Lymphedema evaluation using noninvasive 3T MR lymphangiography.

PURPOSE: To exploit the long 3.0T relaxation times and low flow velocity of lymphatic fluid to develop a noninvasive 3.0T lymphangiography sequence and evaluate its relevance in patients with lymphedema. MATERIALS AND METHODS: A 3.0T turbo-spin-echo (TSE) pulse train with long echo time (TEeffective = 600 msec; shot-duration = 13.2 msec) and TSE-factor (TSE-factor = 90) was developed and signal evolution simulated. The method was evaluated in healthy adults (n = 11) and patients with unilateral breast cancer treatment-related lymphedema (BCRL; n = 25), with a subgroup (n = 5) of BCRL participants scanned before and after manual lymphatic drainage (MLD) therapy. Maximal lymphatic vessel cross-sectional area, signal-to-noise-ratio (SNR), and results from a five-point categorical scoring system were recorded. Nonparametric tests were applied to evaluate study parameter differences between controls and patients, as well as between affected and contralateral sides in patients (significance criteria: two-sided P < 0.05). RESULTS: Patient volunteers demonstrated larger lymphatic cross-sectional areas in the affected (arm = 12.9 ± 6.3 mm2 ; torso = 17.2 ± 15.6 mm2 ) vs. contralateral (arm = 9.4 ± 3.9 mm2 ; torso = 9.1 ± 4.6 mm2 ) side; this difference was significant both for the arm (P = 0.014) and torso (P = 0.025). Affected (arm: P = 0.010; torso: P = 0.016) but not contralateral (arm: P = 0.42; torso: P = 0.71) vessel areas were significantly elevated compared with control values. Lymphatic cross-sectional areas reduced following MLD on the affected side (pre-MLD: arm = 8.8 ± 1.8 mm2 ; torso = 31.4 ± 26.0 mm2 ; post-MLD: arm = 6.6 ± 1.8 mm2 ; torso = 23.1 ± 24.3 mm2 ). This change was significant in the torso (P = 0.036). The categorical scoring was found to be less specific for detecting lateralizing disease compared to lymphatic-vessel areas. CONCLUSION: A 3.0T lymphangiography sequence is proposed, which allows for upper extremity lymph stasis to be detected in ∼10 minutes without exogenous contrast agents. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1349-1360.

Rule of 5: angiographic diameters of cervicocerebral arteries in children and compatibility with adult neurointerventional devices.

BACKGROUND AND PURPOSE: The safety of using adult-sized neuroendovascular devices in the smaller pediatric vasculature is not known. In this study we measure vessel diameters in the cervical and cranial circulation in children to characterize when adult-approved devices might be compatible in children. METHODS: For 54 children without vasculopathy (mean age 9.5±4.9 years (range 0.02-17.8), 20F/34M) undergoing catheter angiography, the diameters of the large vessels in the cervical and cranial circulation (10 locations, 611 total measurements) were assessed by three radiologists. Mean±SD diameter was calculated for the following age groups: 0-6 months, 1, 2, 3, 4, 5-9, 10-14, and 15-18 years. To compare with adult sizes, each vessel measurement was normalized to the respective region mean diameter in the oldest age group (15-18 years). Normalized measurements were compared with age and fitted to a segmented regression. RESULTS: Vessel diameters increased rapidly from 0 to 5 years of age (slope=0.069/year) but changed minimally beyond that (slope=0.005/year) (R(2)=0.2). The regression model calculated that, at 5 years of age, vessels would be 94% of the diameter of the oldest age group (compared with 59% at birth). In addition, most vessels in children under 5, while smaller, were still potentially large enough to be compatible with many adult devices. CONCLUSIONS: The growth curve of the cervicocerebral vasculature displays rapid growth until age 5, at which point most children's vessels are nearly adult size. By age 5, most neuroendovascular devices are size-compatible, including thrombectomy devices for stroke. Under 5 years of age, some devices might still be compatible.

Spica MRI after closed reduction for developmental dysplasia of the hip.

Spica MRI is a fast and effective tool to assess morphology after closed reduction for developmental dysplasia of the hip (DDH) without the need for sedation. The multiplanar capabilities allow depiction of coronal and axial reduction of the hips. Due to MRI's inherent ability to delineate soft tissue structures, both intrinsic and extrinsic obstacles to failed reduction may be identified. Technical and interpretative challenges of spica MRI are discussed.