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T Imaeda

Publications and source records attributed to T Imaeda.

At least 19 recordsLinked to original sources
PubMed2000

Does high-resolution MR imaging have better accuracy than standard MR imaging for evaluation of the triangular fibrocartilage complex?

We compared the findings of high-resolution MR imaging and standard MR imaging in the detection of tears of the triangular fibrocartilage in 33 patients with chronic wrist pain on the ulnar side. With arthroscopy as the standard of reference, sensitivity was 100%, specificity 53%, and accuracy 79% with the high-resolution MR imaging, against 83%, 67%, and 76% with the standard MR imaging. High-resolution MR imaging showed a higher sensitivity, but a decreased specificity in the assessment of the triangular fibrocartilage. The results showed that diagnosis of tears in the triangular fibrocartilage by MR imaging, even high-resolution MR imaging, is unsatisfactory, although further technological advances may well improve the accuracy.

Adult↗
PubMed1998

Arthrography is superior to magnetic resonance imaging for diagnosing injuries of the triangular fibrocartilage.

The ability of single-injection radiocarpal arthrography and magnetic resonance imaging (MRI) to detect full-thickness tears of the triangular fibrocartilage were compared with wrist arthroscopy in 102 patients with wrist pain. The sensitivity of arthrography was 85%, and of MRI was 73%. Specificity was 100% for arthrography and 72% for MRI. Accuracy was 92% for arthrography, and 73% for MRI. Although future advances in MRI technology will probably improve its usefulness, single-injection wrist arthrography currently is superior to routine MRI for the detection of full-thickness triangular fibrocartilage tears.

Adolescent↗
PubMed1998

Ulnar styloid malunion with dislocation of the distal radioulnar joint.

Four patients with dorsal dislocation of the distal radioulnar joint and ulnar styloid malunion had corrective osteotomy of the ulnar styloid. Dislocation of the distal radioulnar joint was reduced in three of four patients. Subluxation persisted in the remaining patient. Wrist function improved in all patients. These results support the contention that a displaced ulnar styloid fracture with distal radioulnar joint dislocation should be reduced and internally fixed. Corrective osteotomy is recommended for malunion of the ulnar styloid associated with dislocation of the distal radioulnar joint.

Adolescent↗
PubMed1998

Arthroscopic evaluation of radial osteotomy for Kienböck's disease.

To determine whether osteoarthritic changes of the perilunate articular cartilage improve following radial osteotomy for Kienböck's disease and correlate with clinical results, arthroscopic examination was performed in 18 patients concurrently with radial osteotomy and at the time of removal of implants after an average of 21 months. Clinical results were satisfactory. All patients improved the preoperative level of pain. Wrist function was improved in range of motion and grip strength. Radiographic findings also demonstrated prevention of further collapse of the lunate. However, follow-up arthroscopic examination revealed progression of osteoarthritis in the area of the lunate in two thirds of the cases. There was no correlation between arthroscopic observations and clinical results. A long-term follow-up period is therefore advocated for evaluation of radial osteotomy because of the possibility of additional progression of osteoarthritic changes.

Adolescent↗
PubMed1997

Management of trans-scaphoid perilunate dislocations. Herbert screw fixation, ligamentous repair and early wrist mobilization.

A retrospective review of 28 patients with 29 trans-scaphoid perilunate dislocations who underwent open reduction and Herbert screw fixation is presented. The majority of the patients had satisfactory results at 24 months of follow-up. A significantly better range of wrist motion was obtained in postoperative patients treated with cast immobilization for 4 weeks compared with those treated for longer than 5 weeks. The scaphoid fractures united well, with proper alignment of the carpal bones, regardless of the length of cast immobilization. We recommend open reduction, internal scaphoid fixation using a Herbert screw, carpal ligament repair and early cast removal in the management of trans-scaphoid perilunate dislocations.

Adolescent↗
PubMed1997

The ulnocarpal stress test in the diagnosis of ulnar-sided wrist pain.

Forty-five patients with persistent ulnar-sided wrist pain and a positive ulnocarpal stress test were investigated by X-ray, arthrography, 99mTechnetium bone scanning, magnetic resonance imaging and wrist arthroscopy. Ulnar wrist pathology was positively identified in nine of 45 patients by X-ray, 18 of 37 by arthrography, 19 of 27 by bone scan, four of 33 by MRI, and in all 45 patients by arthroscopy. The final diagnosis was ulnocarpal abutment syndrome in 28 patients, traumatic triangular fibrocartilage (TFC) tear in six, lunotriquetral (LT) ligament tear in five, TFC and LT ligament tear in one, wrist arthritis in four and cartilaginous free body in one. The ulnocarpal stress test is a useful provocative test, and a positive test suggests the presence of ulnar-sided wrist pathology. The test is sufficiently sensitive to warrant further investigation by arthroscopy.

