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Biomedical subjects

I Tsukaguchi

Publications and source records attributed to I Tsukaguchi.

At least 19 recordsLinked to original sources

Intraosseous ganglion.

A 48-year-old man presented with pain in the right wrist. A roentgenogram showed symmetrically located, well-demarcated lucencies in both scaphoids. These lesions showed homogeneous intermediate signal intensity on T1-weighted MR images and homogeneous high signal intensity on T2*-weighted MR images. Histopathological analysis revealed the lesion in the right hand as an intraosseous ganglion. The reason why the lesions were located on the palmar side is discussed.

Bone Cysts

Acute Budd-Chiari syndrome due to inferior vena cava occlusion following blunt trauma.

Inferior vena cava (IVC) thrombosis or obstruction is a complication rarely associated with blunt trauma. We present a case of IVC thrombo-occlusive lesion with both hepatic and renal failure which developed after a thoracoabdominal blunt trauma. Direct thrombectomy and patch cavoplasty were successfully carried out under deep hypothermia using cardiopulmonary bypass.

Acute Disease

MRI of the brain in diabetes mellitus.

We studied the MRI appearances of the brain in 159 patients with diabetes mellitus (DM) and 2566 age-matched individuals without DM (controls). The images were reviewed for cerebral infarcts, hemorrhage, atrophy and subcortical arteriosclerotic encephalopathy. Cerebral atrophy was significantly more frequent in patients with DM than in controls (P > 0.005) from the sixth to the eighth decade. The frequency of atrophy was 41.2% in the 6th decade, 60.0% in the 7th and 92.3% in the 8th decade in DM, and 19.8%, 38.9% and 56.8% respectively in controls. Unexpectedly, there was no statistically significant difference in the incidences of cerebrovascular diseases at any age.

Adolescent

MR diagnosis of discoid lateral menisci of the knee.

OBJECTIVE: To establish explicit criteria for MR imaging diagnosis of discoid lateral menisci of the knee. SUBJECTS: Materials included surgically proved 38 discoid lateral menisci and 36 normal lateral menisci of adult patients. A discriminant analysis was used to identify the optimal cut-off points of the following eight parameters: (1) transverse width of a lateral meniscus on the coronal image at the midportion of a meniscal body; (2) ratio of transverse width between a lateral meniscus and a tibia; (3) height of the lateral margin of a lateral meniscus; (4) difference in height between lateral and medial menisci; (5) transverse area of a lateral meniscus; (6) the number of consecutive sagittal slices demonstrating continuity of the meniscus between the anterior and posterior horns (bow tie appearance); (7) height of the anterior horn of a lateral meniscus on the sagittal image; (8) height of the posterior horn of a lateral meniscus on the same sagittal image. RESULTS: The transverse width of a lateral meniscus on the coronal image was the best parameter, with a cut-off point of 14 mm. Using this criterium, 33 knees of 38 discoid lateral menisci and all 36 normal menisci were correctly identified, yielding an overall accuracy of 93%. CONCLUSION: A discoid lateral meniscus should be present if the transverse width of a lateral meniscus at the midportion of a meniscal body exceeds 14 mm, independent of the tibial width.

Adult

Evaluation of cerebral vasoreactivity by three-dimensional time-of-flight magnetic resonance angiography.

BACKGROUND AND PURPOSE: Cerebral vasoreactivity is an important indicator of the reserve capacity of the cerebral circulation. To make a quantitative analysis of cerebral vasoreactivity in individual major arterial territories, we evaluated the response to acetazolamide using three-dimensional time-of-flight magnetic resonance angiography. METHODS: We examined 10 healthy volunteers and 6 patients with unilateral stenosis of the middle cerebral artery by a 1.5-T superconducting magnetic resonance imaging system. After a baseline vascular image was obtained, each subject received 17 mg/kg IV of acetazolamide; a second scan was performed 20 minutes later. Using a generally available personal computer and image analysis software, we measured the areas of the individual major arteries on collapsed axial vascular images and then calculated the vasoreactivity. RESULTS: The average vasoreactivity of individual major cerebral arterial territories in the healthy volunteers was as follows: anterior cerebral artery complex, 33%; right middle cerebral artery, 71%; left middle cerebral artery, 74%; right posterior cerebral artery, 68%; and left posterior cerebral artery, 68%. In the patient group, the vasoreactivity of the stenotic middle cerebral arteries was significantly smaller than that of the nonstenotic arteries (P < .05). In addition, the nonstenotic middle cerebral arteries showed significantly less vasoreactivity than the right arteries of the healthy volunteers (P < .01). CONCLUSIONS: Three-dimensional time-of-flight magnetic resonance angiography can be used to quantitatively evaluate acetazolamide-induced vasoreactivity in individual major cerebral arterial territories.

Acetazolamide

A pitfall in detection of intracranial unruptured aneurysms on three-dimensional phase-contrast MR angiography.

We report three cases of intracranial unruptured aneurysm evaluated with MR angiography using both three-dimensional time-of-flight and three-dimensional phase-contrast techniques. It has been said that the phase-contrast technique has advantages over the time-of-flight technique in the detection of intracranial aneurysms. However, in our three cases, three-dimensional time-of-flight MR angiography clearly showed the intracranial unruptured aneurysms, but three-dimensional phase-contrast MR angiography failed to show them.

