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Biomedical subjects

R Tello

Publications and source records attributed to R Tello.

At least 19 recordsLinked to original sources
PubMed1995

A system for automated procedure documentation.

Quantitative information regarding competency in performing procedures is invaluable in attesting to a house officer's abilities when assessments need to be made. Thus, the means by which procedures, proficiency, and experience can be recorded and organized in an automated fashion need not be any further away than the nearest micro-computer. The procedure documenting system (PDS) automates the documenting of procedures and quantitative information pertaining to these procedures, and shortens the time demanded of the house officer to document procedures from a mean of 5.5 to 1.9 min. This paper is a description of the work done to automate the recording of procedures performed by housestaff at a teaching hospital and the acceptance by housestaff. This computer program takes the specific information and places it into a specialized database so that house officers can have detailed documentation attesting to their proficiency in various procedures. In addition, the program director can access the database to document the quantity of procedures to which an individual house officer has attained competence.

Automation↗
PubMed1995

In vivo three-dimensional evaluation of the tracheobronchial tree.

Traditionally computed axial tomography has had limitations in evaluating diseases that affect the tracheobronchial tree because of respiratory-induced artifacts, with the likelihood of missing lesions as a result of misregistration. Spiral computed tomography (CT) differs from conventional CT in that the entire thorax can be rapidly imaged in the axial plane after a single breath-hold. Five patients underwent non-contrast-enhanced volumetric CT, with emphasis on three-dimensional reconstruction, and endoscopic evaluation with pathologic confirmation. In all cases, there was complete corroboration between volumetric CT and endoscopic evaluation. The use of selective thresholds allowed the air within the tracheobronchial tree to be used as a negative contrast agent. Thus with the integration of selective windowing, detailed three-dimensional tracheobronchial anatomy may be elucidated. The absence of respiratory registration artifact due to the single breath-hold technique raises the confidence that three-dimensional and multiplanar images generated from such studies are accurate representations of the pathologic conditions at hand. By the integration of volumetric CT techniques and rapid three-dimensional display of tracheobronchial structures, volumetric CT bronchography becomes practical.

Aged↗
PubMed1994

The use of personal computers in nuclear medicine.

Consolidating personal computers (PCs) with nuclear medicine technology can create high computational power comparable with that produced by vendor-specific computer equipment, and at more affordable prices. The integration of a standard platform and operating system with a large installed base has enabled our department to maintain itself at the cutting edge of technology with minimal expense. Along with the savings from the purchase of PC software and hardware come the added advantage of rapid training of staff with minimal in-house effort, especially given the vast educational support in the general community. The integration of a standard platform and operating system with a large installed base has provided the nuclear medicine department with computational resources once unheard of because of economies of scale. The acceptance and integration of a pervasive, flexible technology into nuclear medicine have shown that state-of-the-art studies can be performed at low cost.

Microcomputers↗
PubMed1994

Detection of myocardial ischemia: value of combined myocardial perfusion and cineangiographic MR imaging.

OBJECTIVE: Established noninvasive methods for assessing myocardial ischemia have limitations that might be overcome by MR imaging. We investigated MR myocardial perfusion imaging and MR ventriculography, before and after dipyridamole-induced stress, to determine whether the superior spatial and temporal resolution of MR imaging has advantages for the evaluation of myocardial ischemia. SUBJECTS AND METHODS: Eighteen patients with symptoms suggestive of myocardial ischemia were examined by use of MR perfusion imaging and MR cineangiography before and during dipyridamole-induced stress. Multiplanar gradient-echo MR cineangiography and cardiac gated fast low-angle shot (turbo-FLASH) MR imaging during injection of gadopentetate dimeglumine were used. Results were compared with findings from perfusion scintigraphy and coronary arteriography. RESULTS: The accuracy of the combination MR technique for detecting myocardial ischemia was similar to that of scintigraphy. No significant difference was found between the MR technique and scintigraphy for detecting segments of myocardium supplied by stenosed coronary arteries (> 70% reduction in diameter, as determined by coronary arteriography). The sensitivity of the combination MR technique for angiographically detecting significant coronary artery narrowing was 92%, and the specificity was 100%. For scintigraphy, the sensitivity was also 92% and the specificity was 100%. CONCLUSION: Initial results indicate that a combination of stress MR myocardial perfusion imaging and MR ventriculography is feasible and that this technique can detect myocardial ischemia with an accuracy similar to that of scintigraphy. This technique may make more complete noninvasive assessment of myocardial ischemia possible.

