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Biomedical subjects

I Okuda

Publications and source records attributed to I Okuda.

12 recordsLinked to original sources
PubMed2006

[Evaluation of imaging before lung volume reduction surgery for pulmonary emphysema; fused image of multi-detector row computed tomography and scintigram].

Lung volume reduction surgery (LVRS) is performed as surgical therapy for severe pulmonary emphysema. In assessing diagnostic imaging indications, emphysematous change is the strongest in the thoracic computed tomography (CT), while the accumulation decrease is most remarkable in ventilation scintigram and lung perfusion scintigram. Preoperative evaluation of imaging using multidetector-row CT (MDCT) and scintigram were performed, and the multiplanar reconstruction (MPR) image of the MD CT and the single photon emission CT (SPECT) image of the scintigram were fused by the workstation. It was possible to evaluate the excision and the range of LVRS easily by looking at the fused image, and it was useful in deciding on the surgical approach. It is believed that accurate, comprehensible imaging information contributed to an improvement in the surgical outcome of LVRS.

Evaluation Studies as Topic↗
PubMed2005

[Imaging aid for thoracoscopic thymectomy; thymic vein visualization].

The spread and progress of thoracoscopic surgery has been remarkable. There are many important organs and blood vessels in the mediastinal space, thus, as inadvertent injury invites serious consequences, it is necessary to understand the anatomical position of existing structures. When enucleating the thymoma under a thoracoscope, one of the blood vessels to be careful about is the thymic vein. Therefore, we examined whether the thymic vein could be confirmed using a multidetector-row computed tomography (MD CT). We believed we could understand the anatomical position of the thymic vein by analyzing the high resolution slice data provided in MD CT using a work station. The diameter of the thymic is from a little less than 1 mm to 3 mm, and there were individual variations in position and the number of the vein. The thymic vein flowed into the left brachiocephalic vein in many cases. In some cases, the thymic vein flowed into the right internal thoracic vein or superior vena cava. It appears that visualization of the thymic vein could provide useful data when performing thoracoscopic thymectomy.

Adult↗
PubMed1999

[A gastrointestinal radiographic study of 18 patients with esophageal adenocarcinoma arising from Barrett's epithelium].

Gastrointestinal radiographs were reviewed with pathological correlation in 18 patients with histologically proven esophageal adenocarcinoma arising from Barrett's epithelium. Comparison was also made with postoperative radiographs of resected esophageal specimens from 3 of the patients. Esophageal carcinoma could be observed in the gastrointestinal radiographs in 17 of the 18 patients. In 14 of the 17, the classification based on the gastrointestinal radiographs was consistent with the gross classification. In 10 of the 18 patients, rough mucosa was seen on gastrointestinal radiographs in the same area in which Barrett's epithelium was observed in the histopathological specimens. Sliding esophageal hiatus hernia was present in 12 of the 18 patients, a relatively high incidence. Regular granular or reticular shadows were observed on the mucosal surface of the esophagus on the postoperative radiographs of 3 patients. It is believed that a diagnosis of Barrett's epithelium can be made from gastrointestinal radiographs if these mucosal patterns are present. Although a definitive diagnosis of Barrett's epithelium based on upper gastrointestinal radiographs is considered difficult, the presence of rough mucosa in the esophagus around the carcinoma in combination with esophageal hiatus hernia are suggestive of esophageal adenocarcinoma arising from Barrett's epithelium.

Adenocarcinoma↗
PubMed1997

[Mediastinal lymph node metastasis from esophageal carcinoma: CT assessment with pathologic correlation].

Computed tomographic (CT) scans were performed in 179 patients with esophageal carcinoma to evaluate mediastinal lymph node metastasis. Histopathologic findings were compared with CT findings in a total of 7,218 resected lymph nodes. First, the criterion for lymph node metastasis on CT scans was 10 mm or more in long transverse diameter. The overall sensitivity and positive predictive value (PPV) were 19% (60 of 317 nodes) and 33% (60 of 180 nodes), respectively. Analysis of each of the eight subgroups of mediastinal nodes revealed that the PPV was more than 70% in node Nos. 105, 108, 110, and 112. In other subgroups, however, the PPV was less than 60%. Sensitivity was less than 50% in all eight subgroups. Second, the criterion for metastasis was 10 mm or more in short transverse diameter. The overall sensitivity and PPV were 8% (26 of 317 nodes) and 63% (26 of 41 nodes), respectively. Analysis of subgroups showed that the PPV in No. 106 nodes increased to 92%. In No. 106 nodes, use of a 5 mm criterion in long transverse diameter increased sensitivity to only 55%. Of the 317 histopathologically proven metastatic lymph nodes, 90 nodes (28%) were 10 mm or more in size, 112 (35%) were 5-10 mm, and 115 (36%) were less than 5 mm. Of the 6,901 non-metastatic lymph nodes, 473 nodes (7%) were 10 mm or more in size. Small (less than 5 mm in size) metastatic nodes were present in all eight subgroups. Among No. 107 and 109 nodes, large (10 mm or more in size) nonmetastatic nodes were prominent, resulting in low sensitivity and PPV. We conclude that CT does not provide an accurate assessment of metastatic versus non-metastatic mediastinal lymph nodes in patients with esophageal carcinoma.

