Acta Radiologica

Direct infiltration of the colon by hepatocellular carcinoma (HCC) is a rare condition. Only a few reports can be found in the literature. Here we present a case of direct infiltration of the ascending colon by an exophytic growing HCC of the right posterior liver lobe, in which treatment with transarterial chemoembolization (TACE) had been performed. Tumor invasion became evident by abdominal pain and lower gastrointestinal bleeding. Diagnosis was established by contrast-enhanced multidetector computed tomography (CE-MDCT), demonstrating the direct tumor invasion with concomitant perforation of the infiltrated colon segment. Based on these findings, rapid and effective surgical treatment could be achieved.

Mammography. Guide to Interpreting, Reporting and Auditing Mammographic Images. Re.Co.R.M. By V. Lattanzio and G. Simonetti. Springer-Verlag, Berlin, Heidelberg, New York 2005. ISBN 3-540-20018-5. Hardback. xvi + 280 pages, 400 figures. Price EUR 229.00

We report the case of a 30-year-old woman with persistent pain at the right hypochondrium, relapsing fever, and normal serum tests. Ultrasound showed a hyperechoic inhomogeneous mass; following sulfur hexafluoride injection, uniform enhancement at 14–16 s and rapid wash-out at 26 s was found. Multidetector computed tomography showed an inhomogeneously hypodense mass, with no detectable negative density values, characterized by inhomogeneous enhancement at the arterial phase and wash-out at the portal phase. Histopathology demonstrated a hepithelioid angiomyolipoma with a poor fatty component. This diagnosis should always be considered in the presence of a very rapid wash-out after intravenous contrast injection. However, a hepatocellular carcinoma cannot be excluded and the final diagnosis of low-fat angiomyolipoma must be pathologically proved based on immunohistochemistry.

Color Doppler twinkling artifact is known as a rapidly changing mixture of red and blue behind certain strongly reflecting structures. This artifact has been described behind calcifications in various tissues. We describe a case of twinkling artifact related to chronic pancreatitis with parenchymal calcification.

Purpose: To describe the findings on computed tomography (CT) of the aortic sac (AS) in patients operated on for abdominal aortic aneurysm (AAA) with insertion of a coated Dacron prosthesis.

Material and Methods: A prospective study of 36 consecutive patients operated on for AAA over 2 years and followed longitudinally with CT for up to 10 years.

Results: All patients had a fluid-filled AS on CT 7–10 days postoperatively. At 6 months, the AS had decreased in most patients, mainly in the antero-posterior diameter, and in two had disappeared completely. In five patients with complications, the AS increased in size. The AS disappeared completely at 10 years' follow-up in 13 patients. When present, a retroperitoneal hematoma always disappeared after 6 months.

Conclusion: These data indicate that the AS after graft implantation will diminish gradually but will persist for at least 6 months. Usually the transverse diameter is bigger than the antero-posterior diameter. If the AS enlarges and becomes rounded and distended with an inhomogeneous interior, it might be a sign of graft infection. In these cases an ultrasound-guided or CT-guided puncture is recommended.

Purpose: To evaluate the angiographic findings of patients who have inadvertently injected oral formulations of drugs into an upper extremity artery.

Material and Methods: The radiology files for the previous 4 years were analyzed retrospectively. Seven patients were referred from the Emergency Department for angiography and possible thrombolysis during that time period.

Results: The worst clinical results were found among the patients whose angiographic examinations showed absent flow. Two patients who were treated with local thrombolysis had no better results compared to the other five patients.

Conclusion: Findings of delayed flow and absent flow in angiography should lead to intensified conservative treatment, especially among patients who have clinical findings of delayed capillary refilling or/and impaired muscular strength.

A left atrial aneurysm is a rare cardiac anomaly. The etiology is usually congenital, but it can also occur as an acquired pathology secondary to mitral valve disease or a degenerative process. We report a case which, on routine PA chest radiography, presented as cardiomegaly with a bulge on the left cardiac contour. Further evaluation by contrast-enhanced computed tomography proved it to be caused by a large left atrial aneurysm.

Purpose: To evaluate dose reduction and image deterioration using in-plane bismuth breast-shielding and thyroid-shielding for MDCT.

Material and Methods: Skin and organ doses of thyroid and breast were measured with thermoluminescent dosimeters in a female Alderson-Rando Phantom with and without a 4-ply in-plane bismuth shield. Routine neck (120 kVp, 150 mAs_eff; 16×1.5 mm) and chest (120 kVp, 100 mAs_eff; 16×1.5 mm) scan protocols were simulated on a 16-row MDCT scanner in three different settings: without shielding, with the shield directly on the surface, and with a 1-cm-thick cotton spacer between surface and shield. Image noise was quantified and compared using the t test.

