Efficacy and safety of mangafodipir trisodium (MnDPDP) injection for hepatic MRI in adults: results of the U.S. Multicenter phase III clinical trials. Efficacy of early imaging.

The efficacy of contrast-enhanced magnetic resonance imaging (MRI) for detecting and characterizing, or excluding, hepatic masses was assessed in 404 patients, following the intravenous administration of mangafodipir trisodium (MnDPDP) injection, a hepatic MRI contrast agent. An initial contrast-enhanced computed tomography (CT) examination was followed by unenhanced MRI, injection of MnDPDP (5 micromol/kg IV), and enhanced MRI at 15 minutes post injection. Agreement of the radiologic diagnoses with the patients' final diagnoses was higher for enhanced MRI and for the combined unenhanced and enhanced MRI evaluations than for unenhanced MRI alone or enhanced CT using the clinical diagnosis as the gold standard. Mangafodipir-enhanced MRI uniquely provided additional diagnostic information in 48% of the patients, and patient management was consequently altered in 6% of the patients. MnDPDP-enhanced MRI was comparable or superior to unenhanced MRI and enhanced CT for the detection, classification, and diagnosis of focal liver lesions in patients with known or suspected focal liver disease.

Evaluation of a mandatory radiology resident research rotation.

RATIONALE AND OBJECTIVES: This purpose of this study was to determine if a 1-month, mandatory research rotation results in resident interest and productivity in research. MATERIALS AND METHODS: A survey composed primarily of closed-end questions was constructed to evaluate the opinions and experience of 24 residents who completed the research rotation during a 3 1/2-year period. RESULTS: All 24 residents filled out the survey. Seventeen residents did clinical projects, two did bench research, and two did projects that were socioeconomic or legal in nature. Thirteen residents presented data at a meeting, and three of these presentations won awards. Resident research projects resulted in 18 manuscripts at the time of the survey (seven published, eight in preparation, and three in revision or review). Seventeen residents thought the experience was worthwhile and the research month should be continued; two residents did not. Ten residents reported that in retrospect, they would have done the rotation even if it had not been required, and eight reported the experience increased their appreciation of the value of research in medicine. CONCLUSION: A 1-month, mandatory resident research rotation produces resident interest in research and enhances departmental research productivity.

Effect of Health Care Financing Administration regulation on radiology fellowship training.

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the effect of Health Care Financing Administration (HCFA) regulations on radiology fellowship training. MATERIALS AND METHODS: Surveys were sent to 157 fellowship program directors in body imaging and vascular/ interventional radiology. Questions addressed program accreditation status, faculty supervision of fellows, and any change in faculty supervision of fellows in response to HCFA's revised plan for Medicare Part B reimbursement. RESULTS: Eighty of 157 (51%) surveys were returned. Thirty (37%) respondents indicated supervision of fellows had changed after institution of the new HCFA rules in July 1996. Vascular/interventional program directors (n = 25, 49%) were more likely to have changed their practice than body imaging program directors (n = 5, 17%). Nearly all respondents (29 of 30, 97%) indicating a change stated supervision had increased. Twenty-seven (33%) respondents also indicated faculty supervision was beyond that necessary for patient care and house staff education; most of these respondents (21 of 27, 78%) stated the new HCFA regulations were responsible. Many program directors also expressed concern the HCFA regulations might prevent fellows from obtaining sufficient experience to effectively learn independent clinical decision-making. CONCLUSION: HCFA regulations intended to address attending physician billing practices at teaching institutions may have had the unintended effect of substantively altering the training of radiology fellows.

Lateral pharyngeal fat pad pressure during breathing in anesthetized pigs.

It has been hypothesized that the pressure in tissues surrounding the upper airway is one of the determinants of the size and shape of the upper airway. To our knowledge, this pressure has not been measured. The purpose of this study was to test whether the pressure in a tissue lateral to the upper airway, the lateral pharyngeal fat pad pressure (Pfp), differs from atmospheric and pharyngeal pressures and whether it changes with breathing. We studied six male lightly sedated pigs by inserting a transducer tipped catheter into their fat pad space by using computerized tomographic scan guidance. We measured airflow with a pneumotachograph attached to a face mask and pharyngeal pressure with a balloon catheter. Pfp differed from atmospheric pressure, generally exceeding it, and from pharyngeal pressure. Pfp correlated positively with airflow and with pharyngeal pressure, decreasing during inspiration and increasing during expiration. Changes in Pfp with ventilation were eliminated by oropharyngeal intubation. We conclude that Pfp differs from atmospheric and pharyngeal pressures and that it changes with breathing.

Attitudes of radiology residents toward personal computing: results of survey.

