Computer-aided detection of breast cancer.
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Breast Neoplasms↗
Biomedical subjects
Elizabeth A Krupinski
Publications and source records attributed to Elizabeth A Krupinski.
Telemedicine consultations: failed cases and floundering specialties.
The Arizona Telemedicine Program began as a multi-service provider, with teleconsultations in over 53 subspecialties. Although new sites often use numerous subspecialties at first, this is typically followed by a longer period when only a few subspecialties are used. A retrospective analysis of the referral rates from the sites showed wide variations, some exhibiting extreme fluctuations. There was a high correlation (0.84) between personnel turnover rates at each site (i.e. the number of personnel changing) and the degree to which the fluctuations were 'out of control'. Over six years, 402 teleconsultations were scheduled but did not occur. Of these, 82% were closed with no further contact, although 63% were managed eventually via telemedicine, all in telepsychiatry. The reasons for these appointments not taking place were that the patient did not show up (45%), the patient cancelled (32%), the telepsychiatrist cancelled (22%) or bad weather prevented travel (1%). Of the unsuccessful teleconsultations, 84% were realtime and 16% were store and forward. The average cost to the provider of a missed realtime teleconsultation was US$228 for a 1 h session.
Appointments and Schedules↗
An analysis of unsuccessful teleconsultations.
Over six years, 4317 teleconsultations were scheduled in the Arizona Telemedicine Program. A total of 402 scheduled teleconsultations (9.3%) did not take place. A review showed that 254 were cancelled but eventually took place (5.9%), while 148 never took place (3.4%). The cost of a teleconsultation to the service provider was, at minimum, 228 US dollars. Telepsychiatry accounted for all the missed consultations that eventually took place, and 92% of these were from three of the six sites referring telepsychiatry patients. Pain management (23%) and psychiatry (21%) accounted for the largest proportions of teleconsultations that never took place. Telepsychiatry cases accounted for 71% of all unsuccessful consultations and accounted for only 34% of successful teleconsultations during the same period. Most missed teleconsultations had been scheduled as realtime sessions (84%). The most common reason for unsuccessful teleconsultations was that the patient did not attend (26%), followed by the patient having to be seen in person (17%). Although all referring sites had unsuccessful cases, certain sites accounted for more than others. These were sites that scheduled more telepsychiatry consultations than the others. The proportion of unsuccessful cases per site ranged from 4% to 17% of the total number of scheduled teleconsultations.
Adult↗
The challenges of following patients and assessing outcomes in teledermatology.
We retrospectively reviewed the follow-up and outcomes of 50 store-and-forward teledermatology patients, and compared the findings with those from a control group of 50 patients who had been seen in person. Patient records were examined for a six-month period following the initial referral to a dermatologist. Variables examined included medical records from the referral, evidence of actions taken (e.g. biopsy), evidence of follow-up visits, and what (if any) clinical outcomes were noted. There were few differences between the teledermatology and in-person groups. The main difference was whether there was any report in the record that the referring clinician took some action based on the consultation with the specialist: there were more reports of action being taken in the teledermatology group than in the in-person group. Reports of outcomes were found in only 6% and 8% of the records of the teledermatology and in-person groups, respectively. The challenges of assessing outcomes in teledermatology for rural patients include patient loss to follow-up, lack of information in the patient records and low rates of patient return to the referring clinician for follow-up.
Dermatology↗
Home health and telemedicine: where are we today?
This chapter will review the current state-of-the-art of home health services in the telemedicine environment. Special attention will be paid to some of the studies that our telemedicine program has conducted in the past few years. The chapter will conclude with some recommendations and a look to the future.
Adult↗
Musculoskeletal magnetic resonance imaging: importance of radiography.
OBJECTIVE: To determine the usefulness of radiography for interpretation of musculoskeletal (MSK) magnetic resonance imaging (MRI) studies. DESIGNS AND PATIENTS: In a 1-year period, 1,030 MSK MRI studies were performed in 1,002 patients in our institution. For each study, the interpreting radiologist completed a questionnaire regarding the availability and utility of radiographs, radiological reports and clinical information for the interpretation of the MRI study. RESULTS: Radiographs were essential, very important or added information in 61-75% of all MSK MRI cases. Radiographs were judged as essential for reading of MRI studies more often for trauma, infection/inflammation and tumors than for degenerative and miscellaneous/normal diagnoses (chi(2)=60.95, df=16, P<0.0001). The clinical information was rated as "essential" or "useful" significantly more often than not (chi(2)=93.07, df=16, P<0.0001). The clinical and MRI diagnoses were the same or partially concordant significantly more often for tumors than for trauma, infection/inflammation and degenerative conditions, while in the miscellaneous/normal group they were different in 64% of cases. When the diagnoses were different, there were more instances in which radiographs were not available. CONCLUSIONS: Radiographs are an important, and sometimes essential, initial complementary study for reading of MSK MRI examinations. It is highly recommended that radiographs are available when MSK MRI studies are interpreted.
