Utility of nifedipine use for Doppler ultrasound early after liver transplantation to predict short-term complications and long-term outcomes.

PURPOSE: To evaluate the response to nifedipine administration measured by changes in hepatic arterial (HA) flow on post-operative Doppler ultrasound (US) to predict short-term complications and long-term outcomes in liver transplant (LT) patients. METHODS: Patients who underwent LT with post-operative Doppler US within 3 days between 1 January 2005 and 31 December 2015 were included in this retrospective single center study. The patients who received and did not receive nifedipine during the Doppler US comprised the study and control groups, respectively. A positive response to nifedipine was defined as the detection of HA flow when none was present initially or a reduction in HA resistive index (RI) ≥ 0.1 after nifedipine administration. The rates of re-transplantation, re-operation, percutaneous intervention (PCI), and overall survival (OS) were recorded. Cox proportional hazards regression was used to evaluate the association of clinic-demographic variables and Doppler findings with the outcome measures. RESULTS: 444 LT patients (305 M/139F, mean age 51.7 ± 17.4 years, mean interval between LT-Doppler US 1.12 ± 0.9 days) are presented. 220 patients comprised the nifedipine study group [n = 157/220 (71.4%) responder, n = 63/220 (28.6%) nonresponder] and 224 patients comprised the control group. There was no difference in re-transplantation or PCI rates between the groups (all p-values ≥ 0.2 and ≥ 0.08, respectively). The responder group had a lower rate of re-operation vs. the control group (15.9% vs. 24.1%, p = 0.03) and nonresponder group (15.9% vs. 31.8%, p = 0.004). 1-year and 2-year OS were similar between the groups (all p-values > 0.37). CONCLUSION: Short-term complication rates and long-term outcomes for patients with liver transplant who responded to nifedipine administration on Doppler US are similar to those who did not require nifedipine administration. A lack of response to nifedipine was associated with a higher re-operation rate.

Prostate MRI using a rigid two-channel phased-array endorectal coil: comparison with phased array coil acquisition at 3 T.

BACKGROUND: To compare image quality, lesion detection and patient comfort of 3T prostate MRI using a combined rigid two-channel phased-array endorectal coil and an external phased-array coil (ERC-PAC) compared to external PAC acquisition in the same patients. METHODS: Thirty three men (mean age 65.3y) with suspected (n = 15) or biopsy-proven prostate cancer (PCa, n = 18) were prospectively enrolled in this exploratory study. 3T prostate MRI including T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) was performed using an ERC-PAC versus PAC alone, in random order. Image quality, lesion detection and characterization (biparametric PI-RADSv2.1) were evaluated by 2 independent observers. Estimated signal-to-noise ratio (eSNR) was measured in identified lesions and the peripheral zone (PZ). Patient comfort was assessed using a questionnaire. Data were compared between sequences and acquisitions. Inter/intra-observer agreement for PI-RADS scores was evaluated. RESULTS: Twenty four prostate lesions (22 PCa) were identified in 20/33 men. Superior image quality was found for ERC-PAC compared to PAC for T2WI for one observer (Obs.1, p < 0.03) and high b-value DWI for both observers (p < 0.05). The sensitivity of PI-RADS for lesion detection for ERC-PAC and PAC acquisitions was 79.2 and 75% for Obs.1, and 79.1 and 66.7%, for Obs.2, without significant difference for each observer (McNemar p-values ≥0.08). Inter-/intra-observer agreement for PI-RADS scores was moderate-to-substantial (kappa = 0.52-0.84). Higher eSNR was observed for lesions and PZ for T2WI and PZ for DWI using ERC-PAC (p < 0.013). Most patients (21/33) reported discomfort at ERC insertion. CONCLUSION: Despite improved image quality and eSNR using the rigid ERC-PAC combination, no significant improvement in lesion detection was observed, therefore not supporting the routine use of ERC for prostate MRI.

Gadoxetate disodium-enhanced MRI: Assessment of arterial phase artifacts and hepatobiliary uptake in a large series.

