Shear wave elastography of the brachial plexus roots at the interscalene groove.

OBJECTIVES: Sonoelastography is an emerging technology that has been used to evaluate the musculoskeletal system including the brachial plexus of peripheral nerves, which has been only recently considered for study by shear wave elastography. The purpose of this study is to establish the normal sonoelastographic features of the C5-C7 nerve roots of the brachial plexus. METHODS: Forty healthy individuals (21 males and 19 females) were enrolled in the study. Shear wave elastography was used to evaluate the C5-C7 nerve roots of the brachial plexus at the interscalene interval. Normal sonoelastographic values were obtained. RESULTS: The mean shear elastic modulus of the C5 nerve root was 16.9 kPa (range 5.9-28.8 ± 4.9 standard deviation, SD), 15.7 kPa (range 5.4-26.3 ± 4.3 SD) for the C6 nerve root, and 16 kPa (range 8-29 ± 4.6 SD) for the C7 nerve root. There was a significant statistical difference between both sexes in the elastic modulus at the C6 and C7, but not at the C5 nerve roots. Significant inverse correlation with height was noted at the C6 nerve root. There was no statistical significant difference in tissue stiffness between right- and left-handed subjects, age, and body mass index. CONCLUSION: The elastic modulus of the C5-C7 nerve roots has been determined in asymptomatic individuals and can serve as a reference when studying pathological conditions of these structures. ABBREVIATIONS: BMI: body mass index; SWE: shear wave elastography.

Renal involvement in lymphoma: prevalence and various patterns of involvement on abdominal CT.

OBJECTIVE: The kidney is a frequent site of involvement in lymphoproliferative disorders. The aim of this study was to demonstrate the prevalence and spectrum of morphologic appearances of renal involvement in patients with lymphoma on helical computed tomographic (CT) scan. METHODS: Three phases of post-contrast helical CT of the abdomen in 74 patients with lymphoma were reviewed for possible renal involvement: the cortico-medullary, nephrographic and delayed excretory phases. Tumor characteristics, patterns of distribution and enhancement features were evaluated. RESULTS: Of the 74 patients with lymphoma, 11 had CT evidence of renal involvement--ten with non-Hodgkin's lymphoma and one with Hodgkin's lymphoma--representing 15% of all patients scanned for routine staging of histologically diagnosed lymphoma. Five types of renal involvement were observed: enlarged lobular non-enhancing kidneys (four patients); bilateral multiple renal masses (two patients); focal single non-enhancing mass (two patients); perirenal infiltrations from retroperitoneal extension (two patients); bilateral diffuse areas of non-enhancing hypo-densities (one patient). CONCLUSION: Five distinct patterns of renal involvement with lymphoma were detected with helical CT. The most common appearance was enlarged lobular kidneys. CT with intravenous contrast enhancement is currently the approach of choice for both the evaluation of renal involvement as well as for accurate staging of lymphoma. Awareness of different patterns of renal involvement in lymphoma allows proper differentiation from other similar diseases.