Interobserver Variation of Colonic Polyp Measurement at Computed Tomography Colonography.

BACKGROUND: The concept of "advanced polyps" is well accepted and is defined as polyps ≥10 mm and/or those having a villous component and/or demonstrating areas of dysplasia. Of these parameters, computed tomography colonography (CTC) can only document size. The accepted management of CTC-detected "advanced polyps" is to recommend excision if feasible, whereas the management of "intermediate" (6-9 mm) polyps is more controversial, and interval surveillance may be acceptable. Therefore, distinction between 6-9 mm and ≥10 mm is important. METHODS: Datasets containing 26 polyps originally reported as between 8-12 mm in diameter were reviewed independently by 4 CTC-accredited radiologists. Observers tabulated the largest measurement for each polyp on axial, coronal, sagittal, and endoluminal views at lung-window settings. These measurements were also compared to those determined by the computer-aided detection (CAD) software. RESULTS: The interobserver reliability intra-class correlation coefficient (ICC) for sagittal projection was 0.80 ("excellent" category of Hosmer and Lemeshow [2004]), 0.71 for axial ("acceptable"), 0.69 for coronal, and 0.41 for endoluminal ("unacceptable"). The largest of sagittal/axial/coronal measurement gave the best reliability with the smallest variance (ICC = 0.80; 95% CI 0.67-0.89). For 8 of 26 polyps, at least one radiologist's measurement placed the polyp in a different category compared to a colleague. For the majority of the polyps, the CAD significantly overestimated the readings compared to the largest of the manual measurements with an average difference of 1.6 mm (P < .0001 for sagittal/axial/coronal). This resulted in 33% of polyps falling into a different category-10% were lower and 23% were higher (P < .034). CONCLUSION: It is apparent that around the cutoff point of 10 mm between "advanced" and "intermediate" polyps, interobserver performance is variable.

Improved technical success and radiation safety of adrenal vein sampling using rapid, semi-quantitative point-of-care cortisol measurement.

Objective Primary aldosteronism is a curable cause of hypertension which can be treated surgically or medically depending on the findings of adrenal vein sampling studies. Adrenal vein sampling studies are technically demanding with a high failure rate in many centres. The use of intraprocedural cortisol measurement could improve the success rates of adrenal vein sampling but may be impracticable due to cost and effects on procedural duration. Design Retrospective review of the results of adrenal vein sampling procedures since commencement of point-of-care cortisol measurement using a novel single-use semi-quantitative measuring device for cortisol, the adrenal vein sampling Accuracy Kit. MEASUREMENTS: Success rate and complications of adrenal vein sampling procedures before and after use of the adrenal vein sampling Accuracy Kit. Routine use of the adrenal vein sampling Accuracy Kit device for intraprocedural measurement of cortisol commenced in 2016. Results Technical success rate of adrenal vein sampling increased from 63% of 99 procedures to 90% of 48 procedures ( P = 0.0007) after implementation of the adrenal vein sampling Accuracy Kit. Failure of right adrenal vein cannulation was the main reason for an unsuccessful study. Radiation dose decreased from 34.2 Gy.cm2 (interquartile range, 15.8-85.9) to 15.7 Gy.cm2 (6.9-47.3) ( P = 0.009). No complications were noted, and implementation costs were minimal. Conclusions Point-of-care cortisol measurement during adrenal vein sampling improved cannulation success rates and reduced radiation exposure. The use of the adrenal vein sampling Accuracy Kit is now standard practice at our centre.

Acute traumatic renal arteriocalyceal fistula: selective angioembolisation for haemodynamic instability.

Abdominal angiography with selective arteriography and subsequent embolisation is an accepted management modality in the treatment of selected solid organ injuries following blunt abdominal trauma. This management practice is well established in the haemodynamically stable patient; however, this remains more controversial in haemodynamically compromised patients, though warrants consideration in both cases due to the associated benefits of non-operative management. This case report describes the successful non-operative management of a severe renal injury in a young polytraumatised patient following a high-speed motor vehicle crash. In addition, the rare CT diagnosis and management of an acute traumatic arteriocalcyeal fistula is discussed with a focus on the importance of renal parenchymal preservation.

Sonographic twinkle artefact in renal calculus detection: Impact of scanning factors in a phantom model.

INTRODUCTION: A common clinical use of the twinkle artefact is to detect and confirm renal calcification on ultrasound. There is however variable demonstration of this artefact using newer generation ultrasound machines. The purpose of this study was to assess the impact of altering multiple scanning factors on ultrasound machines from four major manufacturers on the demonstration of the twinkle artefact. Two custom-made phantoms and five-point Likert-like Scale were utilised. METHODS: These phantoms contained a range of urinary calculi varying in size, composition, surface contour and depth. The calculi were serially imaged with each ultrasound machine, using manufacturers presets and varying just one imaging factor or parameter at a time. The documented twinkle artefact in the images were subsequently analysed, together with the imaging preset and factor changes that had been made. RESULTS: Those factors that had the greatest effect in order of impact were colour write priority, colour gain, transducer type, depth of calculus, acoustic power and size of calculus. Variability was also demonstrated between manufacturers. CONCLUSION: By isolating the effect of scanning factor changes, their importance and contribution to appearances in the ultrasound image can be assessed. Image interpretation in the clinical setting requires an understanding of the underlying physics, particularly in the evaluation of artefacts associated with renal calculi.

CT grading scales for splenic injury: why can't we agree?

