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Biomedical subjects

M Mitomo

Publications and source records attributed to M Mitomo.

At least 19 recordsLinked to original sources
PubMed2002

[Coronary sinus atrial septal defect diagnosed by cyanosis after operation of ventricular septal defect].

We have experienced a case of coronary sinus atrial septal defect (ASD) with ventricular septal defect (VSD). Cardiac catheterization revealed a step-up of oxygen saturation in right ventricle, L-R shunt 70.3%, R-L shunt 6.9% and pulmonary hypertension (PH). Since diagnosis of coronary sinus ASD was difficult, the operation was performed under diagnosis of VSD. Although the operation was success, cyanosis appeared after the operation. Contrast echocardiography using subcostal 4 chamber view showed coronary sinus ASD with a large Thebesian valve and the right-to-left shunt of the ASD. The Thebesian valve seemed to lead the venous return flow to the left atrium. Coronary sinus ASD was closed using a Xenomedica patch.

Cyanosis↗
PubMed2001

Magnetic resonance imaging and clinical findings examined in adulthood-studies on three adults with Rett syndrome.

PURPOSE: To clarify magnetic resonance imaging (MRI) findings in three adult patients with Rett syndrome who had been diagnosed with mental retardation and autism. METHOD: Clinical and MRI findings in three adult cases with Rett syndrome were studied. Ages (in years) in three adult cases with Rett Syndrome were 46 in Case 1, 35 in Case 2 and 20 in Case 3. They were able to walk and their convulsions were well controlled. RESULTS: MRI findings in all patients showed mild cerebral atrophy, especially in the frontal and temporal lobes and two of the cases also had mild cerebellar atrophy. One case also showed a narrowing of the brainstem and thinning of the corpus callosum. CONCLUSIONS: These results indicate that abnormalities in MRI imaging, in cases where there is narrowing of the brainstem and thinning of the corpus callosum, may be due to congenital hypoplasia. It was also seen that cerebellar atrophy became more distinct in older cases.

Adult↗
PubMed2001

[Efficacy of continuous hepatic arterial infusion of high-dose 5-FU for liver metastases of gastric cancer].

We studied the efficacy of continuous hepatic arterial infusion of high-dose 5-FU (high-dose CHAI) in two patients with multiple (five or more) bilobar liver metastases of gastric cancer. 5-FU was given continuously via the hepatic artery at 1 g/day for 3 days, followed by one day off therapy and repetition of the initial treatment as one course. Case 1 was a 67-year-old man with Borrmann type 2 gastric cancer who had undergone total gastrectomy. Metachronous multiple liver metastases (maximum diameter: 3.5 cm) were detected at 11 months after surgery. One month later, we started high-dose CHAI and gave two courses with a 4-day interval between them. After that, 5-FU was given twice by hepatic arterial infusion (HAI) at dose of 1.5 g/week. The tumor diameter had decreased by 50% at 3 months after high-dose CHAI. Case 2 was a 64-year-old man with Borrmann type 3 gastric cancer who had synchronous multiple liver metastases (maximum diameter: 9 cm) and liver dysfunction. One month after distal gastrectomy, we started high-dose CHAI and finished one course. After that, liver function returned to normal and 5-FU was given by HAI at dose of 1 g/week on an outpatient basis. The tumor diameter decreased to 1/3 of the initial size at four months after high-dose CHAI. High-dose CHAI using 5-FU may be safe and effective for liver metastases from gastric cancer.

Aged↗
PubMed1999

Power Doppler sonography of hepatocellular carcinoma treated by transcatheter arterial chemoembolization. Assessment of the therapeutic effect.

PURPOSE: To evaluate the usefulness of power Doppler sonography (PDS) in assessing the therapeutic effect of transcatheter arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC). MATERIAL AND METHODS: TACE was performed in 43 patients (48 lesions) with HCC. All patients were examined with both PDS and color Doppler sonography (CDS) to assess the therapeutic results 1 week after TACE. Follow-up hepatic angiography was performed in 39 patients 3-4 months after TACE and then CT after iodized oil reinjection was also performed 3-4 weeks after a repeat TACE; in the remaining 4 patients, hepatectomy was performed within one month after chemoembolization and histologic study was undertaken to confirm the Doppler findings. RESULTS: Determination of therapeutic results with PDS and CDS were in agreement with those of follow-up findings in 37 and 29 of the 48 lesions, respectively. There was a significant difference in overall accuracy (p=0.038) between PDS and CDS results. CONCLUSION: PDS is more effective than CDS for evaluating changes in tumor vascularity after TACE. PDS may also replace angiography in assessing the therapeutic effects of TACE for HCCs, except in deep-seated areas.

