Management of Acute Contrast Reactions-Understanding Radiologists' Preparedness and the Efficacy of Simulation-Based Training in Canada.

PURPOSE: Acute radiologic emergencies, primarily severe contrast reactions, are rare but life-threatening events. Given a generalized paucity of formalized or mandated training, studies have shown that radiologists and trainees perform poorly when acutely managing such events. Moreover, skill base, knowledge, and comfort levels precipitously decline over time given the infrequent occurrence of these events during one's daily practice. The primary aim of this study was to assess radiologists' preparedness for managing acute radiologic emergencies and to determine the efficacy of a high-fidelity simulation based training model in an effort to provide a rationale for similar programs to be implemented on a provincial or national level. METHODS: This was a prospective, observational study of radiology residents and attending radiologists throughout the province who were recruited to attend a full-day simulation-based course presenting various cases of acute radiologic emergencies. Participant demographics were collected at the time of commencement of the workshop. Course materials were disseminated 4 weeks prior to the workshop, and a 17-question knowledge quiz was administered before and after the workshop. Likert-type questionnaires were also distributed to survey comfort levels and equipment familiarity. The knowledge quiz and questionnaire were redistributed at 3- and 6-month intervals for acquisition of follow-up data. RESULTS: A total of 14 attending radiologists and 7 residents attended the workshop, with all participants completing the preworkshop questionnaire and 90.5% (19 of 21) completing the post-workshop questionnaire. Participants' principle locations of practice were as follows: academic institutions (50%), community hospitals (36.9%), and private clinics (13.1%). A significant increase in knowledge was demonstrated, with average scores of 10 out of 17 (59%) and 14.5 out of 17 (85%) (P < .001) before and after the workshop, respectively. A significant increase in participants' comfort levels in recognizing acute anaphylactic reactions (3.5; 4.7, P < .001), commencing initial management for acute radiologic emergencies (3.3; 5.0, P < .001), and administering the correct dose for anaphylactic reactions (2.5; 4.8, P < .001) was also demonstrated. Moreover, participants became increasingly familiar with the contents and equipment found within contrast reaction kits (2.8; 3.8, P < .01). Repeat evaluations at 3 and 6 months found an average knowledge test score of 13.8 out of 17 (81%) and 10.8 out of 17 (64%), respectively. Comfort levels were also reassessed in recognizing acute anaphylactic reactions (4.5; 4.1), commencing initial management (4.0; 3.9) and administering the correct dose of medication (4.0; 3.7) at 3- and 6-month intervals. CONCLUSIONS: Acute radiologic emergencies are rare but life-threatening events that require rapid diagnosis and treatment to mitigate associated morbidity and mortality. Simulation-based workshops are a highly efficacious training model to increase knowledge, comfort levels, and equipment familiarity for radiologists and trainees alike; however, retraining at regular intervals is required.

Transradial Access for Interventional Radiology: Single-Centre Procedural and Clinical Outcome Analysis.

PURPOSE: The study sought to describe a single centre's technical approach to transradial intervention and report on clinical outcomes and safety. METHODS: A total of 749 transradial access (TRA) procedures were performed at a single hospital in 562 patients (174 women and 388 men). Procedures included 445 bland embolizations or chemoembolizations of the liver, 88 uterine artery embolizations, and 148 procedures for Selective Internal Radiation Therapy (Y90), which included mapping and administration. The mean age of the patients was 62 years (range 27-96 years). RESULTS: Four cases (0.5%) required crossover to transfemoral (tortuous anatomy, inability to secure a stable position for embolization, vessel spasm and base catheter not being of a sufficient length). A single asymptomatic, short-segment radial artery occlusion occurred (0.3%), 3 patients (0.4%) developed small hematomas postprocedurally, and 2 patients (0.7%) had transient neurological pain, which was resolved within a week without treatment. It was found that 98% of patients who had a previous femoral access procedure would choose radial access for subsequent procedures. CONCLUSIONS: Transradial access is a safe, effective technique, with a learning curve; however, this procedure has the potential to significantly improve departmental workflow and cost savings for the department and patient experience.

The Role of Contrast-enhanced Ultrasound in Guiding Radiofrequency Ablation of Hepatocellular Carcinoma: A Retrospective Study.

