Splenic implants detected by SPECT images of Tc-99m labeled damaged red blood cells.
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Choristoma↗
Biomedical subjects
Max P Rosen
Publications and source records attributed to Max P Rosen.
Imaging utilization in the era of the hospitalist.
OBJECTIVE: We sought to determine whether hospitalists specifically reduce inpatient radiologic testing and radiology costs, which to our knowledge has not previously been studied. We examined the number of radiologic studies ordered, total cost of radiology utilization, cost per patient, mean length of stay, and readmission rates for hospitalists and nonhospitalists across the top-10 discharge diagnosis related groups for hospitalists from October 2000 to September 2001. CONCLUSION: We found no decreases in the utilization of radiology resources by hospitalists. Given the increasing volume and importance of radiology in clinical decision making, there will be increased pressure to justify the costs of these studies. We believe that more data should be collected about the use of radiology resources.
Aged↗
Expect the unexpected: thoughts, insights and musing about research in radiology.
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Biomedical Research↗
Detection of pulmonary embolism: comparison of paddlewheel and coronal CT reformations--initial experience.
In five patients with acute multilobar pulmonary embolism (PE) who were imaged with multi-detector row CT angiography, maximum intensity projection images were reformatted from axial images into rotated paddlewheel and coronal planes with three slab thicknesses and were reviewed for evidence of PE on a per-vessel basis with consensus of two readers. Paddlewheel reformations had a significantly higher percentage of overall detection of PE than did coronal reformations obtained with equivalent slab thickness (P <.0001). Paddlewheel reformations with 5.0-mm slab thickness had no significantly different percentage of overall detection of PE compared with that of axial images obtained with 2.5-mm collimation.
Adult↗
Acute appendicitis: effect of increased use of CT on selecting patients earlier.
PURPOSE: To explore the possibility of a relationship between increased use of computed tomography (CT) for diagnosis of appendicitis and increased occurrence of minimal or subtle CT and surgical findings. MATERIALS AND METHODS: Two groups, each with 50 consecutive patients who underwent CT before appendectomy in 1997 and 2000, were compared. CT scans and surgery-pathology reports were evaluated on a six-grade scale from normal to abscess or inflammatory mass. The demographics, surgical techniques, hospital stay, and grade distribution for the two groups were compared, and the CT results were correlated with surgical findings. RESULTS: In 1997, CT was performed in 33% (50 of 152) of patients undergoing appendectomy, as compared with 59% (50 of 85) 3 years later (P <.001). There was excellent correlation between surgical-pathologic and CT grades (weighted kappa, 0.75; P <.001; Spearman rank correlation, 0.83). There was no significant difference in demographics, rate of surgery, or surgical techniques used, but there was a significant decrease in the median surgical-pathologic grades, from 3.0 to 2.5 (P =.05) for all patients and from 3.5 to 2.6 (P =.003) for patients who underwent CT. Similarly, the median CT grade decreased from 4 to 3 (P <.001). Seven patients had subtle CT findings in 1997 compared with 16 in 2000 (P =.004), and there was a significant decrease in mean hospital stay, from 2.8 days +/- 4 (SD) to 1.5 days +/- 2 (P =.008). CONCLUSION: With increased CT use, there were less severe imaging findings, including absence of periappendiceal stranding, and a significant decrease in surgical-pathologic severity of appendiceal disease and hospital stay.
Acute Disease↗
CT predictors of failed laparoscopic appendectomy.