Aged↗
PubMed1999

[A case report: successful resection of advanced intrahepatic cholangiocarcinoma responding to preoperative hepatic artery infusion of 5-FU].

A patient with advanced intrahepatic cholangiocarcinoma had a tumor embolus in the right main branch of the portal vein and lymph node metastases. Hepatic arterial infusion (HAI) therapy with 5-FU (1 g/day) was given as a continuous infusion for 6 days. The treatment was repeated after a one-week interval. As a result the tumor diameter decreased by half, and the tumor embolus contracted. Cytoreductive surgery was then performed. The patient has been disease-free for over 9 months postoperatively with adjuvant HAI with 5-FU. We consider preoperative HAI with 5-FU (two courses of 1 g/day x 6 days) is both safe and effective.

Antimetabolites, Antineoplastic↗
PubMed1998

Patterns of care study of radiation therapy for cervix cancer in Japan: the influence of the stratification of institution on the process.

BACKGROUND: To improve the quality of radiation oncology in Japan, Patterns of Care Study (PCS), a widely known quality assurance (QA) program in the USA, was introduced. The feasibility was tested by collecting nationwide data by extramural audit for cervix cancer. METHODS: From July 1996 through February 1997, PCS audits were performed for 29 institutions nationwide. On the basis of the facility survey by Tsunemoto, 13 institutions were classified as A1 (university hospital/cancer center), 10 as B1 (other institutions treating >120 patients/year) and six as B2 (other institutions treating <120 patients/year). Medical charts for the patients treated for cervix cancer between 1992 and 1994 were reviewed based on the data format of the US PCS. The total number of patients surveyed was 432. RESULTS: Simulation was used for >90% of the patients in both A1 and B1-2 institutions. However, in B1-2, planning for 5% of the patients was performed with only a clinical set-up (p = 0.0287). A daily fraction with a size of 200 cGy was given to >65% of patients in A1 and to <47% in B1-2. On the other hand, >50% of those in B1-2 were treated with daily fractions of 180 cGy and less compared with 25% in A1 institutions (p < 0.0001). Brachytherapy was utilized more frequently for patients in Stages II (p = 0.0365), III (p = 0.0015) and IV (p = 0.0483) in A1 than in B1-2. As for external beam equipment, linear accelerators with 10 MV or more were used for 83% of the patients in A1. However, in B1-2 institutions, machines with lower energy were used for 38% of the patients (p < 0.0001). The median number of full-time-equivalent (FTE) radiation oncologists was 2.7 in A1, 0.65 in B1 and 0.2 in B2. CONCLUSIONS: Institutional stratification, including equipment and personnel, was found to affect significantly the patterns of care for cervix cancer. Therefore, to improve the quality of radiation therapy nationwide, improvements in equipment and in supply of FTE personnel are extremely important. PCS was found to have great potential for a practical evaluation of how much improvement will be required in Japan.

Adult↗
PubMed1997

Visualization of tumor vessels in hepatocellular carcinoma. Power Doppler compared with color Doppler and angiography.

PURPOSE: To assess the visualization of tumor vessels in hepatocellular carcinoma (HCC) by power Doppler sonography. MATERIAL AND METHODS: We examined 40 patients with 47 HCC lesions by means of power Doppler sonography and compared its visualization of tumor vessels with those of color Doppler and angiography. RESULTS: In 38 (81%) of the 47 lesions, power Doppler sonography improved the visualization of tumor vessels compared with color Doppler sonography; in the remaining lesions no significant difference was noted. In lesions located within 7 cm in depth, there was no significant difference between power Doppler sonography and angiography. In 10 (83%) out of 12 small (< or = 2 cm in diameter) lesions and in 11 (85%) out of 13 hypovascular lesions, power Doppler sonography performed considerably better than angiography. In deeper-seated lesions, however, angiography was significantly superior to power Doppler sonography. CONCLUSION: Power Doppler sonography is more sensitive in detecting the fine tumor vessels in most HCCs than color Doppler sonography. In addition, power Doppler sonography can replace angiography in evaluating tumor vascularity in HCCs except in lesions that are deep-seated or located near the heart. In these lesions, angiography can complement power Doppler sonography in demonstrating tumor vessels.

Aged↗
PubMed1997

[Radiological diagnosis of viral encephalitis].