PURPOSE: The objective of the study was to determine the efficacy of contrast-enhanced ultrasound (CEUS) using ultrasound (US)-specific microbubbles in guiding radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC). METHODS: A retrospective analysis of 50 patients with HCC treated with CEUS guided RFA using perflutren at our institution was performed. CEUS images were first compared to B-mode US images performed at the same RFA session to determine the ability of CEUS to increase the conspicuity of lesions. A qualitative score (1 = poor, 2 = fair, 3 = excellent) was used to grade the ability to visualize the lesions. The preprocedure CEUS images were then evaluated using the most recent prior contrast enhanced computed tomography (CT) or magnetic resonance imaging (MRI). The efficacy of the treatment was evaluated with short-term follow-up imaging (median 1 month) for presence of residual or recurrent disease. RESULTS: CEUS allows at least fair visualization (score ≥2) in 78% (reader 1) and 80% (reader 2) of the lesions not visualized by B-mode US, and 50% (reader 1) and 42% (reader 2) of the lesions poorly visualized by B-mode US. Lesion appearances on CEUS are largely concordant with those on CT or MRI: 88% for reader 1, 96% for reader 2. With CEUS-guided RFA, complete response was achieved in the vast majority of the lesions at short-term follow-up: 82% for reader 1, 94% for reader 2. CONCLUSIONS: CEUS increases the conspicuity and provides better characterization of hypervascular HCC that are either not seen or poorly seen on B-mode US, and CEUS provides real-time guidance of RFA with good short-term treatment responses.

Contralateral Hypertrophy Post Yttrium-90 Transarterial Radioembolization in Patients With Hepatocellular Carcinoma and Portal Vein Tumor Thrombus.

Objectives Contralateral hypertrophy of non-irradiated liver following Yttrium-90 (90Y) transarterial radioembolization (TARE) is increasingly recognized as an option to facilitate curative surgical resection in patients that would otherwise not be surgical candidates due to a small future liver remnant (FLR). This study aimed to investigate the correlation between patient features and liver hypertrophy and identify potential predictors for liver growth in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT) undergoing TARE. Methodology Twenty-three patients with HCC and PVTT were included. Contralateral liver hypertrophy was assessed at six months posttreatment based on CT or MRI imaging. Thirteen patient features were selected for statistical and prediction analysis. Univariate Spearman correlation and analysis of variance (ANOVA) tests were performed. Subsequently, four feature-selection methods based on multivariate analysis were used to improve model generalization performance. The selected features were applied to train linear regression models, with fivefold cross-validation to assess the performance of the predicted models. Results The ratio of disease-free target liver volume to spared liver volume and total liver volume showed the highest correlations with contralateral hypertrophy (P-values = 0.03 and 0.05, respectively). In three out of four feature-selection methods, the feature of disease-free target liver volume to total liver volume ratio was selected, having positive correlations with the outcome and suggesting that more hypertrophy may be expected when more volume of disease-free liver is irradiated. Conclusions Contralateral hypertrophy post-90Y TARE can be an option for facilitating surgical resection in patients with otherwise small FLR.

The DePICTORS Study: discrepancies in preliminary interpretation of CT scans between on-call residents and staff.

At many academic hospitals, radiology residents provide preliminary interpretations of CT studies performed outside of regular working hours. We examined the rate of discrepancies between resident interpretations and final reports issued by staff. We prospectively obtained 1,756 preliminary reports and corresponding final reports for computed tomography (CT) scans performed on call between November 2006 and March 2007. The overall rate of clinically significant discrepancies (those that would potentially alter the patient's clinical course prior to issue of the final report) was 2.0%. Major discrepancy rates for abdominal/pelvic, chest, cervical spine and head CT were 4.1%, 2.5%, 1.0% and 0.7%, respectively. Senior residents had fewer major discrepancies compared to their junior colleagues. Time of interpretation was also evaluated, but a statistically significant relationship was not observed. In summary, this study demonstrates a low discrepancy rate between residents and staff radiologists and identifies areas where after-hours service may be further improved.

Percutaneous autologous pancreatic islet cell transplantation for traumatic pancreatic injury.

CONTEXT: Traumatic pancreatic injury with pancreatic duct disruption is surgically managed with at least a partial pancreatectomy, often leading to poor blood glucose control and the subsequent development of diabetes mellitus. Autologous ß-islet cell transplantation may therefore help to preserve pancreatic endocrine function. CASE DESCRIPTION: We describe 3 patients with pancreatic duct disruption from traumatic pancreatic injury who were treated with a partial pancreatectomy followed by autologous ß-islet cell transplantation via a percutaneous transhepatic approach. Immediately after trauma, 2 of the 3 patients had difficulty with glucose control that resolved after autologous ß-islet cell transplantation. At follow-up, all patients remained normoglycemic. CONCLUSION: In patients requiring partial pancreatectomy after pancreatic trauma, percutaneous transhepatic autologous ß-islet cell transplantation should be considered to minimize the risk of development of diabetes mellitus.

