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Biomedical subjects

W Martel

Publications and source records attributed to W Martel.

At least 19 recordsLinked to original sources
PubMed1995

The rich tradition of radiology at the University of Michigan.

The evolution of radiology at the University of Michigan after Roentgen's discovery in 1895 has had a profound influence on radiology. The school has had notable firsts in medicine: it was among the first of the state-supported universities to have a medical school (1850), had the first teaching hospital owned by a university (1869), and had the first university department of roentgenology (1917). Given these circumstances, teaching and research were early high priorities. The original small hospital, a remodeled private residence in Ann Arbor (1869), proved inadequate and was replaced in 1891 by the Catherine Street Hospital, viewed then as the largest teaching hospital in the nation. This served the medical school well for many years but was succeeded by the magnificent new University Hospital in 1925. Built for $4.4 million with a bed capacity of 700 in a double-Y architecture, it was an entirely new concept in hospital design and was the pride of the state [1].

History, 19th Century↗
PubMed1992

Precision of hyaline cartilage thickness measurements.

Measurement of cartilage thickness in vivo is an important indicator of the status of a joint as the various degenerative and inflammatory arthritides directly affect the condition of the cartilage. In order to assess the precision of thickness measurements of hyaline articular cartilage, we undertook a pilot study using MR imaging, plain radiography, and ultrasonography (US). We measured the cartilage of the hip and knee joints in 10 persons (4 healthy volunteers and 6 patients). The joints in each patient were examined on two separate occasions using each modality. In the hips as well as the knee joints, the most precise measuring method was plain film radiography. For radiographs of the knees obtained in the standing position, the coefficient of variation was 6.5%; in the hips this figure was 6.34%. US of the knees and MR imaging of the hips were the second best modalities in the measurement of cartilage thickness. In addition, MR imaging enabled the most complete visualization of the joint cartilage.

Adult↗
PubMed1991

Dialysis-related amyloid arthropathy: MR findings in four patients.

Dialysis-related amyloidosis is a recently recognized complication of long-term hemodialysis. It is caused by the deposition of a unique form of amyloid derived from circulating beta 2-microglobulin. This study describes the MR imaging characteristics in five articular sites of four symptomatic patients with biopsy-proved (three patients) or clinically and radiographically suspected (one patient) dialysis-related amyloidosis. Three wrists, one knee, and one cervical spine were examined. The extent of osseous and soft-tissue involvement at each joint site was well shown by MR imaging. Lesions that were apparently intraosseous on conventional radiographs were shown to be caused by well-defined erosions that extended to the articular surface. The MR signal characteristics of the amyloid deposition were intermediate between those of fibrocartilage and muscle on all sequences, distinguishing the deposition from cellular lesions or those containing large amounts of water, such as inflammatory masses, acute or chronic synovitis, and brown tumors of hyperparathyroidism. The intraarticular masses were associated with a moderate joint effusion in the large joint imaged, and small effusions were present in the wrist. Use of a fat-suppression sequence enhanced visualization of amyloid deposits within the wrist of one patient but provided no additional information in the knee of a second patient. Our experience suggests that MR imaging is well suited to showing the extent and distribution of articular disease in dialysis-related amyloidosis.

Amyloidosis↗
PubMed1991

Distal interphalangeal joint abnormalities in children with polyarticular juvenile rheumatoid arthritis.

Involvement of the distal interphalangeal (DIP) joints was noted radiographically in 24 (43.6%) of 55 patients with polyarticular juvenile rheumatoid arthritis. DIP changes were apparent later in the course of the disease and were less severe than in other affected joints. Soft tissue swelling and joint space narrowing were the most frequent abnormalities in the DIP joints. Erosive changes and angular deformities were uncommon. There was no significant correlation between DIP joint involvement and sex, age at presentation, involvement of the hands and wrists at presentation, or positivity of either rheumatoid factor or antinuclear antibody. There was a strong correlation between the presence of extraarticular signs and symptoms and involvement of the DIP joints; however, this may reflect the greater severity of the disease in these patients generally.

Adolescent↗
PubMed1991

Magnetic resonance imaging of the normal craniovertebral junction.