Adult↗
PubMed1993

[Clinical and etiologic study of 90 cases of chronic diarrhea].

90 patients with chronic diarrhoea underwent this prospective study. They were seen in a private hospital of Lima during 1990 and 1991. According to a methodologic plan for determining sources and the diseases that originate chronic diarrhoea. In all patients hematologic, bioquimic, coprocultures, coproparasitologic exams were done, chest and intestinal transit X-rays. All underwent duodenal content culture. Colon X-ray in 25 cases; proctosigmoidoscopy in 14 and upper digestive endoscopy in 19 patients. Abdominal echography in 12 and TAC in 2 cases. The final results showed as determinant diseases for chronic diarrhoea, according to their frequency: enteroparasitosis (23.3%), functional digestive disorders (20.0%), intestinal bacterial overpopulation (15.5%) of unknown origin (8.8%), colon diverticulus (7.7%) proven and probably (5.5%), lactose intolerance (3.3%), diabetes mellitus (2.2%), and in one case (1.1%) the following: intestinal linfoma, pancreas malignancy, AIDS, colonic and deformation and megaloblastic anemia. The causes of chronic diarrhoea are several and multifactorals and in this study we prove the preeminence of the intestinal parasitosis, functional disorders and intestinal bacterial overpopulation and with less frequency other pathologies.

Adolescent↗
PubMed1992

Spiral CT of the thorax with reduced volume of contrast material: a comparative study.

The effectiveness of spiral computed tomography (CT) of the thorax performed with 60 mL of 60% contrast material was compared with that of conventional dynamic incremental CT performed with 120 mL of 60% contrast material. Fifty patients in whom contrast material-enhanced thoracic CT examination was necessary were assigned to undergo either spiral CT or dynamic incremental CT. Vascular opacification and mediastinal-lung image quality were graded independently by two observers. Vascular opacification and lung image quality were better with spiral CT than with conventional CT. Results of this pilot study encourage the use of spiral CT to decrease the volume of contrast medium used in patients undergoing thoracic CT.

Adult↗
PubMed1992

Assessment of the thoracic aorta by spiral CT.

A recently developed technique, spiral CT, allows rapid data acquisition through an entire anatomic region during a single breath-hold. High-quality spiral CT scans of the thoracic region have been obtained with volumes of contrast material that are small relative to those used with conventional CT. This essay illustrates the diseases of the aorta as seen on spiral CT performed with low volumes of contrast material.

Aged↗
PubMed1985

Flow determination using computed tomography: application to aortic dissection. Part I.

The CT method of flow determination evaluated in this study was based on the application of contrast enhancement dynamics. In order to characterize flow, such parameters as mean transit time, rise time, peak CT value, curve width and variance, and others were derived from the venoarterial indicator dilution curves using a perfect mixers-in-series model of curve fitting analysis and a bolus injection of contrast medium. The technique was first validated in a steady state phantom model that simulated in vivo conditions of right-sided mixing closely by the introduction of a number of mixers. A series of flows through small tubes was measured. Good correlation was obtained (r = .85). For a fixed number of mixers, the central second moment of the primary peak of the indicator dilution curve or variance decreased with increasing flow and peak CT value increased. Applied to the clinical situation, this method would allow characterization of blood flow using an intravenous bolus of contrast.

Aortic Dissection↗
PubMed1982

Single dose treatment with praziquantel (Cesol R, EmBay 8440) of human cestodiasis caused by Diphyllobothrium pacificum.

Diphyllobothrium pacificum, a large tapeworm of seals, is often found as an accidental parasite of man in Perú. The main symptoms is causes are abdominal pain, meteorismus and flatulence, and diarrhea. We report the results of 32 single-dose (10 mg/kg weight) treatments with Praziquantel (Cesol R, EmBay 8440) in 31 patients. One of these patients was shown to be cured but presented a reinfection 270 days later, and required retreatment. Praziquantel was effective in all cases. All patients were clinically cured. No ova were found in stool examinations at 30, 60, and 90 days after treatment, while pretreatment stools were positive for ova with all the techniques used. The antiparasitic effect was evident in 11 cases which segments of the tapeworm were eliminated within the first 3 days of treatment: the fragments were all partially digested or autolysed. A treatment scheme incorporating a purge may be best, to recover the parasite in its entirety and thus ascertain cure with no repeated controls.