Advanced colon cancer before the age of 20 years: a case for extension of the current colonoscopy surveillance guidelines in hereditary nonpolyposis colorectal cancer syndrome.

BACKGROUND: Hereditary nonpolyposis colorectal cancer (HNPCC) currently accounts for between 2% to 6% of all colorectal adenocarcinomas. Controversies exist regarding the current guidelines for colonoscopic screening for colon cancer. CASE REPORT: A case of colon cancer in a young Japanese man with a family history of colon cancer that did not meet the criteria for HNPCC is reported. A malignant pelvic mass discovered shortly before his 20th birthday prompted a colonoscopy. The findings at colonoscopy determined that the patient and his family fulfilled the criteria of HNPCC. CONCLUSION: Before finding a pelvic mass metastatic from adenocarcinoma of the ascending colon, this patient was clearly outside of the current guidelines for HNPCC screening. It is suggested that in similar patients, even if they do not fulfill all the criteria for HNPCC, it would be appropriate to consider screening well before the recommended lower age.

Treatment of a juxtaglomerular tumour with radiofrequency ablation.

Juxtaglomerular tumors, or reninomas, are a rare cause of hypertension, almost always benign and accurately localized by a combination of biochemical tests and imaging. Because the tumors are usually small at presentation, and there are good markers for recurrence, we consider treatment by radiofrequency ablation a useful alternative to nephron-sparing surgery and describe its use in one patient.

Dalteparin versus enoxaparin for venous thromboembolism prophylaxis in acute spinal cord injury and major orthopedic trauma patients: 'DETECT' trial.

BACKGROUND: To compare the impact of switching from enoxaparin 30 mg subcutaneously (SC) twice daily to dalteparin 5,000 units SC once daily for venous thromboembolism (VTE) prophylaxis in critically-ill major orthopedic trauma and/or acute spinal cord injury (SCI) patients. METHODS: DETECT was a retrospective, cohort study at a tertiary care referral teaching center-phase 1 from December 1, 2002 to November 30, 2003 (enoxaparin); and phase 2 from January 1, 2004 to December 31, 2004 (dalteparin). Major orthopedic trauma patients with pelvic, femoral shaft, or complex lower extremity fractures, and/or acute SCI patients admitted to the intensive care unit and who received a low-molecular-weight heparin (LMWH) for VTE prophylaxis were included. RESULTS: DETECT reviewed 135 patients (63 enoxaparin, 72 dalteparin), with similar baseline demographics, clinical characteristics, injuries, severity of illness, and risk factors for VTE. Clinically symptomatic proximal deep vein thrombosis (DVT) or pulmonary embolism (PE) rates were 1.6% with enoxaparin and 9.7% with dalteparin (p=0.103, absolute risk increase [ARI] of 8.1% [-0.6% to 15.6%]), with no differences in major bleeding (6.4% versus 6.9%) or minor bleeding (64% versus 69%), or mortality (4.8% versus 6.9%). Switching from enoxaparin to dalteparin was associated with $12,485 (CAD) in LMWH acquisition cost savings. CONCLUSIONS: DETECT raises the hypothesis that dalteparin 5,000 units SC daily may not be clinically noninferior to enoxaparin 30 mg SC twice daily for VTE prophylaxis in this high-risk population. Until an adequately-powered, prospective noninferiority trial is performed, enoxaparin is supported by level 1 evidence and should be the prophylactic agent of choice.

Spatulated end-to-end bile duct reconstruction in orthotopic liver transplantation.

