Acta Radiologica

Intrahepatic mass-forming cholangiocellular carcinoma (IMC) is the second most common primary liver tumor. The differentiation between IMC and solitary hypovascular liver metastases (SHLM) represents a diagnostic challenge due to many overlapping magnetic resonance imaging (MRI) features.

To determine the value of diffusion-weighted imaging (DWI) in addition to conventional MRI for the distinction between intrahepatic mass-forming cholangiocarcinoma and solitary hypovascular liver metastases.

Fifty-three patients with pathologically proven IMC (n = 31) and SHLM (n = 22) who had undergone MRI and DWI before surgery or percutaneous biopsy were enrolled in this study. The following MRI features were analyzed: the size and shape of the lesion, presence of capsular retraction and segmental biliary dilatation, T2-weighted (T2W) signal intensity, the presence of target sign on DWI and enhancement pattern. Apparent diffusion coefficient (ADC) values were calculated for each lesion (b = 800 s/mm²). Univariate and multivariate logistic regression analyses were used to identify significant differentiating features between IMCs and SHLMs.

Univariate analysis revealed that following parameters favor diagnosis of IMCs over SHLMs: lobulating shape, heterogeneous T2W signal intensity, capsular retraction, segmental biliary dilatation, target sign on DWI and rim-like enhancement on arterial phase followed by progressive enhancement in delayed phases. ADC values measured in the periphery of the lesion were significantly lower in IMCs in comparison to SHLMs. Multivariate analysis revealed that target sign on DWI was the most significant predictor of IMCs.

Qualitative DWI analysis with target sign significantly improves diagnostic accuracy for differentiation among IMC and SHLM lesions.

According to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS), background echotexture in breast ultrasound (US) can be categorized as homogeneous or heterogeneous.

To prospectively evaluate the inter-observer agreement of a four-category classification in background echotexture assessments of breast US and to determine whether background echotexture is related to breast cancer risk factors, including mammography density.

Thirty-eight healthy women (age range, 25–72) were recruited. Eleven radiologists performed breast US on all participants and classified each background echotexture into four categories (homogeneous, mild, moderate, and marked heterogeneous). The inter-observer agreement in the assessments was measured using kappa statistics (к). The association between background echotexture and breast cancer risk factors, including mammographic density, menopausal status, and parity, were evaluated using Spearman’s correlation coefficient (ρ) and multiple linear regression analysis.

There was moderate inter-observer agreement between the radiologists for the four categories of background echotexture (average к = 0.45). Heterogeneity of the background echotexture was positively correlated with mammographic density in both pre- and postmenopausal women (premenopausal, ρ = 0.42, P < 0.0001; postmenopausal, ρ = 0.56, P < 0.0001). Multiple linear regression analysis revealed that mammographic density and parity were significantly associated with background echotexture.

Background echotexture assessment of breast US using a four-category classification showed moderate inter-observer agreement, and more heterogeneous background echotexture was associated with denser breasts and lower parity.

The ability to accurately assess tumor size in ductal carcinoma in situ (DCIS) is an important clinical issue when selecting the appropriate treatment plan.

To compare the accuracy of using mammography, ultrasound (US), and magnetic resonance imaging (MRI) to assess DCIS tumor size based on imaging and histopathological findings.

Fifty-six patients with DCIS were included. Mammography, US, and MRI were reviewed, and the accuracy of the measured tumor sizes were compared with the imaging and histopathological parameters.

If visible, tumor measurements demonstrated high reliability with the pathologically determined size, with the best results obtained using US (k = 0.851) followed by mammography (k = 0.815) and MRI (k = 0.738). Tumor size assessment was significantly more accurate when the lesion was shown as a mass on US (P = 0.003) or MRI (P < 0.001) with minimal and mild background parenchymal enhancement (P = 0.016) on MRI. When mammography was used to assess tumor size, the tumors with positive estrogen receptor status and luminal A subtype demonstrated a significantly more accurate tumor size.

The combination of US and MRI, in addition to mammography, has an important role in assessing the exact tumor extent of DCIS.