RATIONALE AND OBJECTIVES: The authors' purpose was to evaluate radiology residents' assessment of their own computer skills for potential development of computer training in a residency curriculum. METHODS: The authors conducted a survey to evaluate the attitudes of radiology residents concerning personal computing. Surveys were completed by 136 radiology residents from six academic institutions. RESULTS: Sixty percent of residents surveyed considered themselves to be computer literate and 93% would like further computer training. Fifty-six percent had a computer at home and 9% had a laptop. Almost all residents had access to a computer at work. Word processing and medical literature searches were the most common computer tasks performed by residents. Image processing was the least common task performed. Although all hospitals surveyed were connected to the Internet, only 26% of residents used the Internet and 14% used Internet teaching files. Most residents expressed a preference for self-paced, on-line evening training sessions. CONCLUSION: Most radiology residents believed they possessed adequate computer skills. This proportion has markedly increased over that found in previous surveys. Radiology residents desire and could likely benefit from computer training included as part of the residency curriculum.

Processes involved in reading imaging studies: workflow analysis and implications for workstation development.

Software development for imaging workstations has lagged behind hardware availability. To guide development and to analyze work flow involved in interpretation of cross-sectional imaging studies, we assessed the cognitive and physical processes. We observed the performance and interpretation of body computed tomography (CT) scans and recorded the events that occurred during this process. We studied work flow using a bottleneck analysis. Twenty-four of a total of 54 cases (44%) involved comparing the images with those of prior scans. Forty-seven of 54 scans (87%) were viewed using windows other than soft tissue, or compared with precontrast scans. In 46 cases (85%), the interpretation stopped to return to a previous level for review. Measurement of lesions was performed in 24 of 54 (44%) cases, and in 15 (63%) of these cases, measurements were taken of lesions on old studies for comparison. Interpretation was interrupted in 14 of 54 cases (26%) by referring clinicians desiring consultation. The work flow analysis showed film folder retrieval by the film room to be the bottleneck for interpretation by film. For picture archiving and communication system (PACS) reading, the CT examination itself proved to be the bottleneck. We conclude that workstations for CT interpretation should facilitate movement within scans, comparison with prior examinations, and measuring lesions on these scans. Workstation design should consider means of optimizing time currently not used between interpretation sessions, minimizing interruptions and providing more automated functions currently requiring physician interaction.

Thoracic sonography for diagnosis and intervention.

Many physicians believe that ultrasound has limited usefulness in chest disease. Our clinical experiences and a review of the literature in preparation for this monograph have convinced us that sonography can be a very useful and versatile tool for thoracic diagnosis and intervention. Although there are some limitations caused by interposed ribs and air-containing lung, almost all of the compartments of the chest can be evaluated with ultrasound, which gives unique and clinically useful information. Ultrasound guidance for biopsy and drainage does take some time to learn, but we feel that the effort is very worthwhile. The same advantages ultrasound enjoys for other body regions make it a modality that will see increased use in the chest as well. We hope that this monograph will stimulate our colleagues to explore and expand upon the techniques described.

Lateral pharyngeal fat pad pressure during breathing.

The purpose of this study was to test whether pressure in tissue lateral to the upper airway, the lateral pharyngeal fat pad, differs from atmospheric and pharyngeal pressure and whether it changes with breathing. We studied five male pigs by inserting a transducer-tipped catheter into their fat pad space using computed tomography (CT) scan guidance. We measured airflow with a pneumotachograph attached to a face mask and pharyngeal pressure with a balloon catheter. Fat pad pressure correlated positively with airflow and with pharyngeal pressure, decreasing during inspiration and increasing during expiration. Pressure in the fat pad differed from atmospheric pressure, generally exceeding it, and from pharyngeal pressure. We conclude that lateral pharyngeal fat pad pressure differs from atmospheric and pharyngeal pressure and that it changes with breathing.

Focal liver disease: comparison of breath-hold T1-weighted MP-GRE MR imaging and contrast-enhanced CT--lesion detection, localization, and characterization.

PURPOSE: To compare breath-hold T1-weighted magnetization-prepared gradient-echo (MP-GRE) magnetic resonance (MR) imaging with contrast material-enhanced computed tomography (CT) in the assessment of focal liver disease. MATERIALS AND METHODS: The MR and CT images obtained in 64 patients with focal liver disease were reviewed by six independent reviewers in a randomized, blinded fashion. Sets of axial T1-weighted MP-GRE images, three-plane (a compilation of axial, sagittal, and coronal) T1-weighted MP-GRE images, and contrast-enhanced CT scans were analyzed. T2-weighted spin-echo (SE) MR images were also compared with CT scans. RESULTS: Lesions were detected, localized, and characterized more accurately and generally with greater confidence with three-plane T1-weighted MP-GRE imaging than with CT (P < .01). Axial T1-weighted MP-GRE imaging was also superior (P < .05) to CT (although slightly less superior than three-plane imaging) except in the characterization of specific lesions, where both techniques were equal. T2-weighted SE MR imaging and CT were about equal. CONCLUSION: Lesion detection, localization, and characterization are performed more accurately and confidently with breath-hold T1-weighted MP-GRE imaging than with contrast-enhanced CT, particularly when breath-hold images are obtained in three planes.

