ECG-gated quiescent-interval single-shot MR angiography of the lower extremities: initial experience at 3 T.

AIM: To evaluate the feasibility of unenhanced electrocardiography (ECG)-gated quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) of the lower extremities at 3 T. MATERIALS AND METHODS: Twenty-five patients with known or suspected peripheral arterial disease underwent ECG-gated QISS-MRA and contrast-enhanced MRA (CE-MRA) at 3 T. Two independent readers performed a per-segment evaluation of the MRA datasets. Image quality was rated on a four-point scale (1 = excellent to 4 = non-diagnostic; presented as medians with interquartile range). Diagnostic performance of QISS-MRA was evaluated using CE-MRA as the reference standard. RESULTS: QISS-MRA and CE-MRA of all patients were considered for analysis, resulting in 807 evaluated vessel segments for each MRA technique. Readers 1 and 2 rated image quality of QISS-MRA as diagnostic in 97.3% and 97% of the vessel segments, respectively. CE-MRA was rated diagnostic in all vessel segments. Image quality of the proximal vessel segments, including the infrarenal aorta, iliac arteries, and common femoral artery, was significantly lower on QISS-MRA compared to CE-MRA [image quality score across readers: 2 (1,3) versus 1 (1,1) p < 0.001]. In the more distal vessel segments, image quality of QISS-MRA was excellent and showed no significant difference compared to CE-MRA [image quality score across readers: 1 (1,1) versus 1 (1,1) p = 0.036]. Diagnostic performance of QISS-MRA was as follows (across readers): sensitivity: 87.5% (95% CI: 80.2-92.4%); specificity: 96.1% (95% CI: 93.6-97.6%); diagnostic accuracy: 94.9% (95% CI: 92.6-96.5%). CONCLUSIONS: QISS-MRA of the lower extremities is feasible at 3 T and provides high image quality, especially in the distal vessel segments.

Three-dimensional body scanning: a new method to estimate body surface area in neonates.

BACKGROUND: Body surface area (BSA) is usually estimated by calculation with mathematical formulae. Three-dimensional body scanning (3D scan) offers a suitable alternative. OBJECTIVES: We determined the BSA in healthy term and near-term neonates by 3D scanning. This system should be useful in the setting of intensive care medicine. METHODS: The measuring system consisted of a projector, two cameras, mirrors and a computer, and used the fringe projection technique with visible light. The infants were examined in a supine position; the hidden parts of the bodies were corrected for using a mathematical factor developed with a baby doll model. Results of the 3D scans were compared with those from five mathematical formulae for each subject. RESULTS: A total of 209 infants were studied by 3D scanning, of whom 53 had acceptable images and were selected for further analysis. The mean BSA was 2,139 cm(2) (SD 223.72). The minimal BSA was 1,587 cm(2), the maximal 2,670 cm(2), with a good correlation to body weight and length. One mathematical formula (Du Bois and Du Bois) showed a distinct underestimation of BSA compared to 3D scanning, the others an overestimation. Mean percentage similarity was from 96.8 to 100.9%. CONCLUSIONS: 3D scanning is an accurate and practical method to estimate BSA in newborns. Individual and repeated measurements from day to day are possible. Further studies are warranted in preterm and sick neonates.