Prospective evaluation of the value of dynamic contrast enhanced (DCE) imaging for prostate cancer detection, with pathology correlation.

INTRODUCTION: The aim of this study was to evaluate the value of dynamic contrast enhanced (DCE) imaging in multi-parametric prostate MRI (mpMRI) for the detection and staging of prostate cancer in comparison with T2W and DWI images alone in biparametric MRI (bpMRI) in treatment naïve patients. MATERIALS AND METHODS: One hundred consecutive patients who underwent a prostate MRI at our institution from June-August 2017, as well as a systematic ultrasound-guided prostate biopsy or prostatectomy, were included. Strictly following PIRADSv2, the MRI studies were independently interpreted by a body radiologist and a body-imaging fellow on two different occasions 8-10 weeks apart. Initially, with all mpMRI sequences and then without the DCE sequence (bpMRI). The readers were blinded to the clinical information. Ethics approval was obtained. RESULTS: One hundred treatment-naïve patients were included (median age 64, age range 48-81, mean PSA 10.3). There was almost perfect intra-observer agreement for mpMRI versus bpMRI for both readers [Cohen's Kappa (k) 0.88-0.86] and substantial inter-observer agreement (k = 0.74 for mpMRI and 0.76 for bpMRI). The sensitivity and specificity did not significantly change between multi-parametric and bi-parametric MRI (Sensitivity 91.7% and 90%, Specificity of 85.5% and 85% for mpMRI and bpMRI, respectively). CONCLUSION: Based on our findings, prostate MRI without DCE (bpMRI) is of comparable diagnostic accuracy to mpMRI in treatment-naïve patients. Performing prostate MRI without DCE (bpMRI) will reduce acquisition time, decrease cost and potentially improve patient safety.

Diagnostic accuracy of virtual non-contrast enhanced dual-energy CT for diagnosis of adrenal adenoma: A systematic review and meta-analysis.

OBJECTIVE: To compare the diagnostic accuracy of dual-energy (DE) virtual non-contrast computed tomography (vNCT) to non-contrast CT (NCT) for the diagnosis of adrenal adenomas. METHODS: Search of multiple databases and grey literature was performed. Two reviewers independently applied inclusion criteria and extracted data. Risk of bias was assessed using QUADAS-2. Summary estimates of diagnostic accuracy were generated and sources of heterogeneity were assessed. RESULTS: Five studies (170 patients; 192 adrenal masses) were included for diagnostic accuracy assessment; all used dual-source dual-energy CT. Pooled sensitivity for adrenal adenoma on vNCT was 54% (95% CI: 47-62%). Pooled sensitivity for NCT was 57% (95% CI: 45-69%). Pooling of specificity was not performed since no false positives were reported. There was a trend for overestimation of HU density on vNCT as compared to NCT which appeared related to contrast timing. Potential sources of bias were seen regarding the index test and reference standard for the included studies. Potential sources of heterogeneity between studies were seen in adenoma prevalence and intravenous contrast timing. CONCLUSIONS: vNCT images generated from dual-energy CT demonstrated comparable sensitivity to NCT for the diagnosis of adenomas; however the included studies are heterogeneous and at high risk for some types of bias. KEY POINTS: • Similar sensitivity of vNCT to NCT for diagnosis of adenoma • Heterogeneity could be related to vNCT from early (<=60 sec) CECT studies • Could not pool specificity as there were no false positives • Small number of heterogeneous studies at high risk of bias.

Evaluation of apparent diffusion coefficient and MR volumetry as independent associative factors for extra-prostatic extension (EPE) in prostatic carcinoma.

BACKGROUND: To assess mean apparent diffusion coefficient (ADC) and MR-derived tumor volume (Vt) as associative factors for extra-prostatic extension (EPE) in prostate cancer (PCa). METHODS: With institutional review board approval, 73 consecutive patients diagnosed with PCa at trans-rectal ultrasound biopsy underwent preoperative multi-parametric (T2W+DWI+DCE) 3 Tesla MRI before radical prostatectomy between 2012 and 2014; 52% (38/73) patients had EPE. Clinical parameters including: age, prostate serum antigen (PSA), digital rectal examination (DRE) and percentage positive cores (PPC) were recorded. Two blinded radiologists subjectively evaluated for EPE using PI-RADS with T2W-MRI. A third blinded radiologist recorded: mean ADC (mm(2) /s) of tumor and tumor volume on ADC and T2W (derived from planar volumetry). VtMAX (the largest volume on ADC or T2W) was documented. Multivariate and receiver operator characteristic analyses were performed. RESULTS: There were no significant differences in age, DRE, or Gleason score between groups (P = 0.52, 0.06, 0.61, 0.36). PSA approached significance being higher with EPE (12.9 ± 12.6 versus 8.2 ± 7.4; P = 0.06). PPC was higher with EPE (60.9 ± 21.9% versus 38.3 ± 21.6%; P < 0.01) with an area under the curve (AUC) of 0.78 and sensitivity/specificity = 75.7/75% when PPC ≥ 45%. AUC for T2W-MRI was 0.46-0.51 with sensitivity/specificity = 40.0-42.9/48.6-57.1% (R1, R2). Inter-observer agreement was fair, k = 0.39. There was no difference in mean ADC between groups (0.89 ± 0.25 versus 0.88 ± 0.19 [EPE] mm(2) /s), P = 0.70. T2W-Vt, ADC-Vt, and VtMAX were larger with EPE (5.1 ± 7.4, 5.8 ± 6.5, 6.3 ± 7.4 cm(3) versus 1.6 ± 1.8, 1.8 ± 1.3, 2.1 ± 1.8), P < 0.01. VtMAX AUC was 0.77 with sensitivity/specificity = 78.4/73.5% when VtMAX ≥ 2.1 cm(3) which outperformed all other parameters (P > 0.05) except PPC (P = 0.6) for the diagnosis EPE. CONCLUSION: MR volumetry and percentage of positive core biopsies are associated with EPE; whereas, in this study, other clinical and MR parameters including mean ADC and subjective T2W-MR analysis were not useful for assessment of EPE.

