A three-dimensional image registration technique for CT and MR studies of the cervical spine was evaluated for feasibility and efficacy. Registration by means of external fiducial markers was slightly more accurate than registration by anatomic landmarks. The interrelationships between bony (eg, neural foramina) and soft tissue structures (eg, nerve roots) in the cervical spine were more conspicuous on registered images than on conventional displays. Registration of CT and MR images may be used to examine more precisely the relationships between bony and soft tissue structures of the cervical spine.
Exclusion criteria: lower limb varices, history of leg surgery, trauma, infection, or thromboembolic events. Ultrasound examinations are performed in B-mode technique, equipped with a linear broadband (7.5-14-MHz) transducer. The right femoral vein and the inguinal ligament are examined in a supine position. The inguinal ligament is identified along its longitudinal axis. The measurements levels are identified as follow: - proximal level: 20 mm caudally to the inguinal ligament identified along the femoral artery imaged with US - distal level: 20 mm caudally to the inguinal crease visually identified and along the femoral artery imaged with US The cross-sectional area (CSA) of the right femoral vein is examined at both levels in transverse plane and is measured automatically after manual tracing of the vessel on a static image in three leg positions: abduction, abduction + external rotation, abduction + external rotation + 90º knee flexion/frog-leg. Attention must be taken to avoid any compression or displacement of the examined vein.
To determine reference values and tolerance limits of between-side differences for the calibers of the common femoral artery (CFA), superficial femoral artery (SFA), popliteal artery (PA), dorsalis pedis artery (DPA), and posterior tibial artery (PTA). Calibers of arteries, defined as the largest distance between internal hyperechogenic lines of the intima-media complex of the arterial wall, were measured during the diastole phase determined from echo-tracking B mode ultrasound scanning and grey-scale ultrasound in 228 healthy volunteers aged 18–81 years (43.1 ± 16.7). The mean, 95% confidence and tolerance limits covering 90% of population for left and right side of each artery were: CFA: 8.1 mm, 7.9–8.3 mm, 6.0–10.3 mm; 8.1 mm, 7.9–8.5 mm, 5.9–10.2 mm; SFA: 6.2 mm, 6.0–6.3 mm, 4.7–7.6 mm; 6.1 mm, 6.0–6.3 mm, 4.7–7.6 mm; PA: 6.1 mm, 6.0–6.2 mm, 4.6–7.6 mm; 6.1 mm, 5.9–6.2 mm, 4.5–7.6 mm; DPA: 2.0 mm, 1.9–2.0 mm, 1.2–2.7 mm; 2.0 mm, 1.9–2.0 mm, 1.2–2.8 mm; PTA: 2.1 mm, 2.0–2.1 mm, 1.4–2.8 mm; 2.1 mm, 2.1–2.2 mm, 1.4–2.8 mm, respectively. Tolerance limits for between-side differences and ratios were: CFA - 0.5–0.7 mm, 0.9–1.1; SFA - 0.5–0.6 mm, 0.9–1.1; PA - 0.5–0.5 mm, 0.9–1.1; DPA -0.4-0.4 mm, 0.8–1.2; PTA - 0.4–0.4 mm, 0.8–1.2. Regression analysis showed weight and age dependency of vessels diameters. There are no differences between men and woman in vessels size, except in DPA's, when body weight and age are taken into account in a regression analysis. We estimated normal reference tolerance limits of side-to-side differences in diameters of lower limb arteries. The limits can inform an investigator what differences in diameters occur in healthy individuals, and hence can serve as cut-offs in diagnostic and screening strategies.
Transcranial color-coded Doppler ultrasonography (TCCD) is used by radiologists for detection of middle cerebral artery spasm. In this study, TCCD examination was performed in 100 patients, refereed by neurosurgeons for arterial angiography. Angiographic images were used to establish the four-grade scale of spasm, which was combined with TCCD blood flow measurements. The overall performance of TCCD in detection of MCA narrowing was estimated by means of Receiver Operating Characteristics (ROC). The ROC analysis proved very high efficiency (over 90%) of TCCD for detection of moderate-to-severe spasm. The multi-parameter classification of TCCD data was also performed by LVQ networks. LVQ networks showed very good accuracy (80–95%), not only for binary outcome, but also for classification of TCCD data in a multi-grade scale of spasm.
BACKGROUND AND PURPOSE: Nonimaging transcranial Doppler sonography (TCD) and imaging TCD (TCDI) are used for determination of the risk of stroke in children with sickle cell disease (SCD). The purpose was to compare angle-corrected, uncorrected TCDI, and TCD blood flow velocities in children with SCD. MATERIALS AND METHODS: A total of 37 children (mean age, 7.8 3.0 years) without intracranial arterial narrowing determined with MR angiography, were studied with use of TCD and TCDI at the same session. Depth of insonation and TCDI mean velocities with and without correction for the angle of insonation in the terminal internal carotid artery (ICA) and middle (MCA), anterior (ACA), and posterior (PCA) cerebral arteries were compared with TCD velocities with use of a paired t test. RESULTS: Two arteries were not found on TCDI compared with 15 not found on TCD. Average angle of insonation in the MCA, ACA, ICA, and PCA was 31°, 44°, 25°, and 29°, respectively. TCDI and TCD mean depth of insonation for all arteries did not differ significantly; however, individual differences varied substantially. TCDI velocities were significantly lower than TCD velocities, respectively, for the right and left sides (mean SD): MCA, 106 22 cm/s and 111 33 cm/s versus 130 19 cm/s and 134 26 cm/s; ICA, 90 14 cm/s and 98 27 cm/s versus 117 18 cm/s and 119 23 cm/s; ACA, 74 24 cm/s and 88 25 cm/s versus 105 23 cm/s and 105 31 cm/s; and PCA, 84 27 cm/s and 82 21 cm/s versus 95 23 cm/s and 94 20 cm/s. TCD and angle-corrected TCDI velocities were not statistically different except for higher angle-corrected TCDI values in the left ACA and right PCA. CONCLUSION: TCD velocities are significantly higher than TCDI velocities but are not different from the angle-corrected TCDI velocities. TCDI identifies the major intracranial arteries more effectively than TCD.