Sagittal magnetic resonance images of the normal craniovertebral junction in 25 patients were examined for visualization of bony, synovial, and ligamentous structures. The excellent delineation of soft tissue by magnetic resonance imaging enabled recognition of the joint space between the dens and anterior arch of C1 in 14 out of 25 patients. High-signal-intensity tissue was noted immediately superior to the dens in all patients; an anatomic specimen confirmed the fibrofatty nature of this tissue. The medullary space of the dens had lower signal intensity than did the marrow in the body of C2 in more than one half of the cases. Additional thin-section images suggested that this was a partial-volume artifact. Understanding of the normal appearances of structures in this region is necessary to assess correctly the presence or absence of disease.

Adult↗
PubMed1991

Overview: new methods in imaging osteoarthritis.

The new imaging modalities, namely computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US) provide potentially powerful tools for in vivo assessment of osteoarthritis (OA), monitoring the progress of the disease and understanding its natural course. However, to use these tools effectively, we need more prospective research focused on correlating imaging data with biochemical and gross and microscopic pathologic findings. MRI is clearly the most powerful tool for demonstrating the various articular components which may be affected in OA. CT is excellent for delineating osseous abnormalities and with US we are able to evaluate the thickness and surface characteristics of those portions of articular cartilage that are accessible. The advantages and limitations of these 3 modalities are discussed as they pertain to OA of the hip and knee.

Arthrography↗
PubMed1990

Magnetic resonance imaging appearance of the muscles in childhood dermatomyositis.

Documentation of muscle involvement in a child thought to have dermatomyositis may require the performance of invasive procedures such as electromyography and/or muscle biopsy. We describe four patients with dermatomyositis in whom magnetic resonance imaging (MRI) demonstrated the muscle involvement. The involved muscles had increased signal intensity on the T2-weighted images (SE 2500/80) and normal appearance on the T1-weighted images (SE 600/20). The involvement of the muscles was not uniform. There was good correlation between the distribution of muscle involvement by MRI and functional testing. Follow-up MRI scans in patients with favorable outcome demonstrated that the affected muscles had returned to normal signal intensity. Although the MRI findings are not specific, in the proper clinical context they may be helpful in establishing the diagnosis of dermatomyositis. MRI may also be used in establishing an appropriate muscle biopsy site. In addition, MRI may be used for monitoring the progress of the disease.

Adolescent↗
PubMed1989

Soft tissue involvement, mediastinal pseudotumor, and venous thrombosis in pustulotic arthro-osteitis. A study of eight new cases.

A syndrome of hyperostosis of the thoracic wall, nonspecific signs of inflammatory disease, and palmar and plantar pustulosis is described in eight patients (Table 1). Seven had intersternocostoclavicular ossification, and one had chronic recurrent multifocal osteomyelitis. This complex of findings has been called "pustulotic arthro-osteitis". This report emphasizes the periosseous soft tissue inflammation and the unexplained subclavian and mediastinal vein thrombosis seen in two patients. Inflammatory periosseous and mediastinal lesions were seen on plain films in all eight patients and on computed tomographic (CT) scans in seven. Radiographs of the spine showed a spondyloarthropathy in three patients. This was characterized by ossification of the vertebral ligaments and sclerosis of the vertebral bodies. Awareness of the radiologic features of pustulotic arthro-osteitis is important because the clinical, biochemical and pathologic findings are often nonspecific and misleading.

Adult↗
PubMed1988

Long-term radiographic follow-up after isotretinoin therapy.

We evaluated the effects of long- and short-term isotretinoin therapy on the skeletons of patients. Eight patients who were treated with isotretinoin for disorders of keratinization received frequent radiographic evaluations for 4 to 9 years. Seven patients developed multiple hyperostoses at the spine and extremities. Hyperostoses increased in size and number over the course of therapy, although relatively few sites were symptomatic. Hyperostoses typically developed first in the spine and later in the extremities, where both bilaterally symmetric and asymmetric involvement was observed. After 5 years of therapy one patient did not develop hyperostosis. In a group of nine patients who received a relatively high dose of isotretinoin in 1982 for the treatment of acne, two patients developed tiny, asymptomatic hyperostoses. One patient had hyperostoses 1 year after isotretinoin therapy, which remained unchanged 3 years later, whereas the other patient had one hyperostosis 4 years after therapy had been stopped. Although we suspect that these hyperostoses were retinoid induced, they should not be of concern for the patient needing routine isotretinoin therapy for the treatment of cystic acne.

Acne Vulgaris↗
PubMed1988

Radiologic features of well-differentiated osteosarcoma.

