Interpretation Of Screening Mammograms Research Articles

Association of volume and volume-independent factors with accuracy in screening mammogram interpretation.

Early detection of breast cancer is associated with the accurate reading of screening mammograms, but factors that influence reading accuracy are not well understood. We thus investigated whether reading volume and other factors were independently associated with accuracy in reading screening mammograms in a population of U.S. radiologists. A random selection of 110 of 292 radiologists who agreed to participate, if selected, interpreted screening mammograms from 148 randomly selected women. Original index mammograms (i.e., mediolateral oblique and craniocaudal views of each breast) were used; comparison original mammograms were provided when available. Radiologist-level and facility-level factors were surveyed. Two standard metrics of screening accuracy, both based on receiver operating characteristic curves, were analyzed. The influence of volume on accuracy after controlling for other factors was assessed with multiple regression analysis. Current reading volume was not statistically significantly associated with interpretive accuracy. More recently trained radiologists interpreted mammograms more accurately than those trained earlier (-0.76% [95% confidence interval (CI) = -1.75% to -0.02%] reduction in sensitivity per year since residency). Facility-level factors that were statistically significantly and independently associated with better accuracy were the number of diagnostic breast imaging examinations and image-guided breast interventional procedures performed (0.55% [95% CI = 0.11% to 2.40%] increase in accuracy per examination or procedure offered), being classified as a comprehensive breast diagnostic and/or screening center or freestanding mammography center (1.39% [95% CI = 0.15% to 3.82%] higher than a hospital radiology department or multispecialty medical clinic), and being a facility that practiced double reading (1.61% [95% CI = 1.99% to 11.65%]) higher than in a facility without such practice). Individual radiologists' current reading volume was not statistically significantly associated with accuracy in reading screening mammograms, but several other factors were. Expertise reflects a complex multifactorial process that needs further clarification.

Computer aids for detection and diagnosis in mammography

Screening: Interpreting screening mammograms is difficult; radiologists must maintain specificity while reading films with a very low incidence of cancer. Estimates suggest sensitivity is no higher than 75%.CAD: Commercial systems are now available that prompt radiologists to look at suspicious regions. Such systems achieve high sensitivity but at low specificity.Evaluations: Evaluations of these CAD systems reveal that they do well at detecting microcalcifications but less well at detecting masses.Impact on decision-making: The low specificity of the computer prompts seems to hinder their capacity to influence radiologists' decision-making.Prospective trials: Only one prospective trial has been carried out of a CAD system for mammography. A replication of this trial in a UK setting is awaited.

Effect of Training with the American College of Radiology Breast Imaging Reporting and Data System Lexicon on Mammographic Interpretation Skills in Developing Countries 1

Rationale and Objectives The authors evaluated the effect of training in the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) lexicon on the interpretive skills of radiologists evaluating screening mammograms in Ukraine. Materials and Methods As part of a program to improve breast cancer detection and treatment in Ukraine, a series of training sessions was given to a group of radiologists across Ukraine to improve their interpretive skills in screening mammography. The training sessions focused on the use of the lexicon and assessment categories developed by the ACR BI-RADS committee. Participants ( n = 14) evaluated 30 test screening mammograms before and after the training sessions. The test sets were randomly selected from a larger collection of training sets containing normal, benign, and abnormal mammograms. False-positive, false-negative, true-positive, and true-negative evaluations were determined, and sensitivity, specificity, and positive predictive values were calculated for each participant before and after training. Results The mean baseline sensitivity, specificity, and positive predictive values were 50%, 77%, and 43%, respectively. Each of these measures of interpretive skills improved significantly after training in the use of the lexicon, to 87%, 89%, and 78% ( P < .0001, P < .01, and P < .0001, respectively). Conclusion As the use of mammography spreads throughout developing countries, it is essential to address training and educational needs, as well as equipment needs. The ACR BI-RADS lexicon provides a systematic and efficient method for training radiologists to interpret screening mammograms. Educating radiologists on the use of this lexicon proved an effective way to improve their interpretive skills in screening mammography.

