O. Buckley

Imaging of acute pyelonephritis in the adult

The diagnosis of acute pyelonephritis in adults is predominantly made by a combination of typical clinical features of flank pain, high temperature and dysuria combined with urinalysis findings of bacteruria and pyuria. Imaging is generally reserved for patients who have atypical presenting features or in those who fail to respond to conventional therapy. In addition, early imaging may be useful in diabetics or immunocompromised patients. In such patients, imaging may not only aid in making the diagnosis of acute pyelonephritis, but more importantly, it may help identify complications such as abscess formation. In this pictorial review, we discuss the role of modern imaging in acute pyelonephritis and its complications. We discuss the growing role of cross-sectional imaging with computed tomography (CT) and novel magnetic resonance imaging (MRI) techniques that may be used to demonstrate both typical as well as unusual manifestations of acute pyelonephritis and its complications. In addition, conditions such as emphysematous and fungal pyelonephritis are discussed.

Imaging of Budd-Chiari syndrome

Budd-Chiari syndrome occurs when venous outflow from the liver is obstructed. The obstruction may occur at any point from the hepatic venules to the left atrium. The syndrome most often occurs in patients with underlying thrombotic disorders such as polycythemia rubra vera, paroxysmal nocturnal hemoglobinuria and pregnancy. It may also occur secondary to a variety of tumours, chronic inflammatory diseases and infections. Imaging plays an important role both in establishing the diagnosis of Budd-Chiari syndrome as well as evaluating for underlying causes and complications such as portal hypertension. In this review article, we discuss the role of modern imaging in the evaluation of Budd-Chiari syndrome.

Pictorial review: magnetic resonance imaging of colonic diverticulitis.

Magnetic resonance imaging (MRI) is rapidly emerging as a useful imaging modality for the evaluation of the gastrointestinal tract. Increasingly rapid sequences and improving hardware have significantly improved the visualisation of diseases of the colon. MRI has a major advantage over CT in that there is no ionising radiation. In our institution, MRI has increasingly been used as a complimentary imaging modality to CT in the diagnosis and evaluation of diverticulitis and its complications. In this review article, we illustrate the emerging role of MRI in the diagnosis and evaluation of colonic diverticulitis.

Imaging of horseshoe kidneys and their complications

Horseshoe kidney is the most common renal fusion anomaly and the patients are prone to a variety of complications, such as stone disease, pelviureteric junction (PUJ) obstruction, trauma, infections and tumours. As result of the abnormal anatomy of a horseshoe kidney, imaging and treatment pathways vary substantially from the normal kidney. In this review, we describe the role of modern imaging in depicting horseshoe kidneys and their complications, in tandem with the role the interventional radiologist plays in treating these patients.

Imaging of adenomyomatosis of the gall bladder.

Adenomyomatosis is a relatively common abnormality of the gall bladder, with a reported incidence of between 2.8 and 5%. Although mainly confined to the adult study group, a number of cases have been reported in the paediatric study group. It is characterized pathologically by excessive proliferation of the surface epithelium and hypertrophy of the muscularis propria of the gall bladder wall, with invagination of the mucosa into the thickened muscularis forming the so‐called ‘Rokitansky–Aschoff’ sinuses. The condition is usually asymptomatic and is often diagnosed as an incidental finding on abdominal imaging. The radiological diagnosis is largely dependent on the visualization of the characteristic Rokitansky–Aschoff sinuses. As the condition is usually asymptomatic, the importance of making a correct diagnosis is to prevent misinterpretation of other gall bladder conditions such as gall bladder cancer, leading to incorrect treatment. In the past, oral cholecystography was the main imaging method used to make this diagnosis. In most institutions, oral cholecystography is no longer carried out, and the diagnosis is now more commonly seen on cross‐sectional imaging. In this review article, we describe the manifestations of adenomyomatosis on the various imaging methods, with an emphasis on more modern techniques such as magnetic resonance cholangiopancreatography. A brief section on oral cholecystography to aid readers familiar with this technique in understanding the comparable imaging features on more modern imaging techniques is included.

