Limited Utility of Dynamic Contrast Enhancement Imaging Sequences Within the PI-RADS v2.1 Classification Scheme: A Retrospective Cross-Sectional Study of MRI Reports.

Background/Objective: We sought to characterize the proportion of peripheral zone lesions "upgraded" within the PI-RADS v2.1 protocol using DCE imaging sequences in a large patient population undergoing multiparametric prostate MRI. Methods: A retrospective review of radiologist reports for 2742 prostate MRI exams at 2 large Alberta teaching hospitals between January 2017 and January 2022 was conducted. Prostate specific antigen (PSA), prostate volume, sequence specific and overall PI-RADS scores, and lesion positivity for DCE were collected if present in the accompanying radiology report. Further, pathology reports of biopsies of the upgraded lesions within upgraded patients were reviewed to see if upgraded lesions were deemed clinically significant by gleason score/grade group. Results: The median age was 63 years, with a median PSA and PSA density of 7.5 ng/mL and 0.13 ng/mL2 respectively. A total of 1809 lesions were reported, with 69.4% of all lesions being DCE positive. Of the lesions within the peripheral zone, 548 were overall PI-RADS 4. A total of 87/2742 (3.2%) of patients were upgraded to a PI-RADS 4 by DCE imaging. Within these patients, 65 had pathology reports available, of which 18 had a clinically significant lesion at the upgrade site. Conclusion: Contrast enhancement is only beneficial for a very small portion of patients undergoing prostate MRI. Given the invasive nature of contrast enhanced studies, potential contrast induced side effects, added imaging time, and the cost of contrast agent, routine use of contrast for prostate MRI is questioned. Further studies are necessary to determine if it should be part of routine prostate MRI imaging protocols.

Adrenal Mass Biopsy in Patients Without Extraadrenal Primary Malignancy: A Multicenter Study.

BACKGROUND. Adrenal washout CT is not useful for evaluating incidental adrenal masses in patients without known or suspected primary extraadrenal malignancy. OBJECTIVE. The purpose of our study was to evaluate the diagnostic utility of adrenal mass biopsy in patients without known or suspected extraadrenal primary malignancy. METHODS. This retrospective six-center study included 69 patients (mean age, 56 years; 32 men, 37 women) without known or suspected extraadrenal primary malignancy who underwent image-guided core needle biopsy between January 2004 and June 2021 of a mass suspected to be arising from the adrenal gland. Biopsy results were classified as diagnostic or nondiagnostic. For masses resected after biopsy, histopathologic concordance was assessed between diagnoses from biopsy and resection. Masses were classified as benign or malignant by resection or imaging follow-up, and all nondi-agnostic biopsies were classified as false results. RESULTS. The median mass size was 7.4 cm (range, 1.9-19.2 cm). Adrenal mass biopsy had a diagnostic yield of 64% (44/69; 95% CI, 51-75%). After biopsy, 25 masses were resected, and 44 had imaging follow-up. Of the masses that were resected after diagnostic biopsy, diagnosis was concordant between biopsy and resection in 100% (12/12). Of the 13 masses that were resected after nondiagnostic biopsy, the diagnosis from re-section was benign in eight masses and malignant in five masses. The 44 masses with imaging follow-up included one mass with diagnostic biopsy yielding benign adenoma and two masses with nondiagnostic biopsy results that were classified as malignant by imaging follow-up. Biopsy had overall sensitivity and specificity for malignancy of 73% (22/30) and 54% (21/39), respectively; diagnostic biopsies had sensitivity and specificity for malignancy of 96% (22/23) and 100% (21/21), respectively. Among nine nondi-agnostic biopsies reported as adrenocortical neoplasm, six were classified as malignant by the reference standard (resection showing adrenocortical carcinoma in four, resection showing adrenocortical neoplasm of uncertain malignant potential in one, imaging follow-up consistent with malignancy in one). CONCLUSION. Adrenal mass biopsy had low diagnostic yield, with low sensitivity and low specificity for malignancy. A biopsy result of adrenocortical neoplasm did not reliably differentiate benign and malignant adrenal masses. CLINICAL IMPACT. Biopsy appears to have limited utility for the evaluation of incidental adrenal masses in patients without primary extraadrenal malignancy.

