Does intra-tumoural fat on MRI predict visibility of small (≤3 cm) hepatocellular carcinomas during ultrasound-guided tumour ablation?

AIM: To assess if intra-tumoural fat on magnetic resonance imaging (MRI) affects the ultrasonographic (US) visibility of small (≤3 cm) hepatocellular carcinomas (HCC) during radiofrequency ablation (RFA). MATERIALS AND METHODS: Institutional review board approval was obtained. A retrospective review of all patients who underwent image-guided ablation between 1 January 2010 and 31 April 2015 was performed. Patients with HCC who underwent US RFA were included. Inclusion criteria included small tumours (≤3 cm), treatment-naive cases or new focus of HCC in a different and untreated segment, and pre-procedural MRI. The presence of intra-tumoural fat was determined retrospectively via in-and-out-of-phase MRI. Other factors that potentially affect ultrasonographic visibility, such as background fatty liver, presence of cirrhosis, tumour size, and distance from diaphragm, were recorded. RESULTS: Ninety procedures performed on 74 patients (62 men and 12 women; mean age: 67.3 years; range: 39-88 years). Seventy-two tumours were visible on US (hypoechoic n=35, hyperechoic n=28, heterogeneous n=9). Intra-tumoural fat was seen in 23 tumours (25.6%, hyperechoic n=17, hypoechoic n=6). The presence of intra-tumoural fat (p=0.005) and distance from diaphragm (p=0.007) were found to be statistically significant factors affecting tumour visibility on planning US. The presence of background fatty liver (p=0.485), cirrhosis (p=0.48), and tumour size (p=0.15) were not found to be significant. CONCLUSION: The present study shows that the presence of intra-tumoural fat in small HCCs on pre-procedural MRI can accurately predict their visibility on planning US during percutaneous tumour ablation.

Emergency computed tomography for acute pelvic trauma: where is the bleeder?

Contrast medium extravasation at computed tomography (CT) is an accurate indicator of active haemorrhage in pelvic trauma. When this is present, potentially lifesaving surgical or endovascular treatment should be considered. Identification of the site or territory of haemorrhage is helpful for the interventional radiologist as it allows for focused angiographic evaluation and expedites haemostatic angio-embolisation. Even with thin-section arterial phase CT, tracing the bleeding vessel is not always possible and is often time consuming. We introduce a technique for predicting the bleeding vessel based on knowledge of the cross-sectional anatomical territory of the vessel as an alternative to tracing the vessel's course. Several case examples with digital subtraction angiography (DSA) correlation will be provided.

Case report. Spontaneous cholecystocolic fistula and locoregional liver tumour ablation: a cautionary tale.

A liver abscess is a feared and potentially fatal complication following transarterial chemoembolisation (TACE) and radiofrequency ablation (RFA) of liver tumours. Iatrogenic bilio-enteric communications, such as bilio-enteric anastomosis, sphincterotomy and biliary stents, are considered major risk factors and are due to bacterial colonisation of the biliary tree with enteric flora. Naturally occurring spontaneous cholecysto-enteric fistula poses a similar risk as its iatrogenic counterparts but is rarely described in the literature. We present a case where abscess formation complicated a combined TACE and RFA in an unrecognised cholecystocolic fistula.

Mesenteric desmoid tumour masquerading as a fat-containing cystic mass.

Mesenteric desmoid tumour (MDT) is an uncommon neoplasm that typically presents as a solid soft-tissue mass on cross-sectional imaging. MDT manifesting as a fat-containing cystic mass on CT has not been described in the literature. We report such an unusual case with clinicopathological correlation.

Critical limb ischaemia in a diabetic population from an Asian Centre: angiographic pattern of disease and 3-year limb salvage rate with percutaneous angioplasty as first line of treatment.

