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Biomedical subjects

C Matos

Publications and source records attributed to C Matos.

At least 37 records · Page 2Linked to original sources
PubMed1993

Gadodiamide injection as a contrast medium for MRI of the central nervous system: a comparison with gadolinium-DOTA.

The tolerance and diagnostic efficacy of a new nonionic, intravenous MRI contrast medium, gadodiamide injection (Omniscan) are reported and compared with those of gadolinium-DOTA after completion of a double-blind, randomized, parallel study in 60 patients using a dose of 0.1 mmol/kg. Two patients were excluded from the statistical analysis after trial entrance since no contrast medium was injected. The indications for the MRI examination were known or suspected CNS lesions. Vital signs, chemical and haematological parameters were monitored. No significant abnormalities were observed, confirming the excellent tolerance of both contrast media. The usefulness of gadolinium-containing contrast media was again documented, since in 8.6% (5/58) of the patients the lesion(s) could be seen only after injection. Contrast enhancement was seen in 87.8% (43/49) of the patients with abnormal findings, and provided additional diagnostic information in 24.5% (12/49). Lack of contrast enhancement in 12.2% (6/49) of patients with abnormal findings was a significant negative finding.

Brain↗
PubMed1993

Gadolinium enhancement of vertebral endplates following lumbar disc surgery.

Gadolinium enhancement may be normal in the vertebral endplates adjacent to previously operated intervertebral discs. To determine the frequency of this finding and to differentiate this normal healing process from early lesions due to focal infection, we studied 135 patients who had undergone surgery for herniated lumbar disc, and compared them with 249 unoperated patients with radicular symptoms and 15 with known spondylodiscitis. Hypointense foci which enhanced with gadolinium were identified in the endplates of 25 (18.5%) of the operated patients, 9 of whom required a second operation for recurrent disc herniation, at which time the absence of infection was confirmed. Gadolinium enhancement within the endplates adjacent to the operated disc occurs during normal healing after surgery. Care should be taken before invoking a diagnosis of focal infection or secondary spondylodiscitis.

Adult↗
PubMed1993

Pineal cyst: normal or pathological?

Review of 500 consecutive MRI studies was undertaken to assess the frequency and the appearances of cystic pineal glands. Cysts were encountered in 2.4% of cases. Follow-up examination demonstrated no change in these cysts and they were considered to be a normal variant. Size, MRI appearances and signs associated with this condition are reported in order to establish criteria of normality.

Adolescent↗
PubMed1993

Stereotactic indications for neuroradiological differential diagnosis.

The modern neurodiagnostic techniques of MR imaging, CT scanning and angiography provide valuable morphological information that, although highly sensitive to tumour localisation, still lacks comparable specificity as to the exact histological nature of those lesions demonstrated. Biopsy remains necessary. To patients with potentially inoperable lesions or lesions best treated by chemotherapy or irradiation, modern techniques of neurosurgery now offer the option of precise stereotactic biopsy through small twist-drill burr holes as opposed to open biopsy. The interrelationships between MR, CT, angiography and stereotactic biopsy and their respective roles in the establishment of a definitive diagnosis are discussed.

Biopsy↗
PubMed1993

Hydrosyringomyelia-Chiari I complex. Prospective evaluation of a modified foramen magnum decompression procedure: preliminary results.

A modified foramen magnum decompression procedure, designed to respect the subarachnoid spaces as much as possible, was prospectively evaluated in eight consecutive patients with a progressive clinical syndrome related to hydrosyringomyelia-Chiari I complex. This evaluation included quantitative clinical and magnetic resonance follow-up of at least 1 year in the first six patients and 6 months for the last two. Magnetic resonance scans at 6 months or more confirmed a persistent reduction of the hydrosyringomyelic cavity in all cases, which was associated with obvious subjective improvement. All patients have maintained this improvement. The operative technique and methods of clinical and radiological follow-up are discussed.

Adolescent↗
PubMed1993

Fracture of the posterior aspect of the lateral tibial plateau: radiographic sign of anterior cruciate ligament tear.