PURPOSE: To report the quality of gadoxetate disodium MRI in a large series by assessing the prevalence of: 1) arterial phase (AP) artifacts and its predictive factors, 2) decreased hepatic contrast uptake during the hepatobiliary phase (HBP). METHODS: This retrospective single center study included 851 patients (M/F:537/314, mean age: 63y) with gadoxetate disodium MRI. The MRI protocol included unenhanced, dual arterial [early and late arterial phases (AP)], portal venous, transitional and hepatobiliary phases. Three radiologists graded dynamic images using a 5-scale score (1: no motion, 5: severe, nondiagnostic) for assessment of transient severe motion (TSM, defined as a score ≥4 during at least one AP with a score ≤3 during other phases). HBP uptake was assessed using a 3-scale score (based on portal vein/hepatic signal). The association between demographic, clinical and acquisition parameters with TSM was tested in uni- and multivariate logistic regression. RESULTS: TSM was observed in 103/851 patients (12.1 %): 83 (9.8 %) in one AP and 20 (2.3 %) in both APs. A score of 5 (nondiagnostic) was assigned in 7 patients in one AP (0.8 %) and none in both. Presence of TSM was significantly associated with age (p = 0.002) and liver disease (p = 0.033) in univariate but not in multivariate analysis (p > 0.05). No association was found between acquisition parameters and TSM occurrence. Limited or severely limited HBP contrast uptake was observed in 87 patients (10.2 %), and TSM was never associated with severely limited HBP contrast uptake. CONCLUSION: TSM was present in approximately 12 % of gadoxetate disodium MRIs, rarely on both APs (2.3 %), and was poorly predicted. TSM was never associated with severely limited HBP contrast uptake.

Characterization of solid renal neoplasms using MRI-based quantitative radiomics features.

PURPOSE: To assess the diagnostic value of magnetic resonance imaging (MRI)-based radiomics features using machine learning (ML) models in characterizing solid renal neoplasms, in comparison/combination with qualitative radiologic evaluation. METHODS: Retrospective analysis of 125 patients (mean age 59 years, 67% males) with solid renal neoplasms that underwent MRI before surgery. Qualitative (signal and enhancement characteristics) and quantitative radiomics analyses (histogram and texture features) were performed on T2-weighted imaging (WI), T1-WI pre- and post-contrast, and DWI. Mann-Whitney U test and receiver-operating characteristic analysis were used in a training set (n = 88) to evaluate diagnostic performance of qualitative and radiomics features for differentiation of renal cell carcinomas (RCCs) from benign lesions, and characterization of RCC subtypes (clear cell RCC [ccRCC] and papillary RCC [pRCC]). Random forest ML models were developed for discrimination between tumor types on the training set, and validated on an independent set (n = 37). RESULTS: We assessed 104 RCCs (51 ccRCC, 29 pRCC, and 24 other subtypes) and 21 benign lesions in 125 patients. Significant qualitative and quantitative radiomics features (area under the curve [AUC] between 0.62 and 0.90) were included for ML analysis. Models with best diagnostic performance on validation sets showed AUC of 0.73 (confidence interval [CI] 0.5-0.96) for differentiating RCC from benign lesions (using combination of qualitative and radiomics features); AUC of 0.77 (CI 0.62-0.92) for diagnosing ccRCC (using radiomics features), and AUC of 0.74 (CI 0.53-0.95) for diagnosing pRCC (using qualitative features). CONCLUSION: ML models incorporating MRI-based radiomics features and qualitative radiologic assessment can help characterize renal masses.

Volumetric quantitative histogram analysis using diffusion-weighted magnetic resonance imaging to differentiate HCC from other primary liver cancers.

OBJECTIVE: To evaluate the ability of volumetric quantitative apparent diffusion coefficient (ADC) histogram parameters and LI-RADS categorization to distinguish hepatocellular carcinoma (HCC) from other primary liver cancers [intrahepatic cholangiocarcinoma (ICC) and combined HCC-ICC]. METHODS: Sixty-three consecutive patients (44 M/19F; mean age 62 years) with primary liver cancers and pre-treatment MRI including diffusion-weighted imaging (DWI) were included in this IRB-approved single-center retrospective study. Tumor type was categorized pathologically. Qualitative tumor features and LI-RADS categorization were assessed by 2 independent observers. Lesion volume of interest measurements (VOIs) were placed on ADC maps to extract first-order radiomics (histogram) features. ADC histogram metrics and qualitative findings were compared. Binary logistic regression and AUROC were used to assess performance for distinction of HCC from ICC and combined tumors. RESULTS: Sixty-five lesions (HCC, n = 36; ICC, n = 17; and combined tumor, n = 12) were assessed. Only enhancement pattern (p < 0.015) and capsule were useful for tumor diagnosis (p < 0.014). ADC 5th/10th/95th percentiles were significant for discrimination between each tumor types (all p values < 0.05). Accuracy of LI-RADS for HCC diagnosis was 76.9% (p < 0.0001) and 69.2% (p = 0.001) for both observers. The combination of male gender, LI-RADS, and ADC 5th percentile yielded an AUROC/sensitivity/specificity/accuracy of 0.90/79.3%/88.9%/81.5% and 0.89/86.2%/77.8%/80.0% (all p values < 0.027) for the diagnosis of HCC compared to ICC and combined tumors for both observers, respectively. CONCLUSION: The combination of quantitative ADC histogram parameters and LI-RADS categorization yielded the best prediction accuracy for distinction of HCC compared to ICC and combined HCC-ICC.