Adult

[Doses of epirubicin used in oily chemoembolization of hepatocellular carcinoma].

Epirubicin (EPIR), an anticancer agent, has recently been used with increasing frequency in transcatheter oily chemoembolization (TOCE) of hepatocellular carcinoma. We conducted a dose-finding study of EPIR with regard to its safety. One hundred thirty-four patients were divided into five groups according to the EPIR doses (mg/m2), Group A (< 30 mg/m2), Group B (> or = 30 - < 40 mg/m2), Group C (> or = 40 - < 50 mg/m2), Group D (> or = 50 - < 60 mg/m2), and Group E (> or = 60 mg/m2). The number of leukocytes decreased at 2 weeks but recovered at 4 weeks with no significant differences among the groups. However, there were significantly fewer leukocytes in Group E than in Groups A to D. There were no significant differences among the groups in either the number of erythrocytes or platelets. The number of platelets tended to remain at increased levels even at 4 weeks. Liver function as represented by GOT, GPT, LDH, and total bilirubin was not aggravated, but tended to improve. GOT and LDH in Groups D and E, in particular, improved significantly at 4 weeks, probably because of the antitumor effect of TOCE. These results suggest that EPIR can be administered up to 50 mg/m2 for TOCE.

Carcinoma, Hepatocellular

Acetazolamide challenge for three-dimensional time-of-flight MR angiography of the brain.

PURPOSE: We compared three-dimensional time-of-flight MR angiograms obtained before and after acetazolamide administration to evaluate whether use of this drug could improve visualization of small peripheral intracranial arteries and atherosclerotic stenosis. METHODS: For evaluation of small peripheral arteries, 10 patients with clinical diagnosis of ischemic cerebrovascular disease and 10 healthy volunteers were investigated, and for evaluation of stenosis, another 6 patients were investigated. Vascular images were obtained by three-dimensional time-of-flight MR angiography. After a baseline scan, 17 mg/kg acetazolamide was injected intravenously and the second scan was performed 20 minutes later. RESULTS: Several small peripheral arteries that had not been seen on the baseline images were visible on the acetazolamide images without any augmentation of the background signals. Stenotic lesions in the main trunks of the major cerebral arteries were detected more clearly on acetazolamide images. CONCLUSIONS: Acetazolamide improves visualization of small peripheral intracranial arteries and sensitivity in detecting atherosclerotic stenosis in the main trunk of major cerebral artery by three-dimensional time-of-flight MR angiography without changing MR apparatus and software.

Acetazolamide

[MR imaging of pigmented villonodular synovitis of knee].

Six cases of pigmented villonodular synovitis (PVNS) of the knee are presented. MR images and surgical findings were available in all cases. Four of six cases were diffuse form, and the other two were localized form. The MR appearance of PVNS varied, depending on the relative proportion of the pathological component. It most commonly consisted of scattered areas of low signal intensity due to hemosiderin deposition in the hypertrophied synovium on T2*-weighted images, and dotted areas of low signal intensity presumably resulting from the fibrous component of the lesion on T1-weighted images. The latter finding was described for the first time in our study. One case was associated with osteochondromatosis and osteoarthritis, and another case with osteoarthritis. In the remaining four cases, the osseous structures, cruciate ligaments and menisci were normal.

Adolescent

[Semidiscoid lateral meniscus].

We propose a new entity known as "semidiscoid lateral meniscus" of the knee. The diagnostic criteria for semidiscoid lateral meniscus is the appearance on a thin-sliced axial 3-D image of a crescent-shaped meniscus whose transverse width is within 11.6 mm to 14.3 mm on the coronal image. These numerical values were calculated by discriminant analysis. A retrospective review of MR examinations of the knees revealed 15 patients (15 knees) with this entity. These patients were our subjects. Of these 15 patients, complicated lateral meniscal tears were seen in only three cases. Nine knees were free from complications, and five were asymptomatic. Six patients were examined with MR on the contralateral side, and discoid lateral menisci were revealed in all cases. Thus semidiscoid lateral meniscus shows a cross-relationship with discoid menisci.

Adolescent

Malignant fibrous histiocytoma coexistent with mucinous cystadenoma of the pancreas.

A patient with malignant fibrous histiocytoma (MFH) coexistent with mucinous cystadenoma of the pancreas is reported. Primary MFH of the pancreas is rare, with only six patients reported in the world medical literature. A patient with MFH coexistent with a pancreatic mucinous epithelial tumor has not been reported previously, although two patients with pseudosarcomatous tumor associated with mucinous cystadenocarcinoma of the pancreas have been reported. Mural nodules of similar histologic appearance have been reported in ovarian mucinous tumors. The authors believe this to be the first report of the occurrence of MFH in mucinous cystadenoma of the pancreas.

Adult

[MR angiography enhanced by sodium acetazolamide].

We tried to use sodium acetazolamide to enhance MR angiography (MRA). Sodium acetazolamide, one of carbonic anhydrase inhibitors, has an effect to increase regional cerebral blood flow. We made a direct comparison between pre and post enhanced MRA (both 3D-TOF and 3D-PC techniques). MRA after administration of sodium acetazolamide could depict more details of cortical branches without enhancement of back-ground. So we recommend this simple method to be used widely in any examination of MR angiography.

Acetazolamide

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

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