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Amy H Klym

Publications and source records attributed to Amy H Klym.

7 recordsLinked to original sources
PubMed2006

The effect of image display size on observer performance an assessment of variance components.

RATIONALE AND OBJECTIVE: Our goal was to investigate the effect of the displayed image size on variance components during the performance of an observer performance study to detect masses on abdominal computed tomography (CT) examinations. MATERIALS AND METHODS: A previously performed receiver operating characteristic (ROC) study with eight observers to detect abdominal masses on 166 CT examinations was reanalyzed to assess variance components when comparing two similar modes with displayed image sizes varying by a factor of 2. Case, mode, and reader-related variance components were estimated for the group of eight observers and subsets of readers after excluding each of the participants. RESULTS: There was no significant difference in the average area under the ROC curves between the two modes using the two image sizes (P > .05). Reader and reader-by-case variability were substantially larger for the mode displaying enlarged images for the group and all subsets formed by excluding a single reader. Reader variability was affected by one observer who actually performed better with the enlarged images. CONCLUSION: Sequential viewing of enlarged CT images for the detection of abdominal masses did not improve performance and increased reader variability.

Abdominal Neoplasms↗
PubMed2006

Screening mammography: do women prefer a higher recall rate given the possibility of earlier detection of cancer?

PURPOSE: To prospectively survey women undergoing screening mammography to assess their attitudes toward and preference for the level of recall rates given the possibility that an increase in recall rates may result in earlier detection of cancer. MATERIALS AND METHODS: This HIPAA-compliant survey was performed with an institutional review board-approved protocol. Women who arrived for their routine screening mammographic examination from November 2004 to March 2005 were informed before they consented to participate. The distribution of responses for each survey question was summarized, and proportions for the entire group and different subgroups were computed. The z score statistic was used to assess significant differences between subgroups. RESULTS: Fifteen hundred seventy anonymized questionnaires were collected; 1171 (75%) were from women between 40 and 59 years of age. Of 1528 respondents, 1486 (97%) believed that a false-positive result would not deter them from continuing with regular screening, and most would have been willing to be recalled more often for either a noninvasive (86% [1308 of 1519 respondents]) or an invasive (82% [1248 of 1515 respondents]) procedure if it might increase the chance of detecting a cancer (if present) earlier. Compared with respondents undergoing their initial screening mammographic examination, women who had undergone at least one prior screening examination reported that they were more likely to continue with screening if they had received a previous false-positive result (P = .02). Women younger than 60 years and those previously recalled were more willing to be called back more often for a noninvasive or, when indicated, an invasive procedure (P < .05). CONCLUSION: A substantial fraction of women in this study would have preferred the inconvenience of and anxiety associated with a higher recall rate if it resulted in the possibility of detecting breast cancer earlier.

Adult↗
PubMed2005

Trends in recall, biopsy, and positive biopsy rates for screening mammography in an academic practice.

PURPOSE: To retrospectively evaluate whether recall, biopsy, and positive biopsy rates for a group of radiologists who met requirements of Mammography Quality Standards Act of 1992 (MQSA) demonstrated any change over time during a 27-month period (nine consecutive calendar quarters). MATERIALS AND METHODS: Institutional review board approved study protocol, and informed consent was waived. All screening mammograms that had been interpreted by MQSA-qualified radiologists between January 1, 2001, and March 31, 2003, were reviewed. Group recall rates, biopsy rates, and detected cancer rates for nine calendar quarters were computed and attributed to performance date of original screening mammogram. Type of biopsy performed was classified as follows: stereotactic vacuum-assisted biopsy, ultrasonography (US)-guided core biopsy, US-guided fine-needle aspiration biopsy, surgical excision, and multiple biopsies. chi(2) Test for trend (two sided) and linear regression were used to assess trends over time for recall and biopsy rates, biopsy rates according to type of biopsy performed, and percentage of biopsy results positive for cancer. RESULTS: Group recall rate did not show a statistically significant trend during period studied (P = .59). Biopsy rates increased significantly from 13.02 to 20.12 per 1000 screening examinations (P < .001). A corresponding substantial decrease was seen in percentage of biopsies in which malignancy was found, although this trend was not statistically significant (P = .24). A significant increase (from 4.72 to 9.88 per 1000 screening examinations) was found in rate of stereotactic vacuum-assisted 11-gauge core biopsies performed (P < .001). CONCLUSION: Observed increase in biopsy rates reinforces the need to carefully select patients for biopsy to achieve efficient, efficacious, and cost-effective programs for early detection of breast cancers.

Biopsy↗
PubMed2005

Variability in observer performance studies experimental observations.

RATIONALE AND OBJECTIVES: The aim of the study is to assess variance components in observer performance studies and the possible impact on study results and conclusions. MATERIALS AND METHODS: Two previously performed retrospective receiver operating characteristic-type observer performance studies to evaluate the performance of seven radiologists in detecting interstitial disease on conventional posteroanterior chest films and nine radiologists in detecting interstitial disease on a high-resolution workstation were reanalyzed by using the Beiden, Wagner, and Campbell nine-component model to estimate the different variance components. We estimated case-, reader-, and mode-related components of the variance for the group as a whole and after excluding (round robin) each reader. Overall variance was evaluated, and the effect of individual readers on overall study conclusions was assessed. RESULTS: Overall results and conclusions of the reanalysis agreed with the original one in that, as a group, radiologists performed significantly better when using conventional films (P < .05) in both studies. Reader variability was large compared with all other components, and in one study, it was substantially larger for the workstation reading mode. Reader variability was affected substantially by one observer in each study, and in one study, reader-by-mode variability was affected by another reader who performed better on the workstation. CONCLUSION: Estimates of variance components can shed light on the appropriateness of study design, as well as the sensitivity of results to the inclusion (or exclusion) of individual observers.

Humans↗
PubMed2005

Is maximum positive predictive value a good indicator of an optimal screening mammography practice?

OBJECTIVE: Positive predictive value (PPV1) has been used as one important indicator of the quality of screening mammography programs. We show how the relationship between sensitivity and recall rate may affect the operating point at which optimal (maximum) PPV1 occurs. CONCLUSION: Optimal (maximum) PPV1 can occur at any sensitivity level and should not be used as the sole indicator for practice optimization because it does not take into account the number of cancers that would be missed at that sensitivity.

Breast Neoplasms↗
PubMed2003

Prescreening mammography by technologists: a preliminary assessment.

OBJECTIVE: We assessed the ability of technologists to accurately classify screening mammograms as either showing negative findings or requiring follow-up. SUBJECTS AND METHODS: In a prospective study, 33 technologists at a central facility and five satellite breast imaging facilities recorded whether mammograms obtained during 3019 examinations showed negative findings or findings that indicated that additional procedures were required. The technologists were not specifically trained for the experiment. The technologists' interpretations were compared with radiologists' interpretations. RESULTS: Technologists and radiologists agreed in 82% of the cases (77% negative findings and 5% requiring follow-up). Of the 175 cases recommended for follow-up by only the radiologists, 17 were ultimately biopsied and two were found to be malignant. CONCLUSION: Even without undergoing additional training, technologists can perform at reasonable levels of accuracy in classifying screening mammograms. The possibility of using technologists to group cases after the technologists have undergone training is an interesting concept that should be explored further.

Allied Health Personnel↗