Biomedical subjects

Shoki Takahashi

Publications and source records attributed to Shoki Takahashi.

63 records · Page 4Linked to original sources

PubMedDate not supplied

Case report: chronic expanding hematoma in the adrenal gland with pathologic correlations.

We report a case of chronic expanding hematoma in the adrenal gland. Mixed signal intensity in a mosaic pattern was seen on T2-weighted images. A focal area suggesting a subacute hematoma was also noted. The dynamic CT scan showed heterogeneous contrast enhancement in the arterial phase and heterogeneous spread of the enhanced area within the tumor. Awareness of this finding may prevent the misdiagnosis of a tumor as a neoplastic intratumoral hemorrhage.

Adrenal Gland Diseases↗

PubMedDate not supplied

Adrenal carcinoma with a signal loss on chemical shift magnetic resonance imaging.

A case of primary adrenal carcinoma that showed a decreased signal in part of the tumor on chemical shift magnetic resonance imaging (CSI) is reported. The patient had clinical symptoms of Cushing syndrome. The tumor was a discrete right adrenal mass about 3.4 cm in largest diameter. It was surgically removed and diagnosed as adrenal carcinoma histopathologically. Two portions where clear cells were prominent were recognized. These areas probably contributed to the signal loss on CSI.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Diffuse hepatic angiosarcoma with a portal venous supply mimicking hemangiomatosis.

We report a case of diffuse hepatic angiosarcoma. Dynamic computed tomography (CT) showed gradual contrast enhancement and homogeneity in the late phase. The tumor was homogeneously hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging, mimicking hemangiomatosis. An angiogram demonstrated intrahepatic arterial encasement, which suggested malignancy. The portal venous supply to the tumor was demonstrated by CT during arterioportography. This probably reflected the continuous infiltration of atypical cells into the dilating sinusoids and may also suggest malignancy.

Angiomatosis↗

PubMedDate not supplied

Assessing the extent of breast cancer using multidetector row helical computed tomography.

OBJECTIVE: The aim of the study was to evaluate the usefulness of multidetector row helical computed tomography (MD-CT) in assessing the local extent of breast cancer. METHODS: Seventy-five breast cancer patients were examined using MD-CT with scanning performed in the supine position at 1-mm collimation. The extent of the breast tumors determined using CT was compared with that based on histopathologic mapping with continuous 5-mm slices. RESULTS: The CT evaluation of the maximum diameter of the extent of breast cancer was much better correlated with the histopathologic diagnosis (correlation coefficient=0.90) than the pre-CT diagnosis (correlation coefficient=0.46). Computed tomography correctly detected mammographically and clinically occult cancer other than the index lesion in 14 of 15 patients. The sensitivity, specificity, and accuracy in the diagnosis of the additional lesions were 93.3%, 98.3%, and 97.3%, respectively. Because the images were obtained in the supine position, they were useful for surgical planning. CONCLUSION: The extent of breast cancer can be determined accurately using MD-CT.

Adult↗

PubMedDate not supplied

Preoperative MDCT evaluation of the artery of Adamkiewicz and its origin.

OBJECTIVE: To assess the usefulness of MDCT in the preoperative evaluation of the artery of Adamkiewicz (ARM) and its parent artery. METHODS: Ten patients with thoracoabdominal vascular diseases underwent MDCT of the entire aorta and iliac arteries. The visualization of the ARM, and its branching level and site of origin, and the continuity of the intercostal/lumbar arteries with the ARM were investigated. RESULTS: In 9 of the 10 patients, the ARM was clearly visualized. The entire length from the intercostal/lumbar arteries to the ARM could be traced in 8 of the 10 patients. Surgical treatment or stentgraft insertion was based on a consideration of the vascular supply to the ARM. No postoperative ischemic spinal complications occurred. CONCLUSIONS: MDCT permits the evaluation of the ARM for its entire length and provides information on the intercostal and lumbar arteries and entire aorta.

Adult↗

PubMedDate not supplied

Quantitative vascular measurements in arterial occlusive disease.