PURPOSE: To identify computed tomographic (CT) signs that may help predict possible failure of laparoscopic appendectomy and subsequent conversion to open appendectomy. MATERIALS AND METHODS: Of 234 consecutive patients who underwent preoperative CT and in whom laparoscopic appendectomy was attempted, 26 required conversion to open appendectomy. Conversion was correlated with the following CT findings: appendix location, appendicolith, cecal wall thickening involving the base of the appendix, lymphadenopathy, and appendiceal diameter. The extent of inflammation was graded by using a six-point scale: 0 meant normal appendix; 1, possibly abnormal appendix (6-mm diameter without other abnormality); 2, abnormal appendix (diameter > or = 6 mm with wall enhancement) without adjacent fat stranding; 3, abnormal appendix surrounded by fat stranding; 4, abnormal appendix surrounded by fat stranding and fluid; and 5, inflammatory mass or abscess. Student t and chi2 tests were used for statistical analysis of interval and nominal values, respectively. RESULTS: Although there was a significant difference in appendiceal diameter between the patients in whom laparoscopic appendectomy was successfully completed (11.3 mm +/- 3.5 [SD]) and those who required conversion (12.9 mm +/- 3.9), no distinct cutoff point was identified. Of the five CT findings evaluated, none was a significant predictor of conversion to open appendectomy. Eleven (7%) of 164 patients with a CT inflammation grade of 0-3 required conversion, whereas 15 (21%) of 70 patients with a grade of 4 or 5 required conversion (P <.04). CONCLUSION: The majority of patients with appendicitis can be treated with laparoscopic appendectomy. Nevertheless, patients who require conversion to open appendectomy tend to have high CT inflammation grades of 4 or 5, which indicate the presence of periappendiceal fluid or an inflammatory mass or abscess.
Acute Disease↗
CT colonography of colorectal polyps: a metaanalysis.
OBJECTIVE: For proper evaluation of the accuracy of CT colonography, prospective multiinstitutional trials would be ideal. Until these trials are available, data can be collectively analyzed. The purpose of this study is to use metaanalysis to assess the reported accuracy of CT colonography compared with conventional colonoscopy for detecting colorectal polyps. MATERIALS AND METHODS: Articles comparing CT colonography and conventional colonoscopy were identified, and a standardized form was used to extract relevant study data. Fisher's exact test and the Mantel-Haenszel test were used for pooling of data. A 95% confidence interval (CI) was selected to determine sensitivity and specificity, and the Kruskal-Wallis exact test was used to identify trends relating to polyp size. Meta-analysis methods were used to test strength of results. Comparisons were made for the percentage of polyps detected grouped by size (> or = 10 mm, 6-9 mm, < or = 5 mm) and the percentage of patients identified who had polyps of the same size. RESULTS: Fourteen studies fulfilled all the study inclusion criteria and gave a total of 1,324 patients and 1,411 polyps. The pooled per-patient sensitivity for polyps 10 mm or larger was (sensitivity [95% CI]) 0.88 (0.84-0.93), for polyps 6-9 mm it was 0.84 (0.80-0.89), and for polyps 5 mm or smaller it was 0.65 (0.57-0.73). The pooled per-polyp sensitivity for polyps 10 mm or larger was 0.81 (0.76-0.85), for polyps 6-9 mm it was 0.62 (0.58-0.67), and for polyps 5 mm or smaller it was 0.43 (0.39-0.47). Sensitivity for detection of polyps increased as the polyp size increased (p < 0.00005). The pooled overall specificity for detection of polyps larger than 10 mm was 0.95 (0.94-0.97). CONCLUSION: The specificity and sensitivity of CT colonography are high for polyps larger than 10 mm.
Colonic Polyps↗
Value of abdominal CT in the emergency department for patients with abdominal pain.
