Pubic Insufficiency Fracture: MRI Findings

PURPOSE: To evaluate the characteristic MRI findings of pubic insufficiency fracture. MATERIALS AND METHODS: In nine cases of pubic insufficiency fracture, the findings of plain radiography (n=9), MRI (n=9), and bone scintigraphy (n=8) were reviewed. We retrospectively analyzed, with regard to fracture site, the destructive pattern revealed by plain radiography, and uptake by other pelvic bones, as demonstrated by RI bone scanning. The MR findings evaluated were the fracture gap and its signal intensity, the site and signal intensity of the soft tissue mass, and other pelvic bone fractures. RESULTS: Plain radiography revealed osteolysis and sclerosis of pubic bone in eight of nine cases (89%), and parasymphyseal fractures in seven (78%). RI indicated uptake by the sacrum in six cases (66%), and by the ilium in three (33%). MR findings of fracture gap (seven cases, 78%) were hypo to isointensity on T1WI, hyper-intensity on T2WI and the absence of contrast enhancement. Soft tissue masses were found in seven cases (78%); in four of these the location was parasymphyseal, and in three, surrounding muscle was involved. Hypo to isointensity was revealed by T1WI, hyperintensity by T2WI, and there was peripheral enhancement. Other associated pelvic bone fractures involved the sacrum in seven cases and the ilium in four. CONCLUSION: The characteristic MR findings of pubic insufficiency fracture were parasymphyseal location, fracture gap, peripherally enhanced soft tissue mass formation, and fractures of other pelvic bones, namely the sacrum and ilium.

Ultrasonographic Findings of Carpal Tunnel Syndrome

PURPOSE: To describe the ultrasonographic (US) findings of carpal tunnel syndrome (CTS) and to evaluate the diagnostic value of US in CTS. MATERIALS AND METHODS: Forty-four wrists of 26 patients aged 35 to 67 (mean, 52) years with CTS who were electrophysiologically diagnosed, and 30 wrists of 15 normal control subjects aged 33-62(mean, 48 years) were studied using US with a 7.5MHz linear transducer. Axial images of these wrists in the neutral position were obtained at the level of the distal radius, pisiform, and hook of hamate. The following measurements were taken: at each level, cross sectional area (CSA) and flattening ratio (FR) of the median nerve; at the hamate level, bowing of the flexor retinaculum (palmar displacement: PD); during passive flexion and extension of the index finger, transverse sliding of the median nerve. RESULTS: CSA at each level was significantly higher in patients than in controls (p=0.0001): 9.29 +/-2. 63 mm 2(mean +/-S.D.) vs 5.45 +/-1.98 mm 2 at the distal raidus; 10.68 +/-3.38 mm 2 vs 6.55 +/-2.01 mm 2 at the pisiform; 1 0 . 8 8 +/-2.78 mm2, vs 6.34 +/-2.00 mm2 at the hamate. FR was significantly higher in patients(2.37+/-0.56) than in controls (2.06 +/-0.36) only at the level of the hamate (p=0.0064). In additi on, PD of the flexor retinaculum was also significantly higher in patients (3.44 +/-0.90 mm) than in controls (2.20 +/-0.55mm) (p=0.0001). The sliding distance of median nerve during passive flexion and extension of the index finger was, however, significantly lower in patients (0.98 +/-1.03 mm) than in controls (1.65 +/-1.22 mm) (p=0.0180). CONCLUSION: For the diagnosis of CTS, US proved useful. Significant ultrasonographic findings in CTS were swelling of the median nerve, increased flattening ratio of the median nerve at the distal carpal tunnel, increased bowing of the flexor retinaculum, and decreased mobility of the median nerve during motion of the index finger.