular space [EES] to blood (Kep); and four derived parameters: blood volume (Vb), volume of EES (Ve), capillary permeability surface area product (PS) and transfer from blood to EES (Ktrans). DWI imaging with b-values of 0 and 1000 s/mm2 was performed with generation of apparent diffusion coefficient (ADC) maps.
Results: Endometrial carcinoma tissue exhibited reduced Fb, E, Vb, Ve, PS, and Ktrans compared to normal myometrium. The mean ADC values were significantly lower in the endometrial carcinomas compared to the corresponding values measured in the normal myometrial tissue. Tumor Ve was positively correlated to tumor ADC value.
Conclusions: This study demonstrates the feasibility of DCE-MRI and DWI to reflect microvascular and microstructural changes in primary endometrial carcinomas. The microvascular phenotype assessed by DCE-MRI is currently compared to markers for intra-tumor angiogenesis based on immunohistochemical stainings of vessels in tumor samples from surgical specimen. DCE-MRI may potentially provide future biomarkers for preoperative risk stratification in endometrial carcinomas.
Objectives: To explore the feasibility and value of functional imaging by FDG-PET/CT to provide a better basis for individualized surgical- and targeted therapy in endometrial carcinomas.
Methods: Patients diagnosed with endometrial carcinoma at the Department of Obstetrics and Gynecology, Haukeland University Hospital, have since October 2011 been consecutively referred to preoperative contrast-enhanced FDG-PET/CT according to a standardized imaging protocol.
Results: Presently, 79 patients have been included in the study. In 90 (71/79) of the endometrial carcinoma patients, primary tumor was clearly FDG-avid compared to normal endometrial tissue. Mean maximum standardized uptake value (SUVmax) for the endometrial carcinomas was 14.5. FDG-avid lymph node uptake suggesting metastases was discovered in 15 (12/79) of the patients (seven with isolated pelvic metastases, two with pelvic and para aortic metastases, one with isolated peritoneal metastases, one with isolated para aortic metastases and one with pelvic, para-aortic, and thoracic lymph node metastases). No patients had FDG uptake suggesting distant parenchymal metastases. FDG-avid tissue in the cervix was seen in 18 (14/79) patients suggesting cervical stroma invasion. Incidental pathology (increased FDG uptake in the GI-tract and the thyroid) that required further diagnostic workup was discovered in 19 (15/79) of the patients.
Conclusions: Endometrial carcinomas are typically highly FDG-avid and FDG-PET/CT is well suited for diagnostics of this cancer. FDG-PET findings suggesting metastatic lymph nodes were identified in 15 of the patients, which is similar to reported prevalence based on surgical staging. FDG-PET is a promising method for improved preoperative metastatic lymph node detection in endometrial carcinomas and can aid in preoperative staging and thus promote individualized therapy. The clinical usefulness of tumor SUVmax as a biomarker of tumor aggressiveness and patient prognosis remains to be explored.
G. Wathle, E. Tjora, P. Njlstad and I.S. Haldorsen
Purpose: To characterize and quantify exocrine pancreatic function by secretin-stimulated magnetic resonance cholangiopancreaticography (s-MRCP) and diffusion-weighted imaging (DWI) in healthy subjects and in patients with monogenic diabetes (CEL-MODY and HNF1B-MODY) with exocrine pancreatic dysfunction. Compare s-MRCP and DWI findings to morphological features, i.e. pancreatic volume and fat content and to secretin-stimulated peak bicarbonate concentration measured in pancreatic juice.
Materials and Methods: Pancreatic MRI (1.5 T) was performed in 20 healthy volunteers, in 23 patients with CEL mutation, and in eight patients with HNF1 mutations. MRI included T2-weighted imaging and DWI acquired before and 1, 5, 9 and 13 min after secretin administration. Secreted pancreatic juice volumes were calculated based on the sequential T2-weighted images, and pancreatic volumes and apparent diffusion coefficient (ADC) values were estimated.
Results: In the healthy subjects pancreatic fluid output estimated by s-MRCP was 6.4 mL/min during the first 13 min after secretin. The corresponding figures were 4.5 mL/min and 4.0 mL/min in patients with CEL mutation and HNF1 mutation, respectively.