Breast tomosynthesis is more sensitive than mammography and can detect lesions that are not always visible with conventional methods such as digital mammography (MG) and ultrasonography (US). No standardized approach is available for the management of lesions that are detectable with tomosynthesis but are not visible on MG or US.

To review suspicious breast lesions detected with tomosynthesis but not visible on two-dimensional (2D) MG or US and to determine the management options for these lesions.

Ethical committee approval was obtained. The radiological records, biopsy or surgery results, and follow-up findings of 107 patients who had a tomosynthesis-positive but MG- or US-negative breast lesion between 2011 and 2016 were retrospectively evaluated.

Of 107 lesions visible only with tomosynthesis, 74% were architectural distortions and 26% were asymmetrical opacities. All patients underwent magnetic resonance imaging (MRI) for further evaluation. Among the 48 (45%) MRI-negative lesions, none had a suspicious alteration during the follow-up period. Among the MRI-positive lesions, 28% of the 50 architectural distortions and 11% of the nine asymmetrical opacities were malignant.

Given the inherent high false-positive rate of breast tomosynthesis, breast MRI prior to biopsy may reduce the number of unnecessary biopsies for suspicious breast lesions that are tomosynthesis-positive only.

Differentiating between malignant and benign solitary pulmonary lesions (SPLs) is challenging.

To determine diagnostic performance of intravoxel incoherent motion-based diffusion-weighted imaging (DW-IVIM) in distinguishing malignant from benign SPLs, using histogram analysis derived whole-tumor and single-section region of interest (ROI).

This retrospective study received institutional review board approval. A total of 129 patients with diagnosed SPLs underwent DW-IVIM and apparent diffusion coefficient (ADC). ADC, slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion fraction (f) were calculated separately by outlining whole-tumor and single-section ROI. Inter-observer reliability was assessed by inter-class correlation coefficient (ICC). ADC and DW-IVIM parameters were analyzed using independent-sample T-test. Receiver operating characteristic (ROC) analysis was constructed to determine diagnostic performance. Multiple logistic regression was performed to identify independent factors associated with malignant SPLs.

There were 48 benign SPLs found in 35 patients and 94 patients with lung cancer (LC). ICC for whole-tumor ROI (range, 0.89–0.95) was higher than that for single-section ROI (range, 0.61–0.71). Mean ADC and D were significantly lower in the malignant group. ADC and D 10th showed significantly higher AUC values than did mean ADC and D. D showed significantly higher diagnostic accuracy in mean, 10th, and 25th percentiles than ADC values (all Ps < 0.05). D 10th was found to be an independent factor in discriminating LCs with an odds ratio of –1.217.

Volumetric analysis had higher reproducibility and diagnostic accuracy than did single-section. Further, compared to ADC, D value differentiated benign SPLs from LCs more accurately.

Readout-segmented echo-planar imaging (RS-EPI) could improve the imaging quality of diffusion-weighted imaging (DWI) in various organs. However, whether it could improve the imaging quality and diagnostic performance for the patients with orbital tumors is still unknown.

To compare the image quality and diagnostic performance of RS-EPI DWI with that of conventional single-shot EPI (SS-EPI) DWI in patients with orbital tumors.

SS-EPI and RS-EPI DW images of 32 patients with pathologically diagnosed orbital tumors were retrospectively analyzed. Qualitative imaging parameters (imaging sharpness, geometric distortion, ghosting artifacts, and overall imaging quality) and quantitative imaging parameters (apparent diffusion coefficient [ADC], signal-to-noise ratio [SNR], contrast, and contrast-to-noise ratio [CNR]) were assessed by two independent radiologists, and compared between SS-EPI and RS-EPI DWI. Receiver operating characteristic curves were used to determine the diagnostic value of ADC in differentiating malignant from benign orbital tumors.

