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Biomedical subjects

K Hayasaka

Publications and source records attributed to K Hayasaka.

248 records · Page 14Linked to original sources
PubMedDate not supplied

Histopathologic changes in the infundibular septum after balloon pulmonary valvuloplasty in tetralogy of Fallot.

Balloon pulmonary valvuloplasty (BPV) has been applied to tetralogy of Fallot (TOF) as a palliative procedure. To investigate the histopathologic changes by BPV in the infundibular septum of TOF, we performed histopathologic examinations of the infundibular septum resected at corrective surgery. The subjects were 5 patients with TOF, who underwent BPV at the median age of 2.2 months and the corrective surgery at the median age of 15.0 months (BPV group), and 4 patients with TOF who had no prior BPV and who underwent the corrective surgery at the median age of 14.5 months (control group). There was no significant difference between the two groups in the endocardial thickness, myocardial vacuole degeneration, or fraction of fibrous and interstitial space. However, the specimens from 3 patients in the BPV group had localized dense fibrous lesions in the myocardium. The findings in this limited sample suggest that BPV for TOF does not produce overall histopathologic alterations such as fibrosis, thick endocardium, and myocardial vacuole degeneration, but may sometimes damage the myocardium of the infundibular septum resulting in the formation of localized dense fibrous lesions. The clinical significance of this damage is still unknown, and further cases should be investigated.

Catheterization↗
PubMedDate not supplied

Dynamic MR imaging of splenic tumor.

Inflammatory pseudotumor and hemangioma of the spleen are rare benign tumors, and MRI findings of splenic diseases have been reported only rarely. We recently observed three patients with inflammatory pseudotumor and hemangioma of the spleen. Abdominal ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography demonstrated within the enlarged spleen. MRI and dynamic MRI after administration of gadolinium DTPA provide the characterization of the splenic tumor.

Aged↗
PubMedDate not supplied

Intravenous leiomyomatosis.

We present two cases of intravenous leiomyomatosis with uterine leiomyoma or previous hysterectomy because of uterine leiomyoma in which MRI was characteristic. MRI showed a mass in the inferior vena cava and the heart. These MR findings are useful in diagnosing intravenous leiomyomatosis.

Biopsy↗
PubMedDate not supplied

Severe bleeding tendency in a patient with Bernard-Soulier syndrome associated with a homozygous single base pair deletion in the gene coding for the human platelet glycoprotein Ibalpha.

PURPOSE: The genetic basis of Bernard-Soulier syndrome (BSS) was studied to clarify a relationship between severe clinical manifestations and gene abnormality. PATIENT AND METHODS: A patient with BSS had a severe bleeding tendency that was sometimes life threatening. Flow cytometric analysis of the patient's and normal control platelets was performed to study which glycoprotein (GP) was impaired in glycoprotein Ib/V/IX complex. The genes encoding GPIbalpha from the patient's and control genomic DNA were amplified and directly sequenced. RESULTS: Flow cytometric analysis revealed a defect of GPIbalpha on the surface of the patient's platelets. A homozygous single base pair deletion was identified in seven repeats of adenine at positions 1932 to 1938 in the GPIbalpha gene. This mutation, which has been previously reported, results in a frameshift and predicts a premature stop codon leading to a truncated peptide that cannot fix on the platelet membrane. CONCLUSION: This patient's severe clinical phenotype would be explained by this mutation in the GPIbalpha gene.

Adolescent↗
PubMedDate not supplied

Case report of malignant splenic tumor.

Primary angiosarcoma and malignant lymphoma of the spleen are uncommon. We report such tumors in a 44-year-old-woman and a 51-year-old-man. The value of diagnostic imaging by US and CT is emphasized. These techniques can establish the solid nature of the mass and may be the first methods to suggest malignancy.

Adult↗
PubMedDate not supplied

CT evaluation of primary benign retroperitoneal tumor.

