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Biomedical subjects

C Matos

Publications and source records attributed to C Matos.

At least 19 recordsLinked to original sources
PubMed1998

Magnetic resonance cholangiopancreatography: interest of IV secretin administration in the evaluation of pancreatic ducts.

The aim of this study was to investigate whether IV secretin administration is useful to enhance the delineation of the main pancreatic duct (MPD) and its side branches, and if it provides additional information concerning signal voids and strictures. Twenty-seven patients referred for abdominal pain or laboratory abnormalities (group 1, n = 13) or for the follow-up of chronic pancreatitis (CP; group 2, n = 14) were studied. Magnetic resonance cholangiopancreatography was acquired at 1.5 T before and after IV secretin by a coronal 3D TSE T2-weighted sequence with maximum intensity projection postprocessing. In group 1 secretin provided a better visualization of MPD in 9 patients. In a patient with pancreas divisum, it allowed suggestion of stenosis of the accessory papilla, confirmed at endoscopic retrograde cholangiopancreatography (ERCP). In group 2 secretin provided a better visualization of MPD only in the 3 patients with mild disease. A mild dilation upstream a stricture occurred in 2 cases and a marked dilation appeared upstream a wallstent which was non-patent at ERCP. Few changes were noticed concerning side branches. These preliminary results indicate that in patients without CP, secretin improves MPD delineation avoiding invasive diagnostic ERCP. In patients with mild CP secretin does not improve the characterization of signal voids, but it may be useful to appreciate their significance and to follow-up stenosis.

Adult↗
PubMed1998

Percutaneous transperineal radiofrequency ablation of prostate tumour: safety, feasibility and pathological effects on human prostate cancer.

OBJECTIVE: To evaluate the safety of radiofrequency (RF) energy delivered interstitially in patients with prostate cancer scheduled for radical prostatectomy and to correlate the proposed theoretical lesion size with the pathological findings. PATIENTS AND METHODS: Radiofrequency interstitial tumour ablation (RITA) was performed in 15 patients with localized prostate cancer before radical surgery. RF energy was delivered to the prostate by active needle electrodes (monopolar or bipolar) placed transperineally under transrectal ultrasonography guidance. Needle electrodes were used with different configurations and in some cases were covered by retractable shields to vary the length and circumference of the thermal lesions created. In eight patients, the procedure was performed immediately before radical prostatectomy, in six RITA was performed under spinal anaesthesia 1 week before surgery and in one patient, no surgery was performed but the patient was followed by serial determinations of prostate specific antigen (PSA). At least two lesions were created in each prostate, including both capsule and peripheral zones. NADPH and haematoxylin & eosin (H&E) staining were used to assess the extent of the necrotic lesion in the radical prostatectomy specimen. RESULTS: The mean energy delivered was 10.5 kJ, with central temperatures reaching up to 105 degrees C during 12 min of ablation; rectal temperature remained at < 38 degrees C. There were no complications. Macroscopic examination showed well-demarcated lesions including the prostatic capsule, up to 2.2 x 1.5 x 4.5 cm. With monopolar energy, the observed lesion size was comparable to the predicted 2 x 2 x 2 cm lesion, while with bipolar energy, lesion size was related to interneedle distance and uncovered needle length. Microscopic examination showed clearly delineated lesions both with NADPH (in prostates immediately removed after surgery) and H&E (at 1 week after RITA) staining. The lesion size observed on pathological analysis correlated with the predicted lesion size. In one patient, no residual cancer was found in the specimen. In the patient whose entire prostate was targeted and followed by serial PSA measurements, the latter were undetectable at 3 months of follow-up. CONCLUSION: Transperineally delivered RF energy is capable of safely creating extensive coagulative necrotic lesions in prostate cancer tissue, in a reproducible and controlled manner. The results presented here provide basic information for the potential future application of this form of energy for localized prostate cancer.

Catheter Ablation↗
PubMed1997

Pancreatic duct: morphologic and functional evaluation with dynamic MR pancreatography after secretin stimulation.

