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Biomedical subjects

C L Sistrom

Publications and source records attributed to C L Sistrom.

At least 19 recordsLinked to original sources
PubMed2001

Managing predefined templates and macros for a departmental speech recognition system using common software.

The authors have developed a networked database system to create, store, and manage predefined radiology report definitions. This was prompted by complete departmental conversion to a computer speech recognition system (SRS) for clinical reporting. The software complements and extends the capabilities of the SRS, and 2 systems are integrated by means of a simple text file format and import/export functions within each program. This report describes the functional requirements, design considerations, and implementation details of the structured report management software. The database and its interface are designed to allow all radiologists and division managers to define and update template structures relevant to their practice areas. Two key conceptual extensions supported by the template management system are the addition of a template type construct and allowing individual radiologists to dynamically share common organ system or modality-specific templates. In addition, the template manager software enables specifying predefined report structures that can be triggered at the time of dictation from printed lists of barcodes. Initial experience using the program in a regional, multisite, academic radiology practice has been positive.

Computer Peripherals↗
PubMed2000

A simple method for obtaining original data from published graphs and plots.

OBJECTIVE: To describe a method for deriving original data values from scanned images of graphs and scatterplots published in the medical literature. CONCLUSION: The procedure is simple, reproducible, and relatively error free (when performed carefully). This method is useful in converting published graphic material into numeric data for various uses when the original data are unavailable directly from the authors.

Data Interpretation, Statistical↗
PubMed1996

Detection and estimation of the volume of pneumothorax using real-time sonography: efficacy determined by receiver operating characteristic analysis.

OBJECTIVE: The purpose of this study was to determine the efficacy of real-time sonography for the detection and estimation of the volume of pneumothorax using receiver operating characteristic (ROC) analysis in 27 patients evaluated by five radiologists using previously described sonographic findings. MATERIALS AND METHODS: Bilateral chest sonograms were obtained in 27 patients after we performed 26 needle biopsies of the lung and two transcostal biopsies of lesions at the dome of the liver. Thirteen unilateral pneumothoraces were found on radiographs done at the time of the sonograms. The sonograms were recorded on videotape and later viewed by five blinded readers who scored each hemithorax independently as to the likelihood and size of pneumothorax. From these interpretations we were able to calculate ROC curves and standard accuracy statistics for each observer and for pooled data. The results were correlated with the findings on chest radiographs, which were used to verify the diagnoses. RESULTS: The area under the ROC curves ranged from 0.63 to 0.79 in detecting any pneumothorax. The area under the ROC curve derived by pooling readers and hemithoraces using the jackknife method was 0.73. The average sensitivity of the five observers fro pneumothorax was 73%, the specificity was 68%, and the negative and positive predictive values were 89% and 40%, respectively. No significant correlation was found between readers' estimates of pneumothorax size made on the basis of sonographic findings and actual size as ascertained from chest radiographs. CONCLUSION: Real time sonography is useful to localize known pneumothorax but cannot be used to exclude the diagnosis. Moreover, sonography has a significant false-positive rate and is of no use in estimating the volume of a pneumothorax.

Algorithms↗
PubMed1995

Reversal of flow in the inferior epigastric arteries: Doppler ultrasonographic findings and significance.

The objective of this work is to evaluate the significance of finding reversal of flow in the inferior epigastric artery during noninvasive assessment of the lower extremity circulation using Doppler ultrasonography. This phenomenon is easy to demonstrate when present and predicts aortic or iliac artery stenosis or occlusion at subsequent arteriography. We found collateralization to the leg from the ipsilateral internal mammary artery via the epigastric arteries in all cases in which ultrasonography showed such reversal and these vessels carried the majority of the blood supply to the leg. This finding and its significance should be conveyed to patients and their physicians so that deliberate harvesting or inadvertent surgical damage to the epigastric arteries can be avoided, as this has been shown to lead to worsening of leg ischemia.

Abdominal Muscles↗
PubMed1994

Laparoscopic ultrasound-guided drainage of lymphoceles following renal transplantation.

The development of a lymphocele is an uncommon but well-documented complication of renal transplantation. In most patients, lymphoceles remain asymptomatic, and no intervention is required. In some cases, however, lymphoceles become symptomatic and cause systemic and local manifestations. Ultrasonic scanning can easily diagnose and locate the size and position of perirenal fluid collections. Many of these patients can be managed conservatively by aspiration and drainage of the lymphocele under radiologic guidance. However, if the lymphocele remains symptomatic or reaccumulates after aspiration and drainage, surgical intervention may be required. We describe two different ultrasound-guided laparoscopic techniques for drainage of a perirenal lymphocele into the peritoneal cavity. Successful drainage was accomplished in 5 patients, with 1 patient suffering an injury to the ureter of the transplant kidney. Recommendations regarding patient selection and operative technique are presented.

Catheterization↗
PubMed1994

Breath-holding capability of adults. Implications for spiral computed tomography, fast-acquisition magnetic resonance imaging, and angiography.

