Split-bolus single-pass CT for vascular complications in acute pancreatitis: assessment of radiation dose and multi-phasic contrast enhancement compared to single-bolus multi-pass CT.

AIM: To assess vascular contrast enhancement and radiation dose of split-bolus single-pass computed tomography (CT) compared to single-bolus multi-pass CT for acquiring a multi-phasic study. MATERIALS AND METHODS: Patients who underwent CT for acute pancreatitis were included retrospectively. Thirty consecutive patients scanned with a split-bolus protocol were compared to 30 consecutive patients scanned with a single-bolus protocol. Data were collected on attenuation measurements (aorta, portal vein and spleen) and images were assessed for subjective vascular enhancement quality and splenic homogeneity. Radiation dose was measured by dose-length product (DLP). RESULTS: There was no significant difference in the aortic (p = 0.88) or portal vein (p = 0.35) attenuation values between the two groups. The percentage of examinations reaching the target aortic and portal attenuation in the split-bolus group were 96.7% and 93.3%, and in the single-bolus group were 96.7% and 85.7%, respectively. The mean DLP was 492 mGy.cm for the single-bolus group and 940 mGy.cm for the split-bolus group (p < 0.0001). Subjective assessment revealed higher rates of splenic heterogeneity in the split-bolus group. DISCUSSION: In acute pancreatitis, split-bolus imaging can produce arterial and venous enhancement comparable to a multi-pass technique with a significant reduction in radiation dose. Loss of temporal resolution and increased splenic heterogeneity are the main disadvantages. The low prevalence of pseudoaneurysms favours the lower-dose imaging technique.

Pancreatic allograft thrombosis: Suggestion for a CT grading system and management algorithm.

Pancreatic allograft thrombosis (PAT) remains the leading cause of nonimmunologic graft failure. Here, we propose a new computed tomography (CT) grading system of PAT to identify risk factors for allograft loss and outline a management algorithm by retrospective review of consecutive pancreatic transplantations between 2009 and 2014. Triple-phase CT scans were graded independently by 2 radiologists as grade 0, no thrombosis; grade 1, peripheral thrombosis; grade 2, intermediate non-occlusive thrombosis; and grade 3, central occlusive thrombosis. Twenty-four (23.3%) of 103 recipients were diagnosed with PAT (including grade 1). Three (2.9%) grafts were lost due to portal vein thrombosis. On multivariate analysis, pancreas after simultaneous pancreas-kidney transplantation/solitary pancreatic transplantation, acute rejection, and CT findings of peripancreatic edema and/or inflammatory change were significant risk factors for PAT. Retrospective review of CT scans revealed more grade 1 and 2 thromboses than were initially reported. There was no significant difference in graft or patient survival, postoperative stay, or morbidity of recipients with grade 1 or 2 thrombosis who were or were not anticoagulated. Our data suggest that therapeutic anticoagulation is not necessary for grade 1 and 2 arterial and grade 1 venous thrombosis. The proposed grading system can assist clinicians in decision-making and provide standardized reporting for future studies.

Imaging features of myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPNs) are a heterogeneous group of haematological disorders including polycythaemia vera (PV), essential thrombocythaemia (ET), primary myelofibrosis (PMF), and chronic myeloid leukaemia (CML). These disorders show large overlap in genetic and clinical presentations, and can have many different imaging manifestations. Unusual thromboses, embolic events throughout the systemic or pulmonary vasculature, or osseous findings can often be clues to the underlying disease. There is limited literature about the imaging features of these disorders, and this may result in under-diagnosis. Multiple treatments are available for symptom control, and the development of multiple new pharmacological inhibitors has significantly improved morbidity and prognosis. Knowledge of these conditions may enable the radiologist to suggest an MPN as a possible underlying cause for certain imaging findings, particularly unexplained splanchnic venous thrombosis, i.e. in the absence of chronic liver disease or pancreatitis. The aim of the present review is to outline using examples the different categories of MPN and illustrate the variety of radiological findings associated with these diseases.

Postoperative CT in pancreas transplantation.

AIM: To examine the usage and value of computed tomography (CT) following simultaneous pancreas and kidney (SPK) transplantation. MATERIALS AND METHODS: Indications for postoperative CT, key findings, and their influence on management were determined by retrospective analysis. RESULTS: Ninety-eight patients underwent 313 CT examinations. Common indications for the examinations included suspected intra-abdominal collection (31.1%) and elevated serum amylase/lipase (24.1%). CT findings most frequently showed non-specific mild inflammation (27.6%), a normal scan (17.1%) and fluid collections (16.3%). High capillary blood glucose (CBG) was associated with resultant CT demonstration of graft vascular abnormalities, but otherwise, particular clinical indications were not associated with specific CT findings. CONCLUSION: Clinical findings in patients with SPK transplants are non-specific. The pattern of abnormalities encountered is significantly different to those seen in native pancreatic disease and demands a tailored protocol. CT enables accurate depiction of vascular abnormalities and fluid collections, thus reducing the number of surgical interventions that might otherwise be required. Elevated CBG should prompt urgent CT to exclude potentially reversible vascular complications.