RS-EPI DW imaging produced less geometric distortion and ghosting artifacts, and better imaging sharpness and overall imaging quality than SS-EPI DWI (for all, P < 0.001). Meanwhile, RS-EPI DWI produced significantly lower SNR (P < 0.001) and ADC (P < 0.001), and higher contrast (P < 0.001) than SS-EPI DWI, while producing no difference in CNR (P = 0.137). There was no significant difference on the diagnostic performance between SS-EPI and RS-EPI DWI, when using ADC as the differentiating index (P = 0.529).

Compared with SS-EPI, RS-EPI DWI provided significantly better imaging quality and comparable diagnostic performance in differentiating malignant from benign orbital tumors.

Placement of central venous port catheters (CVPS) and peripherally inserted central catheters (PICC) is an integral component of state-of-the-art patient care. In the era of increasing cost awareness, it is desirable to have more information to comprehensively assess both procedures.

To perform a retrospective analysis of interventional radiologic implantation of CVPS and PICC lines in a large patient population including a cost analysis of both methods as well as an investigation the learning curve in terms of the interventions’ durations.

All CVPS and PICC line related interventions performed in an interventional radiology department during a three-year period from January 2011 to December 2013 were examined. Documented patient data included sex, venous access site, and indication for CVPS or PICC placement. A cost analysis including intervention times was performed based on the prorated costs of equipment use, staff costs, and expenditures for disposables. The decrease in intervention duration in the course of time conformed to the learning curve.

In total, 2987 interventions were performed by 16 radiologists: 1777 CVPS and 791 PICC lines. An average implantation took 22.5 ± 0.6 min (CVPS) and 10.1 ± 0.9 min (PICC lines). For CVPS, this average time was achieved by seven radiologists newly learning the procedures after performing 20 CVPS implantations. Total costs per implantation were €242 (CVPS) and €201 (PICC lines).

Interventional radiologic implantations of CVPS and PICC lines are well-established procedures, easy to learn by residents, and can be implanted at low costs.

Non-Hodgkin’s lymphoma (NHL) accounts for around 4% of new cancer cases annually. Bone marrow involvement is important for staging and management. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is used increasingly to identify this, in addition to bone marrow biopsy (BMB), which is seen as “gold” reference standard.

To compare determination of bone marrow involvement by FDG PET/CT against BMB in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL).

This was a retrospective study of patients with histologically confirmed NHL at a single UK cancer center undergoing pre-treatment FDG PET/CT and BMB between June 2010 and February 2013. Information was collected from patient notes, cancer registry, histological and imaging reports. Diagnostic accuracy of FDG PET/CT was determined, compared to BMB as the reference standard.

Twenty-four patients with DLBCL and 12 with FL were included. Five DLBCL patients had bone marrow involvement on PET/CT; all were confirmed on BMB. Three FL patients had marrow involvement on PET/CT but not on BMB; one FL patient had positive BMB but negative PET/CT. Using BMB as the reference standard, the sensitivity and specificity of FDG PET/CT for detecting bone marrow involvement in DLBCL were 100% and 100%, respectively, and in FL were 0% and 72.7%, respectively.

FDG PET/CT is accurate for detection of bone marrow involvement in newly diagnosed DLBCL, but not FL. In DLBCL, positive FDG PET/CT may negate the need for routine BMB, although BMB in addition or combination may be appropriate if this would influence management or prognosis.

The diagnosis of inconspicuous osteoblastic metastases (OBMs) is a challenge in computed tomography (CT) images. The virtual monochromatic spectral (VMS) image of spectral CT is useful for the detection of the low-contrast lesions.

To select the optimal monochromatic level for VMS images of spectral CT for detecting and diagnosing inconspicuous OBMs of the vertebra from lung cancer.

Thirty-five patients underwent spectral CT for chest or abdomen. The CT number and standard deviation (SD) of lesions and adjacent normal bone and the SD value of subcutaneous fat were measured on the conventional polychromatic image (140 kVp) and 40–140 keV VMS images. The contrast-to-noise ratio (CNR) was compared among the 11 VMS images and 140 kVp images. The scores of two observers for different images and the inter-observer agreement were evaluated. The diameter and CNR of the detected and missed lesions were assessed.

