Cone-beam CT: an additional imaging tool in the interventional treatment and management of low-flow vascular malformations.

PURPOSE: To evaluate the impact of cone-beam computed tomography (CT) during sclerotherapy of low-flow vascular malformations. MATERIALS AND METHODS: Eighty-seven cone-beam CT examinations were acquired during 81 sclerotherapy treatments of low-flow malformations in 48 patients: 81 were performed to evaluate sclerosing agent diffusion and six were performed to evaluate needle or catheter positioning before injection of therapeutic agent. Image quality was rated by two observers. Clinical impact of cone-beam CT in the assessment of therapeutic agent diffusion, needle or catheter positioning, subsequent treatment planning, and complication detection was evaluated. The κ-statistic was used to assess interobserver reliability and proportions, with associated 95% confidence intervals (CIs). RESULTS: All cone-beam CT images were successfully acquired. Image quality was rated as excellent or good for the majority of studies, with substantial interobserver reliability (κ = 0.648). Cone-beam CT studies improved assessment of therapeutic agent diffusion in 83% of cases (67 of 81; 95% CI, 75%-91%) for observer 1, who had access to ultrasound, fluoroscopic, and digital subtraction angiographic (DSA) imaging, and in 95% of cases (77 of 81; 95% CI, 90%-100%) for observer 2, who had access to only stored fluoroscopic spot radiographs and DSA images. Cone-beam CT impacted planning of the next treatment session in 49% of cases (40 of 81; 95% CI, 38%-60%). In 7% of cases (six of 81; 95% CI, 1%-13%), complications such as migration of therapeutic agent or compression of upper airways were detected that were not seen with other imaging. CONCLUSIONS: Cone-beam CT can be a useful adjunctive imaging tool, providing information to help decision-making during percutaneous sclerotherapy and ongoing management of low-flow vascular malformations.

A rare case of gastric varices and splenic artery aneurysm secondary to splenic arteriovenous fistula.

A 33-year-old male with no relevant medical history presented with a few months of fatigue and reduced exercise tolerance and was found to have iron-deficiency anemia. An esophagogastroduodenoscopy revealed a cluster of isolated gastric fundal varices with high-risk stigmata. Serologic workup for cirrhosis was negative, and a FibroScan measured liver stiffness at 4.2 kilopascals. Computed tomography (CT) of his abdomen and pelvis showed non-cirrhotic portal hypertension, as well as the presence of a splenic arteriovenous (AV) fistula and splenic artery aneurysm (SAA). Resection of the fistula, SAA, and spleen completely resolved the gastric varices and anemia.

Survey of radiologists' knowledge regarding the management of severe contrast material-induced allergic reactions.

PURPOSE: To evaluate radiologists' knowledge of the appropriate management of severe contrast material-induced allergic reactions by means of a telephone survey. MATERIALS AND METHODS: Institutional research ethics board approval was obtained. Following verbal consent, a telephone survey of radiologists working in Canada's 13 English-speaking and 13 U.S. university-affiliated radiology departments was performed. Participants were selected by using a multistage sampling scheme and simple random sampling within departments. Given a severe contrast material-induced allergic reaction case scenario, radiologists were first asked their initial medication of choice, then questioned specifically on the use of epinephrine. The Canadian and U.S. cohorts were compared by using the chi(2) and Fisher exact tests, as appropriate, and proportions and 95% confidence intervals (CIs) were computed. RESULTS: A total of 253 (81%) of 311 radiologists from a 30% target population were surveyed. Ninety-one percent (231 of 253; 95% CI: 88%, 94%) of radiologists chose epinephrine as the most important initial medication. No radiologist gave the ideal response, but 41% (94 of 231; 95% CI: 35%, 47%) provided an acceptable administration route, concentration, and dose; 17% (n = 39; 95% CI: 12%, 22%) of radiologists provided an overdose. Only 11% (27 of 253; 95% CI: 7%, 15%) of radiologists knew what concentration of epinephrine was available in their drug kit and/or crash cart and what equipment would be required to administer it to a patient. CONCLUSION: Radiologists' knowledge of epinephrine for the management of severe contrast material-induced allergic reactions is deficient.