Intracellular lipid in clear cell renal cell carcinoma tumor thrombus and metastases detected by chemical shift (in and opposed phase) MRI: radiologic-pathologic correlation.

BACKGROUND: Clear cell renal cell carcinoma (RRC) characteristically contain intracellular lipid which is also detectable in tumor thrombus and metastases. PURPOSE: To assess the incidence of intracellular lipid in clear cell RCC metastases and tumor thrombus using chemical shift MRI. MATERIAL AND METHODS: With REB approval, 33 consecutive patients with clear cell RCC and tumor thrombus/metastatic disease underwent magnetic resonance imaging (MRI) over a 10-year period. Diagnosis was established by histopathology for tumor thrombi (n = 25) and metastases (n = 15) or growth for metastases (n = 14). Two blinded radiologists independently assessed for a signal intensity (SI) drop at chemical shift MRI (indicative of intracellular lipid) and a third radiologist established consensus. Chemical shift SI (CS-SI) index ([SItumorIP - SItumorOP]/SITumorIP x 100) was calculated. Inter-observer agreement was assessed using intra-class correlation (ICC) and tests of association were performed using the Chi-square test and Spearman correlation. RESULTS: Using CS-MRI, intracellular lipid was detected in 36.4% of clear cell RCC, with moderate agreement, (ICC = 0.5). Intracellular lipid was detected in 20% of tumor thrombi and 20% of metastases with strong agreement (ICC = 0.73). Intracellular lipid within tumor thrombi/metastases was not associated with lipid within the primary tumor (P = 0.09). There was a correlation in CS-SI index between primary tumor and thrombi/metastases when lipid was detected in both lesions (r = 0.91, P = 0.005); however, there was no correlation when lipid was not detected in both lesions (r = -0.09, P = 0.72). CONCLUSION: The presence of intracellular lipid in tumor thrombus and metastases from clear cell RCC is uncommon and, is not necessarily associated with lipid within the primary tumor at chemical shift MRI.

Does a cleansing enema improve image quality of 3T surface coil multiparametric prostate MRI?

PURPOSE: To assesses the utility of a preparatory enema in the interpretation of prostate multiparametric (MP) magnetic resonance imaging (MRI). MATERIALS AND METHODS: Under a waiver from the Institutional Review Board (IRB), 32 patients without bowel preparation and 28 patients who underwent a self-administered enema were imaged consecutively with 3T MP-MRI over 6 months. Two blinded radiologists independently assessed image quality on T2 -weighted (T2 W), trace b 1000 mm(2) /sec echo-planar (EPI) and apparent-diffusion coefficient (ADC) and assessed for motion/blur on T2 W and distortion/blur on EPI and ADC. Radiologists also quantified rectal stool and gas. A third blinded radiologist generated contrast curves from dynamic contrast-enhanced (DCE) data at six locations and measured the number of corrupted data points, defined as >10% aberrant signal intensity change. Subjective scores were compared using Wilcoxon sign rank test. Rectal contents were correlated to artifact using Spearman correlation. Contrast curves were evaluated with independent t-tests. RESULTS: There was no difference in image quality on T2 W (P = 0.66-0.74), EPI (P = 0.13-0.36) or ADC (P = 0.49-0.59). There was less rectal stool in the enema group (P = 0.004) and amount of stool correlated with motion artifact on T2 W (r = 0.23, P = 0.02); however, there was no difference in motion artifact between groups (P = 0.47-0.94). Only a minority of patients in the non-enema group had moderate or large amounts of stool (16%) and none of these patients had severe or extensive artifact on T2 . There was less rectal gas in the enema group (P = 0.002); however, amount of gas did not correlate with distortion artifact on EPI or ADC (P = 0.17-0.41) and there was no difference in blur (P = 0.41-0.91) or distortion (P = 0.31-0.99) on EPI or ADC between groups. There was no difference in corrupted data points on DCE (P = 0.46). CONCLUSION: In this study the use of a preparatory enema did not improve image quality or reduce artifact in prostate MP-MRI.