Results: On average, shielding resulted in a 47% organ-dose reduction for the thyroid and 32% for the breast. Placement of the spacer between shield and surface had no significant impact on the measured doses, but significantly decreased the image noise (P<0.05).

Conclusion: In-plane bismuth breast and thyroid shielding significantly decreases radiation dose in MDCT without deteriorating image quality.

Purpose: To evaluate changes in height and wedge angle of treated vertebral bodies and kyphosis angle 1 year after vertebroplasty.

Material and Methods: We reviewed radiographs of 95 vertebral bodies treated with vertebroplasty in 60 patients with osteoporosis. Only vertebral bodies with imaging evidence of a new fracture or avascular necrosis received vertebroplasty. Images were obtained for evaluation before vertebroplasty (B), within 2 weeks after vertebroplasty (T), and after 1 year (T1).

Results: The mean wedge angle decreased by 5.4° from B to T1. Mean of the anterior, central, and posterior heights of the fractured bodies increased by 12.6%, 9.6%, and 3.1%, respectively, from B to T1. The kyphosis angle improved by 3.2° initially from B to T, but the improvement later disappeared. In 48% of these patients, a new fracture developed after vertebroplasty, and 63% of the fractures were adjacent to a vertebroplasty-treated vertebral body.

Conclusion: The increase in height and wedge angle of the vertebral bodies generally lasted at least 1 year. Improvement in kyphosis angles was lost 1 year after vertebroplasty because new fractures occurred in 48% of these patients. Prevention of new fractures after vertebroplasty remains an important task.

Purpose: To evaluate the influence of anthropometric parameters (age, height, and weight) and bone size on bone mineral density (BMD) using volumetric quantitative computed tomography (QCT) and dual X-ray absorptiometry (DXA) in a group of elderly women.

Material and Methods: BMD values were obtained with DXA and QCT at the spine and hip in a cohort of 84 elderly women (mean age 73±6 years). QCT measures included trabecular, integral, and cortical BMD assessed at the hip and spine as well as cross-sectional areas of the mid-vertebrae and proximal femora. Spinal integral and femoral neck BMD measures were well matched to the regions of bone quantified on anteroposterior (AP) spine DXA and the femoral neck region of hip DXA.

Results: When QCT parameters were linearly regressed against body height and weight, only the relationships with weight were found to be statistically significant. Except for cortical BMD at the femoral neck, all BMD and geometric parameters measured from both DXA and QCT showed statistically significant associations with body weight (r ² = 0.4, 0.0001<P<0.02). The strongest associations with weight were found for DXA Neck (DXA_NECK) and DXA lumbar spine (DXA_LSP) (r ² = 0.4, P<0.0001).

Conclusion: The relationship of DXA BMD is stronger than QCT BMD with body weight and it encompasses the response of both bone size and density to increasing body mass.

Purpose: To identify and compare magnetic resonance imaging (MRI) characteristics, with and without intravenous contrast medium, of cavernous synovial hemangiomas and cystic synovial hyperplasia.

Material and Methods: Four cases of cavernous synovial hemangioma and five of cystic synovial hyperplasia of the knee were studied retrospectively. The patients (5 F and 4 M; 15–25 years of age) all had long-standing knee pain. At clinical examination we observed elastic swelling and pain without significant joint effusion. The patients underwent conventional radiography and MRI without and following intravenous contrast medium before arthroscopic biopsy.

Results: The radiographs were interpreted as negative in all patients. MRI examination without contrast medium revealed a similar multicystic appearance for both lesions. Following intravenous contrast agent administration, cavernous synovial hemangiomas demonstrated avid, rather homogenous enhancement, whereas cystic synovial hyperplasia demonstrated less intense, peripheral enhancement only. Arthroscopy with histological examination of the lesions confirmed the MRI diagnosis in every case.

Conclusion: In our experience, cavernous synovial hemangioma and cystic synovial hyperplasia have a similar appearance on unenhanced MRI, but can be reliably differentiated on the basis of enhancement characteristics following intravenous contrast administration.

Diffusion magnetic resonance imaging (MRI) is a method for quantifying the microscopic random motion of water molecules in tissues. Diffusion imaging provides indirect structural information of a kind not available on basic MRI sequences of many pathological conditions. Lately, especially brain tumors have been under active investigation, with numerous papers already published, and their number continues to increase. This review summarizes the heterogeneous and complex research data on diffusion imaging of brain tumors.

Computed Tomography: Fundamentals, System Technology, Image Quality, Applications. 2nd rev. edn. By Willi A. Kalender. Publicis Corporate Publishing 2005. 306 pages, 130 illustrations, 18 tables, with an enclosed CD-ROM.

