Biomedical subjects

Caroline E Blane

Publications and source records attributed to Caroline E Blane.

8 recordsLinked to original sources

PubMed2006

Mammographic density measured with quantitative computer-aided method: comparison with radiologists' estimates and BI-RADS categories.

PURPOSE: To retrospectively compare computer-aided mammographic density estimation (MDEST) with radiologist estimates of percentage density and Breast Imaging Reporting and Data System (BI-RADS) density classification. MATERIALS AND METHODS: Institutional Review Board approval was obtained for this HIPAA-compliant study; patient informed consent requirements were waived. A fully automated MDEST computer program was used to measure breast density on digitized mammograms in 65 women (mean age, 53 years; range, 24-89 years). Pixel gray levels in detected breast borders were analyzed, and dense areas were segmented. Percentage density was calculated by dividing the number of dense pixels by the total number of pixels within the borders. Seven breast radiologists (five trained with MDEST, two not trained) prospectively assigned qualitative BI-RADS density categories and visually estimated percentage density on 260 mammograms. Qualitative BI-RADS assessments were compared with new quantitative BI-RADS standards. The reference standard density for this study was established by allowing the five trained radiologists to manipulate the MDEST gray-level thresholds, which segmented mammograms into dense and nondense areas. Statistical tests performed include Pearson correlation coefficients, Bland-Altman agreement method, kappa statistics, and unpaired t tests. RESULTS: There was a close correlation between the reference standard and radiologist-estimated density (R = 0.90-0.95) and MDEST density (R = 0.89). Untrained radiologists overestimated percentage density by an average of 37%, versus 6% for trained radiologists (P < .001). MDEST showed better agreement with the reference standard (average overestimate, 1%; range, -15% to +18%). MDEST correlated better with percentage density than with qualitative BI-RADS categories. There were large overlaps and ranges of percentage density in qualitative BI-RADS categories 2-4. Qualitative BI-RADS categories correlated poorly with new quantitative BI-RADS categories, and 16 (6%) of 260 views were erroneously classified by MDEST. CONCLUSION: MDEST compared favorably with radiologist estimates of percentage density and is more reproducible than radiologist estimates when qualitative BI-RADS density categories are used. Qualitative and quantitative BI-RADS density assessments differed markedly.

Adult↗

PubMed2005

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.

Biopsy↗

PubMed2004

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.

Biophysical Phenomena↗

PubMed2003

Pulmonary involvement in pediatric lymphoma.

BACKGROUND: The prevalence of pulmonary lymphoma in the pediatric age group is not documented in the literature. OBJECTIVE: This study was designed to assess the prevalence of pulmonary parenchymal lymphoma in children with Hodgkin disease (HD), non-Hodgkin lymphoma (NHL) and post-transplant lymphoproliferative disorder (PTLD). MATERIALS AND METHODS: A 10-year retrospective analysis of 161 lymphoma patients (62 girls and 99 boys), mean age of 12.4 years, was performed. The definition of pulmonary lymphoma excluded those with isolated pleural disease and/or mediastinal adenopathy. RESULTS: Eighty-two patients had HD, 65 had NHL, and 14 had PTLD. Overall prevalence of pulmonary parenchymal involvement was 13% (21/161), including 12% of patients with HD, 10% of patients with NHL, and 29% of patients with PTLD. CT findings included: pulmonary nodules (90%) or mass (38%); interstitial (9%) or alveolar (9%) disease; cavitation (9%); and pleural based mass (9%). CONCLUSIONS: Pulmonary parenchymal disease in our pediatric lymphoma population was more prevalent than expected (13%). This is significant for patient management. New pulmonary lesions in patients with known lymphoma should be regarded with suspicion. In the setting of immune suppression, pulmonary lesions treated as infection may actually represent lymphoma. Expeditious biopsy of lesions failing to respond promptly to antibiotic therapy should be considered.

Adolescent↗

PubMed2003

Pediatric renal pelvic fullness: an ultrasonographic dilemma.

PURPOSE: We conducted a prospective study to define normal renal pelvic size in children. MATERIALS AND METHODS: Institutional Review Board approved consent was obtained to perform renal ultrasound during excretory urography (IVP) scheduled for medical management. Mean patient age (17 females, 11 males) was 5.2 years. Renal ultrasound was conducted concurrent with 10-minute IVP. RESULTS: Fifty kidneys were imaged with 51 collecting systems. IVP defined 44 collecting systems as normal. Mean anteroposterior pelvic diameter on sonography for these 44 systems was 3.3 mm. One normal collecting system on IVP had a diameter greater than 10 mm on ultrasound (14 mm). No sonographic caliceal dilatation was seen in any kidney appearing normal on IVP. The 7 dilated systems on IVP had a mean ultrasound diameter of 17.1 mm. Two dilated collecting systems smaller than 10 mm in diameter on sonography had caliceal distention on ultrasound. CONCLUSIONS: Normal renal pelvis threshold diameter was 10 mm in asymptomatic children. We recommend further evaluation in children with caliceal dilatation and/or dilatation of the anteroposterior renal pelvis greater than 10 mm. Using these criteria, no system appearing abnormal on IVP would have been missed.