PURPOSE: To assess the utility of dynamic MR pancreatography in the evaluation of the behavior of the pancreatic duct after secretin stimulation and to estimate pancreatic exocrine reserve in patients suspected of having acute recurrent or chronic pancreatitis. MATERIALS AND METHODS: Ten healthy volunteers and 13 patients suspected of having pancreatic disease and no obvious markers of chronic pancreatitis were studied. Single-shot turbo spin-echo T2-weighted dynamic MR pancreatograms were obtained before and every 30 seconds during the 10 minutes after secretin administration. Morphologic features and diameter of the pancreatic duct were monitored before and during secretin stimulation. Duodenal filling volume was graded. Results were compared with those of endoscopic retrograde cholangiopancreatography and secretin stimulation testing with collection of pancreatic fluid. RESULTS: Secretin improved the delineation of ductal morphologic features in both groups. Persistent dilatation of the pancreatic duct after stimulation (five patients) was a significant finding (P = .0015) in the diagnosis of papillary stenosis. The mean duodenal filling score was significantly lower in patients with reduced exocrine function (six patients) than that in the volunteers (P < .0001). CONCLUSION: The use of dynamic MR pancreatography with secretin stimulation may be useful for diagnosing pancreatic papillary stenosis or dysfunction and for detecting reduced pancreatic exocrine reserve.

Adult↗
PubMed1997

Vocal fold atrophy: quantitative glottic measurement and vocal function.

Videostroboscopic glottic measurements and vocal function were evaluated in 41 vocal fold atrophy patients with bowed vocal folds. The amount of bowing in the resting position and the glottal gap area and vibratory amplitude during phonation were measured from digitized videostroboscopic images. Vibratory amplitude was not decreased on atrophic vocal folds. With the same amount of total bowing, the glottal gap area for bilateral atrophy was smaller than for unilateral atrophy. These results suggest that vocal fold atrophy is not disadvantageous to thyroplasty type I, and that bilateral procedures may produce a better outcome than a unilateral procedure in the treatment of bilateral atrophy. Acoustic, aerodynamic, and perceptual parameters of vocal function were measured. The acoustic high-frequency power ratio and the H-index correlated with the glottal gap area. The mean flow rate correlated with the amount of bowing. The degree of dysphonia was related to the size of the glottal gap and bowing.

Adult↗
PubMed1997

Imaging in reflex sympathetic dystrophy.

The diagnosis of reflex sympathetic dystrophy (RSD) relies on clinical evaluation, scintigraphy or MR imaging, and routine radiographs. Because RSD has variable manifestations with a strong psychogenic overlap, it is desirable to have a noninvasive test to determine the presence of RSD to allow for appropriate treatment. MR imaging allows a differential diagnosis between RSD and other bone lesions. It proves to be a reliable technique in showing and characterizing RSD better than radiographic examination and radionuclide study.

Diagnosis, Differential↗
PubMed1997

Facet joints diseases.

A review of the normal anatomy, developmental abnormalities, traumas and disorders affecting the facet joints is provided, with a recall of the major imaging modalities.

Arthrography↗
PubMed1996

Transurethral needle ablation of the prostate: clinical experience in patients in urinary acute retention.

OBJECTIVE: To evaluate the clinical outcome of patients in urinary retention due to benign prostatic enlargement (BPE) treated using transurethral needle ablation (TUNA), an outpatient procedure requiring only local intra-urethral anaesthesia and intravenous sedoanalgesia. PATIENTS AND METHODS: The TUNA technique was used in 38 patients in acute retention due to BPE, 34 of whom were a poor surgical risk. A special cytoscopic catheter device delivered low-level radiofrequency (RF) energy interstitially to a localized area of the prostate, producing necrotic lesions within the prostatic parenchyma. After treatment, all men were evaluated using urinary flow rates, residual urine volume, the International Prostate Symptom Score and quality of life score at 1, 3 and 6 months. RESULTS: The mean prostate size was 43.1 g (range 18-90). Tolerance of the procedure when using topical anaesthetic and intravenous sedation was excellent. Of the 38 patients treated using TUNA, 30 (79%) resumed voiding within a mean of 8.7 days (range 2-27). After 6 months, the sustained mean peak flow rate was 10.4 +/- 3.4 mL/s and the mean residual volume was 76 +/- 45 mL. Five of the patients who did not resume voiding after TUNA underwent retropubic prostatectomy and one patient underwent TURP. The mean prostate size in these patients was 55.7 g. Failure to void was associated with the treatment of too few areas of the prostate for its volume. CONCLUSION: This study demonstrated that TUNA is highly effective in relieving patients in urinary retention due to BPE and seems particularly suitable for treating patients who are at greater risk during surgery.