Adolescent↗
PubMed1997

Detection of micrometastatic prostate cancer cells in the bone marrow of patients with prostate cancer.

Thirty-five patients with prostate cancer were examined for micrometastases to the bone marrow using reverse transcription-polymerase chain reaction (RT-PCR) with primers specific for the prostate-specific antigen (PSA) gene. Of nine patients with bone metastases detectable by bone scan imaging, five patients had PSA mRNA expression in the bone marrow detectable by RT-PCR. Of 26 patients with negative bone scan findings, seven patients had PSA mRNA expression detectable in the bone marrow. RT-PCR could detect micrometastatic prostate cancer cells in the bone marrow that were not detectable by bone scan imaging. Of 16 patients with a serum PSA concentration of 25 ng ml(-1) or greater, only nine (56.3%) had bone metastases detected by bone scans. Of the remaining seven patients, five had micrometastases to the bone marrow detected by RT-PCR. Overall, 14 of 16 patients (87.5%) with a serum PSA concentration of 25 ng ml(-1) or greater had metastatic bone diseases including bone marrow micrometastases. Of 19 patients with a serum PSA concentration of less than 25 ng ml(-1), two (10.5%) had only micrometastatic disease detected by RT-PCR. A significant correlation was observed between the incidence of bone involvement and the serum PSA concentration. This study suggests that RT-PCR will potentially develop into a relevant tool to assess bone involvement including bone marrow micrometastases and establish a precise correlation between serum PSA concentration and metastatic bone disease in patients with prostate cancer.

Bone Marrow↗
PubMed1997

Hepatic injury localized to the field of total lymphoid irradiation.

A 37-year-old woman with severe aplastic anemia underwent allogeneic bone marrow transplantation following cyclophosphamide (CY) and total lymphoid irradiation (TLI). On day +30, a CT scan was carried out because of a mild elevation in liver enzymes, and it revealed a low density area with a sharp border in the left lobe corresponding to the irradiated area. MRI showed a hypersignal intensity on both T1 and T2-weighted images and suggested that hepatic damage was mainly severe fatty change. These abnormalities resolved with no treatment. CY with TLI for adult patients with severe aplastic anemia may induce hepatic injury.

Adult↗
PubMed1997

Three-dimensional CT demonstration of intrahepatic portosystemic venous shunt draining into the inferior vena cava.

An unusual form of intrahepatic portosystemic venous shunt draining into the inferior vena cava was demonstrated using three-dimensional images reconstructed from spiral CT during arterial portography, colour Doppler ultrasonography with flow velocity measurement, and digital subtraction portovenography. The utilization of modern radiological techniques in evaluating intrahepatic portosystemic venous shunts is discussed.

Aged↗
PubMed1997

Detection and characterization of hepatic tumors: value of combined helical CT hepatic arteriography and CT during arterial portography.

OBJECTIVE: The purpose of our study was to evaluate the diagnostic accuracy of combining helical CT hepatic arteriography (CTA) with helical CT during arterial portography (CTAP) for detecting and characterizing hepatic tumors. MATERIALS AND METHODS: From January 1994 to September 1995, combined helical CTA and CTAP were performed in 52 patients (38 men and 14 women, 37-83 years old [mean, 64.1 years old]) with suspected primary or metastatic hepatic tumors before they were evaluated for hepatic resection. Retrospectively, two radiologists reviewed the CTAP images alone and subsequently matched CTA and CTAP images. The radiologists recorded a confidence level on a five-point scale for their evaluation of visible perfusion abnormalities as true lesions, and diagnostic accuracy was assessed using receiver-operating-characteristic analysis. Using the data sets obtained at the interpretation sessions by the radiologists, we determined sensitivities for CTAP alone and for combined CTA and CTAP in 28 malignant hepatic tumors that were confirmed in 19 patients who underwent definitive surgery. RESULTS: CTA revealed one hepatocellular carcinoma in a patient with severe cirrhosis and six adenomatous hyperplasias in another cirrhotic patient that CTAP failed to reveal. In comparison with CTAP alone, the combination of CTA and CTAP allowed significantly more accurate detection of lesions (area under receiver-operating-characteristic curve: 0.889 for CTAP alone versus 0.954 for CTA and CTAP combined, p < .01). The combination of CTA and CTAP also significantly raised the accuracy for characterizing hepatic tumors. Sensitivities for malignant hepatic tumors revealed in the 19 patients who underwent surgery were identical: 93% (26 of 28 tumors) with CTAP alone and with CTA and CTAP combined. CONCLUSION: Although combining CTA and CTAP does not significantly increase sensitivity for detecting hepatic tumors, the combined techniques significantly raise specificity in detecting hepatic tumors and accuracy in characterizing hepatic tumors.