Adolescent↗
Myelographic MR imaging of the cervical spine with a 3D true fast imaging with steady-state precession technique: initial experience.
The majority of spinal magnetic resonance (MR) imaging has been performed with spin-echo sequences and spoiled gradient-echo sequences. Advances in gradient MR imaging performance now permit imaging with coherent steady-state sequences. In this study, the authors compare a three-dimensional true fast imaging with steady-state precession sequence with a three-dimensional spoiled gradient-recalled-echo sequence for MR evaluation of the cervical spine in the transverse plane. Initial experience indicates that the steady-state sequence is superior to spoiled gradient-recalled-echo sequences for MR evaluation of cervical spine anatomy and abnormalities.
Adult↗
Rings and things on upper extremity radiographs of emergency patients.
Rings, intravenous lines, and other objects on the injured upper extremities of trauma patients are frequently overlooked by radiology and emergency department (ED) personnel. This can impair proper radiologic evaluation of the injured extremity as well as negatively affect the quality of the patient's treatment. A 1-week sample of radiographs of injured upper extremities from the ED of University Medical Center (UMC), Tucson, Arizona, showed that 20% of the studies (19 of 95) contained at least one object on the injured upper extremity, but only one radiology report (1.1%) mentioned such an object. A review of 2489 upper extremity ED radiology reports from January to June 2002 showed only 47 reports (1.9%) that mentioned the presence of an overlying object. It is important to educate radiology department and ED personnel to remove upper extremity jewelry and place necessary medical devices on noninjured extremities.
Journal Article↗
Oblique reformation in cervical spine computed tomography: a new look at an old friend.
STUDY DESIGN: Cervical spine computed tomograms were evaluated for neural foraminal stenosis in both the standard axial plane and the oblique reformatted plane. OBJECTIVE: To assess whether oblique reformation of cervical spine computed tomograms reduces interobserver variability in the evaluation of neural foraminal stenosis. SUMMARY OF BACKGROUND DATA: Radiographic assessment of neural foraminal stenosis is subjective, may vary among observers, and can affect surgical planning. METHODS: The cervical spine images from 19 patients with various degrees of neural foraminal stenosis were reformatted in an oblique plane perpendicular to the long axis of the right and left neural foramens. Seven independent observers graded the degree of foraminal stenosis (none, mild [1-25%], moderate [26-75%], or severe [>75%]) and their confidence level (definite, probable, possible) on both the axial images and the oblique reformations. RESULTS: The ages of the 12 male (mean, 67.5 +/- 13.24 years) and 7 female (mean, 62.7 +/- 14.79 years) patients ranged from 39 to 83 years. Interobserver variability was assessed with chi2 analysis. Rates of agreement on degree of stenosis (chi2 = 19.94; df= 9; P< 0.02) were significantly higher for oblique reformations. Confidence ratings also were significantly higher for oblique reformations (chi2 = 18.19; df= 7; P< 0.02). CONCLUSIONS: Oblique reformation of cervical spine images significantly reduces the degree of interobserver variability and increases observer confidence in the assessment of neural foraminal stenosis. Oblique reformations should be considered in the routine evaluation of neural foraminal stenosis.
Adult↗
Medical image perception issues for PACS deployment.
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Computer Communication Networks↗
Searching for nodules: what features attract attention and influence detection?
RATIONALE AND OBJECTIVES: The goal of the study was to determine whether there are certain physical features of pulmonary nodules that attract visual attention and contribute to increased recognition and detection by observers. MATERIALS AND METHODS: A series of posteroanterior chest images with solitary pulmonary nodules were searched by six radiologists as their eye-position was recorded. The signal-to-noise ratio, size, conspicuity, location, and calcification status were measured for each nodule. Dwell parameters were correlated with nodule features and related to detection rates. RESULTS: Only nodule size (F = 5.08, P = .0254) and conspicuity (F = 4.625, P = .0329) influenced total dwell time on nodules, with larger, more conspicuous nodules receiving less visual attention than smaller, less conspicuous nodules. All nodule features examined influenced overall detection performance (P < .05) even though most did not influence visual search and attention. CONCLUSION: Individual nodule features do not attract attention as measured by "first hit" fixation data, but certain features do tend to hold attention once the nodule has been fixated. The combination of all features influences whether or not it is detected.