We present the short-term follow-up magnetic resonance (MR) studies and ¹H-MR spectroscopy in a child with malignant peripheral nerve sheath tumor of the oculomotor nerve associated with other less aggressive cranial nerve schwannomas. The tumor revealed perineural extension and diffuse nerve involvement besides rapid growth. ¹H-MR spectroscopy was helpful in excluding an intra-axial neoplasm with exophytic growth, mainly due to the absence of creatine and N-acetyl aspartate peaks, and markedly elevated choline peak.

Purpose: To report a technique developed for visualizing cervical nerve roots and distal nerve fibers using diffusion-weighted magnetic resonance imaging employing parallel imaging.

Material and Methods: We performed maximum intensity projection for a stack of isotropic axial diffusion-weighted images obtained with parallel imaging applying a motion-probing gradient in six directions with a b-value of 500 s/mm² in a preliminary series of 13 subjects.

Results: This method worked well for visualizing the spinal cord and most of the nerve roots, the dorsal root ganglia, and proximal peripheral nerves.

Conclusion: Although the technique remains limited in depicting the brachial plexus and distal nerves, the ability to visualize the proximal peripheral nervous system at the cervical level is promising.

Purpose: To investigate whether measurements of brain structures on routine magnetic resonance (MR) images can be used to distinguish between normal subjects and patients with frontotemporal dementia (FTD) or Alzheimer's disease (AD).

Material and Methods: MRI studies were performed on 30 patients with dementia (FTD, n = 15; AD, n = 15) and 15 age-matched controls. Width measurements, obtained at the corpus callosum, the cingulate gyri, the hippocampi, and the temporal stem of the anterior temporal lobes, were compared among FTD and AD patients and control subjects on oblique-coronal T2-weighted images.

Results: The width of the temporal stem was significantly narrower in FTD than in AD patients and control subjects (6.3±1.3 mm, 7.8±1.1 mm, and 8.2±0.9 mm, respectively) (P<0.05), although there was some overlapping between AD and FTD patients. All patients whose temporal stem width was <6 mm had FTD. While the width of the corpus callosum, cingulate gyri, and hippocampi was significantly narrower in patients with AD and FTD than in the controls, there was no significant difference between the AD and FTD patients.

Conclusion: The width of the temporal stem was significantly narrower in patients with FTD than in those with AD and controls. The described measurements can easily be obtained and may be useful for the diagnosis of FTD.

General paresis (parenchymatous neurosyphilis) is a rare disease, and in recent years the number of papers published on the magnetic resonance imaging findings has been limited. The findings are as follows: cerebral atrophy; mesiotemporal T2 hyperintensity; ventriculomegaly; pathological T2 hypointensity of the globus pallidus, putamen, the head of the caudate nucleus and thalamus. We present a new finding, diffuse cerebral white matter T2 hyperintensity, observed in a patient with general paresis with a 5-year history of progressive dementia.

Purpose: To assess the role of F18-FDG imaging with a dual-head coincidence mode gamma camera (Co-PET) in identifying malignant tumors in patients with a suspicious adnexal mass depicted by conventional imaging methods.

Material and Methods: F18-FDG Co-PET was performed preoperatively in 18 women (mean age 56.38 years) with suspected malignant gynecologic tumors according to clinical and abdomino-pelvic/transvaginal ultrasound or computed tomography findings. Exploratory laparotomy was performed in all patients within the 10 days post-F18-FDG Co-PET study, and the definitive diagnosis of the adnexal masses was established by histopathological examination.

Results: Histopathological examinations of the surgically excised adnexal masses revealed eight malignant, one borderline, and nine benign neoplastic tumors. Four benign tumors had no F18-FDG uptake, while the remaining five tumors, all leiomyomas, showed mild FDG accumulation. Eight malignant tumors showed intense F18-FDG uptake. Sensitivity, specificity, PPV, and NPV of F18-FDG co-PET in differentiating benign from malign adnexal masses were 88%, 44%, 61%, and 80%, respectively. Tumor to background ratios (T/B) in benign lesions (2.04 ± 0.27) were significantly lower than in malignant lesions (7.4 ± 0.99).

Conclusion: F18-FDG Co-PET is of clinical value when assessing suspicious malignant adnexal masses. False-negative F18-FDG results might arise from borderline disease. Moderate F18-FDG uptake in leiomyomas can result false-positive, but T/B ratios may be helpful in such cases.

Adnexal torsion is one of the most common surgical gynecologic emergencies and needs prompt diagnosis. It usually occurs during reproductive age, which makes the early diagnosis all the more important in attempting to preserve ovarian function. If adnexal torsion is suspected from the clinical findings, Doppler ultrasound can be the best tool in diagnosis. It can also be helpful in assessing recovery of the ovary after surgical treatment. We present a case of adnexal torsion successfully diagnosed with power Doppler ultrasound and managed by detorsion. The postoperative gray-scale and power Doppler examination confirmed the recovery of ovarian follicles and stoma.