Copper T380 intrauterine device for emergency contraception: highly effective at any time in the menstrual cycle.

STUDY QUESTION: Does the efficacy of placing a copper intrauterine device (IUD) for emergency contraception (EC) to prevent pregnancy depend on menstrual cycle timing and timing of unprotected intercourse (UPI)? SUMMARY ANSWER: If the urine pregnancy test is negative prior to IUD placement, the copper IUD is highly effective for EC at any point in the menstrual cycle. WHAT IS KNOWN ALREADY: The use of the Copper T380A for EC has been encouraged by the failure of oral EC methods to decrease rates of unintended pregnancy and the documented success of the IUD in reducing unintended pregnancies. However scant data exist regarding the efficacy and safety of IUD insertion for EC when accounting for menstrual cycle timing and time since UPI. STUDY DESIGN, SIZE, DURATION: This is a secondary analysis of data obtained from a previously published prospective cohort study of women who received the Copper T380A IUD for EC between July 1997 and January 2000. We included 1840 participants according to the study inclusion criteria of a known last menstrual period (LMP) and cycle lengths of 25-35 days. PARTICIPANTS/MATERIALS, SETTING, METHODS: The original study included women aged between 18 and 44 years who presented for EC at 18 sites throughout China and who had regular menstrual cycles between 24 and 42 days, a known LMP, UPI within 120 h (5 days) and a negative urine pregnancy test (cutoff <25 IU/ml). Women with uncertain LMP dates were excluded. This study included only participants with cycle lengths of 25-35 days. MAIN RESULTS AND THE ROLE OF CHANCE: Among the 1840 participants with usual cycle lengths of 25-35 days, 850 (46.2%) had their IUD inserted following UPI in the expected fertile window and 84 (4.6%) had the insertion >5 days after the predicted ovulation day and 52 (2.8%) had the insertion >5 days after UPI. There were no pregnancies in the first month among the 1771 women who had information available regarding their 1-month follow-up pregnancy test. LIMITATIONS, REASONS FOR CAUTION: This was a secondary analysis of an observational study, and thus participants were not randomized to an alternative postcoital method. There were a small number of women who had UPI >5 days after their predicted ovulation day thus limiting the confidence of assuring a low risk of pregnancy in this situation. The ovulation day was calculated based on the LMP prior to IUD insertion and not on the subsequent first day of menses following IUD insertion. WIDER IMPLICATIONS OF THE FINDINGS: If the urine pregnancy test is negative prior to IUD placement, the copper IUD is likely to be effective for EC at almost any point in the menstrual cycle. STUDY FUNDING/COMPETING INTEREST(S): The original study was funded by the UNDP/UNPFA/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction. The donors and sponsors of the study had no role in the study design, data collection, data analysis, data interpretation, writing of the report or the decision to submit the paper for publication.

A radiologist's guide to small bowel and multivisceral transplantation.

This review will describe the indications for the various small bowel containing transplants. The importance of early referral will be highlighted. Radiologists play a central role in assessing these complex patients prior to transplantation. Furthermore, in the postoperative period, radiologists play an important part in diagnosing and treating complications.

What can the Interventional Endoscopist Offer in the Management of Upper Gastrointestinal Malignancies?

The therapeutic possibilities of endoscopy have rapidly increased in the last decades and now allow organ-sparing treatment of early upper gastrointestinal malignancy as well as an increasing number of options for symptom palliation. This review contains an overview of the interventional endoscopic procedures in upper gastrointestinal malignancies. It describes endoscopic treatment of early oesophageal and gastric cancers, and the palliative options in managing dysphagia and gastric outlet obstruction. It also provides an overview of the therapeutic possibilities of biliary endoscopy, such as retrograde stenting and radiofrequency biliary ablation. Endoscopic ultrasound-guided therapeutic options are discussed, including biliary drainage, gastrojejunostomy and coeliac axis block. To aid in clinical decision making, the procedures are described in the context of their indication, efficacy, risks and limitations.

Acceptability of virtual unenhanced CT of the aorta as a replacement for the conventional unenhanced phase.