Pancreatic head ADC values significantly increased from baseline (1.29 103 mm2/s) to 1 min post secretin (1.48 103 mm2/s) (P 0.003) in healthy controls. A similar increase in ADC value at 1 min post contrast was not observed in the mutation carriers.
Conclusion: Secretin-stimulated MRCP and DWI can characterize and quantify exocrine pancreatic function in healthy subjects and in patients with exocrine pancreatic dysfunction due to monogenic diabetes. These imaging methods may prove relevant for various patient groups with exocrine pancreatic dysfunction.
An 84-year-old woman was admitted to the medical ward with headache, fever and elevated infection parameters. Differential diagnoses were sinusitis, meningitis or brain abscess, and she was treated with broad spectrum antibiotics.
Suddenly she develops nausea and acute lower abdominal pain. She hasn't vomited and she has passed stool normally during the day. She has never experienced anything similar before. Physical examination reveals soft abdomen with normal bowel sounds, but intense lower left quadrant tenderness. The surgeon on-call is consulted and a low-dose abdominal CT is requested. Free air? Bowel obstruction?
Objective: In Finland dental X-rays can be taken by dental hygienists, dental nurses, radiographers, radiologists or dentists. In October 2011 Radiation and Nuclear Safety Authority Finland published a Guide presenting the radiation safety requirements concerning dental X-ray practices. In order to find out the need for education of healthcare staff performing dental X-rays we made a survey study aiming to describe dental X-ray quality assurance procedures performed by by dentists, dental hygienists, dental assistants and radiographers in Finland.
Methods: Target group of the study was all the healthcare organizations in Finland having the cone beam CT (CBCT) in their use. Postal questionnaires were sent and 25/33 of them were returned.
Results: The dental imaging quality assurance tests were well performed. Almost all the respondents (22/25) had received some kind of life-long education in dental digital imaging quality assurance (QA). However only 11 of them had received QA education during their professional education. The participants wanted continuous and regular training in basic radiation protection and practical training. They also wished for education in CBCT quality assurance.
Conclusions: This study implies that the state of quality assurance in dental digital imaging in Finland is quite good. However education of the topic is still needed both inside professional education of dental hygienists, radiographers and dentists and in a form of life-long education. Most urgently is needed education for the basic radiation protection issues and cone beam imaging quality assurance issues.
Objective: Mastophathic changes surrounding a radial sclerosing lesion (RSL/CSL) are nothing unusual in breast imaging, but by its diversity these changes can often lead to diagnostic problems.
Material: We present the case of a severe, unilateral finding that simulated malignancy in the multimodal imaging and clinical examination, but without any detectable malignancy in the histopathological examination. In addition we reviewed current studies concerning this entity.
Discussion: RSL/CSL are often mistaken for carcinoma in the diagnostic work up. The decision if RSL/CSL should be considered a precancerous lesion, and how to discriminate RSL from breast cancer is still a problem mentioned in the literature and studies have shown that cytological diagnoses of RSL/CSL are nonspecific and the diagnosis of RSL/CSL with cancer is unreliable. Furthermore the incidence of RSL/CSL with breast cancer is more common in those older than 50 and in size above 7 mm.
Conclusion: Our case and the reviewed literature show that RSL/CSL is identified as a clear abnormal finding in mammography, ultrasound and MRI. But neither radiological nor cytological examinations could demonstrate correctly whether RSL/CSL is accompanied by breast cancer or not. The most reliable method is a partial resection that is wider than that for surgical biopsy in order to adequately diagnose breast cancer and to achieve resected a margin free from breast cancer if it exists. This should be performed in case of older age with larger RSL/CSL, to avoid oversurgery for cases without breast cancer.
Purpose: The purpose of the project was to insure that the necessary practical and theoretical knowledge was given to each student so that at the end of their internship they could perform radiological examinations independently and correctly.
Methods/Materials: We designed evaluation sheets for practical and theoretical tests that included anatomy, pathology, technical parameters, patient care, contrast use and radiation knowledge.
