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Biomedical subjects

H Hatabu

Publications and source records attributed to H Hatabu.

102 records · Page 6Linked to original sources
PubMed1985

[Production of allotype by bone marrow cells transferred to rabbits subjected to suppressor treatment by allotype].

Inbred rabbits of B/J strain were immunized against Salmonella typhi and their bone marrow cells plus LPS were injected into (Chbb: HM X B/J) F1 hybrids at the age of 3-7 weeks, which had received at birth a treatment of the allotype suppression. Antityphoid antibodies bearing the suppressed allotype were found in the serum of the recipients, which showed no signs of the graft versus host reaction.

Animals↗
PubMedDate not supplied

Effect of oxygen inhalation on relaxation times in various tissues.

The effect of the oxygen inhalation on relaxation times was evaluated in various tissues, including the myocardium, liver, spleen, skeletal muscle, subcutaneous fat, bone marrow, and arterial blood, with a [1H]MR system. Statistically significant decrease of T1 relaxation times was observed in the myocardium, spleen, and arterial blood after inhalation of 100% oxygen, whereas no significant change was observed in liver, skeletal muscle, subcutaneous fat, or bone marrow. The T2 relaxation time of these tissues did not differ significantly between before and after inhalation of the oxygen. These results indicate that [1H]MRI can be used to evaluate changes with oxygen inhalation and that the effect of the oxygen inhalation on T1 relaxation time is different among various tissues.

Adipose Tissue↗
PubMedDate not supplied

Ovarian fibroma: findings by contrast-enhanced MRI.

Ovarian fibromas are solid neoplasms that are difficult to differentiate radiologically from uterine leiomyomas. In this report, we describe the contrast-enhanced magnetic resonance imaging features of a 13-cm-diameter solid pelvic mass that allowed us to make the prospective diagnosis of ovarian fibroma.

Adult↗
PubMedDate not supplied

Oxygen-assisted breath-holding in computed tomography.

To achieve prolonged breath-holding, oxygen was administered just before dynamic CT and high resolution lung CT. Oxygen administration has proved to be a supportive means to improve the quality of CT studies.

Humans↗
PubMedDate not supplied

Fibrolamellar hepatocellular carcinoma: MR appearance.

We report two cases of fibrolamellar hepatocellular carcinoma, each of which had lower signal intensity than normal liver on short repetition time (TR), short echo time (TE) spin-echo (SE) images and demonstrated a central scar-like area of low signal intensity which did not become hyperintense on long time TR/TE SE images.

Adult↗
PubMedDate not supplied

Pulmonary MR angiography utilizing phased-array surface coils.

Magnetic resonance angiography of the pulmonary vasculature was evaluated in 12 subjects using breath-hold gradient echo scans and surface coils at 1.5 T. Flow-compensated GRASS, spoiled GRASS (SPGR), and WARP-SPGR sequences were utilized. Comparisons were made among flip angles of 10-60 degrees, slice thicknesses of 3-10 mm, and body coil as well as Helmholtz pair and phased-array multiple coils. With 30-40 contiguous slices encompassing the lung, intrathoracic vasculature was segmented using a UNIX/X-windows based package dubbed VIDA. Three-dimensional anatomy was visualized by a brightest voxel projection algorithm, following reduction of chest wall pixel intensities by an operator-interactive module. Both SPGR (30 degrees flip angle, 4 mm slice thickness) and WARPSPGR (15 degrees flip angle, 5 mm slice thickness) in combination with phased-array multiple coils provided the most satisfactory images, based upon observations by three radiologists and signal-to-noise ratio measurements. The MR angiograms visualized vessels as distal as sixth to seventh order branches. The technique was successfully applied to three patients with pulmonary embolism. The results of this study demonstrate that the pulmonary vascular tree can be imaged by MR angiography combining a high resolution technique utilizing phased-array multiple coils, fast gradient echo sequences with breath-holding, and postprocessing of the volumetric image data. The technique is attractive since it is noninvasive and provides a full three-dimensional portrayal of the pulmonary vasculature.

Humans↗
PubMedDate not supplied

Evaluation of soft palate function with MRI: application to the cleft palate patient.

Magnetic resonance imaging was employed to evaluate soft palate function in four normal volunteers and four patients with surgically repaired cleft palate, using a GE Signa clinical scanner at 1.5 T and a custom designed receive coil with a sensitivity profile encompassing from the nasopharynx to the larynx. Midsagittal images were obtained using spoiled gradient recalled acquisition at steady state while the subject phonated the following sounds: (a) MMM, (b) SSS, (c) DAH, and (d) EEE. An image at rest with normal breathing was also obtained. The soft palate and its relationship to the airway and the posterior pharyngeal wall were clearly visualized in all cases. Phonation of the prescribed sounds demonstrated the normal range of soft palate motion. The images also depicted the ability of the soft palate to divert airflow to the nasopharynx. Interpretation of functional MRI may be of value in evaluation of surgical results, guidance of speech therapy, and surgical planning in the cleft palate patient. This noninvasive alternative to conventional methods of visualization provides advantages in resolution, repeatability, and patient comfort.

Adolescent↗
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

Pulmonary arteriovenous malformations: diagnosis by gradient-refocused MR imaging.

Six known or suspected pulmonary arteriovenous malformations (AVMs) in four patients were evaluated with magnetic resonance (MR) imaging at 1.5 T. All lesions were imaged using a gradient-refocused echo pulse sequence with a 25/13 ms [repetition (TR)/echo (TE) times] and a 30 degrees flip angle, as well as with a cardiac-gated spin echo short TR/TE pulse sequence technique. Five of the lesions were vascular in nature based on their signal intensity characteristics, and one nonvascular lesion was a carcinoid tumor. On the spin echo images, the AVMs showed a central signal intensity void with a peripheral rim of intermediate signal intensity that was detectable for lesions greater than or equal to 1.5 cm in size. Smaller lesions were more difficult to distinguish from the surrounding air-filled lung, which normally generates no appreciable signal on MR images. The AVMs demonstrated uniform high signal intensity on the gradient echo pulse sequence and were more conspicuous, irrespective of size. With a single breath-hold scan, the vascular nature of the lesion could be rapidly confirmed with an acquisition time of 13 s. In three patients, the cine MR gradient echo images showed a pulsatile quality to the signal intensity in the lesion over the cardiac cycle similar to that within adjacent pulmonary vessels. The results of this study show a potential role for gradient echo MR imaging as a rapid, noninvasive method to evaluate the vascular nature of an atypical pulmonary nodule.

Adult↗