Accuracy in quantifying arterial occlusive disease requires an understanding of the relevant technical considerations and familiarity with the strengths and weaknesses of various imaging modalities in this setting. The degree of stenosis is evaluated in terms of diameter stenosis, which can be measured on either projection images or cross-sectional images, or area stenosis, which can be measured only on cross-sectional images. With projection images, the minimum luminal diameter should be sought on multiple images obtained at different angles. The reference site used for measurement should be noted and may be located at the level of the lesion or in a normal-looking portion of the stenotic vessel near the lesion. Multi-detector row computed tomographic (CT) angiography and magnetic resonance (MR) angiography are starting to replace digital subtraction angiography in quantifying arterial occlusive disease. CT angiography allows accurate evaluation without reducing in-plane resolution, although beam-hardening artifacts from high-attenuation structures can degrade image quality. MR angiography is useful even in cases of severe calcification but has a lower spatial resolution. Ultrasonography (US) may also be helpful in quantifying arterial occlusive disease; US analysis is almost always based on blood flow velocity measurement. Precise measurements of stenotic occlusion will help determine optimal therapy for affected patients.

Aged↗

PubMedDate not supplied

Two cases of adrenal hemangioma: CT and MRI findings with pathological correlations.

We present two cases of adrenal hemangioma, a rare non-functioning adrenal tumor, and correlate the CT and MR imaging findings with the pathological findings. Peripheral spotty contrast enhancement with centripetal enhancement was noted in one case. This pattern of enhancement is crucial for diagnosing adrenal hemangioma. The other case showed only thin rim enhancement without centripetal enhancement. This finding can be seen in other adrenal tumors, making diagnosis difficult. Marked hyperintensity on T2-weighted images and focal hyperintensity on T1-weighted images that showed focal hemorrhage and calcification were noted. These findings can also be seen in other adrenal tumors and are not pathognomonic of adrenal hemangioma. However, observing the combination of these findings can lead to the correct diagnosis.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Comparison of screen-film and full-field digital mammography: image contrast and lesion characterization.

PURPOSE: This study compared screen-film mammography (SFM) with full-field digital mammography (FFDM) of the same patients. MATERIALS AND METHODS: Twenty-four patients underwent surgery or biopsy, including 17 with carcinoma. Patients underwent both SFM and FFDM after providing informed consent. The abnormal findings consisted of 10 masses and 15 areas of microcalcification. The optical density of the breast tissue surrounding any lesion or mass was measured. Three readers evaluated the visibility of the masses and calcifications (contrast, margin, and type) by consensus from hard copies of the images. When evaluating FFDM, SFM was used as the standard of comparison. RESULTS: FFDM showed greater contrast of mass than SFM. The contrast of mass on FFDM was judged visually superior or equivalent to that of SFM, and microcalcifications were the same in most cases. The margin of the mass was better defined by FFDM in two cases. Determination of the type of microcalcification was similar for SFM and FFDM. CONCLUSION: FFDM provided greater contrast than SFM. FFDM might be helpful for detecting masses and observing their margins. Although FFDM may be of some use for detecting calcification, it has no advantage when determining the type of calcification.

Breast Neoplasms↗

PubMedDate not supplied

Comparison of screen-film and full-field digital mammography in Japanese population-based screening.

PURPOSE: To investigate how the greater contrast of full-field digital mammography (FFDM) affects the detection of suspicious lesions in Japanese population-based screening. MATERIALS AND METHODS: Screen-film mammography (SFM) and FFDM were performed in 480 women aged 50 years or more. A set of mediolateral oblique views was obtained with each modality. All mammograms were independently double-read. The five-scale category assessment and type of finding using the Breast Imaging Reporting and Data system (BI-RADS) nomenclature were given. Intraobserver variance, recall rates, and positive predictive value were calculated. RESULTS: The findings between the two modalities were discordant. kappa-values for each reader were 0.619 and 0.385, respectively. Almost half of the microcalcifications were called with both modalities. The detection of masses was less concordant between the readers (27%). The masses were detected more frequently with FFDM (73%). Other findings were only detected with one modality. The recall rate was not significantly different (2.9% with SFM vs. 4.2% with FFDM; p=0.253). The positive predictive value was not significantly different (14% with SFM vs. 10% with FFDM; p=0.69), either. Two patients with breast cancer were detected with both modalities. CONCLUSION: Recall rates and positive predictive value were not significantly different between SFM and FFDM. Cancers were detected with both modalities.

Breast Neoplasms↗