Janet E. Bailey

ROC study of the effect of stereoscopic imaging on assessment of breast lesions

An observer performance study was conducted to evaluate the usefulness of assessing breast lesion characteristics with stereomammography. Stereoscopic image pairs of 158 breast biopsy tissue specimens were acquired with a GE Senographe 2000D full field digital mammography system using a 1.8x magnification geometry. A phantom-shift method equivalent to a stereo shift angle of +/- 3 degrees relative to a central axis perpendicular to the detector was used. For each specimen, two pairs of stereo images were taken at approximately orthogonal orientations. The specimens contained either a mass, microcalcifications, both, or normal tissue. Based on pathological analysis, 39.9% of the specimens were found to contain malignancy. The digital specimen radiographs were displayed on a high resolution MegaScan CRT monitor driven by a DOME stereo display board using in-house developed software. Five MQSA radiologists participated as observers. Each observer read the 316 specimen stereo image pairs in a randomized order. For each case, the observer first read the monoscopic image and entered his/her confidence ratings on the presence of microcalcifications and/or masses, margin status, BI-RADS assessment, and the likelihood of malignancy. The corresponding stereoscopic images were then displayed on the same monitor and were viewed through stereoscopic LCD glasses. The observer was free to change the ratings in every category after stereoscopic reading. The ratings of the observers were analyzed by ROC methodology. For the 5 MQSA radiologists, the average Az value for estimation of the likelihood of malignancy of the lesions improved from 0.70 for monoscopic reading to 0.72 (p=0.04) after stereoscopic reading, and the average Az value for the presence of microcalcifications improved from 0.95 to 0.96 (p=0.02). The Az value for the presence of masses improved from 0.80 to 0.82 after stereoscopic reading, but the difference fell short of statistical significance (p=0.08). The visual assessment of margin clearance was found to have very low correlation with microscopic analysis with or without stereoscopic reading. This study demonstrates the potential of using stereomammography to improve the detection and characterization of mammographic lesions.

Complicated Breast Cysts on Sonography: Is Aspiration Necessary to Exclude Malignancy?

RATIONALE AND OBJECTIVES To determine the incidence of breast cancer in women presenting for fine needle aspiration of sonographically diagnosed complicated breast cysts. MATERIALS AND METHODS Institutional review board approval was obtained. A retrospective study was performed of 186 consecutive women who presented for fine needle aspiration of 243 sonographic complicated cysts detected by clinical examination or imaging between January 2002 and August 2003. Sonographic complicated cysts were defined as those meeting most but not all criteria for simple cysts similar to current Breast Imaging Reporting and Data System classification. We excluded solid masses, cysts with solid components, intracystic masses, and simple cysts. Prospective mammography, ultrasound, and procedure reports were reviewed. A case was considered positive if cytology, core needle biopsy, or surgical excision was positive for cancer. Final diagnosis was established by biopsy, cytology, clinical resolution, or stability over time. RESULTS One of 243 (0.4%) lesions proved malignant (95% confidence interval 0-1.94%); 210/243 (86.4%) of cases yielded fluid on aspiration. Of 141 samples submitted to cytology, 138 (97.9%) were benign and 3 (2.1%) atypical. All cases of atypia were benign at surgical excision. Ninety five of 243 (39.1%) aspiration samples with typical cyst fluid were discarded. A total of 33/243 (13.6%) cases did not yield fluid, 1 of which was positive for cancer. Thirty cases underwent core needle or excisional biopsy for imaging discordance with benign results. CONCLUSIONS Breast cancer presenting as a complicated cyst by ultrasound was rare (0.4%, 95% confidence interval 0-1.94%). These results provide support for classification of complicated cysts as probably benign.

Prevalence of Malignancy in Thyroid Nodules with an Initial Nondiagnostic Result After Ultrasound Guided Fine Needle Aspiration

The objective of this study was to determine the rate of malignancy in thyroid nodules with an initial nondiagnostic fine needle aspiration. From October 2001 to April 2007, biopsies were performed on 1344 thyroid nodules in our practice. Biopsies were performed on nodules using 25-27 gauge needles, ultrasound guidance and multiple passes using both suction and capillary action. We retrospectively reviewed the results of these biopsies as well as any further management of nodules that received nondiagnostic results (IRB HUM00006459). Following initial biopsy, 295/1344 (21.9%) of nodules received nondiagnostic pathologic results. Of this population, 39 nodules (13.1%) were lost to follow-up. Of the remaining 256 nodules that received a repeat FNA, surgical excision, or greater than 24 months of clinical and imaging follow-up, only five cancers were detected, representing only 2% of the population that received an initial nondiagnostic biopsy result. All of these cancers were papillary neoplasms. When rigorous, ultrasound-guided, fine needle aspiration of thyroid nodules is performed, a nondiagnostic histopathologic result should not be interpreted as suspicious for thyroid cancer. Given the low rate of malignancy in this population (2%), we suggest that clinical and imaging follow-up of these nodules, opposed to repeat sampling, is warranted.

