Biomedical subjects

M L Kataoka

Publications and source records attributed to M L Kataoka.

7 recordsLinked to original sources

PubMed1999

Evaluation of ectopic pregnancy by magnetic resonance imaging.

Patients (n = 37) suspected of ectopic pregnancy were prospectively evaluated with magnetic resonance (MR) imaging to assess the capability of MR imaging in the diagnosis of ectopic pregnancy. Five levels of confidence were defined: diagnostic, suspicious, equivocal, questionable, and negative. Tubal wall enhancement and presence of tubal haematoma or gestational sac-like structure were considered diagnostic findings. There were 21 diagnostic, two suspicious, eight equivocal, and six negative findings. MR findings were compared with the surgical findings in 18 patients. Surgical confirmation was obtained in 12 diagnostic, two suspicious, and four equivocal studies. Using the MR diagnostic criteria for tubal pregnancy, MR had 12 true positive, three true negative, three false negative, and no false positive results for the diagnosis of tubal pregnancy. Retrospective analysis of the signal intensity of haematoma and ascites was performed for these 18 surgically confirmed cases. The predominant signal intensity of tubal haematoma was an intermediate signal on T1-weighted image (WI) and a low signal on T2WI. Ascites showed signal intensity higher than that of urine on T1WI in 100% of 13 cases. In conclusion, MR imaging with use of intravenous contrast material allows a specific diagnosis of tubal pregnancy, recognizing tubal wall enhancement and fresh tubal haematoma.

Adult↗

PubMed1999

Unusual appearances of uterine leiomyomas: MR imaging findings and their histopathologic backgrounds.

Typical appearances of uterine leiomyoma at magnetic resonance (MR) imaging are well established, and diagnosis is usually easy. However, cases that, are extremely difficult to differentiate from other conditions are occasionally encountered. To understand the wide spectrum of MR imaging findings, such unusual appearances can be classified into three categories: degeneration and other histopathologic findings, specific types of unusual leiomyomas, and unusual growth patterns. The common types of degeneration are hyaline (>60% of cases), cystic (approximately 4%), myxoid, and red. Edema is not a phenomenon of degeneration but is a common histopathologic finding (approximately 50% of cases). Hemorrhage, necrosis, and calcification (approximately 4% of cases) may also be observed. Specific types of unusual leiomyomas include lipoleiomyoma and myxoid leiomyoma, which may have MR imaging features characteristic enough to allow differentiation from other gynecologic and nongynecologic diseases. Intravenous leiomyomatosis, metastasizing leiomyoma, diffuse leiomyomatosis, and peritoneal disseminated leiomyomatosis represent unusual growth patterns; other unusual growth patterns are retroperitoneal growth, parasitic growth, and the pattern that may occur in cervical leiomyoma. Because leiomyomas are the most common gynecologic tumors and are exclusively benign, it is important to be familiar with the variety of MR imaging appearances of uterine leiomyomas to distinguish them from other significant diseases.

Female↗

PubMed1999

Dermoid cysts of the ovary with malignant transformation: MR appearance.

OBJECTIVE: This study presents the MR appearances of five women with a total of six proven dermoid cysts of the ovary with malignant transformation. To our knowledge, the MR findings of this entity have not been reported. CONCLUSION: The lesions appeared to be fat-containing tumors with a solid component (4/6) that extended transmurally (4/6) and extensively invaded neighboring pelvic organs (3/6). The supervening malignancy was squamous cell carcinoma in four tumors, melanoma in one, and transitional cell carcinoma in one. The mode of spread differed from that of common ovarian tumors in that it included transmural extension and local invasion, reflecting squamous cell carcinoma.

Carcinoma, Squamous Cell↗

PubMed1999

MR imaging of endometrial stromal sarcoma: correlation with pathologic findings.

OBJECTIVE: This study describes MR imaging of eight patients with endometrial stromal sarcoma and correlates the imaging findings with histopathologic findings. To our knowledge, the radiologic findings of this entity have not been reported in the literature. CONCLUSION: Endometrial stromal sarcoma typically presents with extensive myometrial involvement, which is either sharply demarcated or diffusely infiltrative. Bands of low signal intensity are observed within the areas of myometrial involvement on T2-weighted images. These bands correspond to the preserved bundles of myometrium on pathologic examination. Tumor extension along the vessels or ligaments is another characteristic of MR imaging of endometrial stromal sarcoma.

Adult↗

PubMedDate not supplied

Cervical cancer.

The stage estimated by clinical FIGO staging is the main determinant in guiding the treatment decisions. However, clinical FIGO staging does have inherent inaccuracies, because it does not include significant prognostic factors. Presently, MRI is not officially incorporated in the staging workup system; however, it is widely accepted as the most reliable imaging modality in evaluating cervical cancer and in treatment planning. MRI offers direct tumor visualization, accurate assessment of the depth of stromal invasion and tumor volume, lymph node evaluation, and reliable staging accuracy. Published reports show the superiority of MRI over clinical staging, and several recent works on dynamic MRI suggest further improvement of MRI in evaluating cervical cancer.

Contrast Media↗

PubMedDate not supplied

Granulosa cell tumor of the ovary: MR findings.

PURPOSE: Granulosa cell tumor is a rare but unique ovarian tumor that frequently produces estrogen. The purpose of this study is to identify the MR features and clinical manifestations useful in diagnosing this tumor. METHOD: Clinical presentations and MR findings from five patients with pathologically proven granulosa cell tumor were reviewed. RESULTS: All five granulosa cell tumors were hormonally active. Initial clinical presentations were abnormal genital bleeding suspicious of endometrial carcinoma in two patients and adnexal masses in three patients. All tumors were solid masses with variable amount of cystic components. Hemorrhage within the tumor was identified in three patients. Enlargement of the uterus was observed in four patients. Endometrial thickening was also identified in four patients. CONCLUSION: Recognition of these characteristics may help to differentiate granulosa cell tumor from other ovarian tumors.

Adult↗

PubMedDate not supplied

MRI of adenomyotic cyst of the uterus.

The radiologic and pathologic features of three cases of adenomyotic cysts are presented. Two cases were subserosal and one was intramyometrial. All three cases had cystic spaces filled with hyperintense fluid on T1-weighted images, which were surrounded by hypointense tissue on T2-weighted images.

Adult↗