Computer-aided detection (CAD) in screening mammography

Interpretation of radiological (and other complex medical) images is challenging due to an often overwhelming amount of visual data, much of which is of no consequence and which often serves to confound the observer. In addition, there are well-recognized physiologic obstacles to visual search and recognition, which contribute to false-negative radiological interpretations. The interpretation of screening mammograms is particularly challenging, because a large number of cases are viewed to detect a small number of cancers (3–10 cancers per 1000 women screened), which are often manifest by subtle alterations superimposed upon the complex radiographic structure of the breast.

A sequential chart for the audit-based evaluation of screening mammogram interpretation

Auditing has received much attention recently as a method for radiologists to use to evaluate their interpretation of screening mammograms. U.S. Food and Drug Administration regulations require that some sort of audit be in place before a mammography screening facility can receive accreditation. Auditing presents a unique opportunity to monitor accuracy continually and identify problems early. Audit data present unique challenges, however, and appropriate methods must be used to control the risk of errors. This article introduces a simple method for the task of deciding if a radiologist yields an acceptable positive predictive value based on audit. The method is based on "sequential" decision-making techniques that have found wide application in quality control problems. These techniques are developed for diagnostic radiology and embodied in an easy-to-use decision-making chart. Several examples, based on audit data from actual mammography facilities, provide insights into the use of these charts and the influence of (a) the selection of standards, (b) the selection of error risks, and (c) radiologist variability. The examples also serve to demonstrate another important property of this method--that is, it specifies the minimum amount of data that has to be collected before any decision can reliably be made. The chart presented in this article provides a method by which audit data can be used objectively to evaluate the accuracy of screening mammogram interpretation. The method controls the risk of either falsely accepting an unqualified radiologist or falsely rejecting a qualified radiologist. It should be a useful tool to radiologists who must evaluate their own practices.

Patient satisfaction with screening mammography: Online vs off-line interpretation

The purpose of this study was to determine patient satisfaction with online and off-line methods of interpreting screening mammograms and to determine those characteristics that most influence patient preferences. A survey consisting of 17 questions assessing satisfaction and demographics was distributed to women whose screening mammograms were read in one of two ways at the same facility: (a) the "online" method, in which all additional requested studies are completed and results are immediately communicated, and (b) the "off-line" method, in which mammograms are read in batches the next day, results are communicated at a later time, and patients return for diagnostic studies. To ensure statistical power, at least 174 surveys were collected from each group. Of 192 women whose mammograms were interpreted online, 188 (97%) responded, and of 247 women whose mammograms were interpreted off-line, 181 (73%) responded. Overall mean satisfaction with the mammographic experience and with the time it took to receive results differed significantly between the two groups (P < .002). Analysis of the subgroup of very satisfied respondents disclosed that 92% of patients in the online group and 59% of patients in the off-line group were very satisfied with their mammography experience. If allowed to choose the method of interpretation, 97% of patients in the online group and 91% of patients in the off-line group would choose online interpretation. Patients preferred online mammographic interpretation of screening studies.

Variability in the interpretation of screening mammograms by US radiologists

Objective: To evaluate the effectiveness of screening mammography by estimating the variability in radiologists' ability to detect breast cancer within the US population of radiologists at mammography centers accredited by the American College of Radiology. Methods: A two-way sample survey design was used as follows. Fifty mammography centers having an American College of Radiology\p=m-\accreditedunit were randomly sampled from across the United States. One hundred eight radiologists from these centers gave blinded interpretation to the same set of 79 randomly selected screening mammograms. The mammograms were from women who had been screened at a large screening center. Before their sampling, these women had been stratified by their breast disease status, established either by biopsy or by 2-year follow-up. Rates of biopsy recommendations were summarized by the mean, median, minimum, maximum, and range of sensitivity and specificity. Overall cancer detection ability was summarized by similar statistics for receiver operating characteristic curve areas. Ninety-five percent lower confidence bounds on the ranges in accuracy measures were established by bootstrapping. Results: There is a range of at least 40% among US radiologists in their screening sensitivity. There is a range of at least 45% in the rates at which women without breast cancer are recommended for biopsy. As indicated by receiver operating characteristic curve areas, the ability of radiologists to detect cancer mammograms varies by as much as 11%. Conclusions: Our findings indicate that there is wide variability in the accuracy of mammogram interpretation in the population of US radiologists. Current accreditation programs that certify the technical quality of radiographic equipment and images but not the accuracy of the interpretation given to mammograms may not be sufficient to help mammography fully realize its potential to reduce breast cancer mortality. (Arch Intern Med. 1996;156:209-213)