Attention↗
Using a human visual system model to optimize soft-copy mammography display: influence of MTF compensation.
RATIONALE AND OBJECTIVES: The investigators developed an efficient method for optimizing cathode ray tube (CRT) monitor performance for digital mammography, based on the correlation between the performance of human observers and the performance of a mathematical computer model of the human visual system. The investigators examined observer performance on soft-copy display of mammographic images that were either unprocessed or processed to compensate for modulation transfer function (MTF) deficiencies in the CRT display. The results were used to validate the human visual system model. MATERIALS AND METHODS: Six radiologists viewed a series of 250 mammographic images with microcalcification clusters with different contrast levels on a CRT monitor. The images were viewed twice: once without image processing and once with processing designed to compensate for MTF deficiencies in the CRT monitor. The images were analyzed with the JNDmetrix Visual Discrimination Model, which is based on the principles of just-noticeable difference measurement and frequency-channel vision modeling. Receiver operating characteristic (ROC) curves were generated for the human observers and compared statistically with the model observers' performance. RESULTS: Both human and model performance was better overall with the MTF-compensated images, especially for microcalcifications in the midlevel contrast range. There was a very high correlation between human and model observers. CONCLUSION: The use of image-processing methods to compensate for limitations in the MTF of CRT monitors can improve the detection performance of radiologists searching for microcalcifications in mammographic images, and a model based on characteristics of the human visual system can be used to predict human observer results accurately.
Computer Simulation↗
Academic radiology: the reasons to stay or leave.
RATIONALE AND OBJECTIVES: To find major reasons why junior academic radiologists leave academia for private practice and to suggest future changes to motivate them to stay. MATERIALS AND METHODS: 2000 surveys were sent to every tenth member of the Radiological Society of North America (RSNA) who completed training within the past decade. Those in academic institutions and those who left within 5 years were asked to respond. RESULTS: 132 radiologists responded. Thirty-two percent of responders were in academic radiology. Of those in academic radiology, 71% plan to stay at the same institution, 7% are planning to move to another academic institution, 17% are considering private practice, and 5% are leaving for private practice. The main reasons to leave were low pay and lack of academic time. Sixty-eight percent of responders already left academia after an average of 3.28 years. Ninety-five percent feel the decision was good, and 65% would not go back. Forty-nine percent experienced more than 100% pay increase, 60% feel they work harder, and 62% feel quality of life is better. CONCLUSION: Significant changes should be made to motivate junior radiologists to stay in academia. Developing leaders in radiology is a must, and should be a top priority. Academic radiologists should not be expected to read private practice volumes and still have time to produce quality research and teaching. Clinical duties should be limited to 32 hours per week. At least 1 day a week should be protected academic time. Efforts should be made to decrease the discrepancy between incomes. Mentoring is important, allowing a smooth transition for junior faculty members to optimize academic progress and lead to promotion.
Academic Medical Centers↗
The future of image perception in radiology: synergy between humans and computers.
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Clinical Competence↗
Fluctuations in telemedicine case volume: correlation with personnel turnover rates.
Statistical process control (SPC) techniques were used to analyze 5 years worth of telemedicine case volume data from seven remote sites in order to characterize how much fluctuation occurred over time for each site and whether the fluctuation remained within prescribed limits. The points at which the fluctuations were considered beyond the prescribed limits were correlated with the turnover rate in key personnel (e.g., the Medical Director). Though no causal relationship can be implied, sites with higher turnover rates tended to fluctuate more. The analyses suggest that SPC may be a useful tool for analyzing trends in telemedicine consultation volume fluctuations over time and, therefore, may be useful for program management and allocation of personnel resources. It can also be used in the long run to determine when and why fluctuations occur and whether the causes of fluctuations need to be addressed.
Arizona↗
MR Imaging of arrhythmogenic right ventricular cardiomyopathy: morphologic findings and interobserver reliability.