Comparing the Denver criteria sets for blunt trauma: a retrospective study of cases in Edmonton, Alberta.

OBJECTIVE: To determine whether a more conservative Denver criterion set could reduce unnecessary CT angiography (CTA) studies when screening for blunt cerebrovascular injury (BCVI) following blunt trauma. METHODS: Following ethics approval, a retrospective chart review of 447 consecutive patients undergoing emergency CTA at two large teaching hospitals was conducted to determine the presence of risk factors for each Denver criterion set. Imaging studies of adults conducted between January 2016 and June 2020 containing sufficient clinical information for accurate classification were included in the study. Specificity, sensitivity, and predictive values were calculated. A two-sided Fisher exact test was used to evaluate the association between each iteration of the Denver criteria and the presence of BCVI. RESULTS: The specificities of the Original, Modified, and Expanded Denver criteria were 43.58%, 34.32%, and 24.85%, respectively. Positive-predictive values (PPV) followed a different trend, with respective values of 2.77%, 3.06%, and 2.78%. Sensitivity and negative-predictive values (NPV) were found to be 100% for each criterion set. Being positive for a criterion set, and the presence of BCVI, was statistically significant for the original Denver criteria (p = 0.021, n = 443), but not the modified (p = 0.100, n = 345) or expanded Denver criteria (p = 0.202, n = 333). CONCLUSION: Use of the modified and expanded Denver criteria leads to the overuse of cerebrovascular imaging on patients suffering blunt force trauma. ADVANCES IN KNOWLEDGE: The original Denver criteria may more appropriately identify subjects for further evaluation with CTA than the current standard, while retaining diagnostic efficacy for BCVI.

Anastomotic Leaks After Small- and Large-Bowel Surgery: Diagnostic Performance of CT and the Importance of Intraluminal Contrast Administration.

OBJECTIVE: The objective of our study was to evaluate the diagnostic performance of CT in the identification of anastomotic leaks. MATERIALS AND METHODS: This was a study of patients who underwent bowel surgery and a subsequent postoperative CT examination performed specifically for investigating for an anastomotic leak. The study group included patients with surgically confirmed anastomotic leaks (n = 59), and the control group included patients without anastomotic leaks (n = 48) confirmed by either repeat surgery or uneventful clinical follow-up for at least 6 months. Two radiologists and two radiology residents independently reviewed each CT examination for specific CT findings from a set of predetermined imaging predictors. The sensitivity and specificity for each imaging predictor were calculated for each reader, and the interobserver agreement was calculated using the Cohen kappa coefficient. Diagnostic performance was assessed using ROC curve analysis. RESULTS: The most sensitive imaging predictor was intraabdominal free fluid (95.3%). Leakage of intraluminal contrast agent was also a highly specific imaging predictor (96.6%). Substantial interobserver agreement was shown for intraabdominal free gas (κ = 0.76) and leakage of intraluminal contrast agent (κ = 0.76). Overall diagnostic performance in correctly identifying surgically confirmed leaks, as assessed by the area under the ROC curve, ranged from 0.76 to 0.86. Diagnostic performance was higher for all readers when intraluminal contrast agent was used and reached the anastomosis, with the exception of one reader, whose diagnostic performance remained unchanged. CONCLUSION: Diagnostic performance of CT was highest when an intraluminal contrast agent was used. Meticulous and careful use of an intraluminal contrast agent is therefore important in this patient population.

Pleomorphic spindle cell sarcoma (PSCS) (formerly known as malignant fibrous histiocytoma, MFH) of the spleen, mimics an atypical haemangioma on 99mTc-RBC, CT and Ultrasound: staging with 18F-FDG PET/CT.

A 63-year-old male was found to have a 7.5-cm splenic mass that had imaging appearances of an atypical haemangioma on CT, ultrasound and a 99mTc-RBC scan, and he was followed conservatively with serial ultrasounds. Sixteen months later, however, the splenic lesion grew and he developed numerous new liver masses which were biopsy confirmed to be a pleomorphic spindle cell sarcoma (PSCS), formerly known as malignant fibrous histiocytoma (MFH). A staging 18F-FDG PET/CT was performed and showed innumerable, mostly necrotic hepatic and splenic masses. The patient passed away a few days after the PET/CT, before a treatment program could be implemented. The use of 18F-FDG PET/CT in the staging of splenic PSCS has not been previously described. We present the 99mTc-RBC and 18F-FDG PET/CT image characteristics of a patient with splenic PSCS.