Plain radiographs obtained in 25 patients with acute anterior cruciate ligament (ACL) tears detected with magnetic resonance imaging were retrospectively evaluated to identify associated bone lesions. Fracture of the posterior part of the lateral tibial plateau (LTP) was seen in 11 patients, impacted fracture of the lateral femoral condyle (LFC) in two, lateral tibial rim fracture (Segond fracture) in three, and avulsion fracture of the tibial attachment of the ACL in two. The latter three fractures have been associated with an ACL tear. Conversely, fractures of the posterior part of the LTP have not been associated with ACL tear and are recognizable on plain radiographs. Impaction of the LFC on the LTP and avulsion of the posterior tibial capsular junction may account for the association of the fracture of the LTP with the acute ACL tear. This type of fracture represents the most frequent indirect sign of ACL tear seen on plain radiographs.

Adolescent↗
PubMed1993

Characterization of mouse monoclonal antibodies against common and repeated epitopes of different developmental stages of Schistosoma mansoni.

Eight IgM monoclonal antibodies (mAbs) obtained from a Schistosoma mansoni chronically infected mouse immunized twice with adult worms butanolic extract (BE) and soluble egg antigen (SEA) were characterized by immunochemical methods. An intense cross-reactivity between different developmental stages was observed by indirect immunofluorescence assay (IIFA) with five anti-SEA mAbs. These mAbs appeared to recognize glycosidic residues, as suggested by 1) the inhibition of their reactivity by periodate oxidation of SEA, 2) the multiple polypeptide recognition in radioimmunoprecipitation and immunoblot assays and 3) reactivity with KLH. Anti-SEA mAbs were able to mediate in vitro killing of schistosomula but they were not consistently able to mediate passive transfer immunity in vivo. Three of anti-SEA mAbs were suitable for the performance of a sandwich ELISA for antibody detection in S. mansoni infected patients, allowing an increase in the signal to noise ratio as compared to the direct ELISA SEA method. Three anti-BE mAbs showed a more stage restricted pattern of antigen recognition by IIFA. Only one out of three seemed to be directed against glycan residues, but the other mAbs showed a plural pattern of polypeptide recognition on BE immunoblot, suggesting that repeated epitopic motifs are also present in different proteins within the same parasite developmental stage.

Animals↗
PubMed1993

MRI of acute disseminated encephalomyelitis after coxsackie B infection.

Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating condition of the central nervous system, usually developing after a viral infection or vaccination. We report a case of ADEM predominantly affecting the spinal cord in an 8-year old boy evaluated by MRI. The radiographic picture consisted of multiple focal lesions of the spinal cord, a left posterior thalamic lesion and a subcortical right posterior parietal lesion. These lesions regressed several weeks after corticosteroid treatment. The clinical presentation, the laboratory results and the radiological findings suggest the diagnosis of ADEM secondary to viral infection by Coxsackie B.

Brain↗
PubMed1992

Transverse geniculate ligament of the knee: appearance and frequency on plain radiographs.

The aims of the study were to determine the frequency of visualization of the normal transverse geniculate ligament (TGL) of the knee on lateral plain radiographs with magnetic resonance imaging (MRI) as a reference, and to determine features that make this ligament apparent on plain radiographs. 50 consecutive lateral plain radiographs and sagittal T1-weighted images of corresponding knees were evaluated prospectively. A TGL was considered visualized on plain radiographs when an opacity of soft-tissue density was apparent in the posterior part of the Hoffa's fat pad. The TGL was identified in 29 of the 50 (58%) sagittal MR images; a TGL was observed on the lateral plain radiographs of six patients (12%). Correlation with the MR images showed that, when visualized on plain radiographs, the ligament is at least 3 mm thick and completely surrounded by fat. Our study shows that the TGL is a normal variant that can be recognized frequently on lateral plain radiographs of the knee.

Adolescent↗
PubMed1991

[Neonatal pilonidal sinuses and screening by medullary ultrasonography: preliminary results].

The authors report on their preliminary experience with ultrasound as a screening examination in neonates presenting pilonidal sinuses. Of the 100 patients examined over the 2 previous years, three pathological cases were found (1 tethered cord, 1 lipoma of the filum terminale and one localized hydromelia). Abnormal or doubtful cases were confirmed or further investigated by magnetic resonance. Ultrasound seems to be an accurate technique for the detection of malformation of spinal canal content in neonates under one month of age.

Humans↗
PubMed1990

Hyaline membrane disease in the newborn: diagnosis by ultrasound.

