To find any specific radiologic findings of skeletal metastases from hepatocellular carcinoma, we analyzed plain radiographs(n=25), CT(n=16) and MRI(n=5)of 25 patients with metastatic bony lesions from hepatocellular carcinoma. Vertebrae(17/25) and rids(16/25)were most frequently involved and 16 cases showed multiple metastases. The size of the lesions was larger than 5cm in 17 cases. Plain radiographs showed osteolytic destruction(2/25). CT(n=16) showed osteolytic destruction with an isodense expansile mass in all cases. Focal low attenuations suggesting necrosis were found in 2 cases. Calcification within the mass was not detected. MRI(n=5) showed a slight hyperintense area on T1WI and a defimte hyperintense mass on T2WI. After gadopentetate dimeglumine enhancement. The mass showed irregular enhancement. We concluded that skeletal metastatic lesions from hepatocellular carcinoma showed relatively large osteolytic destruction accompanying soft tissue mass and minimum central necrosis.
Carcinoma, Hepatocellular* ; Gadolinium DTPA ; Humans ; Necrosis ; Neoplasm Metastasis*

Detection and evaluation of early soft tissue changes are important in rheumatoid arthritis or other jointdiseases. The most important factors for radiologic demonstration of soft tissue changes are resolving power andthe optimization of contrast differences between structures representing skin and subcutaneous tissue densities.Phantom study was done by using combination of immersion technique and mammography to get the most reliable methodfor improvement of soft tissue contrast without deterioration of resolution. Clinical application was also done in5 normal volunteers and 5 rheumatoid patients. The results indicate that soft tissue contrast, especially betwenskin and subcutaneous tissues can be significantly imporved with combination of immersion technique andmammography with 50% ethanol in both phantom and clinical study.
Arthritis, Rheumatoid ; Clinical Study ; Ethanol ; Healthy Volunteers ; Humans ; Immersion ; Mammography ; Radiography ; Skin ; Subcutaneous Tissue

PURPOSE: To describe the magnetic resonance (MR) findings of pigmented villonodular synovitis(PVNS) of the knee, and to evaluate the clinical value of MR in the diagnosis of PVNS. MATERIALS AND METHODS:MR imagings of seven patients with PVNS were studied. The type of lesion, presence of bony erosion, the signal intensity, and the relationship between contrast enhancement and signal intensity on T2-weighted images were analyzed, retrospectively. RESULTS: The lesion was mainly villous in three patients and nodular in four, and bony erosion was seen in one patient. On T2-weighted image, the signal intensity of the villous form was mixed iso- and hypointense in two, hypointense in one, and that of the nodular form was heterogeneous with hypo-, iso-, and hyperintensities. The hypointense portion on T2-weighted image showed poor contrast enhancement, which may suggest hemosiderin deposition or advanced fibrosis. The iso- or hyperintense portion on T2-weighted image showed strong enhancement, which suggest active cellular proliferation. CONCLUSION:MR imaging could be a very useful modality in the diagnosis as well as prediction of histological findings of the PVNS.
Cell Proliferation ; Diagnosis ; Fibrosis ; Hemosiderin ; Humans ; Knee* ; Magnetic Resonance Imaging* ; Retrospective Studies ; Synovitis, Pigmented Villonodular*

PURPOSE: To describe the MR characteristics of giant cell tumor of bone. MATERIALS AND METHODS: MR iraagings of 15 cases of pathologically proved giant cell tumor were retrospectively analyzed. Signal intensity and homogeneity, involvement of articular surface, low signal intensity rim around the tumor, cortical disruption and soft tissue involvement were evaluated. RESULTS:Tumor showed low signal intensity on T1 weighted images(93%), inhomogenous high signal on T2 or T2* weighted images(93%) and inhomogeneous enhancing pattern(88%). In 11 cases of giant cell tumor of long bones, all cases showed involvement of articular margin and 10 cases(90%) showed rim of low signal intensity between tumor and normal marrow. Disruption of cortical bone(25%) and soft tissue involevement(7%) were also demonstrated. CONCLUSION: We concluded that giant cell tumor showed characteristic MR findings could be helpful in making correct diagnosis.
Bone Marrow ; Diagnosis ; Giant Cell Tumor of Bone ; Giant Cell Tumors* ; Giant Cells* ; Retrospective Studies