Comparison of high-resolution T1W 3D GRE (LAVA) with 2-point Dixon fat/water separation (FLEX) to T1W fast spin echo (FSE) in prostate cancer (PCa).

PURPOSE: To compare T1-weighted (T1W) fast spin echo (FSE) to T1W 3-dimensional gradient recalled echo (LAVA) with fat water separation (FLEX) in prostate cancer (PCa). METHODOLOGY: With institutional review board waiver, 39 patients underwent 3-T magnetic resonance imaging including T1W LAVA FLEX (157s)/T1W FSE (316s). Two radiologists assessed (a) image quality/sharpness, (b) presence/severity of artifacts, and (c) skeletal (N=22)/nodal (N=9) metastases. Results were compared using Wilcoxon signed-rank test/receiver operator characteristic analysis. RESULTS: With T1W LAVA FLEX, image quality/sharpness improved (P<.001) with less motion (P=.002-.03) and no difference in phase-encoding artifact (P>.05). One patient had moderate fat/water swap. Detection of skeletal metastases was unchanged (P>.05) and nodal metastases either improved (P=.002) or were comparable (P=.16) using T1W LAVA FLEX. CONCLUSION: T1W LAVA FLEX improves image quality, lessens motion artifact, and is comparable or improves detection of metastases in PCa with reduction in acquisition time.

Comparison of Quantitative MRI and CT Washout Analysis for Differentiation of Adrenal Pheochromocytoma From Adrenal Adenoma.

OBJECTIVE: The purpose of this study was to use quantitative analysis to assess MRI and washout CT in the diagnosis of pheochromocytoma versus adenoma. MATERIALS AND METHODS: Thirty-four pheochromocytomas (washout CT, 5; MRI, 24; both MRI and CT, 5) resected between 2003 and 2014 were compared with 39 consecutive adenomas (washout CT, 9; MRI, 29; both MRI and CT, 1). A blinded radiologist measured unenhanced attenuation, 70-second peak CT enhancement, 15-minute relative and absolute percentage CT washout, chemical-shift signal intensity index, adrenal-to-spleen signal intensity ratio, T2-weighted signal intensity ratio, and AUC of the contrast-enhanced MRI curve. Comparisons between groups were performed with multivariate and ROC analyses. RESULTS: There was no difference in age or sex between the groups (p > 0.05). For CT, pheochromocytomas were larger (4.2 ± 2.5 [SD] vs 2.3 ± 0.9 mm; p = 0.02) and had higher unenhanced attenuation (35.7 ± 6.8 HU [range, 24-48 HU] vs 14.0 ± 20.9 HU [range, -19 to 52 HU]; p = 0.002), greater 70-second peak CT enhancement (92.8 ± 31.1 HU [range, 41.0-143.1 HU] vs 82.6 ± 29.9 HU [range, 50.0-139.0 HU ]; p = 0.01), lower relative washout CT (21.7 ± 24.7 [range, -29.3 to 53.7] vs 65.3 ± 22.3 [range, 32.9-115.3]; p = 0.002), and lower absolute washout CT (31.9 ± 42.8 [range, -70.6 to 70.2] vs 76.9 ± 10.3 [range, 60.3-89.6]; p = 0.001). Thirty percent (3/10) of pheochromocytomas had absolute CT washout in the adenoma range (> 60%). For MRI, pheochromocytomas were larger (5.0 ± 4.2 vs 2.0 ± 0.7 mm; p = 0.003) and had a lower chemical-shift signal intensity index and higher adrenal-to-spleen signal intensity ratio (-3.5% ± 14.3% [range, -56.3% to 12.2%] and 1.1% ± 0.1% [range, 0.9-1.3%] vs 47.3% ± 27.8% [range, -9.4% to 86.0%] and 0.51% ± 0.27% [range, 0.13-1.1%]) (p < 0.001) and higher T2-weighted signal intensity ratio (4.4 ± 2.4 vs 1.8 ± 0.8; p < 0.001). There was no statistically significant difference in contrast-enhanced MRI AUC (288.9 ± 265.3 vs 276.2 ± 129.9 seconds; p = 0.96). The ROC AUC for T2-weighted signal intensity ratio was 0.91 with values greater than 3.8 diagnostic of pheochromocytoma. CONCLUSION: In this study, the presence of intracellular lipid on unenhanced CT or chemical-shift MR images was diagnostic of adrenal adenoma. Elevated T2-weighted signal intensity ratio was specific for pheochromocytoma but lacked sensitivity. There was overlap in all other MRI and CT washout parameters.

