Macrodystrophia lipomatosa. MR imaging in three patients.

Radiographs and magnetic resonance (MR) imaging of three patients with macrodystrophia lipomatosa are presented. Radiographs of involved extremities and digits demonstrated prominent soft tissues and bony hypertrophy. MR images showed hypertrophy of fatty tissue, cortical bone thickening and fatty infiltration of muscle.

A huge osteoblastoma with aneurysmal bone cyst in skull base.

We reported a case of a huge osteoblastoma in the skull base of a young girl who had developed blindness in her right eye 1 year prior to examination. CT showed a large expansile bony lesion with eggshell margin over the skull base. MR imaging showed mixed solid and cystic parts with multiple fluid-fluid levels in the lesion. The optic chiasma and bilateral optic nerves were severely compressed by the tumor.

MRI appearance of spinal lesions: metastatic tumors or infections?

Three patients with pathologically verified spinal osteomyelitis and another three with metastatic tumors of the spine were investigated. MRI of th spine of four patients showed several unusual findings. The preservation of intervertebral discs and endplates did not predict accurately the diagnosis of either infections or tumors. The "pepper and salt" appearing feature may also occur in a metastatic tumor. Plain radiographs, CT, and radioisotope bone scans were less sensitive than MRI to disclose the lesions. In cases of osteomyelitis, the systemic sources of infections were frequently not found, and the responsible microorganisms could not be identified even from the surgical specimens of two patients. However, mycobacterium tuberculosis was found in the surgical specimen of a patient with cervical spinal lesion whose MRI was indistinguishable from a metastatic tumor. Surgicopathological diagnosis was therefore crucial and mandatory in these instances.

Magnetic resonance imaging of Ebstein's anomaly: report of two cases.

Among 388 cases of congenital heart disease with magnetic resonance imaging (MRI) from September 1990 to February 1992, we came across two cases of Ebstein's anomaly. They had been previously diagnosed as Ebstein's anomaly by echocardiography and cinecardioangiography. The first case was a three-year-old boy with complex congenital heart disease that included Ebstein's anomaly, a double-outlet right ventricle, pulmonary hypertension, tricuspid regurgitation, mitral regurgitation, a ventricular septal defect and an atrial septal defect. The second was a 13-year-old boy who also had Ebstein's anomaly, but had received a tricuspid valve replacement at the age of five. In Ebstein's anomaly, we found that MRI offers exquisite endocardial and epicardial details. We anticipate that in the future MRI will help to eliminate invasive studies.

Magnetic resonance imaging of acoustic schwannomas.

The magnetic resonance imaging (MRI) findings of 27 histologically proven acoustic schwannomas in 24 patients (13 men, 11 women, age 20-79 yr) are described in detail. Three patients had bilateral tumors. Twenty-two tumors (82%) had intra- and extracanalicular components, three tumors (11%) were limited to the internal auditory canal (IAC) and two tumors (7%) were limited to the cerebellopontine angle (CPA). The diameters of extracanalicular lesions in the CPA ranged from 12 to 50 mm, and most of them were round in shape. All IAC portions of CPA tumors had a funnel-shaped appearance on the axial images and short-club-shaped configuration on the coronal images. There was strong homogeneous contrast enhancement of the solid components in 12 tumors (44%) and heterogeneous enhancement in 15 tumors (56%). The cystic components of the tumors correlated well with the histologic features. All tumors could be demonstrated in their enterity by MRI. The "short-club sign", first described in this study, helped to confirm the intracanalicular component of acoustic schwannomas, which were usually found in the cerebellar cistern. The results of this study show that MRI is a sensitive imaging modality for the assessment of acoustic schwannomas located at the CPA or IAC, or in both regions. MRI is non-invasive and does not involve ionizing radiation. It should be considered the imaging examination of choice to evaluate patients with suspected acoustic schwannomas.

Computed tomography and magnetic resonance imaging of diffuse pigmented villonodular synovitis: report of a case.

We describe the computed tomographic (CT) and magnetic resonance imaging (MRI) features of a surgically proven case of diffuse pigmented villonodular synovitis (PVNS) of the knee in a 34-year-old woman. A complex mass consisting of solid and multicystic components was clearly demonstrated by CT and MRI. The solid part showed homogeneous hypodense attenuation relative to adjacent muscles on CT scans, but it showed inhomogeneous signal intensity on spin echo T1- and T2-weighted images (WI). The solid component enhanced homogeneously on CT scans but heterogeneously on MR images. Multiseptated enhancement of the cystic component on both CT and MR images were displayed. All of the above features were better demonstrated on MRI. Multiple marked hypointense round and patchy areas, and also a few areas isointense to subcutaneous fat within the lesion were also found on T1WI, proton density WI and T2WI. These characteristic MRI features of PVNS correlated well with its histologic structures: depositions of hemosiderin and fat in the proliferative synovial villi and bloody cystic content. These features may help to distinguish PVNS from other disease entities arising from the synovium.

Staging of cervical cancer: comparison between magnetic resonance imaging, computed tomography and pelvic examination under anesthesia.

