No abstract available.

Mucin-hypersecreting biliary neoplasm excretes excessive mucin that fills the biliary tree and results in marked dilatation of the bile ducts and obstructive jaundice. In these neoplasm, the mucin produced by the tumor rather than the tumor itself plays an important role in clinical course and radiologic patterns. The purpose of this paper is to report characteristic radiologic patterns of mucin-hypersecreting biliary neoplasms in two cases. These neoplasms were characterized by not only multilocular cystic hepatic mass or extra-hepatic bile duct mass resulting in marked biliary dilatation distal to the mass on US or CT, but also change of shape and extent of amorphous filling defects in the markedly dilated bile duct on serial cholangiograms.
Bile Ducts ; Biliary Tract ; Dilatation ; Jaundice, Obstructive ; Mucins

No abstract available.
Chest Pain* ; Emergencies* ; Emergency Service, Hospital* ; Thorax*

PURPOSE: To evaluate the frequency of peritumoral bone marrow(BM) edema accompanying benign giant celltumor(GCT) of the appendicular bone by magnetic resonance(MR) imaging and to correlate MRI findings with those ofplain radiography and bone scintigraphy. MATERIALS AND METHODS: Eighteen cases of pathologically proven benignGCT of the appendicular bone were retrospectively analyzed using MR images, plain radiographs and bonescintigrams. A plain radiograph was available in 15 cases, and a scintigram in six. Marrow edema was defined asperitumoral signal changes which were of homogeneous intermediate or low signal intensity(SI) on T1WI and high SIon T2WI, relative to the SI of normal BM, and homogeneous enhancement on Gd-DTPA-enhanced T1WI. The transitionzone, sclerotic margin and aggressiveness of the lesion were assessed on the basis of plain radiographs. BM edemaseen on MR images was correlated with plain radiographic and scintigraphic findings. RESULTS: 1. Peritumoral BMedema was seen on MR images in 10 of 18 cases (55.5%). 2. In 8 of 15 cases for which plain radiographs wereavailable, MR imaging revealed BM edema. In six of these eight, transition zone was wide, while in two it wasnarrow. Six of seven patients without marrow edema showed a wide transition zone, and in one this was narrow.There was significant correlation between BM edema shown by MR imaging and the transition zone seen on plainradiographs (x2, p<0.05). But The aggressiveness shown by plain radiographs correlated only marginally, while thepresence of sclerotic rim did not correlate. 3. All six cases for which a bone scintigram was available showed anextended uptake pattern. In five of the six, MR imaging revealed edema. CONCLUSION: Peritumoral BM edema wasfrequently seen (55.5%) in the GCTs of appendicular bone ; it was more often shown in association with a widetransition zone by plain radiographs.
Bone Marrow* ; Edema* ; Giant Cell Tumors* ; Giant Cells* ; Humans ; Magnetic Resonance Imaging ; Radiography ; Radionuclide Imaging ; Retrospective Studies

PURPOSE: The purpose of this study is to examine the frequency of posterior element injury in patients with traumatic thoraco-lumbar burst fractures and to evaluate the correlation between the MR imaging and CT findings. MATERIALS AND METHODS: The MR images of 38 patients with 39 thoraco-lumbar burst fractures and the results of the CT examinations of 28 patients with 29 fractures were retrospectively analyzed. Both procedures were performed within two weeks of injury. Twenty-one males and 17 females were included ; their average age was 51.3 (range, 11-75) years. MR images were evaluated for injury to the posterior ligamentous complex, comprising the supraspinous ligament(SSL), the interspinous ligament(ISL), the flaval ligament(FL), and the capsule of facets. Analysis of the CT findings focused on the posterior bony elements of the lamina, pedicle, spinous process, and facet joint. RESULTS: MR imaging revealed posterior ligamentous injuries in 18(46.2%) of 39 burst fractures ; there was tearing of the ISL in 15 cases(38.5%), of the SSL in 11(28.2%), of the capsule of facets in 11(28.2%), and of the FL in nine(23.1%). Among the 29 burst fracture cases examined by CT, posterior bony injuries were detected in 13(44.8%). Lamina and facet joint fractures were detected in six cases(20.7%), facet separation or dislocation in six(20.7%), and spinous process and pedicle fracture in one(3.4%). In 29 burst fracture cases, both MRI and CT were performed. Among the 18 cases in which MR imaging revealed posterior ligamentous injuries, CT failed to demonstrate posterior element fractures in seven. On the other hand, among the 13 cases in which CT indicated posterior bony fractures, MR failed to reveal posterior ligamentous injuries in two. CONCLUSION: Posterior element injury is frequently found in patients with traumatic thoraco-lumbar burst fractures demonstrated by MR imaging(46.2%) and CT(44.8%). Both MRI and CT are useful tools for the evaluation of posterior element injury, which determines the degree of instability of traumatic burst fracture.
Dislocations ; Female ; Hand ; Humans ; Ligaments ; Magnetic Resonance Imaging ; Male ; Retrospective Studies ; Zygapophyseal Joint

Benign tumors of the trachea are rare, accounting for approximately 10% of all primary tracheal neoplasms. They are frequently misdiagnosed and managed as bronchial asthma or chronic bronchitis. We report a lipoma and a leiomyoma of the trachea with emphasis on the clinical, radiographic and CT findings, and review the literature.
Asthma ; Bronchitis, Chronic ; Leiomyoma ; Lipoma ; Trachea* ; Tracheal Neoplasms

