[Disc alterations of lumbar spine on magnetic resonance images in asymptomatic workers]. / Alteraciones discales de columna lumbar identificadas por resonancia magnética en trabajadores asintomáticos.

OBJECTIVE: to determine abnormal findings of the lumbar spine on magnetic resonance images in asymptomatic subjects. METHODS: prospective, transverse and descriptive study, in workers of the Instituto Mexicano del Seguro Social without low back pain; they were invited to be observed with magnetic resonance images of lumbar spine. A total of 105 cases was interpreted by a radiologist, who did not know the patients' clinical conditions. 107 lumbar spine alterations studies were mixed in order to not influence in the results, and they were not included in the statistic analysis. RESULTS: 55 % of the cases had discal alterations, 38 % presented bulging disk and 17 % presented protrusion. Other alterations were Schmorl's nodule, osteocondrosis, espondilolistesis, and annular tears. CONCLUSIONS: bulging disk and discal protrusion frequency have high prevalence in magnetic resonance images in healthy individuals, so its presence in symptomatic patients is not necessarily cause of low back pain.

[Clinical utility of ultrasound in the identification of dengue hemorrhagic fever]. / Utilidad clínica del ultrasonido en la identificación de dengue hromorrágico.

OBJECTIVE: To evaluate the diagnostic utility of sonography in cases of dengue hemorrhagic fever (DHF) and to describe the correlation grade existing between the most frequent clinical and sonographic findings in DHF. MATERIAL AND METHODS: Prospective, cross-sectional and descriptive study applied to 132 patients, 21 of them with typical dengue fever and 111 with DHF. They went through ultrasound, searching for thickening of the gallbladder wall, pleural effusion and ascites. Dengue fever diagnosis was confirmed by positive IgM serology in all patients. Descriptive statistics, sensitivity and specificity tests, and phi contingency coefficient were used to obtain the correlation grade between clinical and sonographic findings present in DHF. chi2 was used to determine the statistics significance. RESULTS: Fever, retroocular pain and cephalea were found in more than 90% of the cases. The positive tourniquet test and petechiae were present in 70%, and thrombocytopenia, leukopenia and elevation of seric transaminases were found in 100% of the cases. Gallbladder thickening was present in 86% of the patients, pleural effusion in 66%, ascites in 60% and acute alithiasic cholecystitis in 36%. Thickening < 3 mm had a sensitivity of 87%, specificity of 48%, positive predictive value of 90% and negative predictive value of 40%. Certain correlation degree was found (r phi = 0.3, p < de 0.05) between thickening of the gallbladder wall > 5 mm and the presence of alithiasic cholecystitis, and a very slight correlation (r phi = 0.2, p < de 0.05) between thickening > 5 mm and free fluid in the abdominal cavity. CONCLUSIONS: Thickening of the gallbladder wall > 3 mm is a useful sonographic finding to confirm suspicious cases of DHF. The thickening of the gallbladder > 5 mm was just very slightly related with alithiasic cholecystitis and the presence of free fluid in the abdominal cavity, without any relationship with the most frequent laboratory data.

[Exactness of transcutaneous sonography in the diagnosis of gastric wall lesions]. / Exactitud de la sonografía transcutánea en el diagnóstico de lesiones de pared gástrica.

OBJECTIVE: Our objective was to determine sensitivity, especificity and predictive values of transcutaneous sonography for detecting gastric wall lesions. MATERIALS AND METHODS: This prospective study was performed from March 1999 to April 2000 on 150 patients referred for transcutaneous sonography by the Endoscopic Service Unit. Sonographic examinations were performed using RT 4000 General Electric equipment with 5 Mhz transducer and replenishment of stomach with fluid. All scanning was done by the same sonographer, who was unaware of endoscopic, tomographic, or upper gastrointestinal series features. Results from sonography were compared with gastrointestinal tract endoscopy. Sensitivity, specificity, and predictive values were determined using contingency statistical procedure. Sonographic examination accuracy was calculated evaluating sensitivity and specificity confidence intervals (CI). Kappa index was calculated. Diagnostic accuracy differences observed between tumoral and non-tumoral lesions by sonography were evaluated by chi 2 probe. RESULTS: Sensitivity of 85% (95% CI, from 75.2 to 94.8%) and specificity of 90% (95% CI, from 86 to 93.9%) were obtained. Positive predictability was 78% and negative predictability was 94%. Diagnostic accuracy was 87%. Kappa index was 0.717. There were 35 no false-positive results (19 tumoral lesions and 16 non-tumoral lesions), seven false-negative results (one tumoral lesion and six non-tumoral lesions) and 10 false-positive results (two tumoral lesions and eight non-tumoral lesions). Only one of 20 tumoral lesions were diagnosed by ultrasound whereas from 22 non-tumoral lesions were not diagnosed 6 (chi 2 = 3.74, p > 0.05). CONCLUSION: Transcutaneous sonography is a rapid, low cost and non-invasive method that may be useful to establish clinic diagnosis and in the first steps of gastric wall lesions evaluation, it is valuable in assessment of diagnostic orientation for the referring clinic.