High resolution MR imaging of the bilateral hips with dual phased-array coil

We applied dual-flex coils in a phased-array configuration to obtain high resolution MR images of the bilateral hips and compared the image quality with non-phased-array imaging. Multiple fast spin-echo images of both hips were obtained in a single acquisition. Two consecutive acquisitions with and without phased-array capability were performed in 22 hips and a fluid-filled phantom. The signal-to-noise ratio (S/N) enhancement values were calculated. Subjective image analysis was also obtained from three independent reviewers. High quality MR images were obtained using dual-array coils with a S/N enhancement value of 1.40 for a phantom and 1.83 to 2.22 for subject hips. On subjective analysis, the dual array enhanced delineation of the acetabular labrum, articular cartilage, and retained fluid. The dual array may be of diagnostic value with a higher S/N enhancement and subjective superiority of the images obtained.     

Delayed postcontrast CT and MR imaging of chondroid chordoma--case report.

A rare case of intracranial primary chondroid chordoma is reported with special reference to neuroradiological findings. A precontrast computed tomographic (CT) scan revealed an isodense mass with multiple flecks in the right cerebellopontine region. A postcontrast CT scan showed slight ring enhancement. A delayed postcontrast CT scan demonstrated marked homogeneous enhancement extending from the middle cranial fossa to the cerebellopontine region on the right. Magnetic resonance (MR) imaging demonstrated a well-defined lesion as a high-intensity mass on T2-weighted image and a low-intensity mass on T1-weighted image. A MR image 5 minutes after gadolinium-diethylenetriaminepenta-acetic acid administration showed heterogeneous enhancement. A MR image 30 minutes after the contrast administration showed more marked, homogeneous enhancement. Such delayed postcontrast CT and MR imaging are useful in the differentiation of chondroid chordoma from classical chordoma.     

Increase of bone volume in vitamin D-repleted rats by massive administration of 24R,25(OH)2D3

Summary A large dose of 24R,25(OH)₂D₃ was administered to the vitamin D-repleted rat to examine its effect on the bone. Male Wistar rats were fed a diet containing 0, 0.025, 1.25, 4.0, and 12.5 ppm 24R,25(OH)₂D₃ for 2 years starting at age 6 weeks. The estimated amounts of daily intake of 24R,25(OH)₂D₃ were 0, 93, 4640, 14680, and 49580 ng/100 g body weight, respectively. No notable difference was found in either the weight or the death rate of the animal. The long-term administration of massive doses of 24R,25(OH)₂D₃ did not lead to hypercalcemia nor did it affect the blood phosphorus, alkaline-phosphatase, or creatinine levels. Radiographs revealed a striking increase in the bone density on the bones from the animals treated with 1.25 ppm or more 24R,25(OH)₂D₃. Direct single photon absorptiometry revealed a dose-dependent increase in total bone minerals of both the femur and coccyx. Histological examination revealed a marked increase in the cortical thickness of the femur as well as in the cancellous bone volume of the coccyx. Polarizing microscopy demonstrated the lamellar structure of the bone, and undecalcified sections confirmed the increase of mineralized bone. Ash weight, calcium, phosphorus, and magnesium contents on the tibia and fibula also indicated the ascending dose-dependent increase up to 150% of the control. The parameters of bone size were not altered in any group. These results clearly suggest that 24R,25(OH)₂D₃ given in massive doses has the pharmacological action of increasing bone volume in the rat without causing remarkable hypercalcemia.     

Analysis of thallium-201 myocardial SPECT images using fuzzy set theory

Using the fuzzy set theory, a method was developed for analyzing the extent and severity of ischemia by comparing the exercise and delayed SPECT images with Thallium-201. For each short axial image (slice) for exercise and delayed study, a defect probability matrix (DPM) is created so that it shows the severity of ischemia of myocardium in that slice. Each slice is divided into 8 equi-angle sectors, and the left ventricle (LV) also is divided into 8 equi-angle vertical sectors from apex to base. Using DPMs, the defect probability is calculated for each slice, sectors of each slice and vertical sectors of the LV. The results are displayed on a CRT by means of images, curves and histograms. They show what percentage of the area of each slice and that of the lateral, anterior, septum and inferior portions have how much defect. They provide comprehensive and easily understood information about the condition of the LV in exercise and delayed stages. Persistent and transient ischemia can be diagnosed by visual comparison of patients' curves and histograms with their corresponding normal limits.     

Clinical characteristics and prognosis of secondary amyloidosis in patients with rheumatoid arthritis--renal involvement and therapy]

Secondary amyloidosis is an important complication that may have a strong influence on the prognosis of patients with rheumatoid arthritis (RA). We studied 21 RA patients with secondary amyloidosis. The two major initial signs were gastrointestinal symptoms and renal involvement. When 15 of the 21 patients were diagnosed as having secondary amyloidosis, they displayed renal involvement including proteinuria, hematuria and hypercreatininemia. The 15 patients with amyloidosis were either subjected to dialysis or died within 35 months on the average. The causes of death in 13 patients were cardiac failure, gastrointestinal bleeding and infection, which were strongly implicated with renal failure. Dialysis was applied to seven patients. Three of them were maintained with chronic dialysis. We discussed the induction-time and the method of dialysis in patients with amyloidosis secondary to RA.     