Most of viral encephalitis may demonstrate no specific change on CT and MR images. Brain swelling, edema, abnormal density (CT) and abnormal intensity (MR) can be detected in herpes simplex encephalitis and enterovirus encephalitis (coxsackie, echo, polio). The common finding on CT and MRI in patients with HIV encephalopathy are atrophy, leukomalacia. Progressive multifocal leukoencephalopathy (PML) shows multifocal oval or round white matter T2-hyperintensities on MR images. Subacute sclerosing panencephalitis (SSPE) may present slight changes in the subcortical and periventricular white matter, as well as basal ganglia. Progressive disorder makes widespread T1-low, T2-high intensity area and atrophy. MRI of acute disseminated encephalomyelitis (ADEM) shows multifocal subcortical hyper intense foci on T2-weighted studies. The deep white matter, brainstem, thalamus and cerebellum can be affected. Most of ADEM lesions resolve. Imaging findings of acute lymphocytic meningitis by echovirus and coxsackievirus are usually normal.

Encephalitis, Viral↗
PubMed1996

[MR angiography and MR cholangiopancreatography].

MR angiography is an adjunctive for noninvasive evaluation of blood vessels and MR cholangiopancreatography is for bile duct and pancreatic duct. Clinical applications of MR angiography has been focused mainly on head and neck and its applications to the abdomen are still limited. However, this technique has the good potential for the evaluation of portal vein system. MR cholangiopancreatography can depict bile ducts and pancreatic duct simultaneously and three-dimensionally. This technique can evaluate the causes of the lesion and its extent noninvasively. In this article the practical uses of MR angiography and MR cholangiography in the abdomen are discussed.

Abdomen↗
PubMed1992

Pseudoenhancement of intervertebral disc herniation.

Two patients with intervertebral disc herniation appeared to demonstrate abnormally diffuse and intense enhancement of the disc after intravenous administration of gadolinium-DTPA for MRI. Surgery disclosed a dilated epidural venous plexus in one and vascular granulation tissue in the other, associated with the herniated disc material. The mechanism of this "pseudoenhancement" of the disc appears to be a partial volume effect of disc material and the adjacent veins or granulation tissue. Pseudoenhancement of a herniated disc should be included in the differential diagnosis of a diffusely enhancing epidural mass.

Aged↗
PubMed1992

Follow-up MRI in dural arteriovenous malformations involving the cavernous sinus: emphasis on detection of venous thrombosis.

Six patients with a dural arteriovenous malformation (dural AVM) involving the cavernous sinus were followed up with magnetic resonance imaging in order to assess change in the lesions. Spin-echo (SE) imaging of three patients in whom the AVM appeared to have closed at least 1 month earlier (two of them spontaneously, and one after external carotid artery embolization) showed neither apparent flow void in the involved cavernous sinus nor evidence of venous thrombosis. SE images of the other three patients who had not been cured by external carotid artery embolization (two of whom were examined within a week of treatment), detected persisting arteriovenous shunts, including high-flow cortical venous drainage, seen as flow void. Two-dimensional time-of-flight MR angiography (2D TOF MRA) was performed simultaneously in three patients. Whereas shunting blood and the normal cavernous sinus were of high intensity, presumed thrombosed cavernous sinuses were isointense with stationary brain tissue. SE imaging can confirm the resolution of arteriovenous shunts, but poorly delineates very acute and chronic thrombosis of the draining veins. In contrast, 2D TOF MRA directly demonstrates flowing blood, permitting the diagnosis of venous thrombosis; it should be included in follow-up of a dural AVM involving the cavernous sinus when venous thrombosis is suspected.

Adult↗
PubMed1992

MR diagnosis of meniscal tears of the knee: value of axial three-dimensional Fourier transformation GRASS images.

Axial MR images of 40 knees in 37 patients with clinically suspected meniscal tears were obtained by using a three-dimensional (3-D) Fourier transform, gradient-refocused acquisition in the steady state (GRASS) pulse sequence. All knees also were examined in both coronal and sagittal planes with a two-dimensional (2-D) Fourier transform, spin-echo pulse sequence for T1-weighted images and a multiplanar GRASS pulse sequence for T2*-weighted images (conventional 2-D pulse sequences). Arthroscopic confirmation was available in all cases and was used as the gold standard. In these 40 knees, 32 of 33 meniscal tears and 45 of 47 normal menisci were correctly identified with axial 3-D imaging, yielding a sensitivity of 97% and specificity of 96%. Conversely, the sensitivity was 82% and the specificity was 100% for the 2-D technique in the diagnosis of meniscal tears. A combination of both techniques yielded 100% sensitivity, 100% specificity, and 100% accuracy in the evaluation of the menisci. Seven discrepancies between the findings of the two techniques were found in the evaluation of 33 arthroscopically proved torn menisci; six of the seven represented false-negative 2-D images and one was a false-negative axial 3-D image. Of 47 normal menisci, only two false-positives occurred with axial 3-D imaging and none with 2-D imaging. Despite the lack of a statistically significant difference, these preliminary findings suggest that the sensitivity in the diagnosis of meniscal tears can be improved by adding thin-sliced axial images with the 3-D GRASS pulse sequence to conventional 2-D imaging.