Ten days were used for planning of the project. Enough time was allocated on the test day for students to conduct the two tests.
At the first student evaluation we were two head radiographers (1 examiner and 1 observer), plus a representative from the radiographer school in Drammen to evaluate the examiner, seeing that it was the first time. In the future it will only be one examiner.
Results: Students completed two radiological examinations independently. They were also given the opportunity to justify the choices they made during the test and verify for themselves the technical expertise they have gained throughout their internship.
The teaching we planned was sufficient for the theoretical test, but in future we choose to increase the scope of teaching in terms of content and teaching sessions. The requirements we posed to the students could be perceived as high, but since we saw that previous students knowledge including anatomy, pathology and radiation physics was something lacking, we chose to maintain the standards we believe is needed to conduct a radiological survey at a satisfactory and acceptable manner.
We observed later that the time we spent on the theoretical review of the CT test may be shortened to only 1 h and not 1.5 h. We used 30 min on a general radiography and 40 min on a CT examination which provided students ample time in the lab. The students learned that the practice should end with a test and we believe that contributed to a more active and responsible attitude among students in relation to their own learning. They were given specific goals to strive for and proven the expectations we had for them. We therefore believe that they received maximum learning from their internship.
Discussion/Conclusion: After monitoring the students and feedback from them, we believe that we have achieved our project goal which was that students would have a tool to verify for themselves whether they have achieved their goal in their internship. We could document that students did not just participate in an internship, but that they successfully completed their internship in the implementation of the practical and the theoretical tests. It was a positive experience for both student and for us.
Purpose: The whole leg radiograph (WLR) is considered the gold standard for determining axial alignment of the lower extremities. Oslo University Hospital, Rikshospitalet perform an average of 200 WLR each year. Despite its popularity, this technique is argued to be costly, time-consuming, gives high radiation exposure and is not feasible for many hospitals.
Frontal plane malalignment has important biomechanical consequences because it influences the load across the knee joint during weight bearing, subsequently causing knee osteoarthritis.
Method and Materials: The WLR is achieved by placing the patient in an anterioposterior, two-legged stance, barefoot, and with both knees in full extension. A lead marker is placed at the anterior center of the patella and positioned just above the femoral intercondylar notch. If leg-length discrepancy is present, the pelvis is levelled by placing blocks of known height under the shortest limb. A frontal image is acquired by a dynamic exposure covering hip, knee and ankle joints. If further imaging is required to determine limb deformity, a lateral image of the whole leg is acquired separately. The true lateral projection is ensured by outlining the patient's footprint in the AP projection and turning it 90 degrees.
A ruler provides correctly calibrated measurements of the weight bearing mechanical axis alignment, which runs from the center of the femoral head to the center of the ankle.
The WLR is acquired using a Philips MD Eleva FD, with a 48 cm detector and an overcouch tube. The exposure parameters are defined by patient size; however, a Source-Image-Distance of 125 cm, 82 kVp and 320 mA are routinely used in correlation with Philips' intelligent exposure control to rapidly regulate the parameters to acquire optimal exposure.
Results: A two-leg stance is preferred opposed to a one-leg stance as the latter forces the knee in a varus against the lateral stabilising structures. Furthermore, a full-length standing AP radiograph of the entire lower limb, allows for a comprehensive analysis of the magnitude and source of the limb malalignment.
Conclusion: With the introduction of digital exposure, the examination is quick to perform and the dose adheres to the ALARA principle. The radiographic technique is reproducible showing a high intra-class correlation coefficient for both intra-observer and inter-observer reliability.
Purpose: Feedback from radiographers and radiologist suggested that there was a need for a review of the practice of taking CXR in bed-ridden patients. When identifying shortcomings in image quality through a systematic approach, the focus placed on the issue of radiographic image quality is addressed, and an increase in quality can be achieved. The maintenance of any quality improvement needs to be sustained through evaluating and implementing the method chosen. The overall objective is to deliver CXR of Perfect and Good image quality in >75 of all images.
