Kelvin Cortis

An evaluation of the use of oral contrast media in abdominopelvic CT

ObjectivesTo evaluate the diagnostic efficacy of different oral contrast media (OCM) for abdominopelvic CT examinations performed for follow-up general oncological indications. The objectives were to establish anatomical image quality criteria for abdominopelvic CT; use these criteria to evaluate and compare image quality using positive OCM, neutral OCM and no OCM; and evaluate possible benefits for the medical imaging department.MethodsForty-six adult patients attending a follow-up abdominopelvic CT for general oncological indications and who had a previous abdominopelvic CT with positive OCM (n = 46) were recruited and prospectively placed into either the water (n = 25) or no OCM (n = 21) group. Three radiologists performed absolute visual grading analysis (VGA) to assess image quality by grading the fulfilment of 24 anatomical image quality criteria.ResultsVisual grading characteristics (VGC) analysis of the data showed comparable image quality with regards to reproduction of abdominal structures, bowel discrimination, presence of artefacts, and visualization of the amount of intra-abdominal fat for the three OCM protocols.ConclusionAll three OCM protocols provided similar image quality for follow-up abdominopelvic CT for general oncological indications.Key Points• Positive oral contrast media are routinely used for abdominopelvic multidetector computed tomography• Experimental study comparing image quality using three different oral contrast materials• Three different oral contrast materials result in comparable CT image quality• Benefits for patients and medical imaging department

Unusual site for primary arterio-enteric fistula resulting in massive upper gastrointestinal bleeding – A case report on presentation and management

Highlights • Primary arterio-enteric fistula between the common iliac artery and duodenum is rare and radiotherapy is one aetiological factor.• Resuscitation is mandatory on presentation with acute massive haematemesis secondary to ilio-duodenal fistula.• Interventional radiology can be successfully deployed mainly in the form of stenting or coil embolisation.• Follow-up open fistula repair is recommended as a definitive measure to prevent a late recurrent haemorrhagic episode.

Hepatic morphology abnormalities: beyond cirrhosis

The diagnosis of cirrhosis can be reached on the basis of established hepatic morphological changes. However, some other conditions can mimic cirrhosis. The aim of this pictorial essay is to review the CT and MRI appearances of hepatic morphology abnormalities in the cirrhotic liver and other diseases, describing pathologic conditions that can mimic cirrhosis, with useful tips for the differential diagnosis. Mimickers of cirrhosis include congenital hepatic fibrosis, Caroli disease, Budd–Chiari Syndrome, hepatoportal sclerosis, cavernous transformation of the portal vein, pseudocirrhosis from metastatic disease, acute liver failure, post-therapeutic morphologic changes in the liver, and infective conditions including schistosomiasis and oriental cholangiohepatitis. Recognizing the hepatic morphological changes in images can help radiologists to diagnose cirrhosis and other diseases in early stages.

Balloon-Occluded Microwave Ablation: A Potential Therapeutic Option in Liver Lesions Bearing Close Proximity to Major Hepatic and/or Portal Veins