24/7/365 in-house radiologist coverage: effect on resident education.

RATIONALE AND OBJECTIVES To compare programs with and without 24-hour/7 days a week/365 days a year (24/7/365) in-house radiologist coverage regarding resident perceptions of their on-call experience, volume of resident dictations on call, and report turnaround time. MATERIALS AND METHODS Residents from six academic radiology departments were invited to participate in an 11-item online survey. Survey items were related to workload, level of autonomy, faculty feedback, comfort level, faculty supervision, and overall educational experience while on call from 8 pm to 8 am. Each site provided data on imaging volume, radiologist coverage, volume of examinations dictated by residents, number of residents on call, and report turnaround time from 8 pm to 8 am. F-ratios and eta-squares were calculated to determine the relationships between dependent and independent variables. A P value < .05 was considered statistically significant. RESULTS A total of 146 (67%) of 217 residents responded. Residents in programs with 24/7/365 in-house radiologist coverage dictated a lower percentage of examinations (46%) compared with other residents (81%) and rated faculty feedback more positively (mean 3.8 vs. 3.3) but rated their level of autonomy (mean 3.6 vs. 4.5) and educational experience (mean 3.6 vs. 4.2) more negatively (all P < .05). Report turnaround time was lower in programs with 24/7/365 coverage than those without (mean 1.7 hours vs. 9.1 hours). The majority of resident comments were negative and related to loss of autonomy with 24/7/365 coverage. CONCLUSION More rapid report turnaround time related to 24/7/365 coverage may come at the expense of resident education.

Academic Radiology and the Emergency Department:: Does It Need Changing?

RATIONAL AND OBJECTIVES The increasing importance of imaging for both diagnosis and management in patient care has resulted in a demand for radiology services 7 days a week, 24 hours a day, especially in the emergency department (ED). We hypothesized the resident preliminary reports were better than generalist radiology interpretations, although inferior to subspecialty interpretations. MATERIALS AND METHODS Total radiology volume through our Level I pediatric and adult academic trauma ED was obtained from the radiology information system. We conducted a literature search for error and discordant rates between radiologists of varying experience. For a 2-week prospective period, all preliminary reports generated by the residents and final interpretations were collected. Significant changes in the report were tabulated. RESULTS The ED requested 72,886 imaging studies in 2004 (16% of the total radiology department volume). In a 2-week period, 12 of 1929 (0.6%) preliminary reports by residents were discordant to the final subspecialty dictation. In the 15 peer-reviewed publications documenting error rates in radiology, the error rate between American Board of Radiology (ABR)-certified radiologists is greater than that between residents and subspecialists in the literature and in our study. However, the perceived error rate by clinicians outside radiology is significantly higher. CONCLUSION Sixteen percent of the volume of imaging studies comes through the ED. The residents handle off-hours cases with a radiology-detected error rate below the error rate between ABR-certified radiologists. To decrease the perceived clinician-identified error rate, we need to change how academic radiology handles ED cases.

Posterior Acoustic Enhancement in Hepatocellular Carcinoma

The purpose of this study was to assess sonographic appearances of hepatocellular carcinoma with particular attention to posterior acoustic effects.

Radiologic educationAcademic Radiology and the Emergency Department:: Does It Need Changing?

RATIONAL AND OBJECTIVES The increasing importance of imaging for both diagnosis and management in patient care has resulted in a demand for radiology services 7 days a week, 24 hours a day, especially in the emergency department (ED). We hypothesized the resident preliminary reports were better than generalist radiology interpretations, although inferior to subspecialty interpretations. MATERIALS AND METHODS Total radiology volume through our Level I pediatric and adult academic trauma ED was obtained from the radiology information system. We conducted a literature search for error and discordant rates between radiologists of varying experience. For a 2-week prospective period, all preliminary reports generated by the residents and final interpretations were collected. Significant changes in the report were tabulated. RESULTS The ED requested 72,886 imaging studies in 2004 (16% of the total radiology department volume). In a 2-week period, 12 of 1929 (0.6%) preliminary reports by residents were discordant to the final subspecialty dictation. In the 15 peer-reviewed publications documenting error rates in radiology, the error rate between American Board of Radiology (ABR)-certified radiologists is greater than that between residents and subspecialists in the literature and in our study. However, the perceived error rate by clinicians outside radiology is significantly higher. CONCLUSION Sixteen percent of the volume of imaging studies comes through the ED. The residents handle off-hours cases with a radiology-detected error rate below the error rate between ABR-certified radiologists. To decrease the perceived clinician-identified error rate, we need to change how academic radiology handles ED cases.