The lowest image noise was distributed in 70 and 140 keV images and the highest CNR was noted in 70 keV images. Good and moderate inter-observer agreement were identified for the evaluation of diagnostic ability, and the subjective scores of two observers for 60 and 70 keV images were increased compared with 140 kVp images (P < 0.05). The diameter had no significant difference between the detected and missed lesions. The CNR of the missed lesions was reduced compared with detected lesions.

VMS images at 70 keV may be optimal for detecting and diagnosing inconspicuous OBMs from lung cancer.

Accurate diagnosis of injuries to the collateral ligaments of the wrist is technically challenging on MRI.

To investigate usefulness of high-resolution two-dimensional (2D) and isotropic three-dimensional (3D) magnetic resonance imaging (MRI) for identifying and classifying the morphology of the ulnar and radial collateral ligaments (UCL and RCL) of the wrist.

Thirty-seven participants were evaluated using 3T coronal 2D and isotropic 3D images by two radiologists independently. The UCL was classified into four types: 1a, narrow attachment to the tip of the ulnar styloid (Tip); 1b, broad attachment to the Tip; 2a, narrow attachment to the medial base of the ulnar styloid (Base); and 2b, broad attachment to the Base. The RCL was also classified into four types: 1a, separate radioscaphoid and scaphotrapezial ligaments (RS + ST) with narrow scaphoid attachment; 1b, RS + ST with broad scaphoid attachment; 2a, continuous radio-scapho-trapezial ligaments (RST) with narrow scaphoid attachment; and 2b, RST with broad scaphoid attachment. The inter-observer reliability of these classifications was calculated.

Type 1a was the most common of both collateral ligaments. Of UCL classifications, 31.4% were revised after additional review of multiplanar reconstruction (MPR) images from isotropic data. The inter-observer reliability of UCL classification was substantial (k = 0.62) without MPR, and almost perfect (k = 0.84) with MPR. The inter-observer reliability of RCL classification was almost perfect (k = 0.89). Anatomic delineation between the two sequences was not statistically different.

The UCL and RCL were each identified on high-resolution 2D and isotropic 3D MRI equally well. MPR allows accurate identification of the UCL attachment to the ulnar styloid.

Simultaneous multi-slice (SMS) imaging is starting to be used in clinical situation, although evidence of clinical feasibility is scanty.

To prospectively assess the clinical feasibility of SMS diffusion-weighted imaging (DWI) and diffusion-tensor imaging (DTI) with blipped-controlled aliasing in parallel imaging for brain lesions.

The institutional review board approved this study. This study included 156 hyperintense lesions on DWI from 32 patients. A slice acceleration factor of 2 was applied for SMS scans, which allowed shortening of the scan time by 41.3%. The signal-to-noise ratio (SNR) was calculated for brain tissue of a selected slice. The contrast-to-noise ratio (CNR), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were calculated in 36 hyperintense lesions with a diameter of three pixels or more. Visual assessment was performed for all 156 lesions. Tractography of the corticospinal tract of 29 patients was evaluated. The number of tracts and averaged tract length were used for quantitative analysis, and visual assessment was evaluated by grading.

The SMS scan showed no bias and acceptable 95% limits of agreement compared to conventional scans in SNR, CNR, and ADC on Bland–Altman analyses. Only FA of the lesions was higher in the SMS scan by 9% (P = 0.016), whereas FA of the surrounding tissues was similar. Quantitative analysis of tractography showed similar values. Visual assessment of DWI hyperintense lesions and tractography also resulted in comparable evaluation.

SMS imaging was clinically feasible for imaging quality and quantitative values compared with conventional DWI and DTI.

The identification and subsequent management of liver diseases in children is challenging due to the lack of non-invasive imaging biomarkers. Ultrasound shear-wave elastography (US-SWE) is an emerging imaging technique which can quantitatively assess liver stiffness and may be useful as a tool in the management of liver disease in overweight and obese children.

To evaluate US-SWE velocities of the liver in normal-weight and obese children, to correlate US-SWE findings with age and body-mass-index (BMI), and to compare US-SWE values with qualitative assessment (i.e. normal versus abnormal echogenicity) of the liver by conventional US.