PURPOSE: To assess the spinal canal and neural foraminal stenosis associated with spondylolisthesis on MR imaging. MATERIALS AND METHODS: We retrospectively analysed MR findings of 63 cases of spondylolisthesis(degenerative type:23 cases, isthmic type:40 cases) regarding the type and grade of spondylolisthesis, prensence or absence of associated spinal canal stenosis, and the severity of associated neural foraminal stenosis. RESULTS: Central canal stenosis were more frequent in degenerative type(91%) than isthmic type(33%), and more frequent in grade II spondylolisthesis of degenerative type(100%) and isthmic type(89%) than in grade spondylolisthesis of degenerative type(45%) and isthmic type(20%). There was positive correlation between the severity of neural foraminal stenosis and the grade of spondylolisthesis, whereas there was no significant difference between degenerative and isthmic types. CONCLUSION: Degenerative spondylolisthesis were frequently associated with central canal stenosis more than isthmic type. When the grade of spondylolisthesis was higher, it was more frequently associated with central canal stenosis and severe neural foraminal stenosis.
Constriction, Pathologic* ; Magnetic Resonance Imaging ; Retrospective Studies ; Spinal Canal ; Spondylolisthesis*

This study was designed to evaluate the potential applicability of magnetic resonance imaging (MRI) for the diagnosis of acute renal vein thrombosis. Renal vein thrombosis was experimentally induced by surgical ligation of the left renal vein in a total of 21 rabbits. MRI was performed with a 0.5 Tesla superconductive magnetic system. Spin echo technique was used with varying TR and TE parameters. Spin echo images of the rabbit kidney were analysed for morphology and signal intensity. T1 and T2 relaxation times of the renal cortex and medulla were calculated from the images. After venous ligation, kidneys became enlarged. Low signal band along the outer medulla in T2 weighted images were characteristically shown from 1 hour to 3 days after ligation, Changes of cortex to medullar contrast (CMC) values were significant (p<0.05) in T1 - and T2- weighted images of the ligated side. T1 and T2 relaxation times were significantly prolonged (p<0.05) on the ligated side, both in the cortex and medulla from 1 hour to 2 weeks after the ligation, while T2 relaxation time on the contralateral side was significantly prolonged both in the cortex and medulla 2 weeks after venous ligation. The most useful MRI criteria for the diagnosis of renal vein thrombosis were enlarged renal size, and the low signal band along the outer medulla of ligated kidney. The relative intensity difference between cortex and medulla (CMC) in T1-and T2-weighted images, and T1 and T2 relaxation times were suggested to be the useful MR parameters for the diagnosis of acute renal vein thrombosis.
Diagnosis ; Kidney* ; Ligation* ; Magnetic Resonance Imaging* ; Rabbits ; Relaxation ; Renal Veins* ; Thrombosis

This study was designed to evaluate the potential applicability of magnetic resonance imaging (MRI) for the diagnosis of acute renal vein thrombosis. Renal vein thrombosis was experimentally induced by surgical ligation of the left renal vein in a total of 21 rabbits. MRI was performed with a 0.5 Tesla superconductive magnetic system. Spin echo technique was used with varying TR and TE parameters. Spin echo images of the rabbit kidney were analysed for morphology and signal intensity. T1 and T2 relaxation times of the renal cortex and medulla were calculated from the images. After venous ligation, kidneys became enlarged. Low signal band along the outer medulla in T2 weighted images were characteristically shown from 1 hour to 3 days after ligation, Changes of cortex to medullar contrast (CMC) values were significant (p<0.05) in T1 - and T2- weighted images of the ligated side. T1 and T2 relaxation times were significantly prolonged (p<0.05) on the ligated side, both in the cortex and medulla from 1 hour to 2 weeks after the ligation, while T2 relaxation time on the contralateral side was significantly prolonged both in the cortex and medulla 2 weeks after venous ligation. The most useful MRI criteria for the diagnosis of renal vein thrombosis were enlarged renal size, and the low signal band along the outer medulla of ligated kidney. The relative intensity difference between cortex and medulla (CMC) in T1-and T2-weighted images, and T1 and T2 relaxation times were suggested to be the useful MR parameters for the diagnosis of acute renal vein thrombosis.
Diagnosis ; Kidney* ; Ligation* ; Magnetic Resonance Imaging* ; Rabbits ; Relaxation ; Renal Veins* ; Thrombosis

