[Studies on utilisation of diketene. I. Synthesis of alpha-amino acids].
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Alkenes↗
Biomedical subjects
M Yamato
Publications and source records attributed to M Yamato.
Abnormal synovium in the frozen shoulder: a preliminary report with dynamic magnetic resonance imaging.
We studied 16 patients (18 shoulders) with frozen shoulders, 8 patients with subacromial impingement syndrome, and 3 healthy volunteers with dynamic magnetic resonance imaging enhanced with gadolinium diethylenetriaminepentaacetic acid. After intravenous contrast was administered, gradient-recalled echo images were obtained in the oblique coronal plane every 11 to 13 seconds for a total period of 4 to 5 minutes. The signal intensity was measured at the periphery of the glenohumeral joint and in the subacromial bursa. The coefficient of enhancement (percent signal increase per second) in the frozen shoulders was 1.33 +/- 0.43 (mean +/- SD) for the glenohumeral joint and 0.89 +/- 0.47 for the subacromial bursa. These values were far greater than those in subacromial impingement syndrome or in the control group, indicating increased blood flow to the synovium in the frozen shoulders. No previous reports have shown a clinical measure related to the pathophysiology of this disease.
Adult↗
Computed tomography of fatty replacement in extramedullary hematopoiesis.
A case of thoracic extramedullary hematopoiesis with a large fatty component presented a unique CT appearance that has not been previously reported.
Adipose Tissue↗
CT and ultrasound findings of surgically retained sponges and towels.
The CT and ultrasound features of retained sponges (gossypibomas) are described in six patients. They are well-circumscribed cystic masses without surrounding edema. The retained sponges or towels were correctly identified in only three cases. In the other three cases retained sponges were organized and lost their original configuration. Gas was seen in one case and calcification in two cases. Gossypibomas should be included in the differential diagnosis in all patients with a well-circumscribed cystic mass in the abdomen and with a history of previous laparotomy.
Foreign Bodies↗
MRI of patellar tendon anterior cruciate ligament autografts.
Twenty-one MR examinations were performed in 15 patients with clinically stable knees after arthroscopic anterior cruciate ligament (ACL) reconstruction with patellar bone-tendon-tibial bone autografts. The postoperative interval ranged from 3 months to 3 years 3 months (average 9.5 months). Proton- and T2-weighted sagittal images with axial and oblique sagittal T1-weighted images were obtained. The MR appearance of the autografts was categorized depending on distribution of dark signal band into type 1 (continuous, two patients), type 2 (proximal half, eight patients), type 3 (distal half, two patients), and type 4 (nonvisualization, three patients). There was no change in appearance of the grafts in those who had a second imaging within 1 year postoperatively. We conclude that the normal ACL autograft has a variable appearance and that criteria used in evaluating the native ligament is inadequate to assess the autografts.
Adolescent↗
MRI of the knee in rheumatoid arthritis: Gd-DTPA perfusion dynamics.
OBJECTIVE: Seventeen knees in 13 patients with rheumatoid arthritis (RA) were studied with MRI to clarify the dynamics of Gd-DTPA administered intravenously and to determine an optimal imaging time. MATERIALS AND METHODS: Dynamic gradient recalled echo imaging with bolus intravenous injection of Gd-DTPA was performed following unenhanced T1- and T2-weighted SE imaging. Late-phase SE or serial gradient recalled echo images were obtained following dynamic study. RESULTS: There was rapid enhancement of synovium with maximal enhancement ratio of 96-499% (mean 214 +/- 111%) with Tmax ranging from 120 to 660 s (mean 253 s). The synovial enhancement persisted over 80% of the peak enhancement for 6-27 min (average 12 min) with eventual enhancement of joint effusion from the periphery to the center beginning at 6 min to 8 min, 20 s after contrast medium injection. Complete enhancement of joint effusion was noted in four joints at 24-86 min. CONCLUSION: We conclude that enhancement of synovium in patients with RA is a time-dependent phenomenon, and an optimal imaging time would be within 5 min following contrast medium administration.
Adult↗
The effect of 9-ethyladenine on the photodimerization of 1-cyclohexylthymine.
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Adenine↗
Detection of malignant thymoma in primary tumor and metastatic lesions using 99mTc-tetrofosmin scintigraphy.
99mTc-tetrofosmin was developed as a myocardial perfusion imaging agent and can also be used to depict tumors. We have experienced five cases of malignant thymoma delineated on 99mTc-tetrofosmin SPECT. In one case significant activity was clearly detected in the primary tumor and metastatic lesions. In quantitative analysis, similar 99mTc-tetrofosmin and 201Tl-chloride uptake ratios were obtained (1.95+/-0.57 versus 2.27+/-0.85, respectively; n.s.). The ability of 99mTc-tetrofosmin to detect malignant thymoma was comparable to that of 201Tl-chloride. Therefore, 99mTc-tetrofosmin might be a useful tracer for the detection of malignant thymoma, although more studies will be required to evaluate its diagnostic accuracy.
Adult↗
MR findings of surgically retained sponges and towels: report of two cases.
MR findings of surgically retained sponges (gossypiboma) in two patients are reported. The sponges were well-encapsulated round masses with a thick wall of low signal intensity on both T1-weighted images (T1WI) and T2-weighted images (T2WI). The signal intensity of the center of the masses varied in both patients on T1WI and T2WI. In one patient, the mass was high in signal intensity on both T1- and T2-weighted images and had a low signal intensity whirl that represented a surgical sponge. The sponge was rich in serosanguinous fluid with a high protein concentration (8.2 g/dl). In the other patient, the mass was low in signal intensity on both T1- and T2-weighted images, and was mainly composed of organized cotton matrix with little fluid. The protein concentration of the fluid was lower than in the former case (6.4 g/dl).
Aged↗
MR appearance at different ages of osteoporotic compression fractures of the vertebrae.
PURPOSE: To elucidate the MR appearance at different ages of osteoporotic vertebral compression fractures. METHODS: We retrospectively analyzed sequential MR studies of 107 vertebrae in 75 patients with osteoporotic compression fractures. RESULTS: Vertebral deformities comprised 35 anteriorly wedged vertebrae, 65 fish vertebrae, four flat vertebrae, and others. Signal alterations were depicted as geographic areas of low intensity on T1-weighted images (T1-WI) and high intensity on T2*-WI, or linear areas of low intensity on T1-WI and high or low intensity on T2*-WI. In the acute stage, geographic alteration predominated. During a three-month period following the injuries, the extent of the geographic areas increased in 40% of cases on T1-WI. Geographic alteration declined in the chronic stage, whereas the prevalence of linear signals increased. Restoration of fatty marrow was preceded by linear signals without geographic signals on T1-WI (36%). The anteriorly wedged vertebrae collapsed faster than the fish vertebrae. CONCLUSIONS: The acute or subacute stage of compression fractures is characterized by a larger alteration of the geographic signal, whereas the chronic stage was evidenced by a smaller area of alteration of the geographic and linear signals or by restoration of fatty marrow.
Acute Disease↗