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Biomedical subjects

A M Noto

Publications and source records attributed to A M Noto.

16 recordsLinked to original sources
PubMed1991

Tibial cortical bone peg fixation in osteochondritis dissecans of the knee.

Ten knees in nine patients with large, symptomatic osteochondritis dissecans lesions of the knee were treated by cortical bone peg fixation. The follow-up time averaged 2.9 years (range, 0.9-6.6 years). The average age was 19.5 years (range, 15-33 years). The knees were evaluated and rated clinically and roentgenographically. Magnetic resonance (MR) imaging of nine knees was obtained at the follow-up examination to evaluate lesion and bone peg incorporation, evidence of lesion loosening, and the articular cartilage. Eight good to excellent, one fair, and one poor result were obtained clinically. MR imaging showed 33% of knees had poor lesion cartilage and 44% had partial or poor lesion incorporation possibly consistent with loosening. Complications included four partial defect healings, one tibial donor graft-site fracture, and one bone peg loosening. Four symptomatic knees had follow-up arthroscopy at an average of 1.8 years postsurgery and findings included four loose bodies, one loose peg, one meniscal tear, and one symptomatic hypertrophic synovium. MR imaging was a useful tool in evaluating lesion stability, articular cartilage quality, lesion and bone peg incorporation, the menisci, and cruciate ligaments. Bone peg fixation of large osteochondritis dissecans defects of the knee offers a physiologic approach to treatment of this lesion in nearly skeletally mature or skeletally mature patients.

Adolescent↗
PubMed1990

Volumetric three-dimensional computed tomography for acute calcaneus fractures: preliminary report.

Volumetric three-dimensional (3-D) computed tomographic reconstructions were performed on three cadaver specimens before and after fracture for 16 acute calcaneal fractures. This "second-generation" 3-D reconstruction technique produced accurate, detailed images of the extra-articular fracture anatomy. Use of this method provided visualization of specific fracture component displacement otherwise unappreciated prior to surgery. In two cases, vertical splits in the superomedial fragment were demonstrated to best advantage by this 3-D technique.

Calcaneus↗
PubMed1989

MR imaging of the ankle: normal variants.

Thirty asymptomatic ankles were studied with high-resolution surface coil magnetic resonance (MR) imaging to identify normal structures. Several normal variants were demonstrated, including (a) Cortical irregularity of the posterior tibiotalar joint (should not be mistaken for osteonecrosis) in 27 of 30 cases; (b) normal posterior talofibular ligament with irregular and frayed superior edge simulating a tear in 13 of 30 cases; (c) normal navicular insertion of the posterior tibial tendon with heterogeneous signal intensity in 14 of 30 cases; (d) deltoid ligament inhomogeneity in seven of ten cases; and (e) fluid in the shared peroneal tendons sheath (may be confused with a longitudinal tendon tear) in three of 30 cases. Ankle imaging with the use of MR is still a relatively new procedure. Further investigation is needed to better define normal anatomy and normal variants.

Adolescent↗
PubMed1988

Rupture of the posterior tibial tendon: CT and surgical findings.

Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.

Adult↗
PubMed1988

Rupture of posterior tibial tendon: CT and MR imaging with surgical correlation.

Computed tomography (CT) and magnetic resonance (MR) imaging were performed in 32 cases of clinically suspected chronic tears of the posterior tibial tendon. Surgery was performed in 22 patients (69%). Each case was classified radiographically and surgically as normal or a type 1, type 2, or type 3 rupture. The sensitivity and specificity of CT were 90% and 100%, respectively, while those of MR imaging were 95% and 100%. The accuracy in detecting ruptures was 91% for CT and 96% for MR imaging. The overall accuracy, which reflected the percentage of cases correctly diagnosed as well as those correctly classified, was 59% for CT and 73% for MR imaging. Although the differences between the CT and MR imaging parameters were not statistically significant (possibly due to the small population), the results suggest that MR imaging is the method of choice for detecting ruptures of the posterior tibial tendon. MR imaging provided greater definition of tendon outline, vertical splits, synovial fluid, edema, and degenerated tissue. CT was superior to MR imaging in showing associated bone abnormalities such as periostitis, subtalar osteoarthritis, and subtalar dislocation.

Adult↗
PubMed1987

Right ventricular aneurysm due to ischemic disease. Diagnosis by radionuclide angiography with localization of the site of PVC origin by phase analysis.

A case of right ventricular aneurysm due to coronary artery disease in a 69-year-old male with no prior history of surgery or chest trauma is reported. The presence of the aneurysm was diagnosed by gated radionuclide angiography and confirmed by contrast angiography. This is the first description of an isolated right ventricular aneurysm on the basis of ischemic disease. In addition, the patient had recurrent ventricular tachycardia and frequent premature ventricular contractions (PVC's). Using radionuclide angiographic phase analysis of the PVC's, their apparent origin was localized to the margin of the right ventricular aneurysm.

Aged↗
PubMed1987

Tumors of the osseous spine: staging with MR imaging versus CT.

Twelve patients with tumors involving the osseous spine were evaluated with magnetic resonance (MR) imaging and computed tomography (CT), six with and six without intrathecal injection of contrast material. MR imaging was found to be superior to CT without contrast material and equal to CT with contrast material in delineating the anatomic relationships of the tumors, including bone involvement, spinal canal invasion, paraspinal soft-tissue extension, and vascular involvement. Since MR imaging can provide most of the anatomic information necessary for treatment planning, intrathecal injection of contrast material can be avoided in most instances when evaluating tumor involvement of the osseous spine. However, CT without contrast medium was superior to MR imaging in showing critical cortical bone destruction and calcified tumor matrix.

