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Biomedical subjects

T Michigishi

Publications and source records attributed to T Michigishi.

At least 91 records · Page 5Linked to original sources
PubMed1993

[67Ga SPECT in the evaluation of orbital and ocular mass-like lesions].

We evaluated 67Ga SPECT in the differentiation of mass-like lesions in the orbital and ocular areas. A two-headed SPECT system equipped with parallel-hole collimator was used. 67Ga SPECT demonstrated three dimensionally the extent of tumors found by CT and MRI. 67Ga SPECT was especially useful in the assessment of localized lesions in and around the lacrimal gland. In a total of 43 patients studied, the overall accuracy of 67Ga SPECT in diagnosing orbital and ocular lesions was 72%. Sixteen of 21 malignant lesions (76%) showed true positive findings and 15 of 22 benign lesions (68%) showed true negative findings. All seven malignant lymphoma lesions showed true positive findings. One of four cases of malignant melanoma was not visualized. This lesion was less than 15 mm in diameter. None of the three cases of retinoblastoma was visualized, regardless of tumor size. Four of seven cases of pseudotumor or pseudolymphoma showed false positive findings. The differentiation of pseudotumor and pseudolymphoma from malignant lymphoma seemed to be difficult. We conclude that 67Ga SPECT is useful in the differentiation of lesions in the orbital and ocular areas and that evaluation of the extent of malignant lesions can be improved by comparing the findings obtained by morphological diagnostic modalities.

Adult↗
PubMed1993

Risk of bilateral cervical lymph node metastases in papillary thyroid cancer.

We evaluated the risk of bilateral or contralateral cervical lymph node metastases in 135 patients with papillary thyroid cancer who underwent bilateral neck dissection. We confirmed that bilateral jugular lymph node metastases were frequent in patients with obvious carcinoma in both lobes of the gland, in those with cancers arising in the isthmus, in those with clinically detectable bilateral lymphadenopathy, and in those with recurrent thyroid cancer. However, only 24% of the patients who had cancer clinically confined to one lobe with no bilateral or contralateral lymphadenopathy had histologically detected bilateral or contralateral jugular lymph node metastases. But the occurrence of contralateral jugular lymph node metastases was significantly correlated with both clinical lymphadenopathy in the ipsilateral neck and contralateral paratracheal lymph node metastases. Bilateral lymph dissection might be beneficial for these patients.

Adolescent↗
PubMed1993

The psychological and cosmetic aspects of breast conserving therapy compared with radical mastectomy.

An evaluation of the psychological and cosmetic morbidity of 31 patients who had undergone breast conserving treatment (BCT group) and 71 patients who had undergone radical mastectomy (RM group) revealed that 85% and 73%, respectively, were satisfied with their operative results. BCT appeared superior to RM in relation to body image, with 93% of the BCT group indicating BCT as a future choice of treatment, whereas only 35% of the RM group indicated RM as a future choice of treatment. For 59% of the BCT patients, the results were considered excellent or good by a physician, but fear of recurrence was frequently expressed by both groups even though an early stage of breast cancer had been significantly more common in the BCT group than the RM group. Sexual adjustment was the same in both groups. Body image was thus concluded to have been improved by BCT rather than RM, but psychological morbidity was essentially the same in both groups.

Adaptation, Psychological↗
PubMed1993

Visualization of the thymus with therapeutic doses of radioiodine in patients with thyroid cancer.

Two cases of papillary carcinoma of the thyroid are presented in which whole-body scans following therapeutic doses of iodine-131 revealed intense anterior mediastinal uptake. In both cases, the mediastinal uptake was absent from scans obtained after removal of the entire thymus. Histologically, the resected thymus glands showed hyperplasia and contained neither thyroid tissue nor metastatic foci of thyroid carcinoma. We therefore concluded that anterior mediastinal uptake of radioiodine may be caused by hyperplasia of the thymus.

Adult↗
PubMed1993

Mucin-producing poorly differentiated adenocarcinoma of the thyroid. A case report.

A rare case of mucin-producing poorly differentiated adenocarcinoma of the thyroid is reported in a 58-year-old man. Light microscopically, the tumor composed of columnar cells, cuboidal cells and spindle cells and these tumor cells showed a various growth pattern; glandular growth with columnar cells, microfollicular growth with cuboidal cells and solid growth with spindle cells. Mucin histochemistry showed scattered foci of mucin production. Immunohistochemistry showed a focal positive staining for thyroglobulin and carcinoembryonic antigen, but a negative staining for calcitonin throughout the tumor. The patient had cervical and axillary lymph node recurrences after the radical operation. The histologic finding of this tumor is peculiar; we report this case briefly.