Carcinoma, Hepatocellular↗
PubMed1996

Criteria for diagnosing distal radioulnar joint subluxation by computed tomography.

Bilateral wrist computed tomography (CT) was performed in 30 patients with suspected unilateral distal radioulnar joint (DRUJ) subluxation to evaluate dynamic DRUJ CT scanning with a straight elbow. Five CT criteria for diagnosing dorsovolar subluxation were examined. Maximum active supination and pronation on a conventional scanning table yielded satisfactory rotation (mean +/- SD, 119 degrees +/- 29 degrees) at the DRUJ, thus permitting a dynamic diagnosis of DRUJ subluxation. The radioulnar line method and the congruity method frequently yielded false positive results compared with bilateral diagnosis and were unreliable. Modifications of these two methods achieved sensitivity and specificity comparable to the epicenter method. We recommended the modified radioulnar line method for diagnosing dorsovolar subluxation using unilateral CT because of its excellent sensitivity and specificity combined with ease of technique.

Adolescent↗
PubMed1996

Kinematics of the trapeziometacarpal joint: a biomechanical analysis comparing tendon interposition arthroplasty and total-joint arthroplasty.

The kinematics of the trapeziometacarpal joint were studied in 15 cadaver hands; normal joints were compared with simulated arthroplasties-either a total-joint arthroplasty of the ball-and-socket variety or a fibrous suspension arthroplasty of ligament reconstruction with tendon interposition. The motion of the thumb metacarpal was analyzed based on a trapezial coordinate system, using a magnetic tracking system. The pivot point (instantaneous center of rotation) for the thumb metacarpal changed during active and passive circumduction. Compared with normal trapeziometacarpal joint motion, the pivot point after ligament reconstruction with tendon interposition shifted significantly in palmar and ulnar directions in reference to the trapezial coordinate system, whereas after total-joint arthroplasty, the pivot point shifted slightly palmarly and radially. The axes of rotation were also compared for ligament reconstruction with tendon interposition and total-joint arthroplasty during thumb flexion-extension and abduction-adduction motions. After ligament reconstruction with tendon interposition, the center of flexion-extension shifted palmarly and the center of abduction-adduction shifted ulnarly. After total-joint arthroplasty, the center of rotation for flexion-extension shifted distally and palmarly and that for abduction-adduction shifted palmarly and proximally. In comparison with the normal joint, passive circumduction increased after tendon interposition arthroplasty but was less with total-joint arthroplasty. Changes in kinematics suggest a suspensory ligament function of ligament reconstruction with tendon interposition arthroplasty, whereas total-joint arthroplasty results in axes of rotation that reflect the joint replacement rather those of the normal joint.

Arthroplasty↗
PubMed1996

Ulnar impaction syndrome: MR imaging findings.

PURPOSE: To evaluate magnetic resonance (MR) imaging findings in ulnar impaction syndrome and changes after ulnar recession arthroplasty. MATERIALS AND METHODS: MR imaging and arthroscopy were performed in 30 wrists in 27 patients (aged 15-62 years) in whom ulnar impaction syndrome was diagnosed on the basis of physical examinations. MR imaging was performed in 11 wrists before and after surgery. T1- and T2-weighted spin-echo images were obtained. Signal intensities in the lunate, triquetrum, and ulnar head were evaluated. RESULTS: There was focal abnormal signal intensity of the ulnar aspect of the lunate in 87% of wrists, of the radial aspects of the triquetrum in 43%, and of the radial aspects of the ulnar head in 10% before surgery. The signal intensity of the abnormalities was decreased on T1-weighted and decreased or increased on T2-weighted images. After surgery, the signal intensity of the lunate shifted from low through slightly low to normal on T1-weighted and from low through high to normal on T2-weighted images. CONCLUSION: Most ulnar impaction syndrome cases have characteristic focal signal intensity changes in the ulnar part of the lunate. The signal intensity often returns to normal after ulnar recession arthroplasty.

Adolescent↗
PubMed1996

Value of three-dimensional spiral CT hepatic angiography.

