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Biomedical subjects

P Schnyder

Publications and source records attributed to P Schnyder.

At least 19 recordsLinked to original sources
PubMed1992

[Magnetic resonance imaging of the normal and the pathological knee in the child].

The results of magnetic resonance imaging (MRI) studies performed on the knee region of 60 children including 20 normally growing subjects are reported. In healthy children, MRI permitted to study the normal maturation of bone marrow and cartilaginous structures. The patients studied had bone tumors (11 patients), rheumatoid arthritis (8 patients), lesions of traumatic origin (7 patients), osteochondritis (4 patients), vascular and tissular dysplasia (3 patients), osteomyelitis (3 patients) and soft-tissue tumors (3 patients). In all patients, MRI showed clinically relevant abnormalities that were not detected by conventional X-rays or physical examination. MRI offers the ability to study disorders of bone, bone marrow, cartilage, menisci and ligaments in a noninvasive way. MRI has replaced arthrography of the knee and is the examination of choice in pediatric patients.

Adolescent↗
PubMed1992

Magnetic resonance imaging of nontraumatic shoulder instability in children.

Nontraumatic shoulder instability is infrequent in children. We examined prospectively with high-field magnetic resonance imaging (MRI) 11 patients with this disorder, including 2 with Holt-Oram syndrome and 11 healthy control subjects. The MR findings in the glenohumeral joint in normally growing children are presented. Two patients with shoulder instability were considered as normal, one presented with type 2 (Zlatkin) labral lesions, three, type 3 and one, type 4 lesions. Close attention to the normal imaging patterns of the maturing glenohumeral joint is required to avoid pitfalls in the interpretation of the images.

Adolescent↗
PubMed1992

Is tomography of intervertebral disc calcification useful in children?

In the past ten years, we have found cervical intervertebral disc calcifications in three children on plain films of the cervical spine made because of cervical pain. In each case, we required further radiological investigations, antero-posterior and lateral linear tomography for two children and an axial computed tomography for one child. In each case, tomography revealed no supplementary useful information. On retrospect, we think that these examinations caused unnecessary irradiation and that they should only be carried out in the rare circumstances when disc calcification is associated with neurological symptoms.

Adolescent↗
PubMed1992

Do abnormalities of the frontonasal duct cause frontal sinusitis? A CT study in 198 patients.

OBJECTIVE: The purpose of the study was to determine the correlation between frontonasal duct abnormalities (narrowing or obstruction caused by hypertrophic mucosa) and frontal sinusitis. This study was based on the hypothesis that abnormalities of the frontonasal duct cause frontal sinusitis by impairing normal drainage of the sinus. MATERIALS AND METHODS: CT studies of 198 consecutive patients with clinical diagnoses of chronic sinusitis were reviewed retrospectively. Criteria for inclusion were (1) no history of sinus surgery or facial trauma and (2) absence of polyps at rhinoscopy. As 37 frontal sinuses were undeveloped, a total of 359 sinuses were evaluated. CT scans were obtained in oblique axial and coronal planes. The following CT features were assessed: (1) the frequency of detection of the frontonasal duct, (2) the appearance of the frontonasal duct: normal vs abnormal (narrowed or obstructed), and (3) the correlations between abnormalities of the frontonasal duct and frontal sinusitis. RESULTS: The frontonasal duct was detected in all 359 cases, either in both CT planes (81%) or only in the axial oblique plane (19%). In 267 (74%) of 359 cases, the duct appeared normal; among these, isolated frontal sinusitis was detected in five cases (2%). In 92 (26%) of 359 cases, the duct was abnormal; it was narrowed in 18 cases (5%) and obstructed in 74 cases (21%). Frontal sinusitis was noted in 78 (85%) of the 92 cases of frontonasal duct abnormalities. The sensitivity and specificity of the correlations between frontonasal duct abnormalities and frontal sinusitis were 98% and 85%, respectively. CONCLUSION: Because our results show a strong correlation between abnormalities of the frontonasal duct and frontal sinusitis, it seems highly probable that abnormalities of the frontonasal duct cause frontal sinusitis.

Adolescent↗
PubMed1992

[Non-specific bacterial ureteritis: a rare entity].

Based on a recent case of non-specific bacterial ureteritis, the authors review the clinical features of what has now become a rare disease. They also evaluate the role of computed tomography in the differential diagnosis of this disease.

Aged↗
PubMed1992

[X-ray computed tomography of the facial sinuses. Results in 198 patients with chronic sinusitis].