Adenocarcinoma, Mucinous↗
PubMed1993

Postpartum thyroiditis. A clinical, histologic, and immunopathologic study of 15 cases.

Fifteen specimens from 15 patients with clinically and laboratory-proven postpartum thyroiditis were examined histologically; 8 specimens were obtained during the hypothyroid phase and the other 7 during the recovery euthyroid phase. All specimens showed focal or diffuse chronic thyroiditis. In the eight specimens taken during the hypothyroid phase and four specimens during the early recovery phase, follicular disruption and hyperplastic change of the follicle were common and characteristic histologic features. In the three specimens taken during the late recovery phase, only focal infiltration of lymphocytes was observed. This histologic change resembled that in spontaneous silent thyroiditis, as shown in the authors' previous study. The authors believe that postpartum thyroiditis and spontaneous silent thyroiditis may fit the same category clinically and histologically. In addition to performing the histologic examination, the authors examined the intrathyroidal lymphocyte subsets and HLA-DR antigen expression in the follicular cells immunohistochemically and compared them with those in chronic thyroiditis (usual type). In postpartum thyroiditis, a significant increase of helper-T-cell numbers and increased expression of HLA-DR antigen in the follicular cells were observed, suggesting an enhancement of autoimmune reactivity.

Adult↗
PubMed1993

Renal perfusion with Tc-99m DTPA--simple noninvasive determination of extraction fraction and plasma flow.

A simple, noninvasive method for the determination of extraction fraction and renal plasma flow in Tc-99m DTPA studies is presented. This method could be performed in conjunction with the measurement of glomerular filtration rate, providing additional information about renal plasma flow. Graphic analysis of the Patlak plot was employed for the determination of the unidirectional influx rate constant (ku) of Tc-99m DTPA from the blood to the kidney and the initial nonspecific distribution volume (Vn) in the kidney. The first pass extraction fraction was estimated from Ku and Vn, assuming a bolus input to the kidney. The glomerular filtration rate was measured by renal counting corrected for depth and dose. Using the estimated extraction fraction (EF) and glomerular filtration rate (GFR), the renal plasma flow (RPF) was calculated using the formula of RPF = GFR/EF. In a total of 76 kidneys in 38 patients (including 9 patients with normal renal function and without evidence of nephrourologic disease), the value of renal plasma flow showed good correlation with that of effective renal plasma flow measured by renal counting with I-131 orthoiodohippuran. There was a characteristic tendency for the extraction fraction to show a larger value as the renal plasma flow decreased. These results indicate that this method is valid for renal plasma flow estimation and the determinations of extraction fraction and renal plasma flow in Tc-99m DTPA studies is helpful as an adjunct to the measurement of glomerular filtration rate in order to adequately assess the pathophysiologic changes of renal disorders.

Adult↗
PubMed1993

99mTc colloid and 99mTc IDA imagings in diffuse hepatic disease.

Ninety-six patients with various diffuse hepatic diseases were observed using both 99mTc colloid and 99mTc iminodiacetic acid (IDA), focusing on the potential etiologies of the disease process as well as its chronicity and severity. The presence of acute hepatic disease was more sensitively depicted with 99mTc IDA than with 99mTc colloid. In chronic hepatic disease, on the other hand, 99mTc colloid and 99mTc IDA demonstrated a similar sensitivity. The potential etiology of the disease process (differential diagnosis) and the chronicity of the disease could be evaluated better with 99mTc colloid. Among the patients with different stages of liver cirrhosis, however, 99mTc IDA significantly discriminated the severity of the hepatic disease. These results suggest that 99mTc IDA may be used to determine the degree of functional disorder in acute hepatic disease and evaluate the severity of diffuse hepatic disease, whereas 99mTc colloid can effectively evaluate the potential etiology and chronicity of the disease.

Colloids↗
PubMed1993

Evaluation of suspected malignant pulmonary lesions with 201Tl single photon emission computed tomography.

201Tl single photon emission computed tomography (SPECT) was evaluated in 170 patients suspected of having a malignant pulmonary lesion greater than 20 mm in diameter on the surgical specimen. Delayed SPECT (at 3 h after injection) visualized all of the 147 malignant pulmonary lesions and 16 of the 23 (69.6%) benign pulmonary lesions, and generally exhibited the lesion more clearly than the early SPECT images (at 15 min after injection). There was no significant difference in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) among the various histological groups except between the adenocarcinoma and large cell carcinoma groups (P < 0.05), and no difference was noted between the malignant and benign lesions. However, in retention index (degree of retention in the lesion) a significant difference was noted between the malignant and benign lesions (P < 0.01), although there was no significant difference in this index among malignant different histology groups. These results indicate that this method is useful for visualizing malignant pulmonary lesions greater than 20 mm in diameter to exclude the possibility of malignancy in the lesions when no abnormal 201Tl accumulation is observed. When the lesion shows abnormal 201Tl accumulation, the retention index seems to help differentiate malignant from benign lesions.