OBJECTIVE: The aim of this study was to compare with conventional angiography images the diagnostic utility of three-dimensional CT hepatic angiography (CTHA) images reconstructed from spiral CT images obtained during direct injection of contrast material into hepatic arteries. MATERIALS AND METHODS: Three-dimensional CTHA images were reconstructed from spiral CTHA images obtained during direct hepatic arterial contrast material injection in 22 patients. We used maximum-intensity-projection (MIP) and shaded-surface-display (SSD) techniques. We compared matched pairs of MIP CTHA images and SSD CTHA images with conventional angiograms for depiction of peripheral (segmental to subsegmental order branches) and proximal (common to proper) hepatic arteries as well as for conspicuity of the entire hepatic arterial tree in 22 patients and for conspicuity of tumors, recognition of tumor sites, and depiction of tumor-feeding arteries in 21 patients with malignant liver tumors. Our evaluations were performed in a blinded fashion by two experienced radiologists, who reached a consensus. (These radiologists also counted the number of tumors depicted by each method in the 21 patients with malignant liver tumors.) RESULTS: Depiction of peripheral and proximal hepatic arteries and conspicuity of the entire hepatic arterial tree were significantly better on conventional angiograms than on MIP CTHA images and SSD CTHA images. Conspicuity of tumors and recognition of tumor sites were significantly better on MIP CTHA images and SSD CTHA images than on conventional angiograms. Depiction of tumor-feeding arteries was significantly better on MIP CTHA images than on SSD CTHA images and conventional angiograms. For 47 malignant liver tumors, MIP CTHA images showed 40 (85%), SSD CTHA images showed 34 (72%), and conventional angiograms showed 20 (43%). CONCLUSION: MIP CTHA images showed liver tumors, tumor sites, and tumor-feeding arteries better than conventional angiograms. MIP was the preferred method for three-dimensional CTHA analysis.

Aged↗
PubMed1995

Distal radioulnar joint subluxation and dislocation diagnosed by standard roentgenography.

The use of standard lateral roentgenography for diagnosing distal radioulnar joint (DRUJ) subluxation and dislocation was investigated. Using a wrist support, bilateral standard lateral roentgenograms of the wrist were obtained in 42 patients with normal wrists and in 56 patients with a unilateral wrist injury. In normal wrists the difference between the radioulnar distance in the right and the left wrist did not exceed 4 mm when the difference in the pisoscaphoid distance was less than 3 mm. Of the 36 patients with wrist injury whose difference in pisoscaphoid distance was less than 3 mm, 15 had a radioulnar distance of 5 mm or more, and computed tomography (CT) confirmed DRUJ dislocation in 14. Concordance between lateral roentgenograms and CT was present in 33 of 36 patients (92%). These results demonstrate the value of a standardized technique for bilateral lateral roentgenography in diagnosing DRUJ subluxation and dislocation.

Adolescent↗
PubMed1995

Arthroscopic assessment of Kienböck's disease.

Arthroscopic examination was performed on 32 wrists of 32 patients with Kienböck's disease to relate the appearance of the intraarticular structures, particularly the articular cartilage, to the radiographic stage. The articular cartilage showed osteoarthritic changes in stage III, although this was not evident on plain radiographs. Cracking in the distal facet and flapping at the proximal facet of the lunate were identified as features of Kienböck's disease. The incidence of interosseous ligament tears was correlated with radiographically determined stage, whereas changes in triangular fibrocartilage were correlated with age and ulnar variance. Wrist arthroscopy is a useful staging tool for Kienböck's disease, supplying helpful information about the intraarticular pathoanatomy which can be used to guide patient management.

Adolescent↗
PubMed1995

Analysis of proximal fragment sclerosis and surgical outcome of scaphoid non-union by magnetic resonance imaging.

32 patients with scaphoid non-union were examined to clarify the relationship between pre-operative radiographic sclerosis in the proximal fragment and signal intensity on magnetic resonance imaging (MRI). In addition, the correlation between changes in signal intensity in the proximal fragment and surgical outcome after bone grafting and internal fixation was investigated. Proximal fragment sclerosis was observed in seven patients. Comparison of the T1 and T2-weighted images with those of the 25 patients without proximal fragment sclerosis revealed no differences. Therefore, there was no relationship between sclerotic changes on plain radiography and the degree of avascularity of the proximal fragment assessed by MRI. None of the patients who had low signal intensity on both T1 and T2-weighted images achieved union within 5 months after surgery. Thus the detection of signal intensity on both T1 and T2-weighted images can be useful to predict the prognosis after the surgery.

Adolescent↗