Aged↗
PubMed1996

Primary biliary cirrhosis and bone changes.

Two cases of primary biliary cirrhosis with bone lesions are reported. In one case radiographic findings in the hands and right shoulder are found to be characteristic of primary biliary cirrhosis rather than other concomitant diseases present in the patient which are also susceptible to produce bone lesions. The second case is an example of less specific bone changes which may be attributed to primary biliary cirrhosis or other rheumatoid disease.

Aged↗
PubMed1996

[Imaging of acquired pathologies of the thoracic aorta].

For many years, imaging of thoracic aorta has been dominated by angiography. Development of new imaging modalities has modified the diagnostic approach to thoracic aortic pathology. The knowledge of the advantages and limitations of each technique enables a better choice for patient evaluation, in particular under emergency conditions. This study is based on a review of the literature and reports the authors' experience.

Aortic Dissection↗
PubMed1995

Atypical and equivocal sonographic features of the spinal cord in neonates.

Thanks to the wider use of sonography to examine the spinal content in the neonate, normal anatomy and anomalies may be detected easily. Yet, unusual sonographic patterns are also observed. These must be differentiated from true pathologies. During a prospective study of 103 neurologically asymptomatic neonates, atypical sonographic patterns were found in 16 patients, corresponding to normal variants in 13. Nine of these 13 patients presented with a widening of the distal part of the central echo complex (one had a dilated ventriculus terminalis). Nerve roots of the cauda equina were disposed asymmetrically in three patients; the spinal cord movements were still present. In two of these babies, this distribution was associated with thin arachnoid pseudocysts. One patient presented with transitorily hyperechoic and narrow subdural spaces, probably related to neonatal dehydration. None of the 13 patients showing normal variants required any treatment. The other 3 patients (of 16) presented with equivocal entities of unknown evolution: sonographic tethered cord, fibrolipoma of the filum terminale and epidural varices. Sonography is highly accurate in evaluating the spinal cord content and aids differentiation of normal and normal variants from equivocal or pathological entities.

Diagnosis, Differential↗
PubMed1994

Hyperechoic thickened ependyma: sonographic demonstration and significance in neonates.

In the neonate, hyperechoic thickening of the ependyma is believed to be related to ventriculitis. Yet, in our experience, this sign is much more often observed in association with subacute intraventricular hemorrhage (IVH), without infection. Sixty premature neonates were prospectively studied. The observations of transfontanellar sonograms (intracranial hemorrhage, ependymal echogenicity, and ventriculomegaly) were correlated with the results of MRI, lumbar punctures and clinical work-up. Intracranial hemorrhage was detected in 28 patients, and hyperechoic thickening of the ependyma was observed in 21 of them, all of whom had IVH. In 9 of these 21 patients IVH was diagnosed retrospectively thanks to the visualization of the hyperechoic ependyma. In all but one, this sign persisted for at least 2 months after disappearance of other signs of IVH. MRI demonstrated the presence of hemosiderin and ferritin in ependymal or subependymal location only in patients with hyperechoic ependyma. One of our patients had in utero diagnosis of IVH owing to the visualization of the same hyperechoic aspect of the ependyma. Nine of the neonates with hyperechoic ependyma developed ventriculomegaly, and three underwent surgery. Hyperechoic thickening of the ependyma in prematures often results from a subacute IVH. It is related to hemoglobin catabolites which can be detected by MRI. It does not require immediate potentially harmful diagnostic punctures. The presence of this hyperechoic rim allows a retrospective diagnosis of IVH and indicates a clinical and sonographic follow-up in newborns at risk for secondary hydrocephalus.

Cerebral Hemorrhage↗
PubMed1993

Lipomyeloschisis associated with thoracic syringomyelia and Chiari I malformation.

Co-existence of Chiari I malformation and myelomeningocele is uncommon. Syringomyelia, when associated with a Chiari I malformation, classically involves the cervical spinal cord. Intramedullary extension of lipoma is unusual in lipomyeloschisis. A patient with lumbar lipomyelomeningocele with tethered cord, lower thoracic syringomyelia and Chiari I malformation, shown by MRI is reported.

Arnold-Chiari Malformation↗
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↗