Image quality improvement and motion degradation reduction in shoulder MR imaging: comparison of BLADE and rectilinear techniques at 3-Tesla scanning.

OBJECTIVE: MR imaging of joints, particularly shoulder, requires a high degree of spatial resolution to ascertain anatomy and pathology. Unfortunately, motion artifacts can reduce the clinical quality of the examinations. BLADE sequence reduces motion degradation improving overall diagnostic imaging quality. The objective was to compare standard, rectilinear k-space coverage turbo spin echo (TSE), and BLADE sequences. MATERIAL AND METHODS: Over a 4-month period, fifty-seven consecutive patients (22 males, 35 females; mean age: 48.5 years, range: 23-64 years) were scanned using traditional intermediate-weighted spin echo and BLADE sequences. Qualitative evaluation was performed by three musculoskeletal fellowship trained radiologists, each with more than 5 years of experience. Image sequences were evaluated using a Likert scale for each of the following five categories: motion degradation, ghosting/phase misregistration artifacts, star/radial encoding artifacts, fat suppression quality, and overall diagnostic quality. Additionally, image sequences were evaluated for signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) using manually drawn regions of interest (ROI) analysis. RESULTS: Ghosting and phase artifacts were lower within BLADE sequence while streak artifacts were higher (p < 0.001). Image fat suppression, tendon and labral appearances, and the overall SNR and CNR were comparable on both sequences (p > 0.05). CONCLUSION: Addition of BLADE reduces motion degradation and improves overall diagnostic imaging quality. Application of BLADE in patient scans suspected of motion artifacts can reduce the frequency of repeat imaging in patients with claustrophobia or those where motion is a concern. By reducing overall imaging time and call backs, it could reduce the cost burden to patients and healthcare system.

Scoliosis in Neurofibromatosis Type 1 on Whole-Body Magnetic Resonance Imaging: Frequency and Association With Intraspinal and Paraspinal Tumors.

OBJECTIVES: Scoliosis is a common orthopedic problem in patients with neurofibromatosis 1 (NF1). Spinal deformities are found in 77% of all NF1 cases, with no widely accepted etiology. This study aimed to evaluate the frequency and types of scoliosis in NF1 patients using whole-body magnetic resonance imaging and to assess the association of intraspinal and paraspinal tumors with the imaging findings of scoliosis. METHODS: A total of 122 NF1 patients with whole-body magnetic resonance imaging were found from the electronic medical records. Ninety-seven cases that met the inclusion criteria were identified. All patients underwent 3-T magnetic resonance imaging with automated software fusion of the 3 sets of short TI inversion recovery and 3-dimensional T1-weighted coronal images. Frequency and location of scoliosis and intraspinal and paraspinal tumors were recorded. Patients with severe dystrophic-type scoliosis were separately identified, and Cobb angles were measured for all such cases. Association analysis was performed. A P value less than 0.05 was considered statistically significant. RESULTS: Ninety-seven patients with NF1 were evaluated. Two had prior spinal surgery and were excluded. The final sample of 95 patients included 33 (35%) men and 62 (65%) women with a mean ± SD body mass index of 25.82 (4.96) kg/m2. Of the 95 patients, 43 (45.3%) had scoliosis, 13 of 43 (30.2%) of which were severely angled. Of the 95 patients, 25 (26.3%) had locoregional tumor presence. Intraclass correlation for Cobb angles measured 0.99 (confidence interval, 0.98-1.0). Fisher exact test determined no association between scoliosis and presence of either paraspinal or intraspinal tumors (P = 0.485). There was also no association between the tumors and severe dystrophic scoliosis (P = 1.0). CONCLUSIONS: This study found no association between the presence of locoregional spinal tumors and scoliosis in NF1 patients. This work adds to the body of knowledge of scoliosis in NF1 patients and infers that presence of scoliosis should not mandate immediate search for locoregional spinal tumors.

T2 black lesions on routine knee MRI: differential considerations.

The majority of abnormal findings or lesions on T2-weighted fast spin-echo (FSE) magnetic resonance imaging (MRI) are hyperintense due to increased perfusion or fluid content, such as infections, tumours or synovitis. Hypointense lesions on T2-weighted images (both fat-suppressed and non-fat-suppressed) are less common and can sometimes be overlooked. Such lesions have limited differential diagnostic possibilities, and include vacuum phenomenon, loose body, tenosynovial giant cell tumour, rheumatoid arthritis, haemochromatosis, gout, amyloid, chondrocalcinosis, hydroxyapetite deposition disease, lipoma arborescens, arthrofibrosis and iatrogenic lesions. These lesions often show characteristic appearances and predilections in the knee. In this article, the authors describe the MRI features of hypointense T2 lesions on routine knee MRI and outline a systematic diagnostic approach towards their evaluation. Key Points • Hypointense lesions on T2 images (T2 Dark Lesions) encompass limited diagnostic possibilities. • T2 Dark lesions often show characteristic appearances and predilections in the knee. • A systematic diagnostic approach will help radiologists make the correct diagnosis.

Osseous lesions of the pelvis and long tubular bones containing both fat and fluid-like signal intensity: an analysis of 28 patients.

PURPOSE: The purpose of this study was to explore the nature of lesions in the pelvis and the long tubular bones that, with MR imaging, were found to contain both fat and fluid-like signal intensity and to correlate these findings with those of radiography, histologic analysis, and clinical and radiographic follow-up. MATERIALS AND METHODS: A retrospective review of the radiologic, clinical and histologic parameters of 28 patients with lesions in the pelvis and long tubular bones comprised of elements that demonstrated both fat and fluid signal intensity characteristics by MR imaging was performed. Several parameters were analyzed. Histologic analysis was available in 12 patients. Clinical and, or imaging follow-up was available in 13 patients. RESULTS: Imaging and histologic findings suggested the presence of fat and fluid and fluid components in all lesions with which could be divided into distinct MR imaging patterns. Histologic analysis suggested the possibility of a shared pathogenesis among several different lesions. CONCLUSION: All lesions of the long tubular bones in our series revealing both fat and fluid-like signal intensities with MR imaging were nonaggressive on the basis of other imaging findings, follow-up assessment, histologic analysis, or combinations of the three. Histologic findings suggest a relationship among lipomas, fat necrosis and cystic infarct of bone.