BACKGROUND: Magnetic resonance (MR) imaging is frequently used to diagnose arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). However, the reliability of various MR imaging features for diagnosing ARVC/D is unknown. The purpose of this study was to determine which morphologic MR imaging features have the greatest interobserver reliability for diagnosing ARVC/D. METHODS: Forty-five sets of films of cardiac MR images were sent to 8 radiologists and 5 cardiologists with experience in this field. There were 7 cases of definite ARVC/D as defined by the Task Force criteria. Six cases were controls. The remaining 32 cases had MR imaging because of clinical suspicion of ARVC/D. Readers evaluated the images for the presence of (a) right ventricle (RV) enlargement, (b) RV abnormal morphology, (c) left ventricle enlargement, (d) presence of high T(1) signal (fat) in the myocardium, and (e) location of high T(1) signal (fat) on a Likert scale with formatted responses. RESULTS: Readers indicated that the Task Force ARVC/D cases had significantly more (chi(2) = 119.93, d.f. = 10, p < 0.0001) RV chamber size enlargement (58%) than either the suspected ARVC/D (12%) or no ARVC/D (14%) cases. When readers reported the RV chamber size as enlarged they were significantly more likely to report the case as ARVC/D present (chi(2)(= )33.98, d.f. = 1, p < 0.0001). When readers reported the morphology as abnormal they were more likely to diagnose the case as ARVC/D present (chi(2) = 78.4, d.f. = 1, p < 0.0001), and the Task Force ARVC/D (47%) cases received significantly more abnormal reports than either suspected ARVC/D (20%) or non-ARVC/D (15%) cases. There was no significant difference between patient groups in the reported presence of high signal intensity (fat) in the RV (chi(2) = 0.9, d.f. = 2, p > 0.05). CONCLUSIONS: Reviewers found that the size and shape of abnormalities in the RV are key MR imaging discriminates of ARVD. Subsequent protocol development and multicenter trials need to address these parameters. Essential steps in improving accuracy and reducing variability include a standardized acquisition protocol and standardized analysis with dynamic cine review of regional RV function and quantification of RV and left ventricle volumes.
Adult↗
Radial fast spin-echo method for T2-weighted imaging and T2 mapping of the liver.
PURPOSE: To evaluate a multishot radial fast-spin echo (RAD-FSE) method developed to improve the quality of abdominal T2-weighted imaging as well as the characterization of focal liver lesions. MATERIALS AND METHODS: The RAD-FSE sequence used in this work consisted of a preparatory period followed by a short echo train (ETL = 16). A novel radial k-space trajectory was used to minimize streaking artifacts due to T2 variations and motion. Small diffusion gradients (b = 1.2 mm/s(2)) were used to improve flow suppression. The quality of images obtained with RAD-FSE was compared to multishot 2DFT fast spin-echo (2DFT-FSE) and half-Fourier acquisition single-shot turbo-spin-echo (HASTE) images using data from 16 patients. A postprocessing algorithm was used to generate multiple high-resolution images (at different effective TE values) as well as a T2 map from a single RAD-FSE data set. The T2 maps were used to differentiate malignant from benign lesions for a set of 33 lesions ranging from 0.8-194 cm(3). RESULTS: RAD-FSE produces high-resolution images of the liver in a breath-hold without the motion artifacts of 2DFT-FSE methods, and without the blurriness and loss of small lesion detectability of HASTE. The inclusion of diffusion weighting in RAD-FSE decreases the signal from blood in hepatic vessels, which improves lesion visualization. The T2 values obtained by postprocessing a single RAD-FSE data set can differentiate malignant from benign lesions. The mean T2 values obtained for malignancies, hemangiomas, and cysts are 108 +/- 30 msec, 240 +/- 14 msec, and 572 +/- 334 msec, respectively. CONCLUSION: These results indicate that RAD-FSE produces abdominal images of higher quality than 2DFT-FSE and HASTE. In addition, lesions can be characterized using T2 maps generated from a single RAD-FSE data set.
Adolescent↗
Pulmonary nodule detection and visual search: P45 and P104 monochrome versus color monitor displays.
RATIONALE AND OBJECTIVES: The faceplate of a cathode-ray tube (CRT) display monitor is covered on the vacuum side with a phosphor screen. The different phosphors that can be used for this screen have distinctly different physical properties that can affect the noise properties of the display. Differences in noise affect the signal-to-noise ratio and, hence, may affect diagnostic performance. This study evaluated observer performance and visual search parameters in the detection of pulmonary nodules, comparing two monochrome CRT monitors with different phosphors (P45 and P104) and a color CRT monitor. MATERIALS AND METHODS: The receiver operating characteristic paradigm was used to evaluate observer performance with a series of radiographic chest images containing solitary pulmonary nodules. Eye position was recorded as the observers searched the images on each type of monitor. RESULTS: Observer performance, as indicated by the area under the receiver operating characteristic curve and compared by means of an analysis of variance test, was best for the P45 monitor, next best for the P104 monitor, and worst for the color monitor. All differences were statistically significant. Eye-position parameters were also affected by monitor type. The time required to fixate the lesion and overall search times were longest with the color monitor. CONCLUSION: The type of phosphor used in the CRT monitor faceplate can affect diagnostic performance and visual search parameters. Care should be taken in the selection of monitors for use in clinical radiology.
Analysis of Variance↗