Eight cases of well-differentiated, intramedullary osteosarcoma were studied. In three cases, the lesions previously had been diagnosed, pathologically and radiologically, as benign. The distal femur was the most frequent site. Radiographically, the tumor margins were poorly defined in five cases and were well defined in three. In seven cases, the bone response pattern was both lytic and blastic; in one case, it was purely lytic. Tumor matrix patterns were mostly homogeneous and cloudlike. Four of the lesions were expansile. All cases had cortical thinning and discontinuity. Extraosseous involvement of the soft tissues was present in six cases, and active periosteal response was present in two. High-grade malignancies subsequently developed in two patients--one was a local recurrence and the other was a distant metastasis. A broad spectrum of radiologic features was observed in well-differentiated intramedullary osteosarcomas, but all cases had at least two of three radiographic findings (cortical discontinuity, poorly marginated soft-tissue extension, or cloudlike tumor matrix pattern) that strongly suggested malignancy.

Adolescent↗
PubMed1988

Evolution of skeletal hyperostoses caused by 13-cis-retinoic acid therapy.

Seven patients with disorders of keratinization (ichthyosis in six and Darier disease in one) were treated with 13-cis-retinoic acid and followed with annual skeletal surveys for 4-6 years. Six of the seven patients developed hyperostoses attributable to the retinoid therapy, manifested as multifocal entheseal calcifications or ossifications in both the axial and appendicular skeletons. In general, the earliest appearing hyperostoses became the largest with time, although in some instances, growth ceased at some foci and progressed at others. The severity of skeletal involvement was seemingly independent of dose, and may have been related to the patient's age at time of therapy. Involvement of the spine was earlier and more pronounced than the appendicular involvement, consisting of tiny hyperostoses arising from the corners of the vertebral bodies, primarily in the cervical and thoracic spine; these later matured into either discrete ossific spurs, or focal or flowing ossification of the anterior longitudinal ligament. The most prominent appendicular hyperostoses were at the tendinous or aponeurotic insertions on the calcaneus, were often unilateral or asymmetric when small, and became bilateral with time. Appendicular hyperostoses occurring at locations besides the calcanei were much smaller, often unilateral, and occurred later (generally between the third and fifth years of therapy). Our findings indicate that the earliest hyperostoses occurring in patients with 13-cis-retinoic acid occur in the spine and feet, and become the most prominent with time. Most appendicular hyperostoses occur later, are smaller, and frequently are asymmetric or unilateral.

Adolescent↗
PubMed1987

Radiologic features of a pyrophosphate-like arthropathy associated with long-term dialysis.

In a series of 28 long-term dialysis patients with musculoskeletal complaints, the radiologic findings in six cases resembled those occurring in the arthropathy of idiopathic calcium pyrophosphate dihydrate deposition (CPPD) disease. These findings included osteophytes, subchondral cysts, and cartilage loss in the metacarpophalangeal joints, patellofemoral joints, wrists, and shoulders. Chondrocalcinosis was present in three of the six cases. There were no significant differences in renal function or levels of serum calcium, phosphorus, iron, ferritin, aluminum, or parathormone between these patients and a control group matched for sex and age. Long-term dialysis may be associated with a metabolic arthritis similar to the arthritis which occurs in CPPD deposition disease. The etiology may include deposition of CPPD crystals, hydroxyapatite, or other calcium-containing substances in joints, or it may be related to a number of dialysis-induced metabolic abnormalities.

Arthritis↗
PubMed1987

Cervical spine involvement in rheumatoid arthritis: MR imaging.

Magnetic resonance (MR) imaging of the cervical spine was employed in 18 patients with rheumatoid arthritis and suspected cervical involvement. Fifteen patients had symptoms referable to the cervical spine, and seven had neurologic deficits. In three patients who were asymptomatic with regard to the neck, MR imaging was performed because of abnormal cervical radiographs. Cervical radiographs were available for all patients; bone erosion was evident in 14, subluxation in 17, and no abnormalities in one. MR imaging demonstrated indentation or abnormal signal in the caudal brain stem and/or cervical spinal cord in ten patients, including the seven with related neurologic deficits; discrete indentation or distortion of the dura without visible morphologic effect on the underlying neuraxis was observed in five other patients. In all patients with neurologic symptoms, cord or brain-stem abnormalities were seen on MR images. MR imaging therefore appears to provide valuable information regarding the status of the spinal cord and dura in patients with rheumatoid arthritis.

Adult↗