Adolescent↗
PubMedDate not supplied

MR perfusion imaging of the kidney pre- and post-dipyridamole stress.

Animal studies have demonstrated that renal MR contrast enhancement depends on the timing of image acquisition. Limited human studies have demonstrated effects of dipyridamole (DP) on total renal perfusion. This study assessed the effect of DP on total and regional renal perfusion using gated perfusion MRI for patients undergoing DP stress. Five subjects with no evidence of renal ischemia were examined at rest and after DP stress. Rest MRI images in the left kidney were acquired using electrocardiogram (ECG)-gated MR: turbo fast low-angle shot (FLASH); echo time (TE) = 12, repetition time (TR) = 6, flip angle = 12, inversion time (TI) = 100) 10 to 45 seconds after injection of gadopentetate dimeglumine. Stress was induced in the MRI scanner (DP, .56 mg/kg over 4 minutes) followed by stress MRI after a second bolus of gadopentetate dimeglumine in the same position and identical time intervals. MR signal in the whole left kidney and renal medulla and cortex pre- and post-DP demonstrated a 70% depression of total renal perfusion with relative preservation of cortical perfusion at the expense of medullary perfusion. Post-DP MR images demonstrated a decrease in cortical perfusion with an additional 29% depression of medullary perfusion (P < .001) with respect to cortical perfusion. Turbo FLASH MRI can provide adequate time and spatial resolution to demonstrate changes in renal perfusion. Depression of renal medullary perfusion after DP appears to be caused by the intrarenal effect of DP and may have clinical impact.

Aged↗
PubMedDate not supplied

Case report: legionella infected thoracic aortic graft.

A case of a thoracic aortic graft in a patient with Marfan's syndrome infected with legionella is presented. The pathogenesis of graft infection and aspects of examination with aortography, gallium scanning, magnetic resonance imaging (MRI), and spiral volumetric computed tomography (CT) are presented, and the pathophysiology and management of thoracic aortic graft infections is briefly discussed.

Aortic Dissection↗
PubMedDate not supplied

Comparison of spiral CT and conventional CT in 3D visualization of facial trauma: work in progress.

Spiral computed tomography (SCT) differs from conventional CT (CCT) in that regions of the body can be rapidly imaged via continuous scanning. This is accompanied by simultaneous advancement of the patient, thus allowing volumetric data acquisition of up to 60 cm in less than a minute. Thus motion is minimized and slice misregistration is minimized when multiplanar and three dimensional reconstructions are performed. This paper compares the utility of SCT and CCT in facial trauma. A total of six patients were studied with either CCT or SCT of the face after trauma. SCT scans were obtained using a Siemens Somatom Plus-S CT scanner (2 mm thick collimation and 3 mm/sec table feed for 32 s). Three-dimensional (3D) and multiplanar reconstruction images of the facial bones were generated after appropriate thresholds were selected by the radiologist; similar images generated with a CCT (GE quick 9800) were compared using a three point scale with kappa analysis. SCT is able to generate axial and reformatted images of comparable quality to CCT (k = 0.47-0.89) in less than half the time to perform an examination (26 min vs 63 min). SCT can rapidly produce (3D) and multiplanar reformatted images of facial trauma with minimal motion, or misregistration artifact when compared to CCT.

Adult↗
PubMedDate not supplied

In vitro and in vivo effects of three bismuth compounds on fermentation by colonic bacteria.

Three bismuth compounds (tripotassium dicitrate bismuthate, bismuth subsalicylate, and bismuth subnitrate) were tested in vitro and in vivo for their effect on fermentation by colonic bacteria. The studies in vitro were done with use of a technique designed to determine the effect of each one of the bismuth compounds on the fermentation of several stool samples that had been mixed with lactose as additional fermentable substrate (fermentation of lactose-enriched stools, FLES). The three bismuth compounds reduced FLES significantly in 47 (81%) of 58 of the stool samples used to test their effect. Bismuth subsalicylate, which reduced FLES in 10 of 10 stool samples, showed the greatest reduction (mean reduction, 74%; P less than .0001). The in vivo studies, done in six flatulent patients, showed significant reduction (P less than .01) of colonic fermentation of ingested raffinose by oral bismuth subnitrate given for 8 days.

Adolescent↗