Methods and Materials: The PGMI (Perfect, Good, Moderately good and Inadequate) system for quality assurance in mammography was adapted to the CXR examination. A core team of radiographers with specific skills and knowledge in PGMI and conventional imaging was identified, and a PGMI system for CXR in bed-ridden patients was described. Main aspects of radiography such as projection criteria and image criteria was identified (using the European Quality Manual for Radiography), and structured in a classification system for assessing PGMI in CXR. The overall image quality was the scope of the tool and based mainly on radiographers skills of performance. The classification system was validated by classifying 120 randomly sampled images in five batches. Together 11 radiographers were involved (including one experienced PGMI radiographer).
Result:
The classification system and the criteria chosen for assessing image quality proved to be valid, all radiographers who viewed the images found the criteria to be relevant and useful for describing the technical quality of a CXR.
The sample of 120 images uncovered trends in the criteria that were not met. It was therefore possible to focus on a few key criteria, and the overall image quality was improved as a result of the attention the PGMI system gave to CXR.
The attention the project gave was welcome, it is vital that this examination, performed on some of our most critically ill patients, is given the same scrutiny as other, more technically advanced methods in imaging. By addressing this, increased awareness, knowledge and skills were reported by the participants.
Conclusion: By adapting and using PGMI in CXRs of bed-ridden patients, overall image quality was improved, and radiographers reported increased job-satisfaction. The value of producing a perfect image was reported as positive. To make the method known to staff, a workshop was held and evaluated, eight radiographers and three facilitators participated. Feedback was unanimously positive, it was also reported that the self-evaluation that take place when using the system is valuable when it comes to professional awareness and pride taken in ones work.
Objective: In this project we aim at establishing a high-quality DCE MR-acquisition technique giving a precise kinetic modeling for the estimation of the clinical relevant measures of kidney function: renal blood flow (RBF), mean transit time (MTT) and glomerular filtration rate (GFRMR). Further we aim at establishing a DWI-sequence providing accurate ADC-values, analyzed for coherence with renal functional parameters.
Materials and methods: 10 healthy volunteers, 4 men and 6 women, mean age 23.5 3.5 years, were enrolled in this study. The study was approved by the institutional review board and all participants gave their informed consent.
Each volunteer were screened for creatinine clearance and further examined twice with the two different DCE and DWI sequences and once with the clinical reference standard of Iohexol Clearance (blood-samples for the determination of GFRi). Renal functional parameters (GFRMR, RBF, MTT) from MR were estimated using a modified Tofts model.
Two 3D DCE sequences (Flash, KWIC) were designed and optimized to provide good signal-to-noise ratio (SNR), high spatial-temporal resolution, minimization of artifacts and a linear relation between signal intensity changes induced by the contrast agent and concentration. A further two DWI sequences were designed and optimized to provide good SNR, suppress motion artifacts in addition to an optimal selection of 10 b-values.
Image quality analyses will be performed using a combination of subjective (visual grading characteristics, VGC) and quantitative indicators (SNR, CNR). 14 image quality criteria for visual interpretation were formulated reflecting well-known obstacles challenging optimal image quality in MR renography, and will be performed by three blinded observers.
Analyzes and forthcoming results: Analyses will be undertaken to investigate image quality differences between sequences (VGC curves) and subsequent relationship to the variability in the estimations of measures for kidney function (GFRi and GFRMR) as well as RBF and MTT. The apparent diffusion coefficient (ADC) from the diffusion-weighted image sequence will be analyzed for correlation to the perfusion- and filtration parameters from the DCE sequences. Preliminary results will be presented at the congress.
Possible implications of the project: Through the evaluation of conformity of renal functional parameters in each of the two sequence sets and thorough image quality evaluation, our aim is to disclose the acquisition techniques grade of robustness and precision. This will guide us in the selection of the appropriate DCE and DWI acquisition technique, being a contribution in the preparation of a possible clinical application of functional imaging of kidney function.
The project might provide valuable information on the interaction between image quality and diagnostic precision in assessing renal functional parameters. The proposed framework for image quality assessment in MRI will have a possible transfer value to other MR examinations for other indications.