Adolescent↗

PubMed2002

The effect of screening sonography on the positive rate of enemas for intussusception.

BACKGROUND: The referring physicians at our institution used the enema as a diagnostic test in children with suspected intussusception. OBJECTIVE: To determine the change in rate of positive enema findings performed for suspected intussusception with the intervention of screening ultrasound (US). MATERIALS AND METHODS: Since October 1995, 224 children (mean age 2.2 years) with suspected intussusception were referred for enema examination. In January 2001, US was introduced as a screening test for intussusception. Enemas were performed for all children with positive US findings and were offered for those with negative US findings if clinical suspicion persisted. RESULTS: Before 2001, 184 children underwent enema with intussusception documented in 40 (22%). Since January 2001, 40 children have been seen with suspected intussusception (12/40 positive or 30%). Two directly underwent enema (1/2 positive); 38 children underwent US. In 12 of 38 children, the US finding was positive, and an intussusception was found at enema examination in 11 of 12. In 26 cases, the US finding was negative. Seven of the 26 children with a negative sonogram finding had an enema, which was also negative. Nineteen enemas were canceled. With a screening US, the positive rate for enemas is now 58% (11/19). We know of no case of intussusception missed at US. CONCLUSION: Screening US has decreased unnecessary enemas for clinically suspected intussusception, increasing positive findings from 22% to 58%. This has in turn reduced children's exposure to radiation.

Barium Sulfate↗

PubMed2002

Decreasing rate of fatty involution at screening mammography.

RATIONALE AND OBJECTIVES: This study was performed to document the perceived decrease in fatty involution at screening mammography during the past decade and evaluate the influence of hormone replacement therapy (HRT). MATERIALS AND METHODS: In December 1996, the mammograms of 261 consecutive screening patients with a comparison study obtained 5 years earlier were evaluated, and their breasts were categorized according to Breast Imaging Reporting and Data System categories for breast density. The women, aged 50-59 years, included 119 who had been receiving HRT for 0.25-15 years (mean, 3 years). From the files, 261 age-matched screening mammograms from 1986 were obtained; these patients also had comparison mammograms from 1981. Analysis of variance was used to determine differences between the 1980s group, the 1990s group receiving HRT, and the 1990s group not receiving HRT. Scheffé tests were used for post hoc comparisons. Stepwise regression analysis was used to evaluate the relative influence of age, decade, score of the first mammogram, and HRT. RESULTS: Breast density for the 1991 mammograms did not differ significantly from that in 1981 (P < .05). Initial breast density was the best predictor of final breast density in both decades (P < .001), regardless of HRT status. The change in breast density (toward fatty) over the 5-year interval in the 1980s (mean, 0.48) was significantly greater than that in both 1990s groups (mean for HRT group, 0.11; no HRT, 0.30; P < .05). CONCLUSION: These results confirm that breast density at screening mammography in the 1990s did not decrease with age at the same rate as in the 1980s, even in patients not receiving HRT.

Adipose Tissue↗

PubMed2002

Computed tomographic diagnosis of unsuspected pyelonephritis in children.

OBJECTIVE: To emphasize the utility of computed tomography (CT) in the diagnosis of pyelonephritis in children with complex comorbidities. METHODS: We retrospectively reviewed the CT imaging studies and medical records of 12 patients (8 girls, 4 boys; aged 2-18 years [mean 8.6 yr]) who did not have a classic presentation of pyelonephritis but were diagnosed by CT. All patients had fever at clinical presentation, and pyelonephritis was not suspected in any case. Two children had negative urine cultures before imaging. RESULTS: All 12 patients had wedge-shaped areas of hypoattenuation on CT, 7 bilaterally; 10 had enlargement of an involved kidney; 5 had perinephric fat stranding; and 3 had focal abscesses. CONCLUSIONS: Although classic and uncomplicated pyelonephritis is a clinical diagnosis that does not require imaging, sometimes the presentation may be equivocal and the diagnosis unsuspected. Pyelonephritis is one of several potential sources of fever that can be simultaneously evaluated using CT. Using. CT, the unsuspected diagnosis of pyelonephritis can be made and therapy initiated before the urine culture is positive.

Adolescent↗