Observer reliability of CT angiography in the assessment of acute ischaemic stroke: data from the Third International Stroke Trial.

INTRODUCTION: CT angiography (CTA) is often used for assessing patients with acute ischaemic stroke. Only limited observer reliability data exist. We tested inter- and intra-observer reliability for the assessment of CTA in acute ischaemic stroke. METHODS: We selected 15 cases from the Third International Stroke Trial (IST-3, ISRCTN25765518) with various degrees of arterial obstruction in different intracranial locations on CTA. To assess inter-observer reliability, seven members of the IST-3 expert image reading panel (>5 years experience reading CTA) and seven radiology trainees (<2 years experience) rated all 15 scans independently and blind to clinical data for: presence (versus absence) of any intracranial arterial abnormality (stenosis or occlusion), severity of arterial abnormality using relevant scales (IST-3 angiography score, Thrombolysis in Cerebral Infarction (TICI) score, Clot Burden Score), collateral supply and visibility of a perfusion defect on CTA source images (CTA-SI). Intra-observer reliability was assessed using independently repeated expert panel scan ratings. We assessed observer agreement with Krippendorff's-alpha (K-alpha). RESULTS: Among experienced observers, inter-observer agreement was substantial for the identification of any angiographic abnormality (K-alpha = 0.70) and with an angiography assessment scale (K-alpha = 0.60-0.66). There was less agreement for grades of collateral supply (K-alpha = 0.56) or for identification of a perfusion defect on CTA-SI (K-alpha = 0.32). Radiology trainees performed as well as expert readers when additional training was undertaken (neuroradiology specialist trainees). Intra-observer agreement among experts provided similar results (K-alpha = 0.33-0.72). CONCLUSION: For most imaging characteristics assessed, CTA has moderate to substantial observer agreement in acute ischaemic stroke. Experienced readers and those with specialist training perform best.

Necessity for long-term follow-up of patients with head and neck paraganglioma and mutation in the succinate dehydrogenase genes: an index case report and literature review.

OBJECTIVE: To describe a patient with hereditary head and neck paraganglioma (HNPGL) and to review the literature on these rare tumors. METHODS: We review the English-language literature regarding SDH mutations, HNPGL, hereditary paraganglioma-pheochromocytoma syndrome, and the role of functional imaging in the follow-up of these tumors. We also describe the clinical findings, imaging results, and follow-up of a man who initially presented with HNPGL and subsequently developed metastatic pheochromocytoma 20 years later. RESULTS: A 66-year-old man presented with a history of hypertension, palpitations, sweating, and elevated urinary norepinephrine. Iodine-123-metaiodobenzylguanidine (123I-MIBG) scan demonstrated a left suprarenal mass and multiple avid lesions in the abdomen, chest, and posterior cranial fossa. Histologic examination confirmed a metastatic pheochromocytoma, and molecular genetic testing revealed a mutation in the SDHD gene. The patient had had surgery 20 years earlier for HNPGL. Although most HNPGLs arise sporadically, susceptibility genes have been identified in approximately one-third of cases. Optimal follow-up remains controversial. We reiterate a need for long-term follow-up of patients with a mutation in an SDH gene. 123I-MIBG, highly specific for identifying ectopic neuroendocrine tissue, may have a role in long-term follow-up. CONCLUSIONS: Although HNPGLs rarely metastasize, their malignant potential is difficult to predict. Routine surveillance for at-risk patients is recommended. Patients with a mutation in an SDH gene should therefore undergo regular surveillance.