Salvage of bilateral renal artery occlusion after endovascular aneurysm repair with open splenorenal bypass.

We report renal salvage maneuvers after accidental bilateral renal artery coverage during endovascular aneurysm repair of an infrarenal abdominal aortic aneurysm. A 79-year-old man with an infrarenal abdominal aortic aneurysm was treated with endovascular aneurysm repair. Completion angiography demonstrated coverage of the renal arteries. Several revascularization techniques were attempted, including endograft repositioning and endovascular stenting through the femoral and brachial approach. The patient eventually underwent open splenorenal bypass with a Y Gore-Tex graft (W. L. Gore & Associates, Flagstaff, Ariz). After 3 months, computed tomography showed no evidence of endoleak and patent renal arteries. Renal function was well maintained, and the patient did not require dialysis.

Percutaneous sharp recanalization of a membranous IVC occlusion with an occlusion balloon as a needle target.

A 50-year-old male with right upper quadrant symptoms and hepatic dysfunction was found to have multiple dilated hepatic veins (HVs) with intrahepatic collateralization and membranous occlusion of the intrahepatic inferior vena cava (IVC) consistent with primary Budd-Chiari syndrome. Venacavograms depicted drainage of the intrahepatic collaterals through a left-sided HV entering the IVC above the level of the occlusion. Sharp recanalization of the membranous IVC occlusion was performed with an occlusion balloon as a needle target under echocardiographic monitoring followed by balloon angioplasty with restoration of IVC patency. Clinical, laboratory, and venographic procedural success has been demonstrated to 9 months with minimal residual stenosis.

Balloon-occluded retrograde transvenous obliteration for treatment of bleeding gastric varices: case report and review of literature.

Gastric variceal bleeding is a major complication of portal hypertension and is associated with high morbidity and mortality. While esophageal varices are more common, gastric varices are often more challenging to treat. Balloon-Occluded Retrograde Transvenous Obliteration is an interventional procedure whereby the portosystemic gastrorenal shunt is accessed via the left renal vein and the gastric varix outflow tract obliterated using direct sclerotherapy. Herein, we present a case of a 68-year-old female patient with cirrhosis who presented with bleeding gastric varices and successfully treated. This case highlights the procedural steps and the importance of detailed knowledge of the patient's portosystemic anatomy for determining suitability for balloon-occluded retrograde transvenous obliteration of gastric varices.

Utility of relative and absolute measures of mammographic density vs clinical risk factors in evaluating breast cancer risk at time of screening mammography.

OBJECTIVE: Various clinical risk factors, including high breast density, have been shown to be associated with breast cancer. The utility of using relative and absolute area-based breast density-related measures was evaluated as an alternative to clinical risk factors in cancer risk assessment at the time of screening mammography. METHODS: Contralateral mediolateral oblique digital mammography images from 392 females with unilateral breast cancer and 817 age-matched controls were analysed. Information on clinical risk factors was obtained from the provincial breast-imaging information system. Breast density-related measures were assessed using a fully automated breast density measurement software. Multivariable logistic regression was conducted, and area under the receiver-operating characteristic (AUROC) curve was used to evaluate the performance of three cancer risk models: the first using only clinical risk factors, the second using only density-related measures and the third using both clinical risk factors and density-related measures. RESULTS: The risk factor-based model generated an AUROC of 0.535, while the model including only breast density-related measures generated a significantly higher AUROC of 0.622 (p < 0.001). The third combined model generated an AUROC of 0.632 and performed significantly better than the risk factor model (p < 0.001) but not the density-related measures model (p = 0.097). CONCLUSION: Density-related measures from screening mammograms at the time of screen may be superior predictors of cancer compared with clinical risk factors. ADVANCES IN KNOWLEDGE: Breast cancer risk models based on density-related measures alone can outperform risk models based on clinical factors. Such models may support the development of personalized breast-screening protocols.

Consistency of visual assessments of mammographic breast density from vendor-specific "for presentation" images.

