Usefulness of ultrasound fusion technology for hepatocellular carcinoma localisation, pre- and post-thermal ablation.

Introduction: Percutaneous thermal ablation of inconspicuous lesions can be challenging. Fusion ultrasound (FUS) allows the use of previously performed diagnostic imaging like computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET-CT) to localise hepatocellular carcinoma (HCC) for treatment. This paper illustrates FUS case studies of pre-, intra- and post-ablation imaging of inconspicuous HCC, supplemented by use of contrast-enhanced ultrasound (CEUS). Method: Four prospective cases during September 2014 to October 2018, with HCC amenable to ablation, which were poorly identified on ultrasound, underwent FUS. FUS pre-screening was scheduled within three months of the previous CT or MRI, and between one to four weeks prior to the scheduled ablation date. Post-ablation imaging with FUS was performed between four to six weeks to coincide with their routine follow-up CT or MRI. Findings: There were potential benefits observed in the cases with combined techniques of FUS and CEUS for limiting circumstances such as heat sink effect, multiple lesions targeting, inconspicuous lesion detection and pre-ablation technical feasibility assessment. Discussion: The combined use of FUS and CEUS improves tumour visibility, increases operator imaging confidence and reduces heat sink effect during percutaneous thermal ablation. Conclusion: FUS imaging is helpful in targeting poor conspicuity lesions that cannot be detected on grey-scale ultrasound. It facilitates in ensuring optimal treatment of hepatic lesions for improvement of patient prognosis and follow-up imaging.

Deeper may not be better: relationship between catheter dysfunction and location of the catheter tip in right-sided tunnelled haemodialysis catheters.

AIM: To examine the relationship between catheter tip location and catheter dysfunction in the context of tunnelled central venous catheters (CVCs) for haemodialysis. MATERIALS AND METHODS: This was a retrospective study of 993 haemodialysis patients who underwent insertion of tunnelled CVCs of step-tip design via the right internal jugular vein (IJV). Based on intra-procedural radiographs, the catheter tip was characterised as being in the superior vena cava (SVC), cavo-atrial junction (CAJ), or deep right atrium (DRA). Patients were tracked for 90 days post-procedure for complications resulting in catheter replacement, and these were compared between cohorts. Statistical analysis was performed with Pearson's chi-square and Fisher's exact tests for categorical variables and two-sample t-test and one-way analysis of variance (ANOVA) for continuous variables. RESULTS: Ninety-five patients (9.6%) experienced catheter dysfunction necessitating replacement within 90 days of insertion. Tip location in SVC was associated with lower occurrence of catheter dysfunction (1.9%) as compared with the CAJ (8%) and DRA (11%; p=0.049). Catheter replacement due to other complications (catheter-associated bacteraemia, cuff dislodgement, exit-site infection, external catheter damage) showed no statistically significant relation to location of the CVC tip. CONCLUSION: When utilising tunnelled CVCs with a step-tip design inserted via the right IJV, location of the catheter tip in the SVC is associated with reduced occurrence of catheter dysfunction as compared to either the CAJ or DRA.

Subdural haematoma mimics.

A subdural haematoma (SDH) is a frequently encountered pathology seen on an emergency room computed tomography (CT) head scan. An extra-axial crescentic density along the convexity of the brain or within the interhemispheric fissure is generally thought to represent a SDH; however, SDH mimics are known to occur in nature, and can be broadly classified under the subcategories of normal anatomy, artefacts, tumour, inflammation, infection, ischaemia, trauma, and iatrogenic. Understanding the typical characteristics of a SDH, knowledge of normal anatomy, close inspection of the morphology of the subdural process, changes to the adjacent structures, and rigorous attention to clinical details may reveal subtle clues that distinguish a true SDH from a mimic. This is crucial in appropriately directing clinical management. This review amalgamates most of the rare subdural processes that have been reported to mimic SDH, and discusses the imaging and clinical features that help to differentiate between them. This topic is highly valuable for radiology trainees, general radiologists, and emergency room physicians, and may serve as a refresher for the practising neuroradiologist.

Radioembolisation of hepatocellular carcinoma: a primer.

Transarterial radioembolisation (TARE) has gained increasing acceptance as an additional/alternative locoregional treatment option for hepatocellular carcinoma, and colorectal hepatic metastases that present beyond potentially curative options. This is a catheter-based transarterial selective internal brachytherapy that involves injection of radioactive microspheres (usually Y-90) that are delivered selectively to the liver tumours. Owing to the combined radioactive and microembolic effect, the findings at follow-up imaging are significantly different from that seen with other transarterial treatment options. Considering increasing confidence among clinicians, refinement in techniques and increasing number of ongoing trials, TARE is expected to gain further acceptance and become an important tool in the armamentarium for the treatment of liver malignancies. So it is imperative that all radiologists involved in the management of liver malignancies are well versed with TARE to facilitate appropriate discussion at multidisciplinary meetings to direct further management. In this article, we provide a comprehensive review on various aspects of radioembolisation with Y-90 for hepatocellular carcinoma including the patient selection, treatment planning, radiation dosimetry and treatment, side effects, follow-up imaging and future direction.

External anterior abdominal wall and pelvic hernias with emphasis on the key diagnostic features on MDCT.

