Biomedical subjects

T Imaeda

Publications and source records attributed to T Imaeda.

At least 19 recordsLinked to original sources

PubMed1992

Accessory bile duct draining into the stomach: case report and review.

Accessory bile duct with ectopic drainage into the gastrointestinal tract is an extremely rare congenital anomaly, and only 55 cases have been reported in the literature. We present another case of accessory bile duct draining into the stomach. Barium meal study of the stomach first revealed the accessory bile duct, and the diagnosis was confirmed by gastrofiberscopy, ultrasonography, hepatobiliary scintigraphy, computed tomography (CT), and endoscopic retrograde cholangiopancreatography (ERCP).

Adult↗

PubMed1992

Hepatocellular carcinoma with extrahepatic primary neoplasms.

We experienced seven cases of hepatocellular carcinoma (HCC) with extrahepatic primary malignant neoplasms (PMNs), which accounted for 7.5% of 93 HCC cases in our department during a 5.5-year investigation period. No common characteristics of the seven patients with extrahepatic PMNs in terms of age, sex, computed tomographic (CT) features of hepatocellular carcinoma, or presence of liver cirrhosis were evident. One of the seven cases had triple PMNs. Extrahepatic PMNs were found in various organs: stomach, colon, kidney, lung, larynx, and esophagus. Attention to extrahepatic organs should be undertaken in the management of HCC. Two patients in hepatic coma died 4 and 6 months after the diagnosis of HCC due to the advanced HCC, and accompanying extrahepatic malignancies were not the primary cause of death.

Adult↗

PubMed1992

Magnetic resonance imaging in Kienböck's disease.

With a 1.5 tesla superconducting M.R. imager and surface coil, M.R. imaging achieved high resolution analysis of the wrist on five normal wrists and 26 wrists with Kienböck's disease. The purpose of this study was to establish new criteria for diagnosis, staging and prognosis of Kienböck's disease, based on signal characteristics on T1- and T2-weighted images. Focal loss of signal intensity of the lunate on T1-weighted image was an indication of Kienböck's disease. A decreased signal containing a high spot and increased signal intensity of the lunate on T2-weighted images indicated a better prognosis. After osteotomy of the radius, the signal intensity of the lunate returned to normal and Lichtman's stage II cases had better results than those in stage III. M.R. imaging is ideal for evaluating the lunate in Kienböck's disease.

Adult↗

PubMed1992

Magnetic resonance imaging in scaphoid fractures.

The use of a 1.5 tesla superconducting M.R. imager and surface coil was found to enhance the ability of M.R.I. to depict the fine anatomy of the wrist. Five healthy volunteers and 28 patients with scaphoid fractures underwent M.R.I., which made possible a definitive diagnosis of scaphoid fractures at an early stage. A fresh fracture was identified by decreased or iso signal intensity on the T1-weighted image and increased signal intensity on the T2-weighted image. This increase continued until bony union was apparent on radiographs. On the T2-weighted image, high signal intensity was characteristic of fresh fractures and suggested that bony union was possible. When bony union was complete, the intensity of the signal for the scaphoid on both T1- and T2-weighted images returned to normal. M.R.I. should thus prove useful in the diagnosis of scaphoid fractures.

Adolescent↗

PubMed1992

Rupture of hepatocellular carcinoma: predictive value of CT findings.

To assess the value of CT in predicting spontaneous rupture of hepatocellular carcinoma, we reviewed CT scans obtained within 3 months before the rupture of hepatocellular carcinoma in 23 patients (rupture group) and within 3 months before death of any cause other than rupture of hepatocellular carcinoma in 20 patients with tumor contacting or protruding out of the liver margins (nonrupture group). All the carcinomas in the rupture group were located in the periphery of the liver. They protruded out of the liver margins in 18 cases and contacted the liver margins without protrusion in five cases. For the rupture and nonrupture groups, respectively, mean numbers of involved liver segments were 4.2 +/- 2.3 and 2.3 +/- 1.3 (p less than .01); mean maximal tumor areas were 102.0 +/- 57.0 cm2 and 57.7 +/- 50.9 cm2 (p less than .05); frequencies of tumor protrusion was 78% and 50% (NS); mean maximal lengths of protruded margins of the tumor were 188.1 +/- 81.4 mm and 77.2 +/- 50.3 mm (p less than .01); frequencies of extrahepatic invasion of the tumor were 44% and 20% (NS); and frequencies of ascites were 78% and 50% (NS). No significant differences in age or sex of the patients and clinical stage of the cancer were evident between the two groups. Multiple regression analysis (p less than .005, r2 = .428) indicated that, of the CT findings, maximal length of protrusion correlated best (p less than .05) with subsequent rupture. We conclude that increased tumor size and extent of extrahepatic protrusion are associated with an increased risk for rupture of hepatocellular carcinoma.

