10 research outputs found
Developing a Comprehensive Database Management System for Organization and Evaluation of Mammography Datasets
We aimed to design and develop a comprehensive mammography database system (CMDB) to collect clinical datasets for outcome assessment and development of decision support tools. A Health Insurance Portability and Accountability Act (HIPAA) compliant CMDB was created to store multi-relational datasets of demographic risk factors and mammogram results using the Breast Imaging Reporting and Data System (BI-RADS) lexicon. The CMDB collected both biopsy pathology outcomes, in a breast pathology lexicon compiled by extending BI-RADS, and our institutional breast cancer registry. The audit results derived from the CMDB were in accordance with Mammography Quality Standards Act (MQSA) audits and national benchmarks. The CMDB has managed the challenges of multi-level organization demanded by the complexity of mammography practice and lexicon development in pathology. We foresee that the CMDB will be useful for efficient quality assurance audits and development of decision support tools to improve breast cancer diagnosis. Our procedure of developing the CMDB provides a framework to build a detailed data repository for breast imaging quality control and research, which has the potential to augment existing resources
Addressing the Challenge of Assessing Physician-Level Screening Performance: Mammography as an Example
<div><p>Background</p><p>Motivated by the challenges in assessing physician-level cancer screening performance and the negative impact of misclassification, we propose a method (using mammography as an example) that enables confident assertion of adequate or inadequate performance or alternatively recognizes when more data is required.</p><p>Methods</p><p>Using established metrics for mammography screening performance–cancer detection rate (CDR) and recall rate (RR)–and observed benchmarks from the Breast Cancer Surveillance Consortium (BCSC), we calculate the minimum volume required to be 95% confident that a physician is performing at or above benchmark thresholds. We graphically display the minimum observed CDR and RR values required to confidently assert adequate performance over a range of interpretive volumes. We use a prospectively collected database of consecutive mammograms from a clinical screening program outside the BCSC to illustrate how this method classifies individual physician performance as volume accrues.</p><p>Results</p><p>Our analysis reveals that an annual interpretive volume of 2770 screening mammograms, above the United States’ (US) mandatory (480) and average (1777) annual volumes but below England’s mandatory (5000) annual volume is necessary to confidently assert that a physician performed adequately. In our analyzed US practice, a single year of data uniformly allowed confident assertion of adequate performance in terms of RR but not CDR, which required aggregation of data across more than one year.</p><p>Conclusion</p><p>For individual physician quality assessment in cancer screening programs that target low incidence populations, considering imprecision in observed performance metrics due to small numbers of patients with cancer is important.</p></div
Defining adequate performance based on volume.
<p>Plots demonstrate our method for constructing curves by using the benchmark threshold as the limit of 95% confidence based on volume: (A) CDR performance levels are established using 2.4 as the lower boundary for 95% CI of adequate performance (CIs shown) and the upper boundary for inadequate performance (CIs not shown). This methodology shows (indicated with a black dot) that a volume of 2770 is required to confidently assert the CDR benchmark median of 4.4/1000 is adequate; (B) RR performance levels are established using 16.8 as the upper boundary for 95% CI of adequate (CI shown) and inadequate (CI not shown) performance. A volume of 120 (indicated with a black dot) is required to confidently assert the RR benchmark median of 9.7% is adequate. Plots define regions of adequate, uncertain, and inadequate performance for (B) CDR and (D) RR.</p
BI-RADS<sup>*</sup> final assessment categories with associated recommendation.
<p>*BI-RADS Version 4 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089418#pone.0089418-Blanks3" target="_blank">[22]</a>.</p
Individual physician performance assessment based on volume.
<p>Plots of (A) CDR and (B) RR for the 4 included radiologists at 6 volumes from 500 examinations (then at 1000 and subsequently 1000 exam increments) to the maximum volume read over the 3 years or 5000 total (whichever was least).</p
Distribution of study population.
<p>*According to Rosenberg, et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089418#pone.0089418-Rosenberg1" target="_blank">[19]</a>.</p
Annual observed performance values as compared to aggregated data.
<p>Annual CDR for each individual radiologist are shown on this bar graph with performance values and lower bound 95% CI summarized below the bar graph. The fourth bar for each physician represents performance over the 3 years of the study period aggregated (“Agg”) into a consolidated performance metric. Performance values in th first row in italics and bold represent performance values that would be characterized as inadequate using previously published benchmark thresholds.</p
A novel MR-guided interventional device for 3D circumferential access to breast tissue
MRI is rapidly growing as a tool for image-guided procedures in the breast such as needle localizations, biopsy, and cryotherapy. The ability of MRI to resolve small (<1 cm) lesions allows earlier detection and diagnosis than with ultrasound. Most MR-guidance methods perform a two-dimensional compression of the breast that distorts tissue anatomy and limits medial access. This work presents a system for localizing breast lesions with 360° access to breast tissue. A novel system has been developed to perform breast lesion localization using MR guidance that uses a 3D radial coordinate system with four degrees of freedom. The device is combined with a novel breast RF coil for improved signal to noise and rotates 360° around the breast to allow medial, lateral, superior, and inferior access minimizing insertion depth to the target. Coil performance was evaluated using a human volunteer by comparing signal to noise from both the developed breast RF coil and a commercial seven-channel breast coil. The system was tested with a breast-shaped gel phantom containing randomly distributed MR-visible targets. MR-compatible localization needles were used to demonstrate the accuracy and feasibility of the concept for breast biopsy. Localization results were classified based on the relationship between the final needle tip position and the lesion. A 3D bladder concept was also tested using animal tissue to evaluate the device’s ability to immobilize deformable breast tissue during a needle insertion. The RF breast coil provided signal to noise values comparable to a seven-channel breast coil. The needle tip was in contact with the targeted lesion in 89% (25∕28) of all the trials and 100% (6∕6) of the trials with targeted lesions >6 mm. Target lesions were 3–4 mm in diameter for 47% (13∕28), 5–6 mm in diameter for 32% (9∕28), and over 6 mm in diameter for 21% (6∕28) of the trials, respectively. The 3D bladder concept was shown to immobilize a deformable animal tissue phantom during needle insertion. It is concluded that the MR-guidance system accurately localizes small targets on the order of 3–4 mm in a breast phantom with 360° rotational access