Biliary complications continue to be a major source of morbidity following orthotopic liver transplantation. The aim of this study was to analyze the incidence and management of biliary complications related to the technique of bile duct reconstruction. The patients were stratified into two groups: group I (n = 39) had bile duct reconstruction performed by an end-to-end single interrupted suture choledochocholedochostomy (EE-CDCD) and group II (n = 38) had a spatulated end-to-end CDCD (spEE-CDCD) reconstruction; both groups had an intraductal stent. The groups were similar in age, gender, liver transplant indications and Pugh score. Ten biliary complications (26%), including five bile leaks (13%) and five biliary strictures (13%), were observed in the EE-CDCD group, while one biliary stricture (2.6%) occurred in the spEE-CDCD group (p < 0.05). Subsequent imaging studies and endoscopic retrograde cholangiopancreatography were performed less often in patients undergoing spEE-CDCD reconstruction (p < 0.05). The technique of a spatulated end-to-end bile duct reconstruction provides a significant improvement in lowering biliary complication rates in liver transplant patients. Despite the modest number of cases in this study this technique shows promise and has become the technique of choice in our institution.

Computed tomography and angiographic interventional features of ruptured hepatocellular carcinoma: pictorial essay.

Spontaneous rupture is an uncommon and potentially fatal complication of hepatocellular carcinoma (HCC), occurring in approximately 15% of patients with HCC in Asia and 3% in the United Kingdom.3 The prognosis for hemorrhage of HCC is poor, particularly in those patients with underlying cirrhosis and severe coagulopathy. Computed tomography (CT) rather than angiography is the first-line modality for the detection of rupture. CT can confirm the diagnosis of ruptured HCC and can also help in assessing other organs if the diagnosis is not clear prior to imaging. It allows for an assessment of the entire liver, including the portal vein, which aids in determining the feasibility of embolization and resection. Since the rate of bleeding must normally exceed 1 mL/min before it can be detected on angiography and the extravasation of contrast is present in less than 20% of cases, CT is a more helpful modality. The optimal CT protocol for this condition is triphasic: the precontrast phase allows for assessment of ethiodized oil (lipiodol) uptake, the arterial phase demonstrates enhancement of the mass, and the portal venous phase allows for assessment of the portal veins. Various treatment options have been proposed: transarterial catheter embolization (TACE), emergency liver resection, and delayed resection. Surgical treatment is difficult, if not impossible. In most cases, rupture is a result of diffuse intrahepatic spread of the tumour and underlying liver cirrhosis. Many authors have concluded that a multidisciplinary management that includes TACE as the primary procedure followed by a delayed resection is the preferred treatment. This pictorial essay reviews the radiologic features of spontaneously ruptured HCC on CT imaging and of treatment by angiography.

Management of central venous stent migration in a patient with a permanent inferior vena cava filter.

Stent embolization is a rare complication in the treatment of central venous stenoses in patients receiving long-term hemodialysis. The authors report a case of nitinol stent embolization into the right atrium in which the stent could not be repositioned across an indwelling permanent inferior vena cava (IVC) filter. The migrated stent was managed by advancing the stent to the superior margin of the IVC filter and then deploying a second suprarenal IVC filter to prevent repeat embolization.

Intra-abdominal free fluid without solid organ injury in blunt abdominal trauma: an indication for laparotomy.

BACKGROUND: The optimal management of patients sustaining blunt abdominal trauma (BAT), in whom intra-abdominal free fluid but no solid organ injury is found on imaging, remains unclear. The purpose of this study was to determine the incidence and significance of this finding. METHODS: All patients presenting with suspected BAT to a provincial trauma center over a 30-month period were reviewed. A screening focused abdominal sonogram for trauma scan was obtained in every case. Stable patients with positive or indeterminate scans underwent computed tomographic scanning. Those with free fluid but without visible solid organ injury were studied. Radiologic interpretation, clinical management, and operative findings were analyzed. RESULTS: Twenty-eight of 1,367 patients (2%) met inclusion criteria. Twenty-one patients (75%) underwent exploratory laparotomy, which for 16 (76%) was therapeutic: bowel injuries were found in 10 patients, mesentery injuries in 6, and injuries to solid organs in 3. In five patients, laparotomy was nontherapeutic. Those with more than a trace of free fluid were significantly more likely to have a therapeutic procedure. Seven patients (25%) were observed, of whom two failed nonoperative management and underwent therapeutic laparotomies within 24 hours of admission for missed colon, splenic, and hepatic injuries. The presence of abdominal seat belt bruising or a Chance-type fracture in the study patients was associated with a 90% and 100% therapeutic laparotomy rate, respectively. Computed tomographic scan findings were variable and were not able to predict injury severity or need for surgery. CONCLUSION: The finding of more than trace amounts of free fluid in the absence of solid organ injury in BAT is often associated with clinically significant visceral injury. Early laparotomy is recommended for these patients.