Humans↗
PubMed1987

Tendons: high-field-strength, surface coil MR imaging.

High-resolution magnetic resonance (MR) images of the tendons of the hands, wrists, feet, and ankles of six healthy volunteers and six cadavers were obtained using receive-only surface coils and reduced-field-of-view imaging. Normal anatomy was identified and compared with gross anatomic sections of the six cadavers. Experimentally produced tears of the calcaneal (Achilles) tendon in domestic swine were identified on MR images. The hands and feet of 11 patients were examined, and a variety of pathologic lesions were identified, including acute posttraumatic rupture, acute tenosynovitis, chronic tendonitis, and postsurgical complications. MR imaging provides inherently greater soft-tissue contrast than any other currently available imaging modality. With the use of surface coils and reduced-field-of-view imaging to enhance spatial resolution, MR imaging has become a valuable tool for imaging tendons. Advantages over other available modalities include excellent depiction of anatomic detail, superior contrast resolution, and the potential for multiplanar imaging.

Animals↗
PubMed1987

Infections of the musculoskeletal system: high-field-strength MR imaging.

Twenty-two patients with clinical findings consistent with osteomyelitis, soft-tissue infection, or both were studied with magnetic resonance (MR) imaging at 1.5 T. Another 15 patients with joint effusion but no clinical or laboratory signs of infection served as controls. Soft-tissue abscesses, osteomyelitis, joint and tendon sheath effusion, and cellulitis were well depicted on MR imaging, allowing the correct diagnosis of presence and extent of infection in all but two cases. MR imaging was as sensitive as technetium-99m methylene diphosphonate bone scintigraphy in demonstrating osteomyelitis and was more specific and more sensitive than other scintigraphic techniques in demonstrating soft-tissue infections, primarily because of its superior spatial resolution. Computed tomography, performed in seven cases, was as accurate as MR imaging in demonstrating bone and soft-tissue infections. Infected and noninfected synovial effusions had the same signal intensity, but associated findings such as soft-tissue fluid collections or osteomyelitis made the distinction possible.

Abscess↗
PubMed1987

Rheumatoid arthritis: MR imaging manifestations.

Radiologic assessment of the stage and treatment response of rheumatoid arthritis (RA) is based on the presence of bone erosions, joint-space narrowing, and osteoporosis. Most radiologic methods for staging RA lack interobserver correlation and are time consuming. Magnetic resonance (MR) imaging provides excellent depiction of soft-tissue abnormalities of the joints affected by RA, which allows detection of early changes. Nineteen joints of 17 patients with RA were studied with surface-coil MR imaging. Measurable abnormalities demonstrated by MR imaging but not clearly seen on plain radiographs included bone erosions, joint effusion, synovial sheath effusion, and cartilage irregularity and thinning. Seven patients of this group underwent MR imaging before and after 6 months of gold therapy. Four patients had significant interval changes on MR images that were not seen on plain radiographs. MR imaging may become a sensitive and objective method for quantitative assessment of the joint changes of RA.

Adult↗
PubMed1986

Joint effusions: MR imaging.

Magnetic resonance (MR) images of the hips and knees of three healthy volunteers were reviewed and compared with images obtained from the hips of three patients with effusions. Comparison was also made with MR images obtained from two swine knees following the injections of saline in one and blood in the other. The anatomy of the knees and hips was well defined. The hip effusions were all easily recognized. MR images of the swine knees clearly demonstrated the experimentally produced joint effusions. The hip effusions and the experimentally introduced blood and saline all had long T1 and T2 values allowing easy differentiation from articular cartilage. We were unable to distinguish fresh blood from saline in the knee joints.

Adult↗
PubMed1986

Meniscal tears: MR demonstration of experimentally produced injuries.

Magnetic resonance (MR) imaging was performed using a 1.5-T magnet on eight immature swine knees with surgically produced vertical and horizontal meniscal tears. Three radiologists, interpreting the images independently, detected all tears. Tears in the middle portion of the meniscus were best seen on sagittal views, while lesions of the anterior and posterior horns of the meniscus were best seen on coronal views. MR has several advantages over arthrography, the current diagnostic method for knee injuries: it is noninvasive, uses no ionizing radiation, and provides excellent soft-tissue contrast resolution.

Animals↗
PubMed1986

The knee: surface-coil MR imaging at 1.5 T1.

Seven normal knees (in five volunteers) and seven injured knees (in seven patients) were examined by high-resolution magnetic resonance (MR) imaging at 1.5 T with a surface coil. Seven medial meniscal tears, three anterior cruciate ligament tears, one posterior cruciate ligament avulsion, an old osteochondral fracture, femoral condylar chondromalacia, and one case of semimembranous tendon reinsertion were identified. MR images correlated well with recent double-contrast arthrograms or results of surgery. All tears were identified in both the sagittal and coronal planes. Because of its ability to demonstrate small meniscal lesions and ligamentous injuries readily, MR imaging with a surface coil may eventually replace the more invasive arthrography.

Humans↗
PubMed1986

Ankle: surface coil MR imaging at 1.5 T.

High-field surface coil magnetic resonance (MR) images were obtained of 12 ankles: two from healthy volunteers, seven from patients, and three from fresh cadavers. The cadaver ankles were sectioned in the coronal, sagittal, and axial planes for direct comparison with the MR images. Plain film confirmation of pathologic conditions was obtained in all patients, and five underwent arthroscopy or surgery, or both. MR imaging provided excellent delineation of ligaments and cartilaginous structures in all cases.

Ankle↗