Adolescent↗
PubMed1991

[Three-dimensional axial volume acquisition on meniscal lesions of the knee].

Axial three-dimensional volume scans obtained by magnetic resonance (MR) imaging were used to evaluate meniscal lesions of the knee in 28 knees of 26 cases. Axial 0.7 mm thin-sliced images with volume scan outlined the overall meniscal appearance for the first time. Axial volume scan was essential to the diagnosis of discoid lateral meniscus because only it could depict the characteristic elongated appearance of discoid lateral meniscus. Radial meniscal tears were depicted only by this technique: conventional sagittal and coronal views could not detect this type of meniscal tear. Volume scan could detect the precise extent of lesions with horizontal meniscal tears and meniscal degeneration. These MR findings obtained by axial volume scans were confirmed by arthroscopy in all cases. We concluded that volume scans were extremely useful in the evaluation of meniscal lesions because they offered axial views that provided much information on menisci located horizontally in the knee.

Adolescent↗
PubMed1991

[MRI of discoid lateral meniscus].

We retrospectively reviewed the MR examinations of 10 patients (17 knees) with surgically documented discoid lateral meniscus of the knee joint. As MRI of the knee is being used more often, the criteria for diagnosis of this entity with MRI need to be established. We tried to define MRI criteria for the detection of discoid menisci by performing numerical measurements of MR images on a display screen. The transverse diameter of the midbody of a discoid lateral meniscus averaged 21.9 mm (normal control: 8.6 mm), and its proportion to the transverse width of the tibia averaged 29.4% (normal control: 12.0%). The measurable difference in height between the discoid and the medial meniscus was negligible. The number of sagittal sections on which the anterior and posterior horns connected varied from two to five in cases of discoid lateral meniscus, and from zero to two in normal controls. Among these parameters, the transverse diameter and its proportion of the transverse width of the tibia proved to be the most reliable. We concluded that a discoid meniscus is indicated if a transverse diameter of a lateral meniscus exceeds 15 mm (proportion to the tibia: 20%).

Adolescent↗
PubMed1991

[A three-dimensional gradient refocussed 3D volume imaging of discoid lateral meniscus].

An axial 3D volume scan with MRI was applied to the evaluation of discoid lateral meniscus of the knee. By 0.7 mm-thick thin-sliced and gapless images with volume scan, characteristically elongated appearance of discoid lateral meniscus was clearly depicted. These MR findings completely accorded with those on arthroscopy. Our conclusion is that an axial 3D volume scan was essential to the diagnosis of discoid lateral meniscus.

Adolescent↗
PubMed1991

Nerve root avulsion of birth palsy: comparison of myelography with CT myelography and somatosensory evoked potential.

Findings at myelography and computed tomographic (CT) myelography were reviewed in 21 patients (22 limbs) with birth palsy; nerve root shadows were the focus of this study. Myelography demonstrated 51 completely avulsed roots (78%) and 14 incompletely avulsed roots (22%). A traumatic meningocele was detected at 38 roots on myelograms and 51 roots on CT myelograms. Thirteen avulsed roots (eight completely and five incompletely avulsed roots) (20%) were not associated with a meningocele. In nine patients who underwent brachial plexus exploration, myelographic findings were compared with root somatosensory evoked potential (SEP). SEP was not induced at 22 of 25 completely avulsed roots and was induced at all seven incompletely avulsed roots. Myelography and SEP were consistent in 29 of 32 roots (91%). It is concluded that myelography is indispensable for preoperative evaluation of cervical nerve root avulsion of birth palsy, because CT myelography is not sensitive to nerve root avulsion without a traumatic meningocele, and SEP cannot enable one to discriminate incomplete avulsion from intact roots.

Brachial Plexus↗
PubMed1991

A frameless, armless navigational system for computer-assisted neurosurgery. Technical note.

A computer-assisted neurosurgical navigational system has been developed which displays intraoperative manipulation on the preoperative computerized tomography (CT) scans or magnetic resonance (MR) images. The system consists of a three-dimensional digitizer, a personal computer, and an image-processing unit. Utilizing recently developed magnetic field modulation technology, the three-dimensional digitizer determines the spatial position and orientation angles of the resin probe, triangle-shaped pointer, or suction tube with a small attached magnetic field sensor. Four fiducial markers on the scalp were used to translate the spatial data of the probe onto the preoperative CT scans or MR images of the patient. With this frameless, armless navigational system, CT or MR-imaging stereotaxy can be applied to conventional open neurosurgery without limiting the operative field or interfering with the surgical procedures.

Adult↗