Dual-Energy Computed Tomography as an Adjunct in the Evaluation of Peripheral Chronic Total Occlusions: A Feasibility Study.

This study investigated the role of dual-energy computed tomography (CT) for lesion characterization in patients with peripheral arterial disease manifesting with chronic total occlusions (CTOs). Forty-one symptomatic patients with CTOs underwent dual-energy CT angiography before endovascular treatment. The lesions were subsequently analyzed in a dedicated workstation, and 2 indexes-dual-energy index (DEI) and effective Z (Zeff)-were calculated, ranging from 0.0027 to 0.321 and from 6.89 to 13.02, respectively. Statistical analysis showed a significant correlation between the DEI and Zeff values (P < .001). The interobserver intraclass correlation coefficient was 0.91 for the mean Zeff values and 0.86 for the mean DEI values. This technique could potentially provide useful information regarding the composition of a CTO.

CT coronary angiography in asymptomatic male patients with high atherosclerosis risk: Is it justified?

PURPOSE: To study the necessity of coronary artery screening with computerized tomography coronary angiography (CTCA) in asymptomatic male patients. MATERIAL AND METHODS: A total of 226 asymptomatic male patients aged over 50 years were included in this prospective study, according to a clinical protocol approved by the Heraklion University Hospital's Ethics Committee. All participants had at least 3 or more known atherosclerosis risk factors. All patients had none or normal noninvasive cardiological tests in the past and had no contraindications for CTCA. All patients gave their informed consent after being notified regarding contrast medium and radiation dose risks. RESULTS: Significant stenoses were found in 52 asymptomatic males (23%). Out of them, 38 male patients underwent invasive coronography and 14 patients were lost in follow-up. In 18 patients, no lesions were found (47.4%). In the other 20 (52.6%) patients, 28 lesions were found. Stent placement was performed in 11 patients, bypass surgery was proposed in 3 patients, and in another 6 patients conservative treatment was suggested. Patients with findings in CTCA were more likely to have a family history of coronary artery disease, compared to patients with normal CTCA (P < 0.05 by using Fischer's Exact Test). Sensitivity of CTCA for significant stenosis was 74.3% with a specificity of 62%. CONCLUSION: CTCA may be used to screen for clinically significant coronary artery disease (CAD) in asymptomatic male patients, particularly those with positive family history or potentially high-risk patients with >3 risk factors for CAD.

CT Foot Perfusion Examination for Evaluation of Percutaneous Transluminal Angioplasty Outcome in Patients with Critical Limb Ischemia: A Feasibility Study.

PURPOSE: To evaluate foot perfusion in patients with critical limb ischemia (CLI) using quantitative perfusion multi-detector-row CT and estimate perfusion parameter changes before and after percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: This prospective study investigated 13 patients (10 men; median age, 72 y; range, 51-84 y) with CLI who underwent CT foot perfusion examinations with a 128-slice dual-energy CT scanner 1 day before and 1 week after PTA. Key parameters such as permeability surface (PS), blood volume (BV), and blood flow (BF) were analyzed and compared statistically. The studies were also examined by a second observer to determine interobserver reproducibility. RESULTS: Revascularization was technically successful in all patients, and mean ankle-brachial index increased from 0.36 ± 0.16 to 0.75 ± 0.22. After revascularization, mean BV increased from 1.55 mL/100 g ± 0.83 to 4.51 mL/100 g ± 1.53, BF increased from 16.28 mL/100 g/min ± 4.97 to 31.49 mL/100 g/min ± 6.86, and PS increased from 3.1 mL/min/100 g ± 1.95 to 8.67 mL/min/100 g ± 3.85 (P < .05). Patients with poor response to revascularization who finally underwent amputation presented lower post-PTA perfusion parameters values than patients with significant clinical improvement (P < .05). All measurements demonstrated very good interobserver reproducibility, and intraclass correlation coefficients were 0.91 for BV, 0.94 for BF, and 0.95 for PS. The mean effective dose of the examination was estimated at 0.29 mSv. CONCLUSIONS: CT foot perfusion is a reproducible technique that may be a useful modality for the estimation of PTA outcome. Significant restitution of perfusion parameters was observed after successful revascularization.

Hyperthermic isolated limb perfusion. The switch from Steinmann pins to Omni-tract assisted isolation.

BACKGROUND: Hyperthermic isolated limb perfusion (HILP) represents an alternative to amputation for patients with either in-transit melanoma or unresectable soft tissue sarcoma, entailing delivery of high-dose chemotherapy after isolation of the extremity, under hyperthermic conditions. Stabilization of the Esmarch elastic bandage is so far performed with the use of Steinmann pins. In this study, we presented our experience with HILP and demonstrated an alternative technique for limb isolation using an Omni-tract retractor instead of the traditional Steinmann pin, while comparing the two methods. METHODS: Forty patients, 28 with recurrent in-transit melanoma and 12 with locally advanced/recurrent sarcoma of the limbs, underwent HILP in a single institution and were included in the study. The Steinmann pin was applied in the first 23 cases, whereas the Omni-tract retractor was applied in the latter 17 patients. RESULTS: The median follow-up for the whole study group was 17.5 mo, whereas the overall response rate was 92.9% for melanoma and 75% for sarcoma patients. Both overall survival and local progression-free survival differed significantly between patients with complete response and those with partial response, stable disease or progressive disease. The use of the Omni-tract retractor was advantageous in every examined field, with the overall complication rate, duration of analgesic administration, and total opioid and paracetamol dose, being significantly less in the Omni-tract patient group. CONCLUSIONS: Although this study was not a randomized trial, we consider that the noninvasive application of the Omni-tract retractor will gain significant acceptance, by contributing to the reduction of HILP complications.

Therapeutic ERCP and pregnancy: is the radiation risk for the conceptus trivial?

BACKGROUND: Symptomatic choledocholithiasis can be treated during pregnancy. Conceptus doses ranged from 0.1 mGy to 3 mGy in previous studies. OBJECTIVE: The objectives of the current study were to investigate whether the conceptus dose may exceed the threshold of 10 mGy in the case of a pregnant patient undergoing ERCP, and to provide data for the accurate assessment of a conceptus dose. DESIGN: Monte Carlo methodology and mathematical anthropomorphic phantoms were used to determine normalized conceptus dose data. Phantoms simulated pregnant patients of different body sizes and gestational stages. Monte Carlo simulations were performed to estimate the efficiency of external shielding. SETTING: University hospital. PATIENTS: Twenty-four consecutive patients. INTERVENTIONS: All patients underwent therapeutic ERCP. Exposure parameters and dose-area product were recorded during the procedures. MAIN OUTCOME MEASUREMENTS: The total dose-area product recorded during ERCP procedures ranged between 62 x 10(3) and 491 x 10(3) mGy . cm(2). RESULTS: Monte Carlo normalized conceptus dose data are presented as a function of kV(p), total filtration, gestational stage, and body mass index. The conceptus dose may exceed 10 mGy when the total dose-area product surpasses 130 mGy . cm(2). LIMITATIONS: Variations of conceptus location and size from the average. CONCLUSIONS: Conceptus dose from ERCP may occasionally exceed 10 mGy, the dose above which the analytical dose calculation is recommended. The use of external shielding is unnecessary because the associated dose reduction is negligible. The normalized dose data may be used for the accurate estimation of conceptus dose from an ERCP procedure performed on a pregnant patient, regardless of body size, gestational stage, operating parameters, and equipment used.