Evaluation of a single-pass with biphasic intravenous contrast medium injection CT protocol for the assessment of complications post-simultaneous pancreas-kidney transplant.

AIM: To evaluate the use of a single-pass with biphasic intravenous contrast medium injection computed tomography (CT) protocol to provide diagnostic quality CT studies for the assessment of complications post-simultaneous pancreas-kidney transplant (SPK). MATERIALS AND METHODS: This was an audit of practice and the need for informed consent was waived. The protocol was used in consecutive patients undergoing CT to exclude intra-abdominal sepsis post-SPK between June and December 2015. Single CT acquisition of the abdomen and pelvis was initiated 70 seconds after the start of biphasic contrast medium injection (66 ml at 1.2 ml/s, followed by 34 ml at 2.4 ml/s, 370 mg iodine/ml). The named transplant pancreas vessels were identified and the attenuation values of the blood within were measured. Diagnostic quality was confirmed if values were >211 HU and >80 HU in the arteries and veins, respectively. RESULTS: Thirteen CT studies were performed in 10 patients. CT studies were excluded due to complete pancreatic necrosis, and transplant superior mesenteric artery (SMA) thrombus with pancreatic head ischaemia causing effacement of the transplant superior mesenteric vein (SMV). Diagnostic quality of the analysed CT studies were confirmed with mean attenuation value of blood >211 HU in the transplant pancreatic arteries (SMA=259.0±51.4 HU, splenic artery=245.3±37.5 HU), and >80 HU in the pancreatic veins (SMV=195.4±36.2 HU, splenic vein=185.1±54.2 HU). CONCLUSION: Diagnostic quality CT studies were obtained using the single-pass CT protocol. Radiation exposure to patients may be reduced with this protocol, while permitting simultaneous assessment of parenchymal and vascular complications post-SPK.

The 2014 liver ultrasound tracking benchmark.

The Challenge on Liver Ultrasound Tracking (CLUST) was held in conjunction with the MICCAI 2014 conference to enable direct comparison of tracking methods for this application. This paper reports the outcome of this challenge, including setup, methods, results and experiences. The database included 54 2D and 3D sequences of the liver of healthy volunteers and tumor patients under free breathing. Participants had to provide the tracking results of 90% of the data (test set) for pre-defined point-landmarks (healthy volunteers) or for tumor segmentations (patient data). In this paper we compare the best six methods which participated in the challenge. Quantitative evaluation was performed by the organizers with respect to manual annotations. Results of all methods showed a mean tracking error ranging between 1.4 mm and 2.1 mm for 2D points, and between 2.6 mm and 4.6 mm for 3D points. Fusing all automatic results by considering the median tracking results, improved the mean error to 1.2 mm (2D) and 2.5 mm (3D). For all methods, the performance is still not comparable to human inter-rater variability, with a mean tracking error of 0.5-0.6 mm (2D) and 1.2-1.8 mm (3D). The segmentation task was fulfilled only by one participant, resulting in a Dice coefficient ranging from 76.7% to 92.3%. The CLUST database continues to be available and the online leader-board will be updated as an ongoing challenge.