The purpose of our study is to demonstrate the value of CT in the emergency department (ED) for patients with non-traumatic abdominal pain. Between August 1998 and April 1999, 536 consecutive patients with non-traumatic abdominal pain were entered into our study. Using a computer order entry system, physicians were asked to identify: (a) their most likely diagnosis; (b) their level of certainty in their diagnosis; (c) if they thought CT would be normal or abnormal; (d) their treatment plan (prior to knowledge of the CT results); and (e) their role in deciding to order CT. This information was correlated with each patient's post-CT diagnosis and subsequent management. Pre- and post-CT diagnoses were concordant in 200 of 536 (37%) patients. The physicians' certainty in the accuracy of their pre-CT diagnosis was less than high in 88% of patients. Prior to CT, the management plan included hospital admission for 402 patients. Following CT, only 312 patients were actually admitted; thus, the net impact of performing CT was to obviate the need for hospital admission in 90 of 536 (17%) of patients with abdominal pain. Prior to CT, 67 of 536 (13%) of all patients would have undergone immediate surgery; however, following CT only 25 (5%) actually required immediate surgery. Among patients with the four most common pre-CT diagnoses (appendicitis, abscess, diverticulitis, and urinary tract stones) CT had the greatest impact on hospital admission and surgical management for patients with suspected appendicitis. For patients with suspected appendicitis, CT reduced the hospital admission rate in 28% (26 of 91) of patients and changed the surgical management in 40% (39 of 91) of patients. Our study demonstrates the advantage of performing abdominal CT in the ED for patients with non-traumatic abdominal pain.
Abdomen, Acute↗
Outcome analysis of patients with acute pancreatitis by using an artificial neural network.
RATIONALE AND OBJECTIVES: The authors performed this study to evaluate the ability of an artificial neural network (ANN) that uses radiologic and laboratory data to predict the outcome in patients with acute pancreatitis. MATERIALS AND METHODS: An ANN was constructed with data from 92 patients with acute pancreatitis who underwent computed tomography (CT). Input nodes included clinical, laboratory, and CT data. The ANN was trained and tested by using a round-robin technique, and the performance of the ANN was compared with that of linear discriminant analysis and Ranson and Balthazar grading systems by using receiver operating characteristic analysis. The length of hospital stay was used as an outcome measure. RESULTS: Hospital stay ranged from 0 to 45 days, with a mean of 8.4 days. The hospital stay was shorter than the mean for 62 patients and longer than the mean for 30. The 23 input features were reduced by using stepwise linear discriminant analysis, and an ANN was developed with the six most statistically significant parameters (blood pressure, extent of inflammation, fluid aspiration, serum creatinine level, serum calcium level, and the presence of concurrent severe illness). With these features, the ANN successfully predicted whether the patient would exceed the mean length of stay (Az = 0.83 +/- 0.05). Although the Az performance of the ANN was statistically significantly better than that of the Ranson (Az = 0.68 +/- 0.06, P < .02) and Balthazar (Az = 0.62 +/- 0.06, P < .003) grades, it was not significantly better than that of linear discriminant analysis (Az = 0.82 +/- 0.05, P = .53). CONCLUSION: An ANN may be useful for predicting outcome in patients with acute pancreatitis.
Acute Disease↗
Cost analysis of adjunct hypnosis with sedation during outpatient interventional radiologic procedures.
PURPOSE: To compare the cost of standard intravenous conscious sedation with that of sedation with adjunct self-hypnotic relaxation during outpatient interventional radiologic procedures. MATERIALS AND METHODS: Data were reviewed from a prospective randomized study in which patients undergoing vascular and renal interventional procedures underwent either standard sedation (n = 79) or sedation with adjunct hypnosis (n = 82). These data were used to construct a decision analysis model to compare the cost of standard sedation with the cost of sedation with adjunct hypnosis. Multiple sensitivity analyses were performed to assess the applicability of these results to other institutions with different cost structures with respect to the following variables: cost of the hypnosis provider, cost of room time for interventional radiologic procedure, hours of observation after the procedure, and frequency and cost of complications associated with over- or undersedation. RESULTS: According to data from this experience, the cost associated with standard sedation during a procedure was $638, compared with $300 for sedation with adjunct hypnosis, which resulted in a savings of $338 per case with hypnosis. Although hypnosis was known to reduce room time, hypnosis remained more cost-effective even if it added an additional 58.2 minutes to the room time. CONCLUSION: Use of adjunct hypnosis with sedation reduces cost during interventional radiologic procedures.
Adolescent↗