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J T Rhea

Publications and source records attributed to J T Rhea.

At least 37 records · Page 2Linked to original sources
PubMed1997

CT diagnosis of mesenteric adenitis.

PURPOSE: To quantify how frequently mesenteric adenitis clinically mimics appendicitis and to determine its appearance at computed tomography (CT). MATERIALS AND METHODS: The medical records of 651 consecutive patients with an admission diagnosis of appendicitis were reviewed to determine how often mesenteric adenitis was the discharge diagnosis. The CT scans of a separate group of 18 patients with a discharge diagnosis of mesenteric adenitis were reviewed. These patients were part of a group of 100 consecutive patients prospectively evaluated with CT of the appendix for clinically suspected appendicitis. RESULTS: Fifty of 651 patients (7.7%) with an admission diagnosis of appendicitis had a discharge diagnosis of mesenteric adenitis. Mesenteric adenitis constituted 50 of the 252 (19.8%) discharge diagnoses other than appendicitis. All 18 CT scans of mesenteric adenitis showed three or more nodes that measured at least 5 mm in shortest axis clustered in the right lower quadrant, with a normal appendix identified. Eight patients had associated ileal or ileocecal wall thickening. CONCLUSION: Mesenteric adenitis is an important clinical mimic of appendicitis. It appears at CT as clustered, enlarged mesenteric lymph nodes with a normal appendix, and there may be associated ileitis or ileocolitis noted.

Appendicitis↗
PubMed1997

Appendicitis: use of arrowhead sign for diagnosis at CT.

PURPOSE: To determine the frequency of collection of a contrast medium in the upper portion of the cecum, which the authors call the arrowhead sign, on computed tomographic (CT) scans of the lower abdomen and to assess the sensitivity and specificity of this sign for appendicitis. MATERIALS AND METHODS: One hundred consecutive patients clinically suspected of having appendicitis prospectively underwent helical CT limited to the lower abdomen. Contrast media were administered orally and by means of an enema. Each scan was reviewed for the arrowhead sign, and the findings were correlated with surgical and pathologic results or clinical follow-up findings. RESULTS: The arrowhead sign was present in 17 of 56 cases (30%) of appendicitis and in no case of excluded appendicitis. It allowed the unequivocal diagnosis of appendicitis in four cases (7%) of otherwise non-specific right lower-quadrant inflammation and in one case (2%) of subtle appendicitis seen at CT. CONCLUSION: The arrowhead sign is an often present, highly specific sign of appendicitis that can add specificity to the diagnosis of right lower-quadrant inflammatory processes at CT.

Appendicitis↗
PubMed1997

Distal appendicitis: CT appearance and diagnosis.

PURPOSE: To determine the appearance of appendicitis in the distal part of the organ (distal appendicitis) on computed tomographic (CT) scans and to evaluate the accuracy of diagnosis based on CT findings. MATERIALS AND METHODS: CT scans and medical records in 180 consecutive patients with proved appendicitis were reviewed. Fourteen had distal appendicitis with at least a 3-cm length of normal proximal appendix. Appendiceal CT scans and initial reports were reviewed retrospectively. RESULTS: The proximal appendix was collapsed (n = 6) or was filled with contrast material (n = 6) or air (n = 2). Inflamed distal appendices averaged 13.2 mm in diameter and were associated with periappendiceal fat stranding (n = 14), adenopathy (n = 6), appendolith(s) (n = 4), or fluid (n = 2). Transition points consisted of a progressively narrowed appendiceal lumen and thickened wall (n = 5) or appendiceal diameter enlargement (n = 9). No cecal apical changes were seen. Scans in all 14 patients were prospectively interpreted as indicative of appendicitis, including 12 (86%) interpreted as indicative of distal appendicitis. CONCLUSION: CT findings are useful for the accurate diagnosis of distal appendicitis. Visualization of the proximal appendix alone is insufficient to exclude distal appendicitis.

Appendicitis↗
PubMed1997

A focused appendiceal CT technique to reduce the cost of caring for patients with clinically suspected appendicitis.

