Andrew F. Little

Infected (Mycotic) Aneurysms : Spectrum of Imaging Appearances and Management

Infected aneurysms are uncommon. The aorta, peripheral arteries, cerebral arteries, and visceral arteries are involved in descending order of frequency. Staphylococcus and Streptococcus species are the most common causative pathogens. Early clinical diagnosis of infected aneurysms is challenging owing to their protean manifestations. Clinically apparent infected aneurysms are often at an advanced stage of development or are associated with complications, such as rupture. Nontreatment or delayed treatment of infected aneurysms often has a poor outcome, with high morbidity and mortality from fulminant sepsis or hemorrhage. Current state-of-the-art imaging modalities, such as multidetector computed tomography and magnetic resonance imaging, have replaced conventional angiography as minimally invasive techniques for detection of infected aneurysms in clinically suspected cases, as well as characterization of infected aneurysms and vascular mapping for treatment planning in confirmed cases. Doppler ultrasonography allows noninvasive assessment for infected aneurysms in the peripheral arteries. Imaging features of infected aneurysms include a lobulated vascular mass, an indistinct irregular arterial wall, perianeurysmal edema, and a perianeurysmal soft-tissue mass. Perianeurysmal gas, aneurysmal thrombosis, aneurysmal wall calcification, and disrupted arterial calcification at the site of the infected aneurysm are uncommon findings. Imaging-guided endovascular stent-graft repair and embolotherapy can be performed in select cases instead of open surgery. Familiarity with the imaging appearances of infected aneurysms should alert the radiologist to the diagnosis and permit timely treatment, which may include endovascular techniques.

Transjugular Liver Biopsy: A Prospective Study in 43 Patients with the Quick-Core Biopsy Needle

PURPOSE To evaluate the efficacy and complication rate of the Quick-Core biopsy needle system compared with traditional transjugular biopsy needle systems. MATERIALS AND METHODS Between January 1994 and April 1995, 43 patients underwent transjugular liver biopsy with the Quick-Core system; 18-, 19-, and 20-gauge needles were used in 28, 13, and two patients, respectively. Histologic diagnoses, specimen dimensions, and adequacy of the biopsy sample were determined. Immediate and delayed complications were recorded. RESULTS A total of 118 biopsy specimens were obtained with an average of 2.7 passes per patient. Biopsy was successful in 42 of 43 patients (98%); one specimen contained renal parenchyma. Of the specimens that contained liver tissue, 100% were adequate. Mean maximum sample lengths were 1.1 and 1.5 cm with the 18- and 19-gauge needles, respectively. The procedural complication rate of 2% was due to puncture of the liver capsule in one patient, but no clinical manifestations occurred. No delayed complications occurred in any patient. CONCLUSION The Quick-Core biopsy system produces consistently satisfactory, reproducible specimen cores with a very low complication rate.

Influence of posture on transient lower oesophageal sphincter relaxation and gastro-oesophageal reflux in the dog

The hypothesis that suppression of transient lower oesophageal sphincter relaxation (TLOSR) in recumbent postures in the dog is dependent upon the sensing of a gastric pool of liquid in proximity to the lower oesophageal sphincter was examined. Constant gastric insufflation with air (80 ml/min) was used to evoke TLOSR in unsedated, fasting animals. Oesophageal motility was monitored with a perfused manometric sleeve catheter assembly. Gastro‐oesophageal flow was recognized manometrically and by oesophageal pH recording. TLOSR occurred significantly less frequently in three recumbent positions (right lateral, left lateral and supine) than when the dog stood on four legs, but was more likely to be associated with acid reflux when they occurred in recumbent positions. Aspiration of the gastric pool was found to have no effect on triggering of TLOSR although it reduced the frequency with which acid reflux was associated with TLOSR. It is concluded that the low rate of occurrence of TLOSR in recumbent positions is unlikely to be explained by the presence of a gastric pool of liquid in proximity to the lower oesophageal sphincter.

Percutaneous and endovascular embolization of ruptured hepatic artery aneurysm.

A 72-year-old woman presented with an intraperitoneal hemorrhage from a ruptured intrahepatic artery aneurysm, with an associated pseudoaneurysm developing a high-flow arteriovenous fistula. Persistent coagulopathy and a median arcuate ligament stenosis of the celiac axis further complicated endovascular management. Aneurysm thrombosis required percutaneous embolization with coils, a removable core guidewire and polyvinyl alcohol particles.

Adrenal Gland and Renal Sonography

Ultrasound (US) is an established imaging modality for the assessment of the kidneys and adrenal glands. The advantages include its lack of ionizing radiation, speed, multiplanar real time evaluation, and cost compared with more expensive modalities. The addition of color Doppler also permits accurate evaluation of blood flow, which is especially useful in renal assessment. As with all sonography, both renal and adrenal US are highly dependent on the operators skill and experience and require meticulous scanning techniques. In particular, adrenal sonography can be difficult due to the lack of a satisfactory acoustic window through which the incident US beam passes. This review summarizes the various morphologic appearances seen in common renal and adrenal pathologies, many of which have characteristic US appearances enabling accurate diagnosis.

MR cholangiography in the evaluation of suspected intrabiliary rupture of hepatic hydatid cyst

We report a case of intrabiliary hydatid cyst rupture that was indirectly suspected on computed tomography, diagnosed with magnetic resonance cholangiography (MRC), and confirmed with ultrasound and endoscopic retrograde cholangiopancreatography. MRC evaluation is a highly sensitive and accurate method for diagnosing intrabiliary rupture.

Reliability of X-rays and bone scans for the assessment of changes in skeletal metastases from breast cancer.

Aims:  To examine the level of agreement among observers regarding changes between serial images of bone metastases.

Part 1: CT characterisation of pancreatic neoplasms: a pictorial essay

The pancreas is a site of origin of a diverse range of benign and malignant tumours, and these are frequently detected, diagnosed and staged with computed tomography (CT). Knowledge of the typical appearance of these neoplasms as well as the features of locoregional invasion is fundamental for all general and abdominal radiologists. This pictorial essay aims to outline the characteristic CT appearances of the spectrum of pancreatic neoplasms, as well as important demographic and clinical information that aids diagnosis. The second article in this series addresses common mimics of pancreatic neoplasia.

Percutaneous cystic duct stent placement in the treatment of acute cholecystitis

Percutaneous cholecystostomy is well established as a temporising treatment option in selected patients presenting with acute cholecystitis. However, some patients who undergo cholecystostomy will have persistent discharge, which precludes catheter removal, or may not be medically suitable for future cholecystectomy. In these circumstances, percutaneous cystic duct stenting is a novel treatment option. It may delay or avoid the need for cholecystectomy, and thereby provide definitive treatment in a subset of patients who have acute cholecystitis and a high anaesthetic risk or limited life expectancy. Current application has been limited largely to patients with pre‐existing malignant common bile duct strictures, but there is potential for the application to be broadened to include other subsets of patients.

Postoperative Sonographic Evaluation of the Hepatic and Renal Transplant Patient

Summary: Ultrasound is a sensitive screening tool in the liver and renal posttransplant population (5,10). Both gray scale and color duplex Doppler are used in the evaluation of the transplant allograft, and their roles are frequently complementary. Gray scale ultrasound is more useful for evaluating the morphologic features of a vascular abnormality, whereas color confirms flow direction, areas of focal changes in velocity, and vessel patency. Duplex Doppler analysis, then, permits quantification of flow and flow disturbances.