Benign tumors of the trachea are rare, accounting for approximately 10% of all primary tracheal neoplasms. They are frequently misdiagnosed and managed as bronchial asthma or chronic bronchitis. We report a lipoma and a leiomyoma of the trachea with emphasis on the clinical, radiographic and CT findings, and review the literature.
Asthma ; Bronchitis, Chronic ; Leiomyoma ; Lipoma ; Trachea* ; Tracheal Neoplasms

PURPOSE: This study validated the musculoskeletal model of the human lower extremity by comparative study between calculated muscle parameters through simulation using modified hill-type model and measured muscle parameters through isokinetic exercise. The relationship between muscle forces and moments participated in motion was quantified from the results of simulation. MATERIALS AND METHODS: For simulation of isokinetic motion, a three-dimensional anatomical knee model was constructed using gait analysis. The EMG-force model was used to determine muscle activation level exciting muscles. The modified Hill-type model was used to calculate individual muscle force and moment in dynamic analysis. This method was validated by comparing analytical data with experimental data. RESULTS: The results showed that there was a significant correlation between calculated torques from simulation and measured torque from isokinetic motion experiments (R=0.97). We also found that muscle forces and moments during knee flexion and extension have nonlinearly proportional or inversely proportional relationship, since lower extremity muscles were simultaneously involved in flexion/extension motion and inner/outer rotation. CONCLUSION: We concluded that the simulation by using musculoskeletal model may be a useful mean to predict and recover musculoskeletal-related diseases, and analyze complicated experiment such as clash condition.
Gait ; Humans ; Knee Joint* ; Knee* ; Lower Extremity ; Muscles ; Torque

PURPOSE: To assess the patterns of myelodysplastic syndrome(MDS) and aplastic anemia(AA) on MRI of the spinal bone marrow and to find the differential points between the two groups. MATERIALS AND METHODS: Fourteen patients with MDS(n=7) and AA(n=7) were studied using magnetic resonance imaging. Sagittal images from the lower thoracic and lumbar vertebral marrow were evaluated on Tl-weighted and STIR images. Five distinct patterns of signal intensity of the Tl-weighted and STIR images were classified. T1 and T2 relaxation times and T1 marrow/fat signal intensity ratio were measured and analyzed (t-test). The cellularity of bone marrow was evaluated on histologic slides. RESULTS: MDS showed homogeneously low signal intensity on T1WI and high signal intensity on STIR image, indicating hypercellular marrow, whereas AA showed relative high signal intensity on T1WI and low signal intensity on STIR image, representing fatty marrow. T1 and T2 relaxation time(T1 for MDS=750.26msec +/- 177.50, T1 for AA= 413.21 msec +/- 167.39 (p<0.000), T2 for MDS=91.86 msec +/- 14.16, T2 for AA=81.44msec +/- 15.31 (p< 0.001) and T1 marrow/fat signal intensity ratio(0.22 +/- 0.048 in MDS, 0.30 +/- 0.083 in AA(p<0.000)) revealed statistically significant difference between the two groups. CONCLUSION: Although the marrow aspiration and needle biopsy are mandatory in hematologic disease for diagnosis, there are limited in assessing the change of total marrow mass. Therefore MRI of bone marrow might be useful in distinguishing MDS from AA because of its ability of representation of total marrow mass.
Anemia, Aplastic* ; Biopsy, Needle ; Bone Marrow ; Diagnosis ; Diagnosis, Differential* ; Hematologic Diseases ; Humans ; Magnetic Resonance Imaging* ; Myelodysplastic Syndromes* ; Relaxation

PURPOSE: To assess the patterns of myelodysplastic syndrome(MDS) and aplastic anemia(AA) on MRI of the spinal bone marrow and to find the differential points between the two groups. MATERIALS AND METHODS: Fourteen patients with MDS(n=7) and AA(n=7) were studied using magnetic resonance imaging. Sagittal images from the lower thoracic and lumbar vertebral marrow were evaluated on Tl-weighted and STIR images. Five distinct patterns of signal intensity of the Tl-weighted and STIR images were classified. T1 and T2 relaxation times and T1 marrow/fat signal intensity ratio were measured and analyzed (t-test). The cellularity of bone marrow was evaluated on histologic slides. RESULTS: MDS showed homogeneously low signal intensity on T1WI and high signal intensity on STIR image, indicating hypercellular marrow, whereas AA showed relative high signal intensity on T1WI and low signal intensity on STIR image, representing fatty marrow. T1 and T2 relaxation time(T1 for MDS=750.26msec +/- 177.50, T1 for AA= 413.21 msec +/- 167.39 (p<0.000), T2 for MDS=91.86 msec +/- 14.16, T2 for AA=81.44msec +/- 15.31 (p< 0.001) and T1 marrow/fat signal intensity ratio(0.22 +/- 0.048 in MDS, 0.30 +/- 0.083 in AA(p<0.000)) revealed statistically significant difference between the two groups. CONCLUSION: Although the marrow aspiration and needle biopsy are mandatory in hematologic disease for diagnosis, there are limited in assessing the change of total marrow mass. Therefore MRI of bone marrow might be useful in distinguishing MDS from AA because of its ability of representation of total marrow mass.
Anemia, Aplastic* ; Biopsy, Needle ; Bone Marrow ; Diagnosis ; Diagnosis, Differential* ; Hematologic Diseases ; Humans ; Magnetic Resonance Imaging* ; Myelodysplastic Syndromes* ; Relaxation