PURPOSE: The breath-holding capabilities of various groups of individuals were evaluated to develop protocols so that patients undergoing spiral computed tomography (CT), digital angiography, and breath-hold magnetic resonance imaging (MRI) can be studied successfully. METHODS: Twenty-five outpatients and 25 inpatients (all adults) were studied before undergoing body CT. Each subject was asked to hold his or her breath for as long as possible. Then each patient was asked to perform as many repetitive 12-second breath holds as possible. These data were correlated with demographic and historical information. RESULTS: The maximum breath-hold time for inpatients and those outpatients who were heavy smokers or had chronic obstructive pulmonary disease (COPD) or congestive heart failure (CHF) was 18 to 32 seconds (95% confidence interval) with a mean of 25 seconds. For all other outpatients, breath-hold time was 38 to 56 seconds (mean = 45 seconds). The 95% confidence interval for the number of 12-second breath holds for these two groups was 4 to 6 breath holds (mean = 4.9) and 6 to 7 breath holds (mean = 6.6), respectively. One inpatient could not hold his breath at all and three others were only able to hold their breath once for short periods. The sex and age of the patient had no significant effect on breath-holding performance. CONCLUSIONS: Breath-holding protocols must account for the diminished capabilities of most inpatients, and outpatients who are heavy smokers or have COPD or CHF. Most outpatients who are not heavy smokers or without COPD or CHF can achieve a single breath hold of 38 seconds, or up to six 12-second breath holds.

Angiography, Digital Subtraction↗
PubMed1994

The sensitivity and role of ultrasound in the evaluation of biliary obstruction.

Ultrasound is widely advocated as the initial noninvasive imaging study in evaluating suspected biliary obstruction. Some have suggested using ultrasound as the sole diagnostic test before exploratory laparotomy. To evaluate the accuracy of ultrasound in determining the level and etiology of biliary obstruction in patients with biliary dilatation, and to define its role in the evaluation of these patients, we performed a retrospective review of all patients from August 1986 to August 1991 who had biliary dilatation by ultrasound and subsequent endoscopic retrograde cholangiopancreatography and/or a percutaneous transhepatic cholangiography. Forty-two patients were included in this study, and ultrasound delineated the level of obstruction in 88 per cent, defined the etiology of the obstruction in 48 per cent, and diagnosed choledocholithiasis in 33 per cent of patients with this condition. A literature review revealed that ultrasound has a sensitivity of 71 per cent in delineating the level of obstruction, a sensitivity of 57 per cent in defining the etiology of biliary obstruction, and detects choledocholithiasis in 32 per cent of patients with this condition. We conclude that ultrasound is a highly accurate diagnostic test for delineating the level of biliary obstruction. Ultrasound should be the initial radiographic test in the evaluation of the patient with suspected biliary obstruction to guide further radiographic evaluation.

Aged↗
PubMed1993

Factors affecting the thickness of the cervical prevertebral soft tissues.

Lateral cervical spine films of 227 patients examined over 2 years were analyzed to determine the thickness of the soft tissues anterior to C2 through C4. These measurements were correlated with patient age, sex, weight, shoulder width, neck width, and calculated radiographic magnification. We found that only patient weight and age had any statistically significant effect on the soft tissue thickness. A stepwise regression model produced a simple equation for predicting the mean value of the soft tissue thickness (specifically at C3) using the patient's age and weight: C3 width = 3.7 mm-0.02 x age (years) + 0.01 x weight (pounds). Using this formula we determined that weight and age account for 28% of the observed variability in the soft tissue measurements at C3. These relationships were similar at C2 and C4. Interestingly, patient sex and radiographic magnification had no detectable effect on the measured widths.

Adolescent↗
PubMed1993

Methods used for liver computed tomography scanning in community radiology practice.

RATIONALE AND OBJECTIVES: A survey conducted in 1987 of mostly academic radiologists revealed that 8 of 22 (36%) respondents used bolus enhanced dynamic technique when performing computed tomography (CT) of the liver. In the current study, the authors performed a new survey of private practice radiologists that was over four times larger and had more comprehensive questions. METHODS: An 18-item questionnaire was sent to 260 members of the American College of Radiology. The answers from 98 usable responses were tallied and analyzed. RESULTS: Forty-six percent of the radiologists polled use bolus enhanced dynamic CT. Thirty-three percent still use ionic contrast, and a significantly lower iodine dose was used when nonionic contrast was chosen. CONCLUSIONS: There is general agreement in the imaging literature that dynamic enhanced scanning is the method of choice for detecting liver masses with CT. The authors speculate that cost and convenience considerations strongly influence such decisions, because less than 50% of radiologists we polled use this somewhat more expensive and time-consuming technique.

Community Health Services↗
PubMed1992

Ultrasound guidance for biopsy of omental abnormalities.

We review our two-year experience with ultrasound-guided fine needle aspiration biopsy of omental pathology. Eleven patients were referred for biopsy of omental abnormalities. Biopsy was performed without complication in all cases and the aspirates were positive for malignancy in 9. The discharge diagnosis was ovarian carcinoma in 6 patients, adenocarcinoma of unknown origin in 1, lymphoma in 1, and carcinoma of the colon in 1. The technique requires the use of a linear array transducer for biopsy guidance, and is safe, rapid, and easy to perform.

Aged↗