AIM: To evaluate whether virtual unenhanced (VU) computed tomography (CT) images generated of the aorta were of sufficient quality to replace the conventional unenhanced (CU) images. MATERIALS AND METHODS: Forty-nine patients undergoing examination of the thoracic or abdominal aorta were examined using a dual-energy protocol. VU images were generated from the arterial phase images and compared to the CU images. Objective analysis was performed by drawing paired regions of interest (ROIs) within the thoracic and abdominal aorta and measuring the radiodensity in Hounsfield units attenuation within the ROIs. Subjective analysis was performed by two experienced readers evaluating the VU images in terms of noise, quality, calcium loss, and overall acceptability. RESULTS: The attenuation was significantly higher in the VU images compared to the CU images within the thoracic aorta (p < 0.01) but not within the abdominal aorta (p = 0.15). Overall the VU images of the abdominal aorta were deemed acceptable as replacements for the CU images in 93% of cases. For the thoracic aorta, the VU images were deemed acceptable in only 12% of cases, primarily due to pulsation artefact. CONCLUSION: VU images of the abdominal aorta are acceptable as replacements for the CU images in the vast majority of cases; however, they are not suitable as replacements for the CU images of the thoracic aorta.

Don't be a clot: a radiologist's guide to haemostasis including novel antiplatelet and anticoagulant therapies.

Normal haemostasis relies on the complex interactions of the coagulation cascade, platelets, and the endothelium. In this review, the roles of each of these elements are described as well as common causes for their derangement. Haemostasis may be manipulated via pharmacological means and in recent years there has been a significant increase in the number of agents available for influencing haemostatic mechanisms. It is essential that radiologists are aware of these mechanisms and drugs if they are to perform image-guided procedures safely. In addition to describing the relevant pathways and drugs, practical tips are provided.

Copper T380A intrauterine device for emergency contraception: a prospective, multicentre, cohort clinical trial.

OBJECTIVE: To determine the effectiveness of the Copper T380A (CuT380A) intrauterine device (IUD) as an emergency contraceptive in women. DESIGN: Prospective, multicentre, cohort clinical trial. SETTING: Eighteen family planning clinics in China. SAMPLE: A cohort of 1963 women, aged 18-44 years, requesting emergency contraception within 120 hours of unprotected sexual intercourse. METHODS: Women requesting emergency contraception were followed at 1, 3 and 12 months after the insertion of CuT380A. MAIN OUTCOME MEASURES: Efficacy of CuT380A as emergency contraception and for up to 12 months of postinsertion use. Insertion complication rates, reported side-effects and continuation rates at 12 months were also recorded. RESULTS: No pregnancies occurred prior to or at the first follow-up visit, making CuT380A 100% effective as emergency contraception in this study. The pregnancy rate over the 12-month period was 0.23 per 100 women. In all, 29 (1.5%) women experienced a difficult IUD insertion process, requiring local anaesthesia or prophylactic antibiotics. No uterine perforations occurred. The main side-effects were increased menstrual bleeding and menstrual disturbances. The 12-month postinsertion continuation rate was 94.0 per 100 woman-years. CONCLUSIONS: CuT380A is a safe and effective method for emergency contraception. The advantages of CuT380A include its ability to provide effective, long-term contraception.

Virtual unenhanced second generation dual-source CT of the liver: is it time to discard the conventional unenhanced phase?

INTRODUCTION: Dual-energy dual source CT can almost simultaneously image patients using two different tube potentials, allowing material decomposition and creation of 'virtual unenhanced' (VU) images from post-contrast series. METHODS: 75 patients undergoing triple-phase liver CT examinations were imaged using a second generation dual-source CT machine with tube potentials 140/100 kVp. Post-processing VU series were derived from arterial and portal phases. Regions-of-interest from liver parenchyma and within fat ('noise' assessment) were drawn to compare VU series to conventional unenhanced (CU) series. Subjective analysis assessed image quality and the suitability of VU to replace CU series. RESULTS: Mean Hounsfield unit (HU) values of liver were higher in the VU series: portal 51.9 (SD = 10.29), arterial 51.1 (SD = 10.05), compared to the CU series 49.2 (SD = 9.11); P<0.001. However, Pearson's correlation of the VU and CU series remained excellent: 0.838 (portal), 0.831 (arterial). Bland-Altman plots also showed good agreement between both VU and the CU datasets. Noise measurements were significantly lower in both VU series (P<0.001). For subjective analysis, image quality was rated as very good/excellent in 100% of CU images, 93.3% of portal VU and 88.7% of arterial VU series. Overall, portal VU and arterial VU images were acceptable replacements for the CU series in 97.4% and 96.1%, respectively. Post-processing was noted to create a number of artefacts in VU images--knowledge of these is essential for interpretation. CONCLUSIONS: Portal and arterial-derived VU images objectively correlate to CU images and demonstrate good image quality and acceptability. VU image sets could replace the conventional unenhanced images in the vast majority of cases, significantly reducing radiation dose.