Syed Zafar H. Jafri

Current trends in imaging evaluation of acute cholecystitis

This study was designed to retrospectively determine recent clinical trends of initial radiological evaluation in patients pathologically proven to have acute cholecystitis (AC) and to assess the methodology that led to its diagnosis. Over a 28-month period, the medical records and imaging studies of 117 consecutive patients who had pathologically confirmed AC were retrospectively analyzed. The sensitivities of ultrasound (US) and hepatobiliary 99mTc-iminodiacetic acid (HIDA) were computed. The false-negative scans were retrospectively reviewed by a blinded radiologist to determine the limitations and advantages of each modality. The 117 patients were grouped into six categories based on the type of imaging examination they underwent prior to cholecystectomy: initial US evaluation only (n=80, 68.4%), initial US followed by HIDA (n=17, 14.5%), initial HIDA only (n=2, 1.7%), initial HIDA followed by US (n=3, 2.6%), initial CT (n=5, 4.3%), and no imaging evaluation (n=10, 8.6%). HIDA scan had a calculated sensitivity of 90.9% (20 true-positive, 2 false-negative) while US had a sensitivity of 62% (62 true-positive, 38 false-negative). Current practice in the initial radiological evaluation of acute cholecystitis remains outdated. The vast majority of patients in our study group were initially worked up using US, although HIDA scan has been shown to have greater sensitivity for the diagnosis of acute cholecystitis.

Imaging Evaluation of the Inferior Vena Cava

The inferior vena cava (IVC) is an essential but often overlooked structure at abdominal imaging. It is associated with a wide variety of congenital and pathologic processes and can be a source of vital information for referring clinicians. Initial evaluation of the IVC is most likely to occur at computed tomography performed for another indication. Many routine abdominal imaging protocols may result in suboptimal evaluation of the IVC; however, techniques to assist in specific evaluation of the IVC can be used. In this article, the authors review the spectrum of IVC variants and pathologic processes and the relevant findings from magnetic resonance imaging, angiography, sonography, and positron emission tomography. Embryologic development of the IVC and examples of congenital IVC variants, such as absence, duplication, left-sided location, azygous or hemiazygous continuation, and web formation, are described. The authors detail IVC involvement in Wilms tumor, leiomyosarcoma, adrenal cortical carcinoma, testicular carcinoma, hepatocellular carcinoma, renal cell carcinoma, and other neoplasms, as well as postsurgical, traumatic, and infectious entities (including filter malposition, mesocaval shunt, and septic thrombophlebitis). The implications of these entities for patient treatment and instances in which specific details should be included in the dictated radiology report are highlighted. Furthermore, the common pitfalls of IVC imaging are discussed. The information provided in this review will allow radiologists to detect and accurately characterize IVC abnormalities to guide clinical decision making and improve patient care.

Genitourinary trauma: a pictorial essay

Genitourinary trauma is often overlooked in the setting of acute trauma. Usually other more life-threatening injuries take precedence for immediate management. When the patient is stabilized, radiologic imaging often plays a key role in diagnosing insults to the upper and lower genitourinary tract in the setting of trauma. Our aim is to provide a pictorial assay of imaging findings in upper and lower tract genitourinary trauma from a variety of mechanisms including blunt trauma, penetrating trauma, and iatrogenic trauma. A patient archiving and communication system will be used to review imaging studies of patients at our institution with genitourinary tract trauma. Cases of renal, ureteral, bladder, urethral, penile, and scrotal trauma will be considered for inclusion in our study. Multimodality imaging techniques will be reviewed. The imaging and pertinent findings that occur in various types of genitourinary trauma are outlined. Genitourinary trauma is often missed in the frenzy of acute trauma. It is important to have a high suspicion for injury especially in severe trauma, and in particular clinical settings. Although often not life threatening, recognizing the diagnostic imaging findings quickly is the realm of the astute radiologist so appropriate urologic management can be made.

Therapeutic angioinfarction of renal carcinoma: CT follow-up.

Computed tomographic findings in nine patients after renal tumor embolization are reported. All tumors were ablated using absolute alcohol, Gelfoam particles, and occlusion coils. A rim of peripheral enhancement surrounding a central low density area presumed to represent the necrotic infarcted tumor was a constant CT appearance. Intratumoral gas was seen in three patients, persisting for up to 6 months, with eventual resolution. Mild postinfarction syndrome was experienced in all patients. The exact role of preoperative or palliative renal embolization is still controversial, but if the procedure is performed, the natural course of the neoplasm can be best evaluated and followed by serial CT scans.

Normal variants and pitfalls in CT of the gastrointestinal and genitourinary tracts.

Computed tomography (CT) and ultrasound are the primary imaging modalities for evaluating the abdomen. Normal variants are often encountered and their recognition is essential. Factors that might lead to misdiagnosis and consequent errors in management include incomplete or inadequate technique, misinterpretation of normal anatomic structures or variations, and postoperative changes and artifacts. This review article addresses recommendations on how to recognize normal variations and avoid diagnostic pitfalls in CT of the abdomen. The gastrointestinal tract, gallbladder, kidneys, urinary bladder, prostate, and testes are specifically addressed.

Radiologic Assessment of Native Renal Vasculature: A Multimodality Review

A wide range of clinically important anatomic variants and pathologic conditions may affect the renal vasculature, and radiologists have a pivotal role in the diagnosis and management of these processes. Because many of these entities may not be suspected clinically, renal artery and vein assessment is an essential application of all imaging modalities. An understanding of the normal vascular anatomy is essential for recognizing clinically important anatomic variants. An understanding of the protocols used to optimize imaging modalities also is necessary. Renal artery stenosis is the most common cause of secondary hypertension and is diagnosed by using both direct ultrasonographic (US) findings at the site of stenosis and indirect US findings distal to the stenosis. Fibromuscular dysplasia, while not as common as atherosclerosis, remains an important cause of renal artery hypertension, especially among young female individuals. Fibromuscular dysplasia also predisposes individuals to renal artery aneurysms and dissection. Although most renal artery dissections are extensions of aortic dissections, on rare occasion they occur in isolation. Renal artery aneurysms often are not suspected clinically before imaging, but they can lead to catastrophic outcomes if they are overlooked. Unlike true aneurysms, pseudoaneurysms are typically iatrogenic or posttraumatic. However, multiple small pseudoaneurysms may be seen with underlying vasculitis. Arteriovenous fistulas also are commonly iatrogenic, whereas arteriovenous malformations are developmental (ie, congenital). Both of these conditions involve a prominent feeding artery and draining vein; however, arteriovenous malformations contain a nidus of tangled vessels. Nutcracker syndrome should be suspected when there is distention of the left renal vein with abrupt narrowing as it passes posterior to the superior mesenteric artery. Filling defects in a renal vein can be due to a bland or tumor thrombus. A tumor thrombus is most commonly an extension of renal cell carcinoma. When an enhancing mass is located predominantly within a renal vein, leiomyosarcoma of the renal vein should be suspected. ©RSNA, 2017.