The CT studies of 198 consecutive patients with chronic sinusitis were reviewed retrospectively. CT was normal in 47 patients (23.7%). In 151 patients one or many cavities showed abnormalities. In 69 cases (34.9%), the lesions affected one or two sinuses, in 35 cases (17.7%) three to six cavities were abnormal, whereas in 47 cases (23.7%), more than six cavities were abnormal. In 87 cases (57.6%), lesions were observed both in large cavities and ethmoid cells, whereas they were selectively localized in large cavities in 55 cases (36.4%), or in ethmoid cells in 9 cases (6%). Abnormalities were observed in the maxillary sinus in 137 patients (69.2%), in the ethmoid in 96 patients (48.5%), in the frontal sinus in 51 patients (25.8%), and in the sphenoid sinus in 28 patients (14.1%). The most frequent abnormality was hypertrophic mucosa, which was visible in 275 cavities. These results were compared with date of the literature.

Adolescent↗
PubMed1991

Low-dose CT and inflammatory disease of the paranasal sinuses.

Computed tomography (CT) is the gold standard for exact delineation of inflammatory sinus disease, especially before endoscopic surgical treatment, and in cases of postoperative recurrences. In routine CT studies, the radiation dose to the patient is not negligible. Therefore, the authors evaluated prospectively the CT scans of 44 patients with inflammatory disease of the paranasal sinuses, to define the imaging ability of low-dose CT (i.e. 60 mA-3 s, 30 mA-3 s, and 30 mA-2 s), comparatively with the standard mAs settings (130 mA-3 s). In all cases, the exact extent of the disease was correctly assessed on each of the low-dose settings, with no false negative study. The increasing graininess of low mAs sections did not induce errors of interpretation, despite a less pleasant appearance to the eyes. In cases of extensive sinus disease, the thickness and integrity of the ethmoid septa were sometimes more difficult to evaluate on low-dose CT sections. The authors recommend the use of low mAs settings in the evaluation of inflammatory disease of the sinuses, complemented, if necessary, in cases of extensive abnormalities, by one or two sections obtained with standard mAs settings, focused on questionably abnormal bone septa.

Adult↗
PubMed1991

Spontaneous regression of intervertebral disc calcifications in a child.

This article presents the case of a boy who complained of cervical and thoracic spine pain for the first time at the age of nine. Plain films of cervical and thoracic spine showed calcifications of intervertebral disc C4-C5, C5-C6, C6-C7 and D3-D4. The symptoms disappeared after conservative therapy. Plain films taken 16 months later showed spontaneous disappearance of all disc calcifications. This spontaneous regression of intervertebral disc calcifications in childhood has also been described in other cases reported in the medical literature. Except for the rare cases when disc calcifications are associated with disc herniation, the discovery of disc calcifications on a plain X-ray of a child corresponds to a benign abnormality.

Calcinosis↗
PubMed1991

Cyst of the ligamentum flavum: report of six cases.

Six cases of cyst of the ligamentum flavum with compression of a lumbar nerve root are reported. All patients exhibited recurrent back pain and sciatica. Investigation included computed tomography, myelography, or both. The correct diagnosis was reached before operation in only half the patients. High-resolution computed tomography performed in the four last patients outlined the cystic lesion with its low-density center. Surgical excision was performed in all patients. Microscopic examination showed a dense fibrous cyst arising from the ligamentum flavum. The lumen contained myxoid or necrotic material, but no epithelial lining. Cysts of the ligamentum flavum must be considered in the differential diagnosis of causes of sciatica. A firm radiological diagnosis may, at present, still require myelography combined with high-resolution computed tomography. Differentiation from synovial or ganglion cysts of the spine is discussed.

Aged↗
PubMed1991

Computed tomography of the postoperative intervertebral disc and lumbar spinal canal: serial long-term investigation in 19 patients after successful operation for lumbar disc herniation.

The first part of this work, published in 1988, included 25 patients who had computed tomographic (CT) scans without contrast enhancement and plain x-rays of the lumbar spine before, 1 week after, and 6 to 7 weeks after a successful operation for lumbar disc herniation. The present study extends the follow-up period to 3 years in 19 of the 25 original patients. Clinical examinations, lateral plain x-rays, and CT scans without contrast enhancement of the operated disc were repeated. The results indicate a decrease or even a disappearance of the hyperdense extradural material thought to represent fibrosis. An image suggestive of persistent disc herniation was still present in 5 of 8 patients with this finding on early postoperative CT scans. Persistent intradiscal gas was seen in nearly half of the patients. Total normalization of the posterior extraspinal structures was the rule. There was no correlation between CT appearance and residual complaints of the patients. CT scans without contrast enhancement may be sufficient to guide the surgeon in postoperative patients with massive signs and symptoms of recurrent root compression in whom a second operation is indicated on clinical grounds. In all other cases, myelography followed by CT scans is considered appropriate to investigate failed back surgery syndrome.