A prospective study was undertaken to compare magnetic resonance imaging (MRI) with computed tomography (CT) and examination under anesthesia (EUA) in staging cervical carcinoma, with special emphasis on parametrial status. Twenty patients with carcinoma of the cervix, in whom the extent of the disease was surgically confirmed, were analyzed by MRI, CT and EUA. The tumor size estimated by MRI correlated well (r = 0.79, p < 0.001) with those obtained by histopathologic measurement of the surgical specimen. Neither clinical examination nor CT could precisely estimate tumor size. The overall accuracy rate of MRI in staging carcinoma of the cervix was 75%, compared with 32% for CT staging and 55% for clinical staging. The accuracy rate of these modalities for parametrial status was 90% for MRI, 55% for CT and 82.5% for EUA. MRI accurately excluded all 20 patients with pelvic side wall, bladder and rectal involvement. In conclusion, MRI is superior to CT and EUA in assessment of the parametrium (90% vs 55% vs 82.5%, p < 0.005). From MRI, tumor size can be estimated precisely. Although a larger scale study comparing MRI and CT is needed to determine their roles, both should help in the diagnosis and selection of proper treatment for cervical carcinoma. Our preliminary report agrees with previous reports that MRI is promising and indispensable. MRI should be routinely used in conjunction with clinical staging to determine appropriate therapy in patients with cervical carcinoma.

Spinal cord herniation after stabbing injury.

A 19-year-old man presented with delayed paraplegia on the second day after a stab injury of the spine. Magnetic resonance imaging showed herniation of the spinal cord through the dural defect. After emergency surgery, his paraplegia recovered leaving a Brown-Sequard syndrome immediate after injury. Spinal cord herniation should be considered as one of the possible factors in patients developing neurological deterioration after a stab injury of the spine. The possible pathogenesis of symptomatic non-spontaneous spinal cord herniation is discussed.

Intensification of relative myocardial T2-weighted magnetic resonance signals in patients with acute viral myocarditis: report of one case.

A 10-year-old girl was admitted to our hospital because of frequent attacks of syncope over a period of two days. A physical examination, electrocardiogram, echocardiograms and a cardiac enzyme study concluded that the girl was likely to be suffering from acute viral myocarditis. Intensities of the T2-Weighted magnetic resonance signals between the myocardium and the trapezius muscle of this patient on the first, the eighth, and the twenty-eighth hospital day were 5.1, 7.8, and 3.6 respectively. These values were significantly higher than the values of seven other patients without a history of acute viral myocarditis. Therefore, we concluded that the myocardial T2-weighted signal did intensify in patients with acute viral myocarditis.

Giant ossified cavernous hemangioma of an extremity associated with an equinovarus deformity.

A 39-year-old woman suffered from swelling and tenderness of the right leg for 31 years. Imaging studies showed a large soft tissue lesion on the right side extending from the proximal portion of the thigh to the ankle. She underwent several operations due to the leg mass and associated equinovarus deformity of the right ankle. The pathologic findings were those of an ossified cavernous hemangioma. This appears to be one of the largest hemangiomas to be reported. It revealed the three types of calcification characteristic of hemangiomas. Equinovarus deformity of the ankle caused by contracture of the calf in this case was probably related to repeated bleeding.

Phenotypic heterogeneity in a Chinese family with mitochondrial disease and A3243G mutation of mitochondrial DNA.

The A3243G mutation of mitochondrial DNA (mtDNA) has been shown to be responsible for or associated with mitochondrial myopathy, encephalopathy, lactic acidosis, strokelike episodes (MELAS) syndrome, diabetes mellitus (DM) and several other neuromuscular diseases. We used polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) to identify the A3243G mtDNA mutation and an electron microscope to examine mitochondrial derangement in the muscle biopsies of a 38-year-old man suspected to have MELAS syndrome with DM. We found great variability in the clinical presentation and in the proportion of mtDNA with the A3243G mutation in the matrilineal family members of the patient. The proband had atypical MELAS syndrome, recurrent vascular headache, and DM (MELASDM), and his mother manifested chronic progressive ptosis and DM (CPPDM). Brain magnetic resonance imaging of the proband showed high signal intensity in the left temporoparieto-occipital area on T2 weighted images (T2WI). The blood lactate level ranged from 2.32 to 4.70 mmol/l, and two-hour postprandial glucose ranged from 124 mg/dl to 148 mg/dl. The blood lactate and postprandial glucose of the proband's mother were 3.15 mmol/l and 192 mg/dl, respectively. Electron microscopic examination of a muscle biopsy of the patient showed abnormal mitochondria with decreased density of cristae and membrane degeneration. No ragged-red fibers were detected in muscle upon staining with modified Gomori trichrome. The hair follicles and blood cells of the patient and his mother showed the A3243G mutation in the tRNA(Leu)(UUR) gene. The proportions of the mutant DNA in the hair follicles and blood cells of the proband were 36.8% and 35.2%, respectively, and those of the patient's mother were 28.8% and 13.9%, respectively. We conclude that the A3243G mtDNA mutation may manifest with MELASDM or CPPDM in different matrilineal members of the same family as a result of differences in random segregation of the heteroplasmic A3243G mutant mtDNA in the affected tissues of patients.