Non-gadolinium dynamic angiography of the neurovasculature using arterial spin labeling MRI: preliminary experience in children.

OBJECTIVE: We demonstrate the potential clinical utility of a 4D non-gadolinium dynamic angiography technique based on arterial spin-labeling called contrast inherent inflow enhanced multi-phase angiography (CINEMA) in pediatric patients. MATERIALS AND METHODS: CINEMA was qualitatively compared to conventional time-of-flight (TOF) angiography in a cohort of 31 pediatric patients at 3 Tesla. RESULTS: CINEMA data were successfully acquired and reconstructed in all patients with no image artifacts. There were no cases where CINEMA was rated inferior to TOF in depicting intracranial vessel conspicuity. In 19 cases, CINEMA was rated equivalent to TOF and in the 12 remaining cases CINEMA was rated superior to TOF. CONCLUSION: There is a steadily rising concern in adults and children over the potential effects of intracranial deposition of gadolinium. CINEMA is therefore a viable alternative in dynamic neurovascular imaging.

Improved fat-suppression homogeneity with mDIXON turbo spin echo (TSE) in pediatric spine imaging at 3.0 T.

Background Robust fat suppression remains essential in clinical MRI to improve tissue signal contrast, minimize fat-related artifacts, and enhance image quality. Purpose To compare fat suppression between mDIXON turbo spin echo (TSE) and conventional frequency-selective and inversion-recovery methods in pediatric spine MRI. Material and Methods Images from T1-weighted (T1W) and T2-weighted (T2W) TSE sequences coupled with conventional methods and the mDIXON technique were compared in 36 patients (5.8 ± 5.4 years) at 3.0 T. Images from 42 pairs of T1W (n = 16) and T2W (n = 26) scans were acquired. Two radiologists reviewed the data and rated images using a three-point scale in two categories, including the uniformity of fat suppression and overall diagnostic image quality. The Wilcoxon rank-sum test was used to compare the scores. Results The Cohen's kappa coefficient for inter-rater agreement was 0.69 (95% confidence interval [CI], 0.56-0.83). Images from mDIXON TSE were considered superior in fat suppression ( P < 0.01) in 22 (rater 1) and 25 (rater 2) cases, respectively. In 13 (rater 1) and 11 (rater 2) cases, mDIXON TSE demonstrated improved diagnostic image quality ( P < 0.01). In three cases, fat suppression was superior using inversion-recovery and likewise in one case mDIXON had poorer image diagnostic quality. Lastly, mDIXON and conventional fat-suppression methods performed similarly in 17 (rater 1) and 14 (rater 2) cases, and yielded equal diagnostic image quality in 28 (rater 1) and 30 (rater 2) cases. Conclusion Robust fat suppression can be achieved with mDixon TSE pediatric spine imaging at 3.0 T and should be considered as a permanent replacement of traditional methods, in particular frequency-selective techniques.

Comparison of 2D single-shot turbo-spin-echo and spin-echo echo-planar diffusion weighted brain MRI at 3.0 Tesla: preliminary experience in children.

PURPOSE: To qualitatively compare a 2D single-shot turbo-spin-echo (ssTSE) diffusion-weighted imaging MRI technique with a spin-echo echo-planar imaging (SE-EPI) approach in pediatric neuroimaging. METHODS: Images were acquired at 3T in 15 patients (10.6±6.0years). A neuroradiologist rated the data based on the severity of image artifacts from air-tissue interfaces and devices such as ventriculoperitoneal shunts and orthodontia, and whether their presence affected diagnostic image quality. RESULTS: ssTSE was preferred over SE-EPI in diagnostic image quality and exhibited fewer clinically relevant artifacts (p<0.01). CONCLUSION: ssTSE provides superior diffusion-weighted brain images at 3T, particularly in the presence of orthodontia and shunts.

Assessment of cerebral blood perfusion reserve with acetazolamide using 3D spiral ASL MRI: Preliminary experience in pediatric patients.

PURPOSE: To demonstrate the clinical feasibility of a new non-Cartesian cylindrically-distributed spiral 3D pseudo-continuous arterial spin labeling (pCASL) magnetic resonance imaging (MRI) pulse sequence in pediatric patients in quantifying cerebral blood flow (CBF) response to an acetazolamide (ACZ) vasodilator challenge. MATERIALS AND METHODS: MRI exams were performed on two 3 Tesla Philips Ingenia systems using 32 channel head coil arrays. After local institutional review board approval, the 3D spiral-based pCASL technique was added to a standard brain MRI exam and evaluated in 13 pediatric patients (average age: 11.7±6.4years, range: 1.4-22.2years). All patients were administered ACZ for clinically indicated reasons. Quantitative whole-brain CBF measurements were computed pre- and post-ACZ to assess cerebrovascular reserve. RESULTS: 3D spiral pCASL data were successfully reconstructed in all 13 cases. In 11 patients, CBF increased 2.8% to 93.2% after administration of ACZ. In the two remaining patients, CBF decreased by 2.4 to 6.0% after ACZ. The group average change in CBF due to ACZ was approximately 25.0% and individual changes were statistically significant (p<0.01) in all patients using a paired t-test analysis. CBF perfusion data were diagnostically useful in supporting conventional MR angiography and clinical findings. CONCLUSION: 3D cylindrically-distributed spiral pCASL MRI provides a robust approach to assess cerebral blood flow and reserve in pediatric patients.