Assessment of regional and transmural myocardial perfusion by means of intraoperative myocardial contrast echocardiography during coronary artery bypass grafting.

By using intraoperative myocardial contrast echocardiography, we assessed regional myocardial perfusion and transmural blood flow distribution immediately after myocardial revascularization. A total of 62 revascularized myocardial areas were studied in 31 patients undergoing coronary artery bypass grafting. The revascularized areas were divided into three different areas: S area, supplied by significantly stenosed coronary arteries (43 areas); C area, supplied by coronary collateral situation associated with totally occluded coronary arteries (12 areas); MI area, preexisting transmural myocardial infarction (7 areas). Myocardial contrast echocardiography was obtained by direct injection of 2 ml of sonicated 5% human albumin into the saphenous vein grafts at rest and during atrial pacing. Each area was divided into two layers of endocardial and epicardial halves, and myocardial enhancement of peak intensity was measured for each half and endocardial/epicardial gray level ratio was calculated: (1) The peak intensity of myocardial enhancement in S area and C area was significantly higher than that in MI area at rest as well as during pacing after myocardial revascularization. There was no significant difference in the peak intensity between S area and C area both at rest and during pacing. In S area the peak intensity significantly increased during pacing (p < 0.01), whereas it did not change in C area and MI area. (2) S area demonstrated no significant change in endocardial/epicardial intensity ratio during pacing. In contrast, the ratio in C area significantly decreased during pacing. (3) In S area with preoperative percent increase of segmental wall thickening lower than 25%, there was a significant correlation (r = 0.84, p < 0.001) between the peak intensity of myocardial enhancement and the postoperative changes of percent increase of segmental wall thickening in the revascularized areas. Thus, immediately after myocardial revascularization, intraoperative myocardial contrast echocardiography could provide a quantitative assessment of regional myocardial perfusion as well as blood flow distribution in the areas with myocardial infarction and with coronary collateral situation and in the areas supplied by stenosed coronary arteries.     

Intramuscular myxoma with fibrous dysplasia: A report of two cases with a review of the literature

Two cases are reported of a rare association of intramuscular myxoma with fibrous dysplasia in a 70 and 40 year old Japanese woman, respectively. One of them had a solitary intramuscular myxoma, and the other patient suffered from two intramuscular tumors that had been initially misdiag-nosed as myxoid liposarcoma. Only 24 cases of this kind of association have been recorded in the literature. This association should be taken into consideration to avoid inappropriate treatment, when cases of myxoid soft tissue tumor with a bone lesion are encountered.     

Effects of 3 months of non-weight-bearing cycle ergometric exercise on bone metabolism

We evaluated the effect of non-weight-bearing exercise on bone metabolism by measuring serum levels of biochemical markers, N-terminal osteocalcin (OC), and intact OC. N-terminal assay using the radioimmunoassay (RIA) method is considered to be a marker of bone turnover. Intact OC was measured as a marker of bone formation by the sandwich enzyme-linked immunosorbent assay (ELISA) method. As is commonly known, the cycle ergometer is a very popular and useful tool for aerobic exercise used world wide to improve health. In this study, we evaluated the effect of such common exercise on N-terminal OC and intact OC using a cycle ergometer. N-terminal OC was not significantly changed after 30min of aerobic training with a cycle ergometer three times a week for 3 months, whereas intact OC decreased significantly. No changes in bone mineral density of weight-bearing or non-weight-bearing bones were found. These results suggest that the type and duration of exercise using the current training method were insufficient to produce a favorable effect on bone. The current training method consisted of aerobic, non-weight-bearing exercise alone using a cycle ergometer. It is unknown whether the non-weight-bearing form of exercise was responsible for our results, or whether the aerobic exercise itself was insufficient. The 3-month period may have been insufficient to stimulate osteogenesis, and it is possible that an exercise period of this duration may instead result in a tendency to suppress bone formation. At any rate, we believe it is significant that we were able to demonstrate, on the basis of changes in bone metabolism markers and bone mineral density, that the nature of this exercise was insufficient to stimulate osteogenesis.     

Cerebral cysticercosis: A case report

A case of cerebral cysticercosis is reported in a 49-year-old female who presented with headache, nausea, and vomiting. Lumbar CSF showed the findings of mild aseptic meningitis. CT scan revealed an enlargement of the left ambient cistern and a small cystic lesion in the left frontal cortex. MRI demonstrated multilobular cysts in the left ambient cistern with enhancement of their capsules, which compressed and distorted the midbrain. The cysts were surgically excised, and histological examination of the specimen disclosed characteristic features of cysticercus with viable larva. An excellent value of MRI in the diagnosis of intracisternal cysticercosis is emphasized.