Adenocarcinoma↗
PubMed1993

Iodine-induced hypothyroidism in patients on regular dialysis treatment.

Hypothyroidism with a serum concentration of thyroid-stimulating hormone (TSH) above 40 microU/ml was noted in 3 (3.2%) of 93 patients on regular hemodialysis or continuous ambulatory peritoneal dialysis. These 3 patients had no history of thyroid disease and were receiving no medication known to influence thyroid function. They had habitually eaten iodine-rich foods and showed an enlarged thyroid gland with a preserved radioactive iodine uptake and a markedly elevated serum inorganic iodine (II) level. In all 3 patients, both thyroidal microsomal antibody and thyroglobulin antibody titers measured by hemagglutination methods were less than 100, and TSH-binding inhibitory immunoglobulin was negative. Moreover, histologically no lymphocytic infiltrations were observed. With only iodine restriction, serum TSH level markedly decreased from 44.6 to 3.6 microU/ml in case 1, from 90.6 to 3.2 microU/ml in case 2 and from 43.2 to 9.4 microU/ml in case 3 in parallel with decreases in the serum II level. These results suggest that at least in an area like Japan, where the daily intake of iodine is high, iodine-induced hypothyroidism may be induced in patients undergoing regular dialysis treatment even in the absence of apparent underlying thyroid disease.

Adult↗
PubMed1993

Iodine-induced hypothyroidism: a clinical and histological study of 28 patients.

Thirty-three thyroid specimens obtained from 28 patients with clinically and laboratory-proven iodine-induced hypothyroidism were examined clinically, histologically, immunohistochemically, and ultrastructurally. Twenty-eight specimens obtained during the hypothyroid phase showed common histological changes in the thyroid thought to be specific for this disease; hyperplastic change in the follicles with some papillary folding, cuboidal to columnar change of follicular cells with clear and vesicular cytoplasm, scanty or absent colloid material in the large distended follicles, and occasional dilatation of capillary vessels. Lymphocytic infiltration was present in about half of the specimens. No specimens showed either stromal fibrosis or parenchymal atrophy. Immunohistochemical and electron microscopic examination revealed that severe interference with thyroid hormone biosynthesis occurs in the follicular cells. In two patients who had a follow-up biopsy in the recovery (euthyroid) phase after iodine restriction, the histological involvement seen in the hypothyroid phase was no longer present. The histological changes in the thyroid gland seen in patients with iodine-induced hypothyroidism are characteristic. This disease can be diagnosed from laboratory tests, but thyroid biopsy is also a useful tool to differentiate this condition from other diseases causing hypothyroidism. Not only clinicians, but also pathologists, must pay attention to this type of hypothyroidism, because thyroid function may revert to normal by iodine restriction alone.

Adult↗
PubMed1993

[Evaluation of renal function using 99mTc-MAG3: comparison with 123I-OIH and 99mTc-DTPA].

The utility of 99mTc-mercaptoacetyltriglycine (MAG3) with studied clinically. In the renography obtained with 99mTc-MAG3, the abdominal aorta and the common iliac arteries were clearly visualized in the vascular phase. Due to less background activity and high target to background ratio, the quality of 99mTc-MAG3 image was superior to that of 123I-OIH or 99mTc-DTPA image. The parameters on the renogram including Tmax, T2/3, and T1/2 were compared. The correlation of Tmax and T2/3 or T1/2 were not significant between 99mTc-MAG3 and 123I-OIH. Another parameter of C20/Cmax, where C20 and Cmax are renal activities at 20 min after injection and at Tmax respectively, showed an excellent correlation between 99mTc-MAG3 and 123I-OIH. Using C20/Cmax, pattern of renogram can be characterized numerically. Concerning about the relation between C20/Cmax and renogram pattern, standard renogram pattern showed the C20/Cmax value of less than 0.4, while hypofunctioning pattern showed more than 0.5. The correlation coefficient between the renal uptake of 99mTc-MAG3 and 123I-OIH was 0.880 with a correlation plot: "Y = 1.16X-0.043", where X and Y represent renal uptake of 99mTc-MAG3 and 123I-OIH, respectively. It can be concluded that 99mTc-MAG3 is useful renal imaging agent as an alternative to 123I-OIH, in order to evaluate the proximal tubular function and calculate ERPF.

Adult↗
PubMed1992

[Evaluation of the internal mammary nodes by lymphoscintigraphy and ultrasonography in patients with breast cancer].