Multi-Modality Imaging Evaluation of the Whole-Organ Pancreas Transplant.

Pancreas transplants are an important treatment options for patients with severe diabetes mellitus and other medical conditions. Multiple-imaging modalities, including computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US) are available to evaluate the pancreas transplants and their vascular supply, with the graft having a characteristic appearance on each modality. Complications of the graft and its vascular supply present interesting challenges to the clinicians and radiologists caring for this patient population. Being able to identify the imaging appearance of normal and abnormal pancreas transplants, it is necessary to ensure these patients are provided optimal care.

Anatomy and pathology of the canal of Nuck.

The canal of Nuck is the female equivalent of the processus vaginalis in the male but is less well known than its male counterpart. It is a rare entity not commonly encountered by radiologists, particularly in the adult population. Knowledge of the embryology and anatomy of the canal of Nuck is essential for identification of the various pathologic conditions that may occur in this location. Moreover, radiologists should be familiar with this entity to compose an appropriate and thorough differential diagnosis of a labial mass/swelling. In this review, we discuss both the anatomy and the more common pathology that can be encountered within it.

Multiparametric magnetic resonance imaging for transition zone prostate cancer: essential findings, limitations, and future directions.

OBJECTIVE: Review the multiparametric MRI (mpMRI) findings of transition zone (TZ) prostate cancer (PCa) using T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) MRI and to integrate mpMRI findings with clinical history, laboratory values, and histopathology. CONCLUSION: TZ prostate tumors are challenging to detect clinically and at MRI. mpMRI using the combination of sequences has the potential to improve accuracy of TZ cancer detection and staging.

Imaging of acute anorectal conditions with CT and MRI.

Anorectal disorders are a common cause of presentation to the emergency department (ED). While the most frequently encountered anorectal conditions, such as hemorrhoids and anal fissures, are relatively benign and do not require imaging for diagnosis or management, there are multiple potentially life threatening anorectal conditions for which imaging is an important component of evaluation, diagnosis, and management. Although computed tomography (CT) is the most commonly used imaging modality for evaluation of anorectal pathology in the ED, magnetic resonance imaging (MRI) has an increasingly important role in the detection, characterization and management of specific anorectal conditions. This pictorial essay will review the imaging anatomy of the anorectum, summarize imaging protocols, and discuss the clinical presentation, imaging appearance, and differential diagnosis of anorectal conditions that may present to the emergency department, including infectious, inflammatory, malignant and vascular conditions.

IgG4-sclerosing cholangitis in a pediatric patient.

IgG4 sclerosing cholangitis (IgG4-SC) is an immune-mediated process that results in inflammation and fibrosis of the pancreatobiliary tract. Although IgG4-SC is predominantly associated with autoimmune pancreatitis, IgG4-SC as its own entity can be difficult to diagnose. Patients with IgG4-SC are typically men over the age of 60, and present clinically with obstructive jaundice, abdominal pain, and weight loss. The diagnosis of IgG4-SC may be difficult to differentiate from primary sclerosing cholangitis (PSC) or cholangiocarcinoma. IgG4-SC is morphologically characterized by dense lymphoplasmacellular infiltration, particularly IgG4+ plasma cells and CD4+ T cells, extensive fibrosis in bile duct walls, and obliterative phlebitis. In contrast to PSC, those with IgG4-SC often have elevated serum IgG4 and can be successfully treated with immunosuppression. Here, we present the first reported case of IgG4-SC in a pediatric patient with asymptomatic elevation in liver enzymes, bile duct strictures on imaging, characteristic pathology findings, elevated serum IgG4, and excellent response to corticosteroids. Pediatric gastroenterologists and hepatologists, as well as pediatric hepatopathologists, need to be aware of IgG4-SC as a disease entity. Although certain clinical and imaging findings mimic PSC, diagnosis of IgG4-SC and its appropriate treatment with corticosteroids often lead to remission and reversal of disease.

Calcified telangiectatic hyperplastic nodule associated with vascular malformation in a child: a case report.

This is a case report of an asymptomatic 4-year-old girl who was found to have a nodule at the lateral left lobe of the liver. She underwent transabdominal liver ultrasound and abdominal MRI that showed calcification and intense arterial enhancement but they failed to clearly exclude malignancy. The patient underwent an unremarkable laparoscopic wedge liver resection of the lesion because of its location and size. Pathological examination showed features compatible with a benign telangiectatic hyperplastic nodule with vascular malformation and calcification. CD34 immunostained the proliferative vascular lining cells while CK7 and CK19 highlighted the normal bile ducts present within the lesion. The diagnosis of a telangiectatic hyperplastic nodule associated with vascular malformation has been scarcely reported in children and our case shows for the first time that it can also present with calcifications.