Orla Doody

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.

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.

Percutaneous thrombin embolization of a hepatic artery mycotic aneurysm

Sir, We read with interest the excellent case report by Kang et al. in Acta Radiologica regarding a liver abscess in association with a hepatic artery pseudoaneursym (1). The authors eloquently described this rare abnormality and successfully treated their patient by transcatheter embolization. While we concur with the necessity of treating hepatic pseudoaneuysms radiologically and complement the authors on their success, we would like to add to their case by demonstrating a similar case of an abscess in association with a pseudoaneurysm that was successfully treated by percutaneous thrombin injection rather than by conventional transcatheter methods. We believe that this novel technique allows a simpler and quicker method to treat such disorders. A 31-year-old male patient with a history of intravenous drug abuse presented with a 1-week history of upper abdominal pain, swinging pyrexia, and three episodes of coffee-ground vomiting. He had a history of a mitral valve replacement 6 months previously after developing infective endocarditis. On examination he was febrile and had a mild tachycardia of 110 beats per minute. He was otherwise hemodynamically stable. Examination of the abdomen revealed tender hepatomegaly. His blood profile was very abnormal, with a hemoglobin of 7.4 g/dl, WCC 17, and elevation of liver function tests. The patient was resuscitated and transfused with two units of red blood cells. He was commenced on antibiotic therapy. A computed tomography (CT) scan of the abdomen was then performed (Fig. 1), which demonstrated a hepatic abscess with a large pseudoaneurysm within the abscess cavity. Blood was seen in the gall bladder and biliary tree, and this was felt to be related to the bleeding from the pseudoaneuyrsm and to account for the hematemesis. It was decided to treat the patient by percutaneous CT-guided thrombin injection. Using an aseptic technique, a 22-gauge needle was inserted into the center of the pseudoaneurysm sac under direct CT guidance. Contrast medium was injected through the needle to ensure correct position within the pseudoaneurysm sac. Six millimeters of d-stat flowable thrombin was then injected through the 22-gauge needle, and a scan immediately post-thrombin injection showed the typical changes of air and contrast within the aneurysm lumen (Fig. 2) in concordance with a technically successful embolization. The procedure was well tolerated by the patient, and there were no immediate complications. The patient remained Fig. 1. Contrast-enhanced CT demonstrates mycotic aneurysm (arrow) within an abscess cavity.

Central Venous Catheter Care during Contrast-enhanced CT

we also believe that meticulous inspection of contiguous anatomic slices of the UMH with additional histologic analysis at key locations to confi rm the observations is a reliable and proved technique, one that has been used countless times to suffi ciently describe many anatomic structures of the human body. Our inspection of the anatomic slices clearly confi rmed the accuracy of our description of the UMH, especially its distal insertion in the triquetrum. Journal requirements prevented us from publishing additional images to corroborate our fi ndings. We are hopeful that others, perhaps Dr Yoshioka, will further investigate the morphology of the UMH, as well as the spectrum of its pathologic variations and the accompanying clinical manifestations. We look forward to such a study.

A case of back pain associated with neurology in a young man

BackgroundWe present the case of a 14-year-old with a 3-month history of back pain, who on presentation, was demonstrated to have neurological signs.MethodInvestigation with radiographs and subsequent magnetic resonance imaging was performed, which demonstrated an expansile lesion in the tenth thoracic vertebra with posterior extension causing spinal cord compression. This was treated with surgical resection and spinal cord decompression.ResultsDiagnosis of aneurysmal bone cyst was made following histopathological examination of the resected lesion.ConclusionBack pain in childhood is a significant and often sinister symptom, which requires careful evaluation.

The Management of the Symptomatic Patient With a Metal-on-Metal Hip Prosthesis

Metal-on-metal (MoM) hip implants have gained popularity due to their greater stability and reduction in implant failure compare to metal-on-polyethylene prostheses. However, as well as carrying general risks of hip implantation, risks specifically associated with MoM implants have been well documented in recent years. Conditions such as pseudotumours or aseptic lymphocyte-dominated vasculitis-associated lesions are specific to MoM hip implants. In this review we discuss the typical patient presentation, the investigations that should be performed, the typical findings on various imaging modalities, and the treatment options of symptomatic patients with MoM hip arthroplasties.

Answer to Case of the Month #149: Alveolar Soft-Part Sarcoma

A 39-year-old man presented to the emergency department with a 2-week history of a dry cough that was unresponsive to a course of antibiotics. He also suffered from fatigue and believed he had lost some weight over the past 3 months. He had no other specific symptoms and had no significant past medical or surgical history. He was on no medications and was a nonsmoker. On examination, he was apyrexial and his general physical examination was normal apart from the presence of a soft-tissue mass behind his left knee. A full blood count as well as routine serum biochemical analysis was normal. A chest radiograph was performed that showed multiple lung metastases (Figure 1). A magnetic resonance image (MRI) of the left knee was performed. Figure 2A is a sagittal T1-weighted MRI image showing a 5 7 cm soft-tissue mass lying posterior to the knee. The mass involved the posterior muscle compartment. There was no osseous involvement and the femoral artery and vein were separate from it. An unusual feature of the mass was the presence of multiple large vessels present throughout the mass. Figure 2B is a transverse T1-weighted image again showing the mass involving the posterior muscle compartment. Figure 2C is a transverse gadolinium-enhanced image showing marked enhancement of the mass as well as again showing the presence of multiple vessels within the mass. Figure 2D is a T2-weighted image of the mass. The differential diagnosis at this stage included both a large arteriovenous malformation, as well as an alveolar soft-part sarcoma (ASPS). The presence of multiple lung metastases

Answer to Case of the Month #145: Lemierre's Syndrome

A 30-year-old woman presented to the emergency department with a 4-day history of pleuritic chest pain and dyspnoea and a 1-day history of haemoptysis. She had been well until 2 weeks ago when she attended her general practitioner with headaches and a sore throat and was treated with anti-inflammatory medication and a course of antibiotics with improvement of symptoms. On examination, the patient was tachypnoeic with a respiratory rate of 22 breaths per minute and had a pyrexia with a temperature of 38.3 C. Physical examination was otherwise unremarkable. Laboratory investigation showed a leucocytosis with a white cell count of 14 10/L and an increased C-reactive protein of 109 mg/L. The patient went on to have a contrast-enhanced computed tomography of her neck and thorax (Figures 1e3).