Pelvic congestion syndrome due to agenesis of the infrarenal inferior vena cava.

The inferior vena cava (IVC) is the main conduit of venous return to the right atrium from the lower extremities and abdominal organs. Agenesis of the IVC has an incidence of <1% in the general population [1], although it has been reported in the literature as occurring in up to 8.7% of the population [2]. Patients with absent IVC may present with symptoms of lower extremity venous insufficiency [6], idiopathic deep venous thrombosis [7], or pelvic congestion syndrome. To our knowledge there have only been a few cases reported in the literature of agenesis of the IVC associated with pelvic congestion syndrome [3,10,11]. We present another interesting case of pelvic congestion syndrome due to absent IVC.

Effect of Implementing Community of Practice Modified Thyroid Imaging Reporting and Data System on Reporting Adherence and Number of Thyroid Biopsies.

RATIONALE AND OBJECTIVES: Thyroid nodules are common in the population, although the rate of malignancy is relatively low (5%-15%). The purpose of this study was to determine if introducing a modified standardized reporting format and management algorithm (Thyroid Imaging Reporting and Data System [TI-RADS]) affects radiologist reporting adherence, number of thyroid biopsies, and other measurable outcomes. MATERIALS AND METHODS: All thyroid biopsies performed over two 6-month periods were evaluated at a tertiary care hospital with Research Ethics Board approval. The first period was before implementation of TI-RADS and the second was several months after implementation of TI-RADS (using a modified version made through a multidisciplinary collaboration). The number of biopsies performed was determined in each of the two periods as well as the percent of positive malignancy, wait times, and rates of non-diagnostic/unsatisfactory and inconclusive biopsies, which included atypia of undetermined significance (AUS) and follicular lesion of undetermined significance (FLUS). RESULTS: The average number of biopsies performed prior to implementing modified Kwak's TI-RADS was 74 thyroid biopsies per month and the average number of diagnostic ultrasounds was 271. After the introduction of modified Kwak's TI-RADS, the average number of thyroid biopsies decreased to 60 per month (an 18.9% reduction, P < .05), and the number of diagnostic ultrasound increased to 287 per month (a 5.9% increase from 2016 to 2017). The average wait time for a thyroid biopsy decreased from 5 to 3 weeks (P < .05). There was a slight increase in the rate of positive malignancy results (from 15% to 18%), although it was not statistically significant. The rate of non-diagnostic/unsatisfactory and inconclusive results (including AUS and FLUS) remained unchanged (18% AUS/FLUS/15% non-diagnostic/unsatisfactory before and 17% AUS/FLUS/15% non-diagnostic/unsatisfactory after TI-RADS introduction, P > .05). CONCLUSIONS: Introduction of a multidisciplinary-approved standardized reporting system with evidence-based management recommendations led to no statistically significant change in the number of diagnostic ultrasounds but a statistically significant reduction in the number of monthly thyroid biopsies and associated reduction in wait times.

Impact of clinical history on choice of abdominal/pelvic CT protocol in the Emergency Department.

INTRODUCTION: Radiologists and other specialty consultants play a role in diagnosing patients with acute abdominal conditions. Numerous Computed Tomography (CT) protocols are available and radiologists' choices are influenced by the clinical history provided. We hypothesize that the quality of the initial communication between referring physicians and radiologists greatly affects the utilization of health resources and subsequent patient care. The purpose of this pilot study was to employ a grading system to quantitatively evaluate a provided history. We also sought to evaluate inter-rater reliability by having radiologists evaluate sample histories and finally, to assess whether the quality of history has an impact on the number of CT protocols radiologists choose as potentially appropriate, with less potential protocols being seen as a positive outcome. METHODS: Four reviewers, (2 attendings and 2 residents) evaluated 350 consecutive clinical histories provided for patients presenting to a tertiary care Emergency Department (ED) between September-October, 2012. Reviewers graded histories on a 5-point scale using 4 categories of criteria. This includes a) presenting complaint, b) relevant past medical history or symptom evolution, c) objective laboratory or prior examination results and d) differential diagnosis. RESULTS: There was substantial agreement among all four reviewers when evaluating the quality of history, ICC 0.61, (95% CI 0.48-0.71). In particular, agreement amongst attending radiologists was substantial, with ICC 0.69 (0.48-0.80). Significant negative correlation was observed between history grade and number of potentially appropriate protocols in 3 of 4 reviewers (Spearman's rho: -0.394, -0.639, -0.864, p <0.0001 for these reviewers). This correlation was significantly stronger for attending radiologists (Spearman's rho: -0.763, 95% CI -0.7933 to -0.731; p<0.0001). Agreement was poor among reviewers when asked exactly how many protocols could potentially be used to answer the clinical question based on provided history, ICC 0.08, (95% -0.03-0.13). CONCLUSION: Although there is still variability in radiologists' approach to protocoling urgent studies, a more comprehensive requisition history narrowed the number of protocols considered.