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Biomedical subjects

W Martel

Publications and source records attributed to W Martel.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1986

Adrenal tissue characterization using MR imaging.

Using a superconducting magnet operating at 0.35 T, the authors investigated the adrenal tissue characterization potential of magnetic resonance (MR) in 28 patients with 33 adrenal masses. There were 13 adrenal adenomas (12 non-hyperfunctioning, one aldosteronoma), nine adrenal metastases, four pheochromocytomas, two neuroblastomas, two adrenal lymphomas, two myelolipomas, and one adrenal cortical carcinoma. Spin-echo pulse sequences were obtained at TR 0.5, 2.0 sec and TE 28, 56 msec. Both qualitative (visual assessment) and quantitative (absolute signal intensity, intensity ratios, T1, T2) data were used for tissue characterization. The results suggest that non-hyperfunctioning adrenal adenomas can be distinguished from non-adenomas using both qualitative and quantitative data: 16/19 non-adenomas were visually hyperintense compared with liver at TR 2.0 sec, TE 56 msec, while none of the non-hyperfunctioning adenomas was relatively hyperintense at any pulse sequence used. Of the quantitative data, the intensity ratios of adrenal lesion/liver at TR 0.5 sec, TE 56 msec were most useful in diagnosis: all adenomas had ratios less than 0.83, while 19/20 non-adenomas had ratios exceeding this value. It is concluded that MR has considerable promise in adrenal tissue characterization.

Adenoma↗
PubMed1986

Sickle-cell nephropathy: MR imaging.

To study the nephropathy associated with sickle-cell disease (SCD), spin-echo magnetic resonance (MR) imaging of the kidneys was performed in 19 SCD patients, six with beta-thalassemia major (BTM), and ten healthy individuals as controls. Eleven SCD patients had decreased relative cortical signal, most evident on T2-weighted images. No correlation with serum ferritin, urine-concentrating ability, serum blood urea nitrogen, or creatinine levels was established. Iron deposition in the renal cortices of sickle-cell nephropathy patients may, at least in part, be responsible for the relatively diminished cortical signal intensity. No BTM patients, all of whom were clinically and biochemically in iron overload from frequent transfusions, demonstrated diminished renal cortical signal intensity. This suggests that renal changes in SCD seen on MR images are not due simply to systemic iron overload per se but perhaps reflect abnormalities of iron metabolism in the renal cortex peculiar to SCD nephropathy.

Adolescent↗
PubMed1986

MRI and CT evaluation of primary bone and soft-tissue tumors.

Twenty-six patients with primary tumors of bone or somatic soft tissues underwent both magnetic resonance imaging (MRI) and computed tomography (CT); 15 of the patients had radionuclide bone scans as well. Only in a minority of cases did these tomographic methods provide information needed for diagnosis that could not be derived from the plain radiographs alone; however, for assessing the extent of the disease, both CT and MRI proved very valuable, particularly MRI. Specifically, MRI was superior to CT in delineating the extent of the neoplasms and their relation to surrounding structures in 21 of the patients, equal in four, and inferior in only one. Furthermore, in the 13 patients with tumors of long bone, MRI was judged superior to CT in visualizing marrow abnormality in 12 cases, and equal in only one case. Radionuclide scans demonstrated the lesions in 14 of the 15 cases; its primary utility was in excluding additional lesions. It is concluded that for these patients, MRI was the imaging method of choice in assessing the extent of bone and soft-tissue tumors.

Adolescent↗
PubMed1986

The fibromatoses: CT-pathologic correlation.

Although CT has been used in the evaluation of benign fibroblastic tumors (fibromatoses), data are lacking on radiologic-histopathologic correlation. In an attempt to explain the variable CT appearance of these lesions, a retrospective analysis was carried out of CT findings and histopathologic features in nine patients with fibromatoses. In three of four patients who had precontrast CT scans, the tumors were hyperdense relative to muscle, whereas in one patient the lesion was hypodense. The postenhancement appearance was variable. The pathologic specimens were analyzed and graded for collagen content, cellular content, tumor necrosis, and tumor vascularity. No consistent relationship could be established between the CT appearance of these lesions and their histologic appearance.