The authors report a new method of diagnosing hyaline membrane disease (HMD) in newborns: ultrasound. Babies with HMD display a specific pattern with retrohepatic hyperechogenicity on abdominal ultrasound. The specificity of the pattern was verified in 40 prematures with respiratory distress syndrome. The sign was present in 24, and in 22 of these the final diagnosis was moderate or marked HMD. In the last 2, mild HMD was suggested. The pattern was absent in the 16 others, none of whom had HMD. The pattern probably results from an ultrasound artifact: summation of multiple aerated airways surrounded by collapsed alveoli. Follow-up examinations were possible in 13 babies with HMD. Hyperechogenicity disappeared in 8 of these patients within 6-9 days and in 3 within 10-20 days; it persisted for 60 and 70 days in 2 with bronchopulmonary dysplasia. In conclusion, retrohepatic hyperechogenicity in newborns is pathognomonic for HMD and allows an instant diagnosis. The persistence of the pattern could be a useful criterion for evaluation of the prognosis.

Diagnosis, Differential↗
PubMed1990

New device for endoscopic cystoenterostomy.

A new device for endoscopic treatment of pancreatic pseudocysts is described. It aims to provide improved safety and ease of performance of endoscopic cystoenterostomy, even in difficult cases of massive compression of the intestinal wall with upper gastrointestinal obstruction. In this preliminary report, nine patients have been treated without complication.

Adult↗
PubMed1989

Hypothesis: reduced renal mass with glomerular hyperfiltration, a cause of renal hyperechogenicity in children.

A group of 10 pediatric patients had renal hyperechogenicity and reduced renal mass. The authors wish to suggest a relationship between renal hyperechogenicity and glomerular hyperfiltration according to Brenner's theory on the progressive nature of kidney disease. Reduced renal mass was related to multicystic dysplastic kidney (3 cases) nephrectomy (3 cases) and to reflux nephropathy (4 cases). The hyperechogenicity was diffuse in 6 cases with the preservation of cortico-medullary differentiation and was localized in all four cases of reflux nephropathy producing a "pseudotumoral" appearance. Hyperfiltration was confirmed by isotope studies in all 3 cases where it was performed. This condition together with secondary glomerulosclerosis could explain hyperechogenicity. The predictive value of such patterns are still unclear; yet such findings should lead to appropriate radiolocal, functional, clinical and dietary measures.

Child↗
PubMed1989

Percutaneous drainage of subphrenic abscesses.

Forty subphrenic abscesses were drained percutaneously in 37 patients. These abscesses were subsequent to abdominal surgery (28 patients), biliary obstruction and/or fistula (six patients), trauma (two patients) or acute pancreatitis (one patient). The procedures were usually monitored by duplex sonography and fluoroscopy (35 out of 40 cases), with an angled subcostal approach to the subphrenic space in over 85% of the cases. Forty-three drainage catheters were inserted using the Seldinger method; 37 (86%) had a size of 12 F or more, 21 were 16 F in size. Only two out of 43 catheters were double-lumen sump drains. The clinical condition improved after insertion of the catheter in all 37 patients. Definitive successful drainage, defined as hospital discharge without complementary surgery, was achieved in 32 patients (87%), without major complications. A temporizing effect was obtained in three additional patients (8%) who underwent curative surgery for the underlying process after complete drainage of the abscess. Two patients died from multiple organ failure before their abscess healed. Considerations for successful drainage of subphrenic abscesses include a good knowledge of the subphrenic space anatomy, the use of large-bore drainage catheters and the recognition and correct management of underlying enteric, biliary or pancreatic fistulas.

Adolescent↗
PubMed1988

US demonstration of pyelitis and ureteritis in children.

The authors report a new ultrasonic sign of urinary tract infection in children: thickening of the renal pelvis and/or ureteral wall. This thickening as encountered in 10 children, (10 months to 12 years) all with urinary tract infection, appears to result from inflammatory changes and to correspond to a sonographic sign of pyelitis and ureteritis. These alterations of the walls are similar to striations and folds described in this pathology on intravenous pyelograms. The thickening was the only sign of abnormality of the urinary tract in two cases; it was observed without reflux in four cases. The demonstration of this pattern should lead to further uroradiological investigations and to appropriate treatment.

Child↗