To the Editor, Microwave ablation (MWA) is potentially more effective than radiofrequency ablation (RFA), with some studies reporting a lower rate of local tumour progression in MWA [1]. Nonetheless, coagulative necrosis may be difficult to achieve in lesions close to major ([3 mm) hepatic venous tributaries or portal venous radicals due to perfusion-mediated convective cooling. This ‘heat sink’ phenomenon might be less pronounced in MWA as compared to RFA due to the higher temperatures reached with MWA, making it relatively insensitive to perfusion-mediated cooling of small calibre vessels. Temporary venous occlusion has already been described as a way to decrease the magnitude of this effect in RFA [2, 3] and non-clinical MWA studies [4]. We present three cases of balloon-occluded MWA for lesions located close to a major vein. Patient A is a 41-year-old male patient who underwent distal pancreatectomy in 2012 for acinar cell carcinoma. Three liver metastases were noted in December 2013, for which he underwent chemotherapy followed by RFA. Three new liver metastases were noted on follow-up in March 2015. One of these was located in segment VII in direct contact with, but not invading, the main trunk of the right hepatic vein (RHV), 8 mm from the inferior vena cava. US-guided MWA was performed. Residual disease was noted in segment VII on follow-up, in the part of the metastatic deposit located adjacent to the RHV (Fig. 1). CT-guided balloon-occluded MWA was subsequently performed. Patient B is a 46-year-old lady with primary biliary cirrhosis and deranged liver function despite optimal medical management (bilirubin 66 lmol/L; ALP 844 U/L; AST 108 U/L; GGT 508 U/L; MELD 12), but no signs of portal hypertension. She had a history of sigmoid adenocarcinoma, resected in 2014. Four suspicious liver lesions were noted on follow-up MRI, and biopsy showed metastatic colonic adenocarcinoma. Given her poor liver reserve, she was referred for MWA. The metastatic deposit located in segment VIII was closely related to a major tributary of the RHV (Fig. 2). US/CT-guided balloon-occluded MWA was performed in April 2016. Patient C is a 55-year-old male diagnosed with welldifferentiated small bowel neuroendocrine tumour (NET) in September 2015, for which he underwent surgical resection. A single liver metastasis was noted in the right liver lobe (segment VI/VII) on the staging CT—this was very close to both the segment VI branch of the portal vein and to a major tributary of the RHV (Fig. 3). The patient refused surgery and was referred for ablation. Balloonoccluded MWA with temporary occlusion of both right hepatic vein and segment VI branch of the right portal vein was done in May 2016 under ultrasound guidance. In all cases, a 2–6-cm-long 10-mm-diameter balloon (Admiral Xtreme, Medtronic, Dublin, Republic of Ireland) was advanced over a standard guidewire in the RHV from a jugular approach and inflated at a safe distance from the metastatic deposit. Access to the right portal venous branch in Patient C was achieved percutaneously (Neff Percutaneous Access Set, Cook Medical, Bloomington, & Kelvin Cortis kelvin.cortis@gov.mt

Complete spontaneous regression of giant focal nodular hyperplasia of the liver: Magnetic resonance imaging evaluation with hepatobiliary contrast media

Focal nodular hyperplasia (FNH) of the liver is a benign lesion occurring in 0.6%-3% of the general population that probably reflects a local hyperplastic response of hepatocytes to a vascular abnormality. Most lesions are diagnosed incidentally and the natural history of the disease remains largely unknown. It has been shown that most FNH remain stable, or even regress, over a long follow-up period. We present a patient with FNH of the liver who was followed up for 7 years. A 26-year-old woman with a 5-year history of oral contraceptive use was referred to our hospital in February 2005 for further examination of a liver tumour. The diagnosis of FNH was made using magnetic resonance (MR) imaging with hepatospecific contrast media; this technique allows a correct diagnosis, in particular distinguishing FNH from hepatic adenoma, avoiding an invasive procedure such as the lesion biopsy. After 7-year from the diagnosis, we observed the complete spontaneous regression of the lesion by enhanced MR scanning. In this patient, discontinuation of oral contraceptive use and two childbirths may have influenced the natural history of FNH. To our knowledge, in the English literature there is no report illustrating a complete regression of giant FNH but only studies of decreasing in size. The present case suggests that a young patient with giant FNH should be managed conservatively rather than by resection, because FNH has the potential for spontaneous regression.

Aspiration of a speaking valve

Foreign body aspiration (FBA) is a relatively common and serious condition that can result in a spectrum of presentations ranging from incidental to acutely life-threatening. Described here is a case of aspiration of a tracheo-oesophageal speaking valve through a permanent tracheostomy that went unnoticed for a number of years, and an overview of the technique used for its removal. A 70-year-old ex-heavy smoker with a permanent tracheo-oesophageal fistula presented with a relatively recent history of increasing shortness of breath, sputum purulence and haemoptysis. Further investigation with a CT scan and bronchoscopy revealed the presence of a foreign body within his right lower lobe bronchus which was later removed by advancing a flexible bronchoscope over a rigid one.