Discussions of percent breast density (PD) and breast cancer risk implicitly assume that visual assessments of PD are comparable between vendors despite differences in technology and display algorithms. This study examines the extent to which visual assessments of PD differ between mammograms acquired from two vendors. Pairs of "for presentation" digital mammography images were obtained from two mammography units for 146 women who had a screening mammogram on one vendor unit followed by a diagnostic mammogram on a different vendor unit. Four radiologists independently visually assessed PD from single left mediolateral oblique view images from the two vendors. Analysis of variance, intra-class correlation coefficients (ICC), scatter plots, and Bland-Altman plots were used to evaluate PD assessments between vendors. The mean radiologist PD for each image was used as a consensus PD measure. Overall agreement of the PD assessments was excellent between the two vendors with an ICC of 0.95 (95% confidence interval: 0.93 to 0.97). Bland-Altman plots demonstrated narrow upper and lower limits of agreement between the vendors with only a small bias (2.3 percentage points). The results of this study support the assumption that visual assessment of PD is consistent across mammography vendors despite vendor-specific appearances of "for presentation" images.

Immediate defibrillation versus interventions first in a swine model of prolonged ventricular fibrillation.

OBJECTIVES: we compared time-dependent rescue shock success when delivered immediately, to defibrillation preceded by 3 min of CPR, with and without high dose epinephrine (HDE) in a swine model of prolonged ventricular fibrillation (VF). Our hypotheses were that pretreatment with CPR and HDE would produce higher rates of successful first-shock defibrillation and would prevent decay of the VF waveform, as measured by the scaling exponent (ScE), when compared to immediate defibrillation. We also sought to determine the predictive value of the ScE in determining post-shock outcomes. METHODS: we anesthetized and instrumented 60 domestic swine (19.6-26.4 kg). VF was induced electrically and was untreated for 8, 11 or 14 min. ECG was recorded digitally at a rate of 1000 samples/s with 5-s epochs used to calculate the ScE. We assigned randomly swine to seven groups (number denotes timing of first rescue shock). Three groups had rescue shocks as the first intervention (RSF) after 8 min of VF (RSF-8), 11 min of VF (RSF-11), or 14 min of VF (RSF-14): two groups had CPR for 3 min (then rescue shock) beginning at 8 min (CPR-11) or 11 min of VF (CPR-14); and two groups got CPR for 3 min with 0.1 mg/kg epinephrine (adrenaline) (then rescue shock) beginning at 8 min of VF (HDE-11) or 11 min of VF (HDE-14). Fixed-dose 70 J BDW rescue shocks were used for all shocks. Defibrillation outcome was classified immediately and 30 s post-shock as successful (either restoration of spontaneous circulation [ROSC] or restoration of organized electrical activity [ROEA]), or failed (remained in VF, or asystole). Data were analyzed with RMANOVA, multiple logistic regression, Fisher's exact tests, and ROC curves. RESULTS: successful first-shock defibrillation occurred in 3/8 (38%) RSF-8; 1/9 (11%) RSF-11; 2/9 (22%) CPR-11; 7/9 (77%) HDE-11; 0/9 (0%) RSF-14; 0/7 (0%) CPR-14; and 1/8 (13%) HDE-14, (p=0.059 IRS-8 vs. HDE-11). First-shock ROSC occurred in 5/9 (56%) HDE-11 animals, 1/8 (13%) HDE-14 and zero in all other groups (p=0.03). Mean ScE values at 11 min VF for the RSF-11 (1.46) was higher than both CPR-11 (1.26), and HDE-11 (1.27); and RSF-14 (1.60) was higher than CPR-14 (1.47) and HDE-14 (1.46); group by time p=0.002. ROC areas under the curves using the ScE as a predictor of shock outcome were 0.84 for immediate success, 0.85 for sustained success, and 0.81 for ROSC. CONCLUSIONS: HDE-11 showed a tendency for producing a higher rate of first-shock success and ROSC. Interventions prior to rescue shock prevented deterioration of the VF waveform and improved rescue shock outcomes. The ScE accurately predicted 81-85% of post-rescue shock outcomes.