The Relationship of Body Mass Index and Abdominal Fat on the Radiation Dose Received During Routine Computed Tomographic Imaging of the Abdomen and Pelvis

Purpose To determine the relationship of increasing body mass index (BMI) and abdominal fat on the effective dose acquired from computed tomography (CT) abdomen and pelvis scans. Methods Over 6 months, dose-length product and total milliamp-seconds (mAs) from routine CT abdomen and pelvis scans of 100 patients were recorded. The scans were performed on a 64-slice CT scanner by using an automatic exposure control system. Effective dose (mSv) based on dose-length product, BMI, periumbilical fat thickness, and intra-abdominal fat were documented for each patient. BMI, periumbilical fat thickness, and intra-abdominal fat were compared with effective dose. Results Thirty-nine men and 61 women were included in the study (mean age, 56.3 years). The mean BMI was 26.2 kg/m2. The mean effective dose was 10.3 mSv. The mean periumbilical fat thickness was 2.4 cm. Sixty-five patients had a small amount of intra-abdominal fat, and 35 had a large amount of intra-abdominal fat. The effective dose increased with increasing BMI (P < .001) and increasing amounts of intra-abdominal fat (P < .001). For every kilogram of weight, there is a 0.13 mSv increase in effective dose, which is equal to 6.5 chest radiographs per CT examination. For an increase in BMI by 5 kg/m2, there is a 1.95 mSv increase in effective dose, which is equal to 97.5 chest radiographs per CT examination. Conclusion Increasing BMI and abdominal fat significantly increases the effective dose received from CT abdomen and pelvis scans.

Recurrent pyogenic cholangitis due to chronic infestation with Clonorchis sinensis (2006: 8b).

Recurrent pyogenic cholangitis is a common disease in Southeast Asia, where an association with the liver fluke Clonorchis sinensis is postulated. It is characterised by repeated attacks of cholangitis with multiple recurrences of bile duct stones and strictures. We present a case of recurrent pyogenic cholangitis due to chronic infestation with Clonorchis sinensis in a young Asian immigrant, describing its radiological appearances and also therapeutic strategies with a review of additional examples from the literature.

The use of thrombin in the radiology department

Thrombin is a naturally occurring coagulation protein that converts soluble fibrinogen into insoluble fibrin and plays a vital role in the coagulation cascade and in turn haemostasis. Thrombin also promotes platelet activation. In the last few years, there has been a rapid increase in the use of thrombin by radiologists in a variety of clinical circumstances. It is best known for its use in the treatment of pseudoaneurysms following angiography. However, there are now a variety of cases in the literature describing the treatment of traumatic, inflammatory and infected aneurysms with thrombin in a variety of locations within the human body. There have even been recent reports describing the use of thrombin in conventional aneurysms as well as ruptured aneurysms. Its use has also been described in the treatment of endoleaks (type II) following aneurysm repair. In nearly all of these cases, treatment with thrombin requires imaging guidance. Recently, thrombin has also been used as a topical treatment post-percutaneous intervention to reduce or stop bleeding. Most radiologists have only a limited knowledge of the pharmacodynamics of thrombin, its wide range of utilisation and its limitations. Apart from a few case reports and case series, there is little in the radiological literature encompassing the wide range of applications that thrombin may have in the radiology department. In this review article, we comprehensively describe the role and pathophysiology of thrombin, describing with examples many of its potential uses. Techniques of usage as well as pitfalls and limitations are also described.

Ultrasound-guided removal of Implanon devices.

Abstract Our study has shown that ultrasound-guided localisation and removal of Implanon™ rods is safe, practical and highly successful. Over a 4-year period, 119 patients had successful, uncomplicated removal of their subdermal devices.The technique is particularly useful for removal of the device when it is not palpable or when an attempt at removal of a palpable device has not been successful.

A novel technique in selective venous sampling in the localization of parathyroid tumours utilizing a micro-wire and standardized catheter

Selective venous sampling (SVS) is a useful technique to localize a number of hormone-producing tumours, such as parathyroid tumours, when other imaging techniques are inconclusive. Typically, a 5 French selective single end-hole catheter and standard hydrophilic wire are utilized to access the required vessels and an attempt made to withdraw blood. However, most interventional radiologists are familiar with the difficulty and limited success in withdrawing venous blood through an end-hole catheter. We describe a simple, cheap and novel technique utilizing a micro-wire that we have developed in our interventional suite to overcome this common problem. Having reached the target site with the selective end-hole catheter, a Tuohy Borst adapter is attached to the catheter end. A 0.018-inch micro-wire is then inserted through the selective end-hole catheter such that the distal wire tip exits the distal catheter tip. The purpose of the micro-wire exiting the catheter is to both straighten the catheter tip to a position parallel to the vessel, allowing easier aspiration as well as physically preventing blockage of the catheter by the vein intimal wall collapse on suction. The 5-ml sample required for PTH assay is then successfully obtained via the Tuohy Borst adapter.