PURPOSE: Lower extremity amputation prevention (LEAP) is an ongoing program in our institution aimed at salvaging limbs in patients with critical limb ischemia (CLI). Patients in the LEAP program with reconstructible anatomy on initial Doppler imaging received either bypass surgery or percutaneous transluminal balloon angioplasty (PTA). We present the 3 year limb salvage rate and angiographic disease patterns in 42 consecutive diabetic patients with CLI who received PTA in 2005. METHODS AND MATERIAL: 26 women and 16 men with diabetes between the ages of 45 and 91 years old (mean age, 70.8 years) received PTA in 2005. Presenting symptoms were rest pain (n = 22), pre-existing gangrene (n = 17), non-healing ulcer (n = 16) and cellulitis (n = 2). The aim of the PTA was to achieve straight-line flow from the abdominal aorta down to the patent dorsalis pedis or plantar arch, with limb salvage as the ultimate outcome. Failure of treatment was defined as any amputation above the level of a Syme's amputation or the need for further surgical bypass. Technical success was achieved in 90% (38 out of 42 patients). RESULTS: Limb salvage rates were 93% at 1 month, 87% at 3 months, 82% at 6 months, 78% at 1 year, 69% at 2 years and 66% at 3 years. Mortality was 17% (n = 7) at 3 years. Of the 13 patients with failed therapy, 3 underwent bypass, 9 had amputations and 1 had bypass followed by amputation. Four of the cases required further intervention due to worsening gangrene and infection, while the remaining was due to persistent rest pain. The rest of the 32 patients had no lower limb related issues at the end of 3 years, with improvement of the presenting symptoms. Patterns of treated segments were aortoiliac occlusions (n = 3), pure infrapopliteal disease (n = 3), femoropopliteal with at least 1 good infrapopliteal run-off vessel (n = 14) and combined femoropopliteal and infrapopliteal disease (n = 25). CONCLUSION: Involvement of infrapopliteal vessels that needs to be treated is common in Asian diabetics. While early limb salvage rates up to 1 year are similar, the 3 year limb salvage rates in Asian diabetics are lower than the western population.

Multidetector row CT diagnosis of an infected right atrial thrombus following repeated dialysis catheter placement.

Right atrial thrombus formation is a known complication of dialysis catheter placements. We describe the case of a 61-year-old woman with end-stage renal failure who presented with gram-negative septicaemia. A gas-containing filling defect was noted incidentally in the right atrium during a CT scan of the abdomen and pelvis, indicative of a thrombus infected by a gas-forming organism. The finding correlated with a positive blood culture of Klebsiella pneumoniae and the two-dimensional echocardiography finding of an echogenic atrial thrombus.

CT appearance of complications related to thoracic endovascular aortic repair (TEVAR): a pictorial essay.

Thoracic endovascular aortic repair (TEVAR) is a recognized treatment for various diseases involving the thoracic aorta. Patients treated with TEVAR require lifelong surveillance for potential complications, with CT being highly utilized in most centres. Endoleak is the most common complication and can be detected using CT. However, other complications such as stent strut perforations and end organ ischemia can also be detected on CT. The purpose of this pictorial essay is to illustrate the CT appearance of post-TEVAR complications encountered in our institution and to highlight their significance.

Transarterial embolisation of spontaneous adrenal pheochromocytoma rupture using polyvinyl alcohol particles.

The spontaneous rupture of a phaeochromocytoma is a rare and potentially fatal complication. Prompt diagnosis, patient stabilisation and adrenectomy are crucial for survival. However, it is known that adrenectomy performed in the emergency setting is associated with a high mortality rate, in contrast to the negligible mortality rate with elective surgery. We describe transcatheter arterial embolisation (TAE) using polyvinyl alcohol particles (PVA) in restoring haemodynamic stability during an acute phaeochromocytoma rupture in a 67-year-old man to avoid the risks of performing an emergency adrenectomy. TAE improves the prognosis significantly by prolonging treatment time for patient optimisation and to enable the possibility of elective adrenectomy. To the best of our knowledge, TAE using PVA in an acute phaeochromocytoma rupture has not been previously reported in the English literature.