Variability in the interpretation of screening mammograms by US radiologists. Findings from a national sample

Variability in the interpretation of screening mammograms by US radiologists. Findings from a national sample

Variability in the Interpretation of Screening Mammograms by US Radiologists

To evaluate the effectiveness of screening mammography by estimating the variability in radiologists' ability to detect breast cancer within the US population of radiologists at mammography centers accredited by the American College of Radiology. A two-way sample survey design was used as follows. Fifty mammography centers having an American College of Radiology-accredited unit were randomly sampled from across the United States. One hundred eight radiologists from these centers gave blinded interpretation to the same set of 79 randomly selected screening mammograms. The mammograms were from women who had been screened at a large screening center. Before their sampling, these women had been stratified by their breast disease status, established either by biopsy or by 2-year follow-up. Rates of biopsy recommendations were summarized by the mean, median, minimum, maximum, and range of sensitivity and specificity. Overall cancer detection ability was summarized by similar statistics for receiver operating characteristic curve areas. Ninety-five percent lower confidence bounds on the ranges in accuracy measures were established by boo-strapping. There is a range of at least 40% among US radiologists in their screening sensitivity. There is a range of at least 45% in the rates at which women without breast cancer are recommended for biopsy. As indicated by receiver operating characteristic curve areas, the ability of radiologists to detect cancer mammograms varies by as much as 11%. Our findings indicate that there is wide variability in the accuracy of mammogram interpretation in the population of US radiologists. Current accreditation programs that certify the technical quality of radiographic equipment and images but not the accuracy of the interpretation given to mammograms may not be sufficient to help mammography fully realize its potential to reduce breast cancer mortality.

Computerized detection of masses in digital mammograms: Analysis of bilateral subtraction images

A computerized scheme is being developed for the detection of masses in digital mammograms. Based on the deviation from the normal architectural symmetry of the right and left breasts, a bilateral subtraction technique is used to enhance the conspicuity of possible masses. The scheme employs two pairs of conventional screen-film mammograms (the right and left mediolateral oblique views and craniocaudal views), which are digitized by a TV camera/Gould digitizer. The right and left breast images in each pair are aligned manually during digitization. A nonlinear bilateral subtraction technique that involves linking multiple subtracted images has been investigated and compared to a simple linear subtraction method. Various feature-extraction techniques are used to reduce false-positive detections resulting from the bilateral subtraction. The scheme has been evaluated using 46 pairs of clinical mammograms and was found to yield a 95% true-positive rate at an average of three false-positive detections per image. This preliminary study indicates that the scheme is potentially useful as an aid to radiologists in the interpretation of screening mammograms.

Improvement in Radiologists?? Detection of Clustered Microcalcifications on Mammograms

Relatively simple, but important, detection tasks in radiology are nearing accessibility to computer-aided diagnostic (CAD) methods. The authors have studied one such task, the detection of clustered microcalcifications on mammograms, to determine whether CAD can improve radiologists' performance under controlled but generally realistic circumstances. The results of their receiver operating characteristic (ROC) study show that CAD, as implemented by their computer code in its present state of development, does significantly improve radiologists' accuracy in detecting clustered microcalcifications under conditions that simulate the rapid interpretation of screening mammograms. The results suggest also that a reduction in the computer's false-positive rate will further improve radiologists' diagnostic accuracy, although the improvement falls short of statistical significance in this study.