Adipose Tissue↗
PubMed1990

Cystic neoplasms of the exocrine pancreas.

Cystic neoplasms of the pancreas are rare and their diagnosis and treatment can be difficult. This report details 7 patients who had histologically proven serous cystadenoma, mucinous cystadenoma and cystadeno carcinoma. Computed tomography and sonography allowed excellent preoperative assessment but to attempt a distinction between the histological variants may be hazardous. Two tumours were only autopsy findings and 5 patients underwent laparotomy. It is confirmed that potentially malignant mucinous cystadenomas and cytadenocarcinomas should be resected whenever possible; serous cystadenomas are always benign and should therefore be resected only when the diagnosis is doubtful or if they cause symptoms.

Adult↗
PubMed1990

Configuration of a robot dedicated to stereotactic surgery.

The design of a robot for functional stereotactic surgery which is under construction in our laboratory is described. The main features include operation inside the computed tomographic (CT) scanner, the possibility of intraoperative CT scanning and complete handling of the stereotactic probes by the robot.

Brain Diseases↗
PubMed1990

Coronal radiographs and videofluoroscopy improve the diagnostic quality of temporomandibular joint arthrography.

Detection of mediolateral displacement of the temporomandibular joint (TMJ) meniscus and evaluation of the reducibility of this displacement are necessary because surgery is indicated when the displacement is irreducible. During TMJ arthrography, the routine sagittal study does not allow detection of this type of meniscal displacement. In a prospective study of 158 TMJ arthrograms in 83 patients, coronal radiographs were obtained and videofluoroscopy was performed (in addition to routine sagittal films and fluoroscopy) to detect mediolateral shift of the meniscus and to evaluate the reducibility of this displacement. Both upper and lower joint spaces were opacified. Coronal and lateral radiographs were obtained with the mouth open and closed. On coronal images, in 79 cases (50%) the meniscus was shifted medially, in 22 cases (14%) laterally, and in 57 cases (36%) it was in the normal position. In 90 (89%) of the 101 abnormal cases, anterior displacement was associated with a mediolateral shift. In 59 cases (58%), the mediolateral shift was irreducible. Coronal and lateral views and fluoroscopy were reviewed separately by two observers, whose conclusions were identical for all cases. In 32 (54%) of the 59 joints with irreducible mediolateral displacement, surgery was performed. For all of these, comparison of radiologic data with surgical findings indicated that coronal views and videofluoroscopy were diagnostic, whereas mediolateral displacements were not detectable on routine sagittal studies.

Adult↗
PubMed1990

[Computerized tomography of the small bowel].

Computer tomography (CT) is an imaging technique that reveals most useful information in the presence of extramucosal diseases of the small bowel. It is indispensable as a guide to treatment. After a short description of the examination technique and the normal anatomy, the authors describe the CT manifestations of small-bowel diseases, especially inflammatory and neoplastic lesions.

Humans↗
PubMed1990

[Epidermoid cysts of the spleen. Report of 6 cases].

The authors report 6 cases of epidermoid cysts of the spleen. They emphasize the rarity of the lesion, its pathological and clinical features, and describe the abnormalities which can be noted on plain films, ultrasonography and computed tomography.

Adult↗
PubMed1990

Loose bodies of the temporomandibular joint: arthrographic and CT findings in five patients.

We report a series of five patients with symptoms of internal derangements of the temporomandibular joint (TMJ), in whom intraarticular loose bodies were found. Three patients with a single loose body had osteochondrosis dissecans of the temporal part of the joint; one trauma patient had two loose bodies (including a bony and a meniscal fragment). The fifth patient presented with a loose meniscal fragment and a complete meniscal rupture, complicating a long-lasting TMJ dysfunction due to non-reducible anterior meniscus displacement. The diagnosis was made by arthrotomography (3 cases), CT (one case) and by CT and arthrotomography (one case). Surgical confirmation was obtained in all patients. Arthrography and CT are accurate in diagnosing TMJ loose bodies; characteristic findings disclosed in both examinations are described.

Adult↗
PubMed1989

[Dosimetry comparison of pelvimetry methods using conventional radiologic technic and x-ray scanner].

The aim of this study is to compare conventional and CT-scan X-ray pelvimetry. Doses have been measured on the surface and in deep tissues as well as total doses received by the patients. With CT the fetus and the mother were exposed to 1/10th of the total dose delivered using conventional X-rays. The method is acceptable and the high quality of the films achieved make CT-scanning pelvimetry safer than X-ray pelvimetry.

Female↗