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.

Hiring preferences of diagnostic radiology groups: results of a 1994 survey.

RATIONALE AND OBJECTIVES: We surveyed diagnostic radiology group preferences and considerations in hiring radiologists and compared these findings with those of a survey performed in 1990. We sought to identify changes in hiring practices that might have occurred because of socioeconomic changes. We also sought to identify features of job candidates that make them more attractive to hiring groups. METHODS: One hundred surveys were mailed to a stratified random sample of diagnostic radiology groups identified by the American College of Radiology. We solicited information on the importance of various attributes and the level of experience of a candidate, the fellowship training considered most desirable, and the effect of changes in the health care socioeconomic environment. The responses were weighted by group size and geographic location to estimate what results might have been obtained if we had surveyed all groups in the United States. RESULTS: Seventy-five groups returned the survey. The two most important factors in choosing a candidate were motivation and radiologic knowledge. The fellowships that groups that were hiring considered to be the most desirable were body imaging, neuroradiology, and angiography/interventional radiology. Groups overwhelmingly preferred recent training over long experience. CONCLUSION: Fellowship training increases a candidate's marketability, but the two factors that hiring groups consider the most important are motivation and radiologic knowledge.

Enlargement of the lateral pharyngeal fat pad space in pigs increases upper airway resistance.

Because the upper airway is partially enclosed in a rigid boundary, enlargement of soft tissue structures within this boundary could narrow the airway. The purpose of this study was to determine whether enlargement of the soft tissue space in the region of the lateral pharyngeal fat pad would increase pharyngeal resistance and narrow the retropalateal upper airway. In five young male anesthetized pigs, we inserted balloon occlusion catheters in the lateral pharyngeal fat pad under computerized tomographic scan guidance. We measured pharyngeal resistance with a pharyngeal catheter and a tightly fitting face mask before and after inflation of the balloons. We also measured pharyngeal airway cross-sectional area before and after inflation of the balloons. In all pigs, balloon inflation significantly increased pharyngeal resistance and significantly decreased the area of the retropalateal airway. We conclude that enlargement of the soft tissue space in the region of the lateral pharyngeal fat pad increases pharyngeal resistance and narrows the retropalateal airway in anesthetized pigs.

Computed tomography appearance of the prostatic fossa following radical prostatectomy.

RATIONALE AND OBJECTIVES: We assessed the value of postsurgical computed tomography (CT) in detecting locally recurrent prostatic carcinoma and determined the most effective CT findings. METHODS: We studied 13 patients with recurrent disease (prostate specific antigen [PSA] > 0.4 ng/ml) and 11 patients with no evidence of recurrence (PSA < 0.3 ng/ml). Pelvic CT scans were independently interpreted by four readers who were unaware of patient status. Readers measured tissue volume in the prostatic fossa and evaluated each scan for the presence of six potentially discriminating criteria. We determined sensitivity and specificity and developed mean and pooled receiver operating characteristic (ROC) curves for each criterion and for overall rating. RESULTS: The respective mean ROC curves, sensitivity, and specificity for each criterion were as follows: irregular tissue margins = .50, .67, and .32; inhomogeneous tissue density = .35, .76, and .11; asymmetric residual seminal vesicles = .68, .86, and .16; fat infiltration around seminal vesicles = .67, .69, and .43; infiltration of perirectal fat = .60, .71, and .40; and margins of the levator ani = .50, .78, and .09. The overall rating of whether a scan was normal or reflected recurrent cancer was .56, .75, and .32. Mean tissue volume in the prostatic fossa was 15.01 cm3 for the positive cases and 11.06 cm3 for the negative cases (p < .05), but because of a large overlap, this difference was not practically significant. CONCLUSION: CT scanning is not an effective technique for detecting recurrent prostate malignancy. Normally, there is a moderate amount of soft tissue in the prostatic fossa postoperatively that should not be confused for malignancy.

Current status of residency programs: survey of program directors.

RATIONALE AND OBJECTIVES: This survey was compiled to provide current data on the structure and content of radiology residency programs and the role of the residency program director. METHODS: A survey, created in electronic form and on paper, was distributed to all United States academic, private, and military radiology residency program directors. RESULTS: Of the 202 survey forms distributed, 168 (83%) were completed and returned. Eighty percent of respondents support national curriculum guidelines, but most do not favor national curriculum requirements. About half (53%) of programs spend 6 months in "view box" nuclear medicine; others provide some experience by lectures and on-call time. Most programs (60%) relieve residents of some call during the senior year. Some programs (28%) allow seniors time away from clinical duties to study for the oral board exam, and 17% permit time away to study for the written boards. Seventy-eight percent of programs have had a "problem resident," and 47% have asked a resident to leave the program. Directors' most frequently expressed concern was threat of diminished residency numbers due to decreased funding.