Roozbeh Houshyar

Altered Doppler flow patterns in cirrhosis patients: an overview

Doppler ultrasonography of the hepatic vasculature is an integral part of evaluating precirrhotic and cirrhotic patients. While the reversal of the portal venous flow is a well-recognized phenomenon, other flow patterns, although not as easily understood, may play an important role in assessing the disease status. This article discusses the different characteristic flow patterns observed from the portal vein, hepatic artery, and hepatic vein in patients with liver cirrhosis or related complications and procedures. Knowledge of these different flow patterns provides additional information that may reinforce the diagnosis of cirrhosis, help in staging, and offer prognostic information for determining the direction of therapy. Doppler ultrasonography is invaluable when liver transplantation is being considered and aids in the diagnosis of cirrhosis and portal hypertension.

Chemotherapy induced liver abnormalities: an imaging perspective.

Treating patients undergoing chemotherapy who display findings of liver toxicity, requires a solid understanding of these medications. It is important for any clinician to have an index of suspicion for liver toxicity and be able to recognize it, even on imaging. Cancer chemotherapy has evolved, and newer medications that target cell biology have a different pattern of liver toxicity and may differ from the more traditional cytotoxic agents. There are several hepatic conditions that can result and keen clinical as well as radiographic recognition are paramount. Conditions such as sinusoidal obstructive syndrome, steatosis, and pseudocirrhosis are more commonly associated with chemotherapy. These conditions can display clinical signs of acute hepatitis, liver cirrhosis, and even liver failure. It is important to anticipate and recognize these adverse reactions and thus appropriate clinical action can be taken. Often times, patients with these liver manifestations can be managed with supportive therapies, and liver toxicity may resolve after discontinuation of chemotherapy.

Collision and composite tumors; radiologic and pathologic correlation

The terms composite and collision tumors have been used interchangeably throughout radiological literature. Both composite and collision tumors involve two morphologically and immunohistochemically distinct neoplasms coexisting within a single organ. However, collision tumors lack the histological cellular intermingling seen in composite tumors. Composite tumors often arise from a common driver mutation that induces a divergent histology from a common neoplastic source while collision tumors may arise from coincidental neoplastic change. The purpose of this review is to provide an overview of abdominal composite and collision tumors by discussing hallmark radiographic and pathological presentations of rare hepatic, renal, and adrenal case studies. A better understanding of the presentation of each lesion is imperative for proper recognition, diagnosis, and management of these unique tumor presentations.

Renal Collision and Composite Tumors: Imaging and Pathophysiology

OBJECTIVE To illustrate the imaging appearances of a spectrum of renal collision and composite tumors. Occurrence of collision and composite tumors in the genitourinary tract is rare compared to the usual occurrence of synchronous tumors. METHODS Case studies were chosen that represent the different tumors. Analysis was made on both the imaging and the pathology if excision was performed. RESULTS Presence of 2 different cell types can lead to confusing imaging findings, and biopsy or excision is typically needed for final diagnosis. Some composite tumors have a characteristic appearance on imaging based on their pathologic features. CONCLUSION Familiarity with imaging findings may help radiologists include these tumors in their differential diagnosis.

Composite liver tumors: a radiologic-pathologic correlation

Bi-phenotypic neoplasm refers to tumors derived from a common cancer stem cell with unique capability to differentiate histologically into two distinct tumor types. Bi-phenotypic hepatocellular carcinoma-cholangiocarcinoma (HCC-CC), although a rare tumor, is important for clinicians to recognize, since treatment options targeting both elements of the tumor are crucial. Imaging findings of bi-phenotypic HCC-CC are not specific and include features of both HCC and CC. A combination of imaging and immuno-histochemical analysis is usually needed to make the diagnosis.

Choledochoduodenal fistula in the setting of Crohn’s disease

Of all the spontaneous fistulas that occur between the extrahepatic biliary system and the intestine, a choledochoduodenal fistula is rarely seen. When it does occur, it is most often secondary to a perforated duodenal ulcer, choledocholithiasis, or cholelithiasis. It may also be seen following complications related to iatrogenic injury or tuberculosis. Generally, choledochoduodenal fistulas are asymptomatic, but may present with vague abdominal pain, fever, and other symptoms related to cholangitis. As a result, they can be difficult to diagnose clinically before imaging is obtained. We present a case of a 74 year old, asymptomatic, female with a past medical history significant for Crohns disease who was found to have a choledochoduodenal fistula demonstrated on MRCP, possibly secondary to her underlying inflammatory bowel disease.

Massive hemorrhage from unsuspected pseudoaneurysm within an ulcer following "Roux-en-Y" gastric bypass.

Massive Hemorrhage from Unsuspected Pseudoaneurysm Within an Ulcer following “Roux-en-Y” Gastric Bypass

Validation of Prostate Imaging-Reporting and Data System Version 2: A Retrospective Analysis

PURPOSE Use of magnetic resonance imaging (MRI)/transrectal ultrasound fusion biopsies to determine the accuracy of multiparametric MRI (mpMRI), using Prostate Imaging-Reporting and Data System version 2 (PI-RADSv2), for detecting clinically significant prostate cancer in the overall gland and specifically the peripheral zone (PZ) and transitional zone (TZ). METHODS A retrospective analysis of patients who underwent fusion biopsy identified 137 men with 231 prostate lesions was approved by the Institutional Review Board. Subjects initially classified under PI-RADSv1 criteria were regraded using PI-RADSv2 by a radiologist blinded to PI-RADSv1 score and biopsy results. Spearman correlation, chi-squared, and logistic regression analysis were performed. RESULTS There was positive correlation between PI-RADSv2 and Gleason scores (P < 0.001). In the PZ, mpMRI demonstrated 100% sensitivity, 100% negative predictive value, and 35.9% positive predictive value, compared to 100%, 100%, and 27.1%, respectively, for TZ lesions. When predicting clinically significant prostate cancer, the PI-RADSv2 area under the curve for TZ lesions was 0.844 (95% CI: 0.753-0.935, P < 0.001) and 0.769 (95% CI: 0.684-0.854, P < 0.001) for PZ lesions. Combining PI-RADSv2 with additional risk factors (body mass index, prostate-specific antigen density, digital rectal examination) improved the area under curve. CONCLUSIONS PI-RADSv2 achieves excellent sensitivity and negative predictive value for both PZ and TZ lesions.

Duplex Doppler Imaging of Dialysis Fistulae and Grafts

Arteriovenous fistulae and grafts for hemodialysis access are a lifeline in patients with end-stage renal disease. A significant cause of morbidity and mortality in this population is dialysis access dysfunction. Duplex ultrasound imaging is an excellent modality to evaluate arteriovenous fistulae and grafts, the 2 main types of long-term hemodialysis access. This review provides a detailed Doppler ultrasound protocol for evaluation of fistulae or grafts to familiarize imagers with their normal appearance, highlighting common dialysis access complications.

40-year-old female with menorrhagia and abdominal pain: A case of metastatic gestational trophoblastic neoplasia.

Choriocarcinoma is part of a rare spectrum of placental abnormalities known as gestational trophoblastic disease (GTD). It is the most invasive form of GTD, with a mortality rate approaching 100% if left untreated. It spreads predominantly hematogenously to multiple target sites, most commonly the lungs. Due to its hypervascular nature, it is often complicated by bleeding. We describe a case of choriocarcinoma in a 40-year-old female with metastases to the lungs, brain, and bilateral kidneys resulting in large retroperitoneal hematomas.