INTRODUCTION: Computed tomography (CT) has been proven to be able to accurately diagnose splenic injury. Many have published CT splenic injury grading scales to quantify the extent of injury. However, these scales have failed at predicting clinical outcomes and therefore cannot be used to accurately predict the need for intervention. We hypothesised that low interrater reliability is the reason why these scales have failed at predicting clinical outcomes. METHODS AND MATERIALS: This is a retrospective study of patients who were admitted to the Royal Perth Hospital with blunt splenic injury as coded in the trauma registry. The abdominal CT images of these patients were reviewed by three consultant radiologists and were graded using the six different splenic injury grading scales. We assessed interrater reliability between each of the scales using generalised kappa and proportion of agreement calculations. RESULTS: The images of 64 patients were reviewed. The interrater reliability yielded a generalised kappa score of 0.32-0.60 and proportion of agreement ranging from 34.4% to 65.5%. CONCLUSION: The six studied CT splenic injury grading scales did not have a high enough interrater reliability to be adequate for clinical use. The poor interrater reliability is likely to contribute to the failure of the scales at predicting clinical outcomes. Further research to improve the interrater reliability is recommended.

The ileocaecal knot.

Variations in intestinal knot syndromes have been described in the past, including ileoileal knots, ileosigmoid knots and appendico-ileal knots. We report a new type of intestinal knot syndrome, an ileocaecal knot, which, to our knowledge, has not been reported before in the world literature. Features on CT that may raise suspicion of an ileal knot syndrome are described.

Vascular complications of pancreatitis.

Vascular complications of pancreatitis are a major cause of morbidity and mortality. Arterial complications include haemorrhage from direct arterial erosion or pseudoaneurysm formation, and visceral ischaemia. Venous complications predominantly are related to splanchnic vein thrombosis. This review, with illustrative cases, describes the main manifestations of these complications and emphasizes the importance of early radiological diagnosis and intervention.

Identification and staging of pancreatic tumours using computed tomography, endoscopic ultrasound and mangafodipir trisodium-enhanced magnetic resonance imaging.

Pancreatic malignancy can be staged by a number of different investigations, either alone or in combination. The purpose of the present study was to compare the use of endoscopic ultrasound, CT and mangafodipir trisodium-enhanced MRI for the staging of pancreatic malignancy, particularly with respect to determining resectability prior to surgery. Twenty-seven patients referred for the investigation of a suspected pancreatic malignancy were entered into the trial. All patients had contrast-enhanced CT, gadolinium and mangafodipir trisodium-enhanced MRI, and endoscopic ultrasound (EUS). Images were assessed for nodal staging, tumour staging and resectability for each investigation, and the results compared with findings at surgery. The results for the accuracy of MRI, CT and EUS, in detecting T4 disease versus T3 or lower was 78, 79 and 68%, respectively; nodal involvement was 56, 63 and 69%, respectively; and overall resectability (including the T stage, presence of involved nodes and metastases) was 83, 76 and 63%, respectively. There was no significant difference demonstrated between the three tests. The present study suggests that for patients referred for investigation and staging of pancreatic malignancy, EUS and MRI scanning convey little advantage over contrast-enhanced CT. Furthermore, although mangafodipir trisodium improved the conspicuity of pancreatic tumours, it has little influence on T staging.

Traumatic pseudoaneurysm and high flow arteriovenous fistula involving internal jugular vein and common carotid artery. Treatment with covered stent and embolization.

We describe the case of a 36-year-old man who presented following penetrating trauma to the neck. Angiography demonstrated a high-flow arteriovenous fistula and large false aneurysm of the common carotid artery that also had contributions from branches of the external carotid artery and the thyrocervical trunk. This was treated with a combination of a covered endovascular stent placed in the common carotid artery and coil embolization of other small feeding vessels.

Treatment of iatrogenic femoral artery false aneurysms with ultrasound-guided thrombin injection.

The aim of this paper is to review our results of treating iatrogenic pseudoaneurysms of the femoral artery with ultrasound-guided thrombin injection. A retrospective review was carried out of all patients referred for this procedure over a 1-year period from December 1999 to December 2000. Forty-five patients were referred and, of these, 44 were eligible for this treatment, with 300-2500 units of thrombin being injected directly into the false aneurysms under ultrasound guidance. The procedure was well tolerated with no patients requiring sedation or analgesia. There was a primary success rate of 95%, although in four of the patients, there was recurrence on repeat ultrasound performed 2-5 days post-procedure and a second injection of thrombin was required for permanent thrombosis to be achieved. No complications relating to the procedure occurred. Our results confirm increasing evidence in the published research that thrombin injection of femoral artery false aneurysms is a safe and effective treatment.

Lumbar artery pseudoaneurysm following renal biopsy: treatment with ultrasound-guided thrombin injection.

latrogenic pseudoaneurysms are usually seen following arterial catheterization. However, we describe a case of a 23-year-old woman who developed a pseudoaneurysm of a lumbar artery following renal biopsy. In view of her progressing renal failure, arterial embolization was felt to be inappropriate, and although the pseudoaneurysm could be seen ultrasonically, guided compression could not be applied because of the location of the aneurysm deep to the lumbar musculature. Hence, the pseudoaneurysm was thrombosed by percutaneous ultrasound-guided injection of thrombin directly into the pseudoaneurysm sac. This resulted in immediate thrombosis of the aneurysm and no recurrence on follow-up imaging. Thrombin injection for femoral artery pseudoaneurysms following catheterization is becoming more widely accepted, and our case demonstrates that this technique might be applied to pseudoaneurysms elsewhere in the body.