Esophageal Neoplasms↗
PubMed1997

[Usefulness and limitations of 99mTc-MIBI scintigraphy for detection of parathyroid lesions].

To evaluate the usefulness of MIBI scintigraphy (MIBI) for parathyroid lesions, the detectability of lesions by MIBI was compared with that by Tl-Tc subtraction imaging, ultrasonography, CT and MRI in 56 histologically proved lesions. In neck lesions, ultrasonography (92%) and MIBI (85%) showed better detectability than those by the other three modalities. With MIBI, detectability was decreased for smaller parathyroid lesions that coexisted with thyroid disease. Among the five modalities, MIBI showed the highest detectability (88%) for ectopic or metastatic lesions. The smallest parathyroid lesions detected by MIBI were a parathyroid adenoma weighing 220mg and a parathyroid hyperplasia weighing 200mg. MIBI was thought to be more valuable for ectopic or metastatic parathyroid lesions.

Adenoma↗
PubMed1995

[99mTc-MIBI scintigraphy for the detection of parathyroid lesions in patients with hyperparathyroidism].

The usefulness of 99mTc-MIBI scintigraphy for the detection of parathyroid lesions was evaluated in 17 patients with hyperparathyroidism. Delayed image was used to evaluate the lesions. Detectability of MIBI for parathyroid lesions was 86% (18/21). The smallest lesion detected was parathyroid hyperplasia weighted 270 mg. Ectopic parathyroid adenoma and bone metastases of parathyroid carcinoma were clearly demonstrated. Detectability of MIBI scintigraphy for the lesions including ectopic and metastatic lesions was the highest among those of ultrasonography, CT and MRI methods. MIBI scintigraphy was thought to be useful for the detection of parathyroid lesions, especially for ectopic and metastatic lesions.

Bone Neoplasms↗
PubMed1995

[A study of rCBF measurement with autoradiography (ARG) method using N-isopropyl-p-[123I]iodoamphetamine (IMP) and SPECT--comparison of rCBF values between look-up table (TLU) and ARG methods, and evaluation of venous blood samplings as a substitute for arterial blood sampling].

Regional cerebral blood flow (rCBF) values obtained by the TLU method with two 123I-IMP SPECT scans and one point arterial blood sampling and rCBF obtained by the ARG method with one 123I-IMP SPECT scan and fixed distribution volume (Vd) values were compared in 17 cases. A case with post ischemic hyperperfusion or luxury perfusion was not observed in our cases. The correlation coefficients between rCBF values and Vd values obtained by the TLU method were 0.49 (p < 0.001) in 184 ROI without hypoactive areas on the early image, and 0.61 (p < 0.001) in 207 ROI with hypoactive areas, respectively. A high rCBF value with a low Vd value was not observed in any region. Mean Vd value was 44.0 +/- 7.0 (mean +/- SD) in all regions. The correlation coefficients between rCBF values using the TLU method and those using the ARG method with Vd fixed at 44 and 50 were also 0.98. Error of the rCBF value was larger in the region of high rCBF, however, noticeable error of the rCBF value was not observed in the ARG method. The ARG method is more convenient for quantifying rCBF. Venous blood radioactivity at 10 min after 123I-IMP infusion was smaller than arterial blood radioactivity, and the blood activity in the distal vein was larger than that in the proximal vein. The ratio of venous blood activity to arterial blood activity was 0.92 +/- 0.04 (mean +/- SD) at the back of the hand, however, the ratio was a variant in each case. Arterial sampling was thought to be a reliable method to obtain more stable and precise rCBF.

Aged↗
PubMed1994

Development of Graves' ophthalmopathy and uveitis after radioiodine therapy for Graves' disease in a patient with HTLV-I associated myelopathy (HAM).

HTLV-I carriers or patients with HTLV-I associated myelopathy (HAM) are prone to immune-mediated inflammatory disorders. We present a 44-year-old female with HAM who developed Graves' disease. She developed severe Graves' ophthalmopathy shortly after 131I therapy, concurrently with a remarkable increase in TSH-receptor antibody titer. Ophthalmopathy was aggravated in spite of prednisolone therapy and euthyroidism being maintained by thyroxine replacement. Uveitis also developed after 131I therapy and iridocyclitis finally required trabeculotomy. This case suggests that HAM patients may have a higher risk of immune-mediated Graves' ophthalmopathy after 131I therapy.

Adult↗
PubMed1991

Diagnosis of rhinoliths with rigid endoscopy.

Three cases of rhinolithiasis are presented in which the diagnosis was facilitated by rigid endoscopic nasal examination. Coronal CT scans were used to delineate accurately the size and site of the rhinoliths. Neutron activation analysis was used in their elemental analysis.

Adult↗
PubMed1991

The organic composition of earwax.

Earwax is a mixture of desquamated keratinocytes and hair combined with the secretions of both the ceruminous and the sebaceous glands of the external ear canal. This study analyzed earwax using the combination analytical technique of gas chromatography and mass spectrometry. The major organic components of earwax identified were long chain fatty acids, both saturated and unsaturated, alcohols, squalene and cholesterol. This study demonstrated that it is not currently possible to quantify statistically the substances which constitute earwax with accuracy. The presence of foreign substances within earwax was identified as a complicating factor in the analysis of earwax.

Cerumen↗