Adult↗

PubMed1992

Functional anatomy and biomechanics of the thumb.

The thumb is a mechanical unit consisting of strong ligaments and dynamic muscles, providing the resistance to the fingers and palm during pinch and grip. Each thumb joint has a mechanical equivalent that helps explain elements of thumb stability. The trapeziometacarpal joint is potentially the most unstable but has adapted to its unique position by special joint geometry and, in particular, a combination of support ligaments that permit a wide range of motion yet stability. New anatomic and mechanical studies demonstrate the key support structures that must be duplicated by reconstructive surgical procedures if thumb stability is to be maintained.

Biomechanical Phenomena↗

PubMed1991

Leiomyosarcoma of the duodenum.

Leiomyosarcoma of the duodenum is a rare disease and its characteristics have been described previously in the literature. We present a case of duodenal leiomyosarcoma, which was diagnosed by several imaging techniques prior to operation. Findings of computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography, and angiography in this case are discussed.

Aged↗

PubMed1991

Agenesis of the right lobe of the liver: case report.

Agenesis of the right liver lobe is extremely rare, and only 30 cases of agenesis or hypogenesis of the right hepatic lobe have been reported in the literature. Another case of agenesis of the right lobe of liver is presented herein. Diagnosis was established by computed tomography (CT), liver scintigraphy, and angiography. The radiological findings and differential diagnosis are reviewed.

Congenital Abnormalities↗

PubMed1991

Gallium-67 citrate scintigraphy in the pre-operative evaluation of soft tissue tumors of the extremities.

We conducted a study of 90 patients with soft tissue tumor in their arms or legs, in order to determine the usefulness of scintigraphy with gallium-67 citrate as a diagnostic means. All patients had adequate scan images, and tumor tissues had been histologically confirmed by surgical resection. The subjects consisted of 19 patients with malignant tumors, 55 patients with benign tumors, and 16 patients with other disorders in which soft tissue tumor-like lesions occurred. When the activity of the tumor was more than the activity of the normal region of the contralateral extremity, it was estimated to be positive. The positive rate was found in 78% (15/19) of patients with malignant tumors, in 25% (14/55) of patients with benign tumors and in 31% (5/16) of patients with other disorders. Classified by diseases, high positive rates were observed in liposarcoma, leiomyosarcoma, malignant lymphoma, neurinoma, extra-abdominal desmoid and sarcoidosis. Out of 7 patients in which the activity of the tumor was equal to, or higher than that of the liver, 6 patients had malignant tumors and one patient was diagnosed as having an abscess. It seemed possible to distinguish between liposarcoma and lipoma by means of a gallium-67 scan. Furthermore, the gallium-67 scan was useful in detecting lesions of sarcoidosis as well as in evaluating the response to treatment.

Adolescent↗

PubMed1991

The influence of age and sex on ulnar variance.

Ulnar variance was measured in 325 normal wrists and 41 wrists with Kienböck's disease. A positive correlation between ulnar variance and age was confirmed in normal wrists, and it was lower in males than in females. Therefore, studies comparing ulnar variance in abnormal and normal wrists require carefully selected age- and sex-matched controls. There was no significant difference in ulnar variance between Japanese with normal wrists and those affected by Kienböck's disease, when the effects of sex and age were taken into account. Based on these results, we believe that ulnar variance is highly unlikely to be an important predisposing factor in Kienböck's disease.

Adolescent↗

PubMed1991

Scaphoid non-union with D.I.S.I. deformity. A survey of clinical cases with special reference to ligamentous injury.

To clarify whether or not scapho-lunate ligamentous injury is common in scaphoid non-union with D.I.S.I. deformity and whether ligamentous repair is required to treat scaphoid non-union with D.I.S.I. deformity, roentgenographic, arthrographic and arthroscopic findings were analysed and compared to those of scaphoid non-union without D.I.S.I. deformity. The carpal alignment of scaphoid non-union with D.I.S.I. deformity treated by reduction and anterior wedge grafting without ligamentous repair was also studied. No significant difference in the scapho-lunate gap was present between 26 patients with D.I.S.I. deformity and 20 without. No statistically significant difference was detected in the incidence of arthrographically-proved scapho-lunate ligamentous tears between the two groups. Arthroscopic examination carried out in 22 patients did not detect massive ligamentous injury, and carpal alignment was satisfactory in most patients who underwent anterior wedge grafting. These results show that ligamentous injury rarely causes D.I.S.I. deformity in scaphoid non-union, and anterior wedge grafting alone is sufficient to correct D.I.S.I. deformity in most cases.

Adolescent↗

PubMed1991

Analysis of scaphoid fracture displacement by three-dimensional computed tomography.