Adult↗
PubMed1985

Magnetic resonance imaging of femoral head development in roentgenographically normal patients.

Magnetic resonance images (MRI) of 22 patients with roentgenographically normal hips were reviewed retrospectively and the findings categorized according to age. With increasing maturity, the MR intensity of the femoral heads on spin echo images increased, as marrow fat became a dominant tissue in the head. The femoral head pattern was relatively inhomogeneous, with a broad band of diminished intensity extending in a posteromedial to anterolateral direction, corresponding to the pattern of trabecular bone. The femoral capital epiphyses were visible in younger patients as structures of bright intensity which remained evident through early adulthood. The articular cartilage of the hip joint was noted as a distinctive "halo" around the femoral head. An understanding of the MR pattern of the normal hip will aid in the early recognition of pathologic conditions, such as osteonecrosis.

Adolescent↗
PubMed1985

Retinoid-induced ossification of the posterior longitudinal ligament.

Vitamin A and its synthetic congeners are known to produce a variety of skeletal abnormalities in patients on prolonged treatment with these medications. Two patients are described who developed posterior longitudinal ligament ossification following treatment with the synthetic retinoid 13-cis-retinoic acid. In both cases, this finding became apparent after other retinoid-induced skeletal abnormalities were observed and was less marked than the ossification of the anterior longitudinal ligament. Although spinal cord compression did not occur in our patients, patients on long-term retinoid therapy should be carefully observed for this complication.

Adolescent↗
PubMed1985

Wilson disease of the brain: MR imaging.

Twenty-three patients with biochemically proved Wilson disease underwent magnetic resonance (MR) imaging of the brain. Positive findings, believed secondary to this condition, were found in 15 subjects. Findings varied among patients, but there were striking similarities between certain groups of patients. Areas of abnormal signal were seen in the lenticular, thalamic, caudate, and dentate nuclei, as well as in the brain stem; in these areas, the abnormalities were bilaterally symmetric. A smaller number of patients had asymmetric focal white-matter lesions. Correlation of the MR findings with clinical symptoms was generally good. Repeat imaging was performed on five patients at intervals ranging from 4 to 8 months; none showed significant interval change.

Adult↗
PubMed1985

Radiographic bone surveys after isotretinoin therapy for cystic acne.

Seven patients underwent retrospective radiographic examination 10 to 16 months after high dose isotretinoin therapy for severe cystic acne. One patient, who received the highest isotretinoin dose (approximately twice the average dose taken by the remaining patients), had multiple small hyperostoses of the thoracic spine and tarsi navicular. These findings were identical to the skeletal changes known to occur during retinoid administration. Prospective studies are needed to ascertain the risk of developing hyperostoses during isotretinoin therapy for acne at the lower doses currently employed. In this preliminary study, clinically significant hyperostoses were not a late sequela of high dose isotretinoin treatment for acne.

Acne Vulgaris↗
PubMed1984

Computed tomography of the sternum and its articulations.

The chest wall present diagnostic difficulties for both the clinician and the radiologist. Because of normal variations in anatomy and ossification, analysis of the sternal region can be particularly confusing. We reviewed the normal computed tomographic (CT) appearance of the sternum in 354 patients. Important normal sternal variants included cortical unsharpness along the posterior aspect of the manubrium , lateral surfaces of the body, and at the sternal fibrocartilaginous articulations; soft tissue prominence at the junction of the sternum and costochondral cartilage; and bony sclerosis at the transitions from manubrium to body and from body to xiphoid. In seven patients with clinically significant sternal abnormality, key CT features were abnormal soft tissue mass (7/7), destruction or irregularity of the cortical contour (7/7), and abnormal increased attenuation of bone (1/7). CT should be the radiologic study of choice in patients with suspected abnormality of the sternum and its articulations.

Adolescent↗