We studied CT patterns in 21 cases of primary benign retroperitoneal tumor including teratoma in nine cases, schwannoma in six, leiomyoma in three, lipoma in one, lymphangioma in one, and neurofibroma in one. The tumors were analyzed for size, internal homogeneity, CT density, calcification, border with neighboring organs, and contrast enhancement (CE). The mean diameter of the tumors was 10.2 (+/- 4.8) cm. Internal homogeneous distribution was observed in 33%, calcification in 43%, and well-defined border in 86%. The CT density and calcification were compared according to histology, and the results were as follows: teratoma showed fat density in 78%, water density in 100%, and calcification in 89%; schwannoma showed water density in 100% and septal CE in 33%; leiomyoma showed soft tissue density in 100%, CE in 100%, and water density in 33%; lipoma showed fat density and calcification; and lymphangioma and neurofibroma showed water density. Internal homogeneity, fat density, cyst formation, and calcification are considered to be important predictors of primary benign retroperitoneal tumor on CT.

Adolescent↗
PubMedDate not supplied

Evaluation of renal and perirenal leiomyoma on US, CT, and angiography.

The findings of US, CT, and angiography were analyzed in five rare cases of renal and perirenal leiomyoma. The margin of the tumors was shown to be regular by each method, and the tumors were found to be heterogeneous by US and CT. US showed hypoechoic (80%) and mixed echoic (20%) echo patterns. CT revealed soft tissue density with contrast enhancement. Angiography disclosed hypovascularity (25%), and slight vascularity (75%), but no arterial encasement, A-V shunt, or vein invasion. Although no findings specific to the differential diagnosis of malignant tumors were found, benign tumors should be considered when the following signs are detected: (1) a large (more than about 5 cm), well-defined, regular abdominal mass with few symptoms, (2) a heterogenous hypoecho on US, (3) enhanced soft tissue density on CT, and (4) angiography without arterial encasement, A-V shunt, or vein invasion.

Diagnostic Imaging↗
PubMedDate not supplied

MRI appearance of thorotrast-induced cholangiocarcinoma in a case of thorotrastosis.

The case of a 71-year-old man with thorotrastosis and a cholangiocarcinoma detected by MRI is presented, and the radiographic appearance of the cholangiocarcinoma is discussed. We concluded that MR is more useful for detecting Thorotrast-induced liver tumors than US and CT, but CT is more useful for the detection of Thorotrast deposits.

Adenoma, Bile Duct↗
PubMedDate not supplied

Desmoplastic fibroma of bone.

We present a rare case of benign intraosseous desmoplastic fibroma, occurring in the tibial bone of a 48-year-old woman. The plain film features consist of a lytic, expansile lesion, in the metaphysis and epiphysis of the bone. We present a case involving the long bone in which the correct diagnosis was suggested by CT and MRI. The appearance of the lesion on CT and MR is described.

Angiography↗
PubMedDate not supplied

MR imaging in alveolar echinococcosis of bone.

We report two cases of alveolar echinococcosis (AE) of the bone, and present the computed tomography (CT) and magnetic resonance (MR) imaging findings of these surgically proven cases of AE of the ilium and clavicle. CT and MR imaging showed destruction of the ilium and clavicle, and numerous cysts of the bone and surrounding tissues. Moreover, CT and MR imaging clearly demonstrated spread of the parailiac region and superior mediastinum. CT and MR imaging were very useful in determining the extent of surgery. Our experience suggested that CT and MR imaging are complementary studies.

Adult↗
PubMedDate not supplied

Cavernous hemangioma of the adrenal gland: MRI appearance.

We describe a case of cavernous hemangioma of the adrenal gland in which MR imaging showed low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, and dynamic MR imaging using Gd-DTPA showed late and delayed enhancement, allowing definitive diagnosis.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Inflammatory pseudotumor of the spleen: US and MRI findings.

The ultrasound and color Doppler sonography characteristics of inflammatory pseudotumor (IPT) of the spleen are nonspecific, and thus preoperative diagnosis of the tumor is difficult. We describe a case of IPT of the spleen studied with ultrasound, color Doppler sonography, CT, and MRI, and we report the usefulness of US and MRI findings of the tumor.

Aged↗