Clinical diagnosis of abdominal wall hernias can be challenging. These common entities can be symptomatic and prone to complications. Pre-surgical planning and investigation of acute presentations can be achieved by multidetector computed tomography (MDCT) with its added multiplanar reformatting capability. Here we delineate the important anatomical landmarks and key signs on CT of a wide spectrum of external anterior abdominal wall and pelvic hernias.

The varied sonographic appearances of focal fatty liver disease: review and diagnostic algorithm.

Focal fat infiltration and focal fat sparing of the liver are less common than diffuse fat infiltration but present a greater diagnostic conundrum. Although typical features of these conditions are well described, there is a wide variety of different appearances. These atypical patterns present significant difficulty in differentiation from other pathological processes and often require additional investigation. We present an innovative diagnostic algorithm and illustrate its effectiveness in diagnosing focal fatty liver disease with typical and atypical examples.

Extra-pulmonary manifestations of sarcoidosis.

Although, the diagnosis and evaluation of sarcoidosis has traditionally remained confined to the chest, its multi-system nature has been widely recognized. Radiological features of pulmonary sarcoidosis are well known but extra-pulmonary manifestations can produce a plethora of non-specific imaging findings that can affect subcutaneous tissue, and the neurological, cardiac, gastrointestinal, urological, liver, spleen, and skeletal systems. In the literature, there are various case reports and specific system reviews but there are few reviews that encompass all the extra-pulmonary manifestations. In this paper, we comprehensively review the imaging features of extra-pulmonary sarcoidosis with characteristic features as well as atypical presentations. In addition, we discuss the emerging role of nuclear medicine in sarcoidosis.

Imaging features of ductal plate malformations in adults.

Ductal plate malformations, also known as fibrocystic liver diseases, are a group of congenital disorders resulting from abnormal embryogenesis of the biliary ductal system. The abnormalities include choledochal cyst, Caroli's disease and Caroli's syndrome, adult autosomal dominant polycystic liver disease, and biliary hamartoma. The hepatic lesions can be associated with renal anomalies such as autosomal recessive polycystic kidney disease (ARPKD), medullary sponge kidney, and nephronophthisis. A clear knowledge of the embryology and pathogenesis of the ductal plate is central to the understanding of the characteristic imaging appearances of these complex disorders. Accurate diagnosis of ductal plate malformations is important to direct appropriate clinical management and prevent misdiagnosis.

Littoral cell angioma in a splenunculus: a case report.

Littoral cell angioma (LCA) is a rare primary splenic vascular tumour that arises from the littoral cells that line the red pulp sinuses. It is usually asymptomatic and is discovered incidentally on imaging for other pathologies. Radiologists should be aware of these lesions as they may be mistaken for malignant lesions and lead to unnecessary surgery. We present a case of LCA recurrence within a splenunculus that was discovered incidentally in a 60-year-old patient being investigated for right upper quadrant pain.

Imaging of illicit drug use.

Illicit drug abuse is a continuing menace of epidemic proportions associated with serious medical and social problems. Drug abuse can have a wide variety of presentations some of which can be life-threatening. The clinical diagnosis can be challenging as the history is usually limited or absent. Radiologists need to be familiar with varied imaging presentations and the related complications of illicit drug abuse to ensure correct diagnosis and appropriate timely treatment. This review will illustrate the imaging spectrum of illicit drug abuse involving several organ systems and also discuss the pathophysiological consequences of drug abuse.

MRI appearances of acute idiopathic scrotal oedema in an adult.

Acute idiopathic scrotal oedema is an uncommon cause of acute painless scrotal swelling that is usually seen in children. Traditionally, ultrasound has been used to help establish the diagnosis in the appropriate clinical setting. We report the MRI appearances of acute idiopathic scrotal oedema in a 51-year-old male with associated involvement of the penis.

MRI appearance of muscle denervation.

Muscle denervation results from a variety of causes including trauma, neoplasia, neuropathies, infections, autoimmune processes and vasculitis. Traditionally, the diagnosis of muscle denervation was based on clinical examination and electromyography. Magnetic resonance imaging (MRI) offers a distinct advantage over electromyography, not only in diagnosing muscle denervation, but also in determining its aetiology. MRI demonstrates characteristic signal intensity patterns depending on the stage of muscle denervation. The acute and subacutely denervated muscle shows a high signal intensity pattern on fluid sensitive sequences and normal signal intensity on T1-weighted MRI images. In chronic denervation, muscle atrophy and fatty infiltration demonstrate high signal changes on T1-weighted sequences in association with volume loss. The purpose of this review is to summarise the MRI appearance of denervated muscle, with special emphasis on the signal intensity patterns in acute and subacute muscle denervation.

Unusual presentation of ulnar artery aneurysm and dissection with associated anomalous radial artery: appearances on multi-detector row CT angiography.

We present a case of ulnar artery aneurysm and dissection associated with a congenitally hypoplastic ipsilateral radial artery. We postulate that the aetiology is due to increased blood flow through the ulnar artery as a consequence of the radial artery anomaly, therefore making the ulnar artery more vulnerable to aneurysm formation and traumatic damage. This might represent a variant of the hypothenar hammer syndrome with associated ulnar artery dissection and recurrent distal embolisation manifesting as Raynaud's phenomenon. Forearm arterial injuries, treatment and the importance of upper limb arterial anatomical variations are also discussed. To our knowledge, this is the first reported case of its type diagnosed by multi-detector row computed tomography angiography.