Apprenticeships Ease the Transition to Independent Call: An Evaluation of Anxiety and Confidence Among Junior Radiology Residents

RATIONALE AND OBJECTIVES The aims of this study were to quantify resident anxiety when beginning independent call and to assess whether an apprenticeship experience (buddy call) can lessen anxiety and improve confidence. MATERIALS AND METHODS A prospective cohort comparison of two groups of radiology residents beginning independent call, one of which was provided with a buddy call experience, was performed. Anxiety and confidence were assessed using the Endler Multidimensional Anxiety Scales-State (EMAS-S), with total score, autonomic emotional, and cognitive worry components, and a five-point, Likert-type scale, respectively. Both groups were asked about the perceived value of a buddy call experience. RESULTS EMAS-S scores improved significantly over 5 days of call in both groups (control, n = 10, P = .0005; buddy call, n = 9, P = .0001), and image interpretation confidence correspondingly increased (control, P = .0004; buddy call, P = .003). Compared to the control group, autonomic emotional scores were significantly lower in the buddy call group on the first day of independent call (P = .040), and cognitive worry and total EMAS-S scores were significantly lower on day 5 (both P values = .03). Buddy call was independently associated with improved autonomic emotional and film interpretation confidence scores (both P values = .02). All members of the buddy call group indicated that the experience was very helpful in preparing for call. CONCLUSIONS Beginning independent call is associated with high anxiety, and buddy call reduces that anxiety, beyond the effect of time alone. Residents who participated in buddy call found it helpful in preparing for independent call. These findings support the use of buddy call and tiered call structures as means to introduce junior residents to independent call.

An observer study comparing spot imaging regions selected by radiologists and a computer for an automated stereo spot mammography technique.

We are developing an automated stereo spot mammography technique for improved imaging of suspicious dense regions within digital mammograms. The technique entails the acquisition of a full-field digital mammogram, automated detection of a suspicious dense region within that mammogram by a computer aided detection (CAD) program, and acquisition of a stereo pair of images with automated collimation to the suspicious region. The latter stereo spot image is obtained within seconds of the original full-field mammogram, without releasing the compression paddle. The spot image is viewed on a stereo video display. A critical element of this technique is the automated detection of suspicious regions for spot imaging. We performed an observer study to compare the suspicious regions selected by radiologists with those selected by a CAD program developed at the University of Michigan. True regions of interest (TROIs) were separately determined by one of the radiologists who reviewed the original mammograms, biopsy images, and histology results. We compared the radiologist and computer-selected regions of interest (ROIs) to the TROIs. Both the radiologists and the computer were allowed to select up to 3 regions in each of 200 images (mixture of 100 CC and 100 MLO views). We computed overlap indices (the overlap index is defined as the ratio of the area of intersection to the area of interest) to quantify the agreement between the selected regions in each image. The averages of the largest overlap indices per image for the 5 radiologist-to-computer comparisons were directly related to the average number of regions per image traced by the radiologists (about 50% for 1 region/image, 84% for 2 regions/image and 96% for 3 regions/image). The average of the overlap indices with all of the TROIs was 73% for CAD and 76.8% +/- 10.0% for the radiologists. This study indicates that the CAD determined ROIs could potentially be useful for a screening technique that includes stereo spot mammography imaging.

Radiology EducationResidents' Ability to Interpret Radiology Images: Development and Improvement of an Assessment Tool

RATIONALE AND OBJECTIVES Despite increasing radiology coverage, nonradiology residents continue to preliminarily interpret basic radiologic studies independently, yet their ability to do so accurately is not routinely assessed. MATERIALS AND METHODS An online test of basic radiologic image interpretation was developed through an iterative process. Educational objectives were established, then questions and images were gathered to create an assessment. The test was administered online to first-year interns (postgraduate year [PGY] 1) from 14 different specialties, as well as a sample of third- and fourth-year radiology residents (PGY3/R2 and PGY4/R3). RESULTS Over a 2-year period, 368 residents were assessed, including PGY1 (n = 349), PGY3/R2 (n = 14), and PGY4/R3 (n = 5) residents. Overall, the test discriminated effectively between interns (average score = 66%) and advanced residents (R2 = 86%, R3 = 89%; P < .05). Item analysis indicated discrimination indices ranging from -0.72 to 48.3 (mean = 3.12, median 0.58) for individual questions, including four questions with negative discrimination indices. After removal of the negatively indexed questions, the overall predictive value of the instrument persisted and discrimination indices increased for all but one of the remaining questions (range 0.027-70.8, mean 5.76, median 0.94). CONCLUSIONS Validation of an initial iteration of an assessment of basic image-interpretation skills led to revisions that improved the test. The results offer a specific test of radiologic reading skills with validation evidence for residents. More generally, results demonstrate a principled approach to test development.