Scaphoid fracture displacement was studied in twenty-five patients using three-dimensional computed tomography. Fracture displacement was more readily detected and distinct in three-dimensional computed tomography images than in plain radiography. Two different types of offset of the distal fragment with respect to the proximal fragment are described on three dimensional computed tomography; volar type and dorsal type. In the volar type, the distal fragment overhung in the volar direction relative to the proximal fragment and was frequently accompanied by humpback deformity and axial rotation. In the dorsal type, the distal fragment slipped dorsal on the proximal fragment and was commonly accompanied by humpback deformity. The volar type had a transverse or vertical fracture line on both the volar and dorsal surfaces of the scaphoid, while the dorsal type had a horizontal fracture line. The volar type was frequently found when the fracture was distal, whereas the dorsal type was noted more frequently for proximally located fracture.

Adolescent↗

PubMed1991

Inhibitory effect of cadmium and mercury ions on induction of the adaptive response in Escherichia coli.

Cadmium and mercury ions inhibited the promotion of ada and alkA gene expression in the adaptive process induced by methylating agents such as N-methyl-N-nitrosourea (MNU), methyl methanesulfonate (MMS) and methyl iodide in Escherichia coli. In fact, the induction of O6-methylguanine-DNA methyl-transferase (MGTase) by MNU was suppressed in E. coli in the presence of these metal ions. These ions potentiated mutagenesis induced by methylating agents such as MNU and MMS, but not that induced by ethylating agents, UV irradiation, or N4-aminocytidine. These comutagenic effects were observed in wild-type and umuC36 strains of E. coli but not in the ada-5 strain, which is unable to induce the adaptive response. These results suggest that the comutagenic effects of Cd2+ and Hg2+ are due to inhibition of ada and alkA gene expression promoted by methylated MGTase.

Cadmium↗

PubMed1991

Scaphoid malunion.

We reviewed 10 patients with symptomatic malunion of a carpal scaphoid fracture. All had displacement with dorsiflexed intercalated segment instability, and suffered from pain, restricted range of movement at the wrist and decreased grip strength. The restriction of flexion-extension and the decreased grip strength correlated with the severity of the DISI deformity. Seven patients had a corrective osteotomy, using an anterior wedge-shape bone graft with internal fixation by Herbert screw, and all had satisfactory results. We believe that symptoms associated with scaphoid malunion are related to consequent carpal deformity.

Adolescent↗

PubMed1990

A case of intermittent bleeding Meckel's diverticulum.

The initial technetium-99m pertechnetate abdominal scintigraphy revealed equivocal or normal results. However, a second scintigraphy without pentagastrin demonstrated a focal area of persistently increasing radioactivity in the right lower quadrant of the abdomen. At surgery, Meckel's diverticulum was confirmed, and histological examination of the excised specimen revealed that it was lined with ectopic gastric mucosa. It has not been satisfactorily explained why the initial imaging failed to demonstrate the ectopic gastric mucosa. The necessity to perform repeated scintigraphy must be emphasized because 50 to 91 percent of bleeding Meckel's diverticula in the pediatric age group are said to contain gastric mucosa.

Gastrointestinal Hemorrhage↗

PubMed1990

Radial shortening for Kienböck's disease: factors affecting the operative result.

The operative results of radial shortening in 23 patients with Kienböck's disease were analysed on the basis of age, stage of disease, ulnar variance and the amount of radial shortening. The patient's age was found to be the factor which affected the operative result most and unsatisfactory results were obtained in patients over 30 years old. However, neither the clinical stage nor ulnar variance affected the results significantly and the results in patients with ulnar zero or plus were no worse than in patients with ulnar minus. The risk of ulnar wrist pain was increased when the radius was shortened more than 4 mm in patients with positive or zero ulnar variance. This was an important cause of unsatisfactory operative results.

Adolescent↗

PubMed1990

Excessive radial shortening in Kienböck's disease.

Two patients with Kienböck's disease who had been treated by radial shortening developed ulnar wrist pain post-operatively due to excessive radial shortening. In both cases, ulnar shortening was required to improve symptoms and function. Excessive radial shortening can cause ulnar wrist pain and compromise the improvement of grip strength and range of motion of the wrist.

Adult↗

PubMed1990

Increased focal uptake of Tc-99m stannous phytate in an irregular fatty liver demonstrated by SPECT imaging.

An area of focally increased uptake of Tc-99m colloid (hot spot) in the liver has been reported in superior vena cava syndrome, Budd-Chiari syndrome, and focal nodular hyperplasia. A case of irregular fatty infiltration in which SPECT imaging clearly demonstrated an area of focally increased uptake in the left lobe of the liver, which was not well visualized by planar imaging, is presented. There have been a few previous reports of this finding on SPECT imaging in patients with irregular fatty infiltration of the liver.

Fatty Liver↗