PURPOSE: To assess the role of blood vessels in the formation of peritumoral abnormal signal intensity which exaggerates the size of malignant tumor on MR images. MATERIALS AND METHODS: We performed MR-microangiographic-pathologic correlation using implanted VX-2 carcinoma in 16 rabbit thighs 1-28 days after tumor implantation. The shape and distribution of abnormal vessels were analyzed on microangiography and on histologic examination in correlation with peritumoral abnormal signal intensity on MR images. RESULTS: Dilated peritumoral blood vessels gave rise to irregular, tortuous tumor vessels penetrated into the tumor. With the tumor growth, hypervascular tumor vessels in peritumoral area and central avascular areas were increased. These hypervascular areas on microangiography were corresponded with abnormal signal intensity on MR images. CONCLUSION: Hypervascularity could be a cause of peritumoral abnormal signal intensity which exaggerates the size of experimentally induced malignant musculoskeletal tumors on MR images.
Blood Vessels* ; Thigh

To evaluate the radiographic characteristics of osteochondritis dissecans (OCD) and useful parameter for predicting mechanical stability, we retrospectively analysed 26 plain radiographic examinations and seven MR imagings in 28 cases of OCD in 24 patients. Typical radiologic findings were osteochondral defect with sclerotic rim of variable thickeness and osteochondral fragment. Sites of osteochondral defect were medial (35.9%) or lateral (32%) femoral chondyle and medial (7.1%) or lateral (25%) side of talar dome. Sclerotic rim was seen in 24 cases (85%) and osteochondral fragments including nine loose bodies were seen in 21 cases (75%). The size of osteochondral defect with unstable fragment (average 2.05cm) and loose body (2.04cm) in the knee joint were similar to, but statistically larger than that with stable fragment (1.35cm). All osteochondral defects were well visualized on MR images. Abnormalities of articular cartilage and effusion in the interface between the parent bone and fragment were seem in five cases of which there were confirmed three unstable cases arthroscopically. We conclude that size of defect may be a good parameter for predicting mechanical stability and MRI may be useful in the diagnosis of OCD and determining the methods of treatment.
Cartilage, Articular ; Diagnosis ; Humans ; Knee Joint ; Magnetic Resonance Imaging ; Osteochondritis Dissecans* ; Osteochondritis* ; Parents ; Retrospective Studies

PURPOSE: To determine the plain film findings of acute neuropathic joint in diabetic foot. MATERIALS AND METHODS: Acute neuropathic joint in diabetic foot was considered when fragmentation of the articular ends of bone and subluxation of the affected joint developed within eight weeks after clinical onset of diabetic gangrene. Eight toes of six diabetics were satisfactory to our criteria. We analyzed plain radiographic findings of the affected joint and soft tissue, interval changes in follow-up radiographs, and deformities after healing. RESULTS: The time interval between clinical onset of gangrene and bone destruction ranged from 2 weeks to 4 weeks(mean 2.6 weeks). Plain radiographs showed fragmentation of the articular ends, subluxation, and soft tissue swelling of the metatarsophalangeal joint or interphalangeal joint. The significant feature of these patients was rapid progression of the lesions. Clinically, all patients had diabetic gangrene in affected toes, however, there was no evidence of osteomyelitis in our series. Amputation was done in 2 cases, and lesions in 3 of the remaining 4 cases were repaired spontaneously with regression of gangrene, leaving radiological residua such as pointed-end, tapered-end, and ball and socket deformity. CONCLUSION: Rapid disorganization of the joint with associated evidence of soft tissue gangrene in plain radiograph is believed to be valuable for the diagnosis of diabetic osteoarthropathy.
Amputation ; Congenital Abnormalities ; Diabetic Foot* ; Diagnosis ; Follow-Up Studies ; Gangrene ; Humans ; Joints* ; Metatarsophalangeal Joint ; Osteomyelitis ; Toes