A cohort of 300 children (mean age, 9.9 ± 5.3 years; age range, 0.06–18.9 years) were studied, comprising 176 normal-weight and 124 obese participants. In each patient, both US-SWE and conventional US of the liver were obtained. Three pediatric radiologists individually and in consensus determined whether liver parenchyma was of normal or abnormal echogenicity.

US-SWE velocities differed between normal-weight and obese children (1.08 ± 0.14 versus 1.44 ± 0.39 m/s; P < 0.001), but not by gender. Multivariate linear regression demonstrated US-SWE velocity to be primarily associated with age in normal-weight children (P < 0.05) and with BMI in obese children (P < 0.001). In the obese group, mean US-SWE velocity was statistically higher in participants with abnormal echogenic livers than in those with normal-appearing livers (1.53 ± 0.38 vs. 1.17 ± 0.27). The difference was not significant in the normal-weight group.

US-SWE provides a useful quantitative imaging biomarker for evaluating liver stiffness in children.

Microcephaly is one of the most common fetal structural abnormalities, and prenatal microcephaly is considered a group I malformation of cortical development diagnosed according to ultrasound (US) skull measurements.

To evaluate the agreement between fetal head US and magnetic resonance imaging (MRI) biometric measurements of suspected microcephalic fetuses.

This institutional review board-approved retrospective study with waived informed consent included 180 pregnant women and was conducted at our medical center from March 2011 to April 2013. Biparietal diameter (BPD) and occipitofrontal diameter (OFD) results of fetal head US normograms were compared to normograms for MRI. We used Pearson and Spearman rho non-parametric correlation coefficients to assess the association between two quantitative variables, paired t-test for paired quantitative variables, and McNemar test for paired qualitative variables.

The average BPD but not the average OFD percentiles in fetal head US differed significantly from the MRI results (P < 0.0001). When looking at the accepted microcephaly threshold, both BPD and OFD percentiles differed significantly from MRI (P < 0.0001 and P < 0.004, respectively). There was no correlation between US-measured skull biometry and MRI-measured brain biometry. Estimated cerebrospinal fluid volumes were significantly lower in the study group compared to 120 fetuses with normal findings in prenatal head US and MRI. Also, we have created a MRI-based normogram of fetal head circumference and gestational age.

The diagnosis of microcephaly by US alone may be insufficient and ideally should be validated by MRI before a final diagnosis is established.

Prostate cancer and stromal hyperplasia (SH) in the transition zone (TZ) are difficult to discriminate by conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI).

To investigate the apparent diffusion coefficient (ADC) of prostate cancer and SH in the TZ with histogram analysis and the ability of ADC metrics to differentiate between these two tissues.

Thirty-three cancer and 29 SH lesions in the TZ of 54 patients undergoing preoperative DWI (b-value 0, 1000 s/mm²) were analyzed. All the lesions on the MR images were localized based on histopathologic correlations. The 10th, 25th, and 50th percentiles, and the mean ADC values were calculated for the two tissues and compared. The efficiencies of the 10th, 25th, and 50th ADC percentiles in differentiating the two tissues were compared with that of the mean ADC with receiver operating characteristic (ROC) analysis.

The 10th, 25th, and 50th percentiles and mean ADC values (×10⁻³ mm²/s) were 0.86 ± 0.15, 0.89 ± 0.16, 0.94 ± 0.16, and 1.03 ± 0.17 in SH and 0.64 ± 0.12, 0.69 ± 0.12, 0.72 ± 0.16, and 0.83 ± 0.15 in TZ cancer, respectively. The parameters were all significantly lower in cancer than SH. The 10th ADC percentile yielded an area under the ROC curve (AUC) of 0.87 for the differentiation of carcinomas from SH, which was higher than the mean ADC (0.80) (P < 0.05), and the AUCs of the 25th (0.82) and 50th (0.83) percentiles exhibited no differences from those of the mean ADC (P > 0.05).

Histogram analysis of ADC values may potentially improve the differentiation of prostate cancer from SH in the TZ.