OBJECTIVE: This investigation analyzed the potential impact on hospitalwide variable costs and total costs of introducing a focused helical CT technique for diagnosing appendicitis. MATERIALS AND METHODS: This investigation had three components. First, we retrospectively reviewed the records of 651 patients who had admitting diagnoses of appendicitis. Second, we determined variable costs and total costs for the components of these patients' care. Third, we projected change in costs if the focused appendiceal CT technique had been used to guide patient management. RESULTS: Using focused appendiceal CT in 100 patients would have decreased the number of nontherapeutic appendectomies by 13. The average length of stay for observation would have also decreased by 1 day because the diagnosis of an abnormal appendix or an alternative diagnosis would have been made more quickly. Savings in variable costs and total costs would have been $23,030 and $45,556 per 100 patients, respectively. CONCLUSION: Routine use of focused appendiceal CT would lower the costs of caring for patients with clinically suspected appendicitis.

Adolescent↗
PubMed1997

Helical CT combined with contrast material administered only through the colon for imaging of suspected appendicitis.

OBJECTIVE: Helical CT combined with contrast material administered by mouth and through the colon has been shown to be accurate for appendiceal imaging. This investigation was performed to determine if helical CT combined with contrast material administered only through the colon has comparable accuracy. SUBJECTS AND METHODS: One hundred patients prospectively underwent appendiceal CT imaging with thin-collimation, helical scanning limited to the lower abdomen and upper pelvis after contrast material was administered only through the colon. CT results were correlated with surgical and pathologic findings at appendectomy (56 patients), other surgery (three patients), or clinical follow-up at least 2 months after the CT scan (41 patients). RESULTS: Fifty-three CT scans were interpreted as positive for appendicitis, including 52 true-positives (with surgical-pathologic correlation) and on false-positive (with clinical follow-up). Forty-seven CT scans were interpreted as negative for appendicitis, including 40 true-negatives with clinical follow-up, three true-negatives with appendectomy and pathologic correlation, three true-negatives with other surgery and pathologic correlation, and one false-negative with appendectomy and pathologic correlation. CT had a 98% sensitivity, 98% specificity, 98% positive predictive value, 98% negative predictive value, and 98% accuracy for diagnosing or excluding appendicitis. In 47 normal appendix cases at CT, the appendix was seen in 44 cases (94%), and an alternative diagnosis was identified in 29 cases (62%). CONCLUSION: For diagnosing appendicitis, helical CT combined with contrast material administered only through the colon proved to be as accurate (98%) as helical CT combined with contrast material administered by mouth and through the colon. Helical CT with contrast material administered only through the colon also could be performed immediately and without any of the potential patient risks or discomforts of contrast material administered i.v. or by mouth.

Adult↗
PubMed1994

Improving the efficiency and service of computed tomographic scanning.

RATIONALE AND OBJECTIVES: This study quantified the impact on service and costs of operational changes in CT. METHODS: Operational and financial analyses were performed in 1988 and 1991 after process flow and management changes were made. RESULTS: The backlog decreased from about 6 weeks to 1 week. The cost per scan decreased 25%. Volume increased 50%. Two technologists were assigned per scanner doing some steps of the process in parallel rather than sequentially. Decreasing throughput time accounted for three fifths of the cost decrease. The reduction in number of scanners and hours of operation, change in radiologists' practice patterns, coordination of scheduling, CT priority for escort personnel, and personnel changes accounted for two fifths of the cost decrease. CONCLUSIONS: It is possible to simultaneously decrease costs and improve the quality of service by careful operations analysis and management. Operational changes had synergistic effects that allowed more improvement than might be anticipated. Advisable management changes may be counterintuitive.

Appointments and Schedules↗
PubMed1993

How to implement a radiology quality improvement program. Pearls and pitfalls.

To get started and to help overcome some of the problems with implementation mentioned above, five essential things need attention: 1. Top level commitment; 2. Physician participation; 3. On-going education; 4. Performance measurement (both of the department and individual); 5. Up-front investment of time and resources. The fundamental changes in technology, financing, and accountability present formidable challenges to departments of radiology today. Fortunately, quality management techniques offer a way to meet the challenges and simultaneously improve efficiency of care and quality. Learning and practicing these techniques is not an easy task, but overcoming the obstacles to implementation and getting on with the job will prove very rewarding.

Humans↗
PubMed1989

Impact of postprocessing on the detection of simulated pulmonary nodules with digital radiography.

