Biomedical subjects

K Togashi

Publications and source records attributed to K Togashi.

207 records · Page 12Linked to original sources

PubMedDate not supplied

Red degeneration of uterine leiomyoma: MR appearance.

OBJECTIVE: Red degeneration (hemorrhagic infarction) of uterine leiomyoma can cause acute abdominal pain. This study was undertaken to identify MR features useful in diagnosing this rare complication of uterine leiomyoma. MATERIALS AND METHODS: Magnetic resonance imaging from five patients symptomatic for 7 to 20 days with pathologic confirmation of red degeneration was retrospectively evaluated and correlated with histopathologic findings. RESULTS: The lesions had a common MRI appearance: hyperintense rim on T1-weighted imaging (WI) and hypointense rim on T2-WI. These findings corresponded with numerous dilated vessels filled with red blood cells at the periphery of the lesion. The signal characteristics of the rim are best explained as an effect of abundant intracellular methemoglobin in these vessels. CONCLUSION: Recognition of these characteristics may help radiologists differentiate symptomatic red degeneration from other clinical conditions that need surgical interventions.

Adult↗

PubMedDate not supplied

MR appearance of malignant lymphoma of the uterus.

OBJECTIVE: The uterus is rarely the initial site of malignant lymphoma. The purpose of this article is to present the MRI of malignant lymphoma of the uterus. MATERIALS AND METHODS: Four cases with pathologically proven malignant lymphoma, in which the uterus was the only and the initial site of recognized visceral involvement, are presented; MRI was retrospectively evaluated. RESULTS: All the lesions exhibited homogeneous hypointense signal on T1-weighted imaging and relatively hyperintense signal on T2-weighted imaging. One case exhibited diffuse and uniform enlargement of the uterine corpus and cervix in the presence of preserved endometrium and cervical epithelium. With these findings, a prospective diagnosis of lymphoma was feasible. The three other cases exhibited MR findings that closely resembled those of carcinoma of the cervix. However, in one case, preserved cervical epithelium in the presence of extensive involvement of the cervical stroma may have been a clue to the diagnosis of malignant lymphoma. Involvement of the vagina (three cases) and the urinary bladder (two cases) was clearly identified on MRI. CONCLUSION: Lymphoma of the uterus exhibited various MR appearances; however, specific diagnosis might be feasible in limited cases. In addition, clear visualization of the extent of disease seen on MRI could contribute to clinical decisions about treatment.

Adult↗

PubMedDate not supplied

MR and CT appearance of urethral clear cell adenocarcinoma in a woman.

We present a case of clear cell adenocarcinoma of the female urethra that has been evaluated with CT and MRI. The lesion was a well-demarcated mass surrounded with peripheral enhancement on CT. On MRI a sharply marginated mass was located in the midurethra, giving rise to a smooth elevation of the bladder base. On T2-weighted imaging, the lesion was hyperintense, being surrounded by a ring of lower signal intensity at the periphery. A central urethral dot of lower signal intensity traversed the anterior one-third of the mass but was preserved in its entire length.

Adenocarcinoma, Clear Cell↗

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↗

PubMedDate not supplied

Sclerosing stromal tumor of the ovary: MRI.

The MR and pathologic findings of a case of sclerosing stromal tumor (SST) are presented. MR findings reflecting pathological features of SST include pseudolobulation, which consists of low-intensity nodules set against high-intensity stroma on T2-weighted images, and striking enhancement on postcontrast images.

Adult↗

PubMedDate not supplied

Yolk sac tumor of the ovary: radiologic-pathologic correlation in four cases.

We report the radiologic and pathologic features of yolk sac tumor (endodermal sinus tumor) of the ovary in four patients. Yolk sac tumors were shown as well-enhancing solid tumors on both CT and MR studies and were associated with prominent signal voids on MRI. A hypervascular nature was confirmed on microscopic studies. Areas of hemorrhage were another common characteristic. These imaging findings seem to have an important implication for the diagnosis of this tumor.

Adolescent↗

PubMedDate not supplied

Primary intracardiac tumors in magnetic resonance imaging.

Fifteen patients suspected of having 18 intracardiac masses by two-dimensional echocardiography underwent MR imaging. In MR imaging, intracardiac masses were evaluated on both short TE (TE = 20-35 msec) and long TE (TE = 50-80 msec) spin echo sequences, and were differentiated from myocardium or papillary muscle. Three masses were excluded (they were papillary muscle) by MR imaging, and three were additionally found in patients with tuberous sclerosis. Fifteen masses were found by both echocardiography and MR imaging, one of which was stagnant blood. Cine MR imaging was needed to differentiate between thrombus and stagnant blood. MR imaging is useful for the evaluation of intracardiac masses. It is recommended in addition to echocardiography when cardiac tumors are suspected, especially in patients with tuberous sclerosis.

Adolescent↗

PubMedDate not supplied

Posterior lobe of the pituitary: identification by lack of chemical shift artifact in MR imaging.

The posterior aspect of the normal sellar content usually displays high intensity signal on T1-weighted images. The shape, size, and location of this high intensity seem to be compatible with the posterior lobe of the pituitary gland. But fatty tissues such as intrasellar fat pad or fatty marrow of the dorsum sellae or both must be excluded as other possible sources of this high intensity signal. Two sellar phantoms were prepared. Both included high intensity posterior parts, one due to high concentration of a paramagnetic ion and the other due to fat. Magnetic resonance imaging of these phantoms showed that the fatty component was accompanied by distinct chemical shift artifacts in a predictable way. The absence of chemical shift artifact in the sellar content of normal volunteers excluded the fatty tissue as representing the high intensity posterior part. The high intensity posterior part of the normal sellar content appears to represent the posterior lobe of the pituitary gland.

Adipose Tissue↗