The efficacy of lymphoscintigraphy and ultrasonography was evaluated in the detection of internal mammary lymph node (IMN) metastases in patients with breast cancer. On histological examination of IMN, 10 patients had metastases (positive group) and 47 did not (negative group). On lymphoscintigraphy, lack of uptake in the parasternal region of the affected side was classified as abnormal. The frequency of this abnormal finding was not significantly different between both groups. On sonography, the thickness of the sonolucent internal mammary area was measured. The thickness of the affected side was 6 mm or more in two patients of the positive group and only one of the negative group. A thickness of over 6 mm on the affected side was statistically significant (p less than 0.05). The difference in thickness between the affected side and the healthy side was 3 mm or more in four patients of the positive group, and was less than 3 mm in all patients of the negative group. A difference in thickness of more than 3 mm between the two sides was extremely significant (p less than 0.001). In conclusion, sonography is valuable in detecting IMN metastases, while lymphoscintigraphy is not useful. Sonography is recommended as an efficient diagnostic modality for IMN metastases.

Adult↗
PubMed1992

Papillary thyroid cancer and its surgical management.

The surgical management in papillary thyroid cancer has been highly controversial. In the Department of Surgery (II), Kanazawa University Hospital, the surgical management especially for cervical lymph node metastases has changed since 1973 from a conservative approach to an aggressive one. In order to determine whether an aggressive approach is warranted, a retrospective multivariate analysis was carried out on 106 cases of papillary thyroid cancer. The patients have been followed for 10-28 years. Multivariate analysis was conducted following Cox's model. By this analysis, aggressive management appeared to have no impact on survival or relapse-free survival. However, age, sex, tumor size, and cervical lymphadenopathy were confirmed to be important prognostic factors in survival and/or relapse-free survival.

Adult↗
PubMed1992

Chronic thyroiditis: thyroid function and histologic correlations in 601 cases.

Six hundred one patients with histologically proven "chronic thyroiditis" were assessed for the correlation of thyroid function to histologic findings. The histology of chronic thyroiditis was classified into four groups (oxyphilic, mixed, focal, and hyperplastic), and the thyroid function of patients was divided into hyperthyroid, euthyroid, latent hypothyroid, and overt hypothyroid, based on the laboratory data of serum triiodothyronine (T3), thyroxine (T4), and thyrotropin (TSH) levels, as well as thyrotropin-releasing hormone (TRH) tests. In the oxyphilic group (137 cases), 116 (85%) of the patients were classified as hypothyroid: 52 (38%) as latent hypothyroid and 64 (47%) as overt hypothyroid. In the mixed group (161 cases), the thyroid function of the patients varied. Thirty-seven (23%) of the patients were classified as hyperthyroid, 61 (39%) as euthyroid, 54 (33%) as latent hypothyroid, and nine (5%) as overt hypothyroid. In this group thyroid function was intimately related to the ratio of replacement by hyperplastic-changed follicles and oxyphilic-changed follicles. In the focal group (149 cases), 123 (83%) of the patients were classified as euthyroid, while 22 (14%) were classified as latent hypothyroid. The frequency of latent hypothyroid patients increased in parallel with the severity of cell infiltration. In the hyperplastic group (154 cases), 130 (85%) of the patients were classified as hyperthyroid. In this series 19 patients under 10 years of age were included, and no difference in the distribution of histologic varieties was observed between juvenile and adult patients. Thyroid needle biopsy is a useful and safe tool, not only for the histologic diagnosis of chronic thyroiditis, but also for the evaluation of thyroid function and the identification of causes for hyperthyroidism or hypothyroidism.

Adult↗
PubMed1992

Tc-99m HMPAO-labeled leukocytes for hematopoietic marrow imaging. Comparison with In-111 chloride.

The current study was initiated to define whether Tc-99m leukocyte imaging, compared to In-111 chloride imaging, could provide additional information on the hematopoietic activity of the bone marrow in diffuse hematologic disorders. A total of 11 patients with hematologic disorders were studied both with Tc-99m leukocytes and In-111 chloride. One patient with myelofibrosis showed disparate tracer distribution in the bone marrow between the two; Tc-99m leukocyte uptake in the central marrow was highly decreased, whereas In-111 chloride showed expanded marrow. The disparate results of granuloid hypoplasia and erythroid hyperplasia obtained by bone marrow biopsy and aspiration in this patient were thought to give an explanation for the radionuclide findings. The remaining 10 patients showed similar tracer distribution in the marrow, and the observation of hematopoietic cellularity confirmed by bone marrow biopsy and aspiration correlated well with the radionuclide findings. These results demonstrate that Tc-99m leukocytes may be a potential imaging agent for evaluating hematopoietic activity in the bone marrow, in particular granulopoietic activity.

Adult↗