The authors compared the impact of five postprocessing algorithms on diagnostic performance in the detection of simulated pulmonary nodules on storage phosphor-based digital chest radiographs. Tissue equivalent paraffin nodules (0.5-2.5 cm diameter) were randomly positioned over the chest of a normal volunteer. Receiver operating characteristics (ROC) analysis of a total of 2500 observations by five readers indicated that the default unenhanced image having the appearance of a conventional chest radiograph (ROC area = 0.87 +/- 0.05) was as good as an image with moderate enhancement of medium frequencies (ROC area = 0.85 +/- 0.03), an image with reversed gray scale polarity (ROC area = 0.84 +/- 0.02), an image with reversed gray scale and moderate enhancement of medium frequencies (ROC area = 0.87 +/- 0.03), and an image with a linear rather than a sigmoid gradation curve and incorporating moderate enhancement of medium frequencies (ROC area = 0.87 +/- 0.03). The authors conclude that the specific algorithms they tested had no effect on the detection of pulmonary nodules.

Algorithms↗
PubMed1989

"Single-exposure" dual energy digital radiography in the detection of pulmonary nodules and calcifications.

We studied the detectability of mineralized and non-mineralized simulated pulmonary nodules with dual energy digital radiography. "Soft tissue" and "bone" images (pixel size = 0.2 mm, 10 bits deep) were obtained with subtraction image processing after a single simultaneous exposure (100 kVp, 8 mAs, 17 mR skin exposure dose) of two storage phosphors with an interleaved 0.9 mm copper wafer. Three classes of paraffin-based nodules (0.5 to 3.0 cm) of varying mineral concentration (0, 120 and 190 mg/cm3 K2HPO4) were randomly positioned on the chest wall of two healthy volunteers to simulate calcified and non-calcified nodules. The average receiver operating characteristics (ROC) area of six readers (n = 2880 observations) showed that digital "bone" images (ROC area: 0.77 +/- 0.03) were significantly better (P less than 0.04) than conventional radiographs (OC Film, Lanex medium screens, 141 kVp, 19 mR skin exposure dose) (ROC area: 0.71 +/- 0.05) in detecting calcification in nodules. The unsubtracted digital images of lower kilovoltage were not superior to the 141 kVp conventional radiographs in a subgroup of two readers (ROC area: 0.73 +/- 0.02). Digital "soft tissue" images were equivalent to conventional chest radiographs in detecting soft tissue pulmonary nodules (ROC areas: 0.92 +/- 0.04 and 0.92 +/- 0.05, respectively.

Adult↗
PubMed1989

The frequency and significance of thoracic injuries detected on abdominal CT scans of multiple trauma patients.

Of 174 multiple trauma patients undergoing abdominal CT examination for suspected abdominal trauma, 65 patients had 109 chest injuries detected by abdominal CT, chest film, or both examinations. Forty-one patients had 55 chest injuries at the base of the thorax which were not detected on the initial chest film. The most frequent chest injuries detected only by CT were pneumothroax, fracture (rib, thoracic spine, and sternum), lung contusion, aspiration pneumonia, hemothorax, and post-traumatic atelectasis. Seven patients whose chest injury initially was seen only at abdominal CT required treatment of the injury, suggesting that a variety of chest injuries which may vitally affect patients can be detected early in multiple trauma patients by abdominal CT, and that all abdominal trauma CT scans should be scrutinized for signs of a chest injury.

False Positive Reactions↗
PubMed1989

Improved control of image optical density with low-dose digital and conventional radiography in bedside imaging.

The technical and diagnostic performance of simultaneously acquired low-dose (44% of standard dose) storage-phosphor digital radiographs (system resolution = 0.2 mm, 10 bits) were compared with those of standard-dose conventional bedside radiographs of the chest in 32 patients. The mean optical density (OD) of the lungs (800 measurements) was closer to the ideal density with digital radiography (1.45 OD +/- 0.20 [standard deviation] vs 1.75 OD +/- 0.53) and was less often outside the usable range (2.5% vs 42.5%). Receiver operating characteristic analysis for detection of simulated nodules and monitoring devices (nine readers, 4,608 observations) showed that digital radiography was superior to conventional radiography (P less than .05) for four of the nine readers and equivalent to conventional radiography for five readers. The authors concluded that digital radiography produces more consistent and ideal image density and performs at least as well as conventional radiography under phantom test conditions.

Absorptiometry, Photon↗
PubMed1986

Broncholithiasis.

Explore the source record for details and available documents.

Bronchial Diseases↗
PubMed1984

Vocal cord paralysis. A latent effect of perivascular thorium dioxide.

The late effects of thorium dioxide (Thorotrast) in the perivascular space of the neck are reviewed. The roentgenographic analysis of the problem consists of both plain films (to detect the residual density of extravasated thorium dioxide) and computed tomography (to help define any involvement of the carotid artery).

Calcinosis↗