Lumbar Disc Herniation at High Levels: MRI and Clinical Findings

PURPOSE: To assess the frequency, location, associated MR findings, and clinical symptoms of the high levellumbar disc herniation(HLDH). MATERIALS AND METHODS: A total of 1076 patients with lumbar disc herniation wereretrospectively reviewed. MR images of 41 of these with HLDH(T12-L1, L1-2, L2-3) were analysed in terms offrequency, location, and associated MR findings, and correlated with clinical symptoms of HLDH. RESULTS: Theprevalence of HLDH was 3.8%(41/1076). HLDH was located at T12-L1 level in four patients(10%), at L1-2 level in14(34%), at L2-3 level in 21(51%), and at both L1-2 and L2-3 levels in two. The age of patients ranged from 20 to72 years (mean, 44), and there were 26 men and 16 women. In 11(27%), whose mean age was 32 years, isolated discherniation was limited to these high lumbar segments. The remaining 30 patients had HLDH associated with variableinvolvement of the lower lumbar segments. Associated lesions were as follow : lower level disc herniation(14patients, 34%); apophyseal ring fracture(8 patients, 19%); Schmorl's node and spondylolisthesis (each 6patients, each 14%); spondylolysis(3 patients, 7%); and retrolisthesis(2 patients, 5%). In 20 patients(49%) withHLDH(n=41), there was a previous history. CONCLUSION: Patients with HLDH showed a relatively high incidence ofassociated coexisting abnormalities such as lower lumbar disc herniation, apophyseal ring fracture, Schmorl'snode, spondylolysis, and retrolisthesis. In about half of all patients with HLDH there was a previous history oftrauma. The mean age of patients with isolated HLDH was lower; clinical symptoms of the condition were relativelynonspecific and their incidence was low.

Efficacy of MR Arthrography in the Diagnosis of the Acetabular Labral Tear

PURPOSE: To determine the accuracy of magnetic resonance (MR) arthrography in the detection and staging of lesions of the acetabular labrum. MATERIALS AND METHODS: Fifteen hips of 14 patients with chronic hip pain and clinical suspicion of labral lesions were examined with direct or indirect MR arthrography and underwent subsequent arthroscopic evaluation. The study population consisted of six women and eight men aged between 40 and 59 years. Nine arthrograms were obtained intra-articular administration of gadolinium solution, and six involved articular motion exercise after intravenous administration of gadolinium solution. In 14 cases a phased-array pelvic coil was used, and a shoulder coil in one. Fat-suppressed T1-weighted images were obtained in the coronal, oblique coronal and oblique axial planes, and T1-and T2-weighted images were obtained in the axial plane. Labral lesions were graded according to the Czerny classification and evaluated on the basis of presence or absence of a tear and location (anteroinferior, anterosuperior, superior, posterosuperior, posteroinferior). The findings were then correlated with the arthroscopic findings. RESULTS: After direct and indirect MR arthography, the findings-based on the Czerny classification -were as follows : stage IA:3; IB:1; IIA:8; IIB:1; IIIA:4; IIIB:0. MR arthrography also showed that seven cases were located in the anterosuperior portion of the labrum, seven in the superior portion, and three in the posteroinferior portion. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MR arthrography for diagnosis of the labral tear was 92%, 75%, 92%, 75 %, and 88 %, respectively. CONCLUSION: In this preliminary study, MR arthrography appears to be a promising imaging modality for accurate diagnosis and useful for screening patients with chronic hip pain.

MR Findings of Chondromalacia Patella: Correlation of the Grade and Associated Lesions with ArthroscopicFindings

PURPOSE: To assess the MR findings of chondromalacia patella and correlate the grade and associated lesionswith the arthroscopic findings. MATERIALS AND METHODS: Twenty-five patients with pain in the anterior part of theknee underwent fat-suppressed axial and coronal T2-weighted, dual echo sagittal proton density-weighted andT2-weighted, and in some cases, T1-weighted and T2*-weighted imaging, using a 10-cm field of view, and a 5-inchgeneral purpose coil. We retrospectively assessed these find dings, and the locations, grades and associatedlesions, and correlated these with the arthroscopic findings. RESULTS: Fourteen cases(56%) of chondromalaciapatellae were arthroscopic grade I / II, nine(36%) were grade III, and two(8%) were grade IV; associated lesionswere medial synovial plicae (16 cases, 64%), meniscus tear (10 ; 40%), cruciate ligament injury (two ; 8%),complete or incomplete discoid meniscus (four ; 16%), bipartite patella (one ; 4%) and Osgood-Schlatter disease(one ; 4%). In 24 cases, MR imaging indicated chondromalacia patella ; 17 cases were grade I / II, five were gradeIII, and two were grade IV. the location of chondromalacia patella was the medial facet (five cases ; 20%), lateralfacet (three ; 12%), junction of the medial and odd facet (13 ; 52%), and diffuse involvement (four ; 16%). Thesensivity and specificity of MR imaging were 72% and 96% respectively. CONCLUSION: We evaluated the exact locationand grade of chondromalacia patella and associated lesions, as seen on MR images. These and the arthroscopicfindings showed close correlation, and in cases involving this condition, MRI is thus a useful indicator of anappropriate surgical method and plan.

Hepatic Hemangioma with Atypical Sonographic Features: Value of Two-Phase Spiral CT

PURPOSE: The purpose of this study was to evaluate enhancement patterns, as seen on two-phase spiral CT, of hepatic hemangiomas in which atypical features had been seen on sonography (US) MATERIALS AND METHODS: Two-phase spiral CT scanning was performed in 18 patients in whom 24 atypical hemangiomas had been seen on US. Two-phase images were obtained at 25-45 seconds (arterial dominant phase) and 2-5 minutes (equilibrium phase) after the initiation of a bolus injection of contrast material (150 ml, 5 ml/sec). Enhancement patterns of hemangiomas during each phase were classified as homogeneous high, peripheral high, or low attenuation, and were retrospectively analyzed. RESULTS: In the arterial dominant phase of spiral CT, low attenuation was seen in nine hemangiomas (38%), globular or spotty peripheral high attenuation in 14 (58%), and homogeneous high attenuation in one (4%). In the equilibrium phase, enhancement patterns were peripheral high attenuation (partial fill-in) in 18 lesions (75%), and homogeneous high attenuation (complete fill-in) in three (12.5%), In the other three (12.5%) enhancement showed no significant change; in one of these, density was slightly less than in the arterial phase, and two showed subtle peripheral high attenuation. Fourteen hemangiomas (58%) showed globular or spotty peripheral high attenuation in the arterial dominant phase and peripheral or homogeneous high attenuation with progressive centripetal enhancement in the equilibrium phase. CONCLUSION: Our results suggest that two-phase spiral CT during the arterial dominant and equilibrium phase is useful in differentiating hepatic hemangiomas with atypical features seen on US from malignant hepatic tumors.