Problem Solved: Integral Applications of Musculoskeletal Ultrasound.

Musculoskeletal ultrasound has grown substantially in use over the past several years as an indispensable companion to magnetic resonance imaging and other imaging modalities. This article reviews 10 integral applications of musculoskeletal ultrasound as a problem-solving tool with correlative case examples. These applications include the following: (1) accessibility and portability, (2) targeted imaging, (3) dynamic imaging, (4) contralateral comparison, (5) Doppler imaging, (6) increased spatial resolution, (7) solid versus cystic comparison, (8) posttraumatic imaging, (9) postsurgical imaging, and (10) treatment delivery and optimization. The review will help the radiologist recognize the complementary uses of musculoskeletal ultrasound with radiography, computed tomography, and magnetic resonance imaging.

Fibrodysplasia ossificans progressiva: a current review of imaging findings.

OBJECTIVE: Fibrodysplasia ossificans progressiva is a rare genetic disorder characterized by congenital skeletal deformities and soft tissue masses that progress to heterotopic ossification. Deformities of the great toes are distinctive, and heterotopic ossification in the soft tissues follows an expected anatomic and temporal pattern. In addition to heterotopic ossification, osteochondromata, middle ear ossification, demyelination, lymphedema, and venous thrombosis are characteristic. Awareness of this constellation of findings is important to early diagnosis and surveillance. CONCLUSIONS: Recognition of the imaging manifestations of fibrodysplasia ossificans progressiva is imperative to early diagnosis in order to appropriately direct patient care and preclude unnecessary biopsies or surgical procedures.

Multiparametric MRI for Differentiation of Radiation Necrosis From Recurrent Tumor in Patients With Treated Glioblastoma.

OBJECTIVE: Differentiation of radiation necrosis (RN) from recurrent tumor (RT) in treated patients with glioblastoma remains a diagnostic challenge. The purpose of this study is to evaluate the diagnostic performance of multiparametric MRI in distinguishing RN from RT in patients with glioblastoma, with the use of a combination of MR perfusion and diffusion parameters. MATERIALS AND METHODS: Patients with glioblastoma who had a new enhancing mass develop after completing standard treatment were retrospectively evaluated. Apparent diffusion coefficient (ADC), volume transfer constant (Ktrans), and relative cerebral blood volume (rCBV) values were calculated from the MR images on which the enhancing lesions first appeared. Repeated measure of analysis, logistic regression, and ROC analysis were performed. RESULTS: Of a total of 70 patients evaluated, 46 (34 with RT and 12 with RN) met our inclusion criteria. Patients with RT had significantly higher mean rCBV (p < 0.001) and Ktrans (p = 0.006) values and lower ADC values (p = 0.004), compared with patients with RN. The overall diagnostic accuracy was 85.8% for rCBV, 75.5% for Ktrans, and 71.3% for ADC values. The logistic regression model showed a significant contribution of rCBV (p = 0.024) and Ktrans (p = 0.040) as independent imaging classifiers for differentiation of RT from RN. Combined use of rCBV and Ktrans at threshold values of 2.2 and 0.08 min-1, respectively, improved the overall diagnostic accuracy to 92.8%. CONCLUSION: In patients with treated glioblastoma, rCBV outperforms ADC and Ktrans as a single imaging classifier to predict recurrent tumor versus radiation necrosis; however, the combination of rCBV and Ktrans may be used to improve overall diagnostic accuracy.