Pavel Crystal

Accuracy of Unenhanced MR Imaging in the Detection of Axillary Lymph Node Metastasis: Study of Reproducibility and Reliability

PURPOSE To investigate the accuracy, reproducibility, and reliability of unenhanced magnetic resonance (MR) imaging techniques for detecting metastatic axillary lymph nodes in patients with newly diagnosed breast carcinoma. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained. Seventy-four consecutive women with invasive breast carcinoma were recruited to undergo preoperative breast MR imaging. Thirteen patients were excluded, two because they were undergoing preoperative chemotherapy and 11 because of the presence of movement or susceptibility artifacts on images. Thus, 61 patients (mean age, 53 years; range, 33-78 years) were included in this study. Axial T1-weighted MR images without fat saturation and diffusion-weighted (DW) MR images were analyzed by two experienced radiologists, who were blinded to the histopathologic findings. Visual and quantitative analyses of unenhanced MR images were performed. Sensitivity, specificity, and accuracy were calculated. To assess the intraobserver agreement, a second reading was performed. Statistical analysis was conducted on a patient-by-affected side basis. RESULTS The sensitivity, specificity, and accuracy were 88%, 82%, and 85%, respectively, for axial T1-weighted MR imaging and 84%, 77%, and 80% for DW imaging. Apparent diffusion coefficients (ADCs) were significantly lower in the malignant group (P<.05 for all four readings), with the average of the four readings ranging from 0.333×10(-3) mm2/sec to 2.843×10(-3) mm2/sec. The mean Lin coefficient comparing the mean ADC reading for each observer was 0.959 (95% confidence interval: 0.935, 0.975), suggesting very high interobserver agreement between the two observers in terms of reproducibility of ADCs. The Bland-Altman plot showed good inter- and intraobserver agreement. CONCLUSION Unenhanced MR imaging techniques showed high accuracy in the preoperative evaluation of axillary status in patients with invasive breast cancer. Results indicate reliable and reproducible assessment with DW imaging, but it is unlikely to be useful in clinical practice.

Diagnostic Performance of Quantitative Shear Wave Elastography in the Evaluation of Solid Breast Masses: Determination of the Most Discriminatory Parameter

OBJECTIVE The purpose of this article is to assess the diagnostic performance of quantitative shear wave elastography in the evaluation of solid breast masses and to determine the most discriminatory parameter. SUBJECTS AND METHODS B-mode ultrasound and shear wave elastography were performed before core biopsy of 123 masses in 112 women. The diagnostic performance of ultrasound and quantitative shear wave elastography parameters (mean elasticity, maximum elasticity, and elasticity ratio) were compared. The added effect of shear wave elastography on the performance of ultrasound was determined. RESULTS The mean elasticity, maximum elasticity, and elasticity ratio were 24.8 kPa, 30.3 kPa, and 1.90, respectively, for 79 benign masses and 130.7 kPa, 154.9 kPa, and 11.52, respectively, for 44 malignant masses (p < 0.001). The optimal cutoff value for each parameter was determined to be 42.5 kPa, 46.7 kPa, and 3.56, respectively. The AUC of each shear wave elastography parameter was higher than that of ultrasound (p < 0.001); the AUC value for the elasticity ratio (0.943) was the highest. By adding shear wave elastography parameters to the evaluation of BI-RADS category 4a masses, about 90% of masses could be downgraded to BI-RADS category 3. The numbers of downgraded masses were 40 of 44 (91%) for mean elasticity, 39 of 44 (89%) for maximum elasticity, and 42 of 44 (95%) for elasticity ratio. The numbers of correctly downgraded masses were 39 of 40 (98%) for mean elasticity, 38 of 39 (97%) for maximum elasticity, and 41 of 42 (98%) for elasticity ratio. There was improvement in the diagnostic performance of ultrasound of mass assessment with shear wave elastography parameters added to BI-RADS category 4a masses compared with ultrasound alone. Combined ultrasound and elasticity ratio had the highest improvement, from 35.44% to 87.34% for specificity, from 45.74% to 80.77% for positive predictive value, and from 57.72% to 90.24% for accuracy (p < 0.0001). The AUC of combined ultrasound and elasticity ratio (0.914) was the highest compared with the other combined parameters. CONCLUSION There was a statistically significant difference in the values of the quantitative shear wave elastography parameters of benign and malignant solid breast masses. By adding shear wave elastography parameters to BI-RADS category 4a masses, we found that about 90% of them could be correctly downgraded to BI-RADS category 3, thereby avoiding biopsy. Elasticity ratio (cutoff, 3.56) appeared to be the most discriminatory parameter.

Performance of computer-aided detection applied to full-field digital mammography in detection of breast cancers

OBJECTIVE The aim of this retrospective study was to evaluate performance of computer-aided detection (CAD) with full-field digital mammography (FFDM) in detection of breast cancers. MATERIALS AND METHODS CAD was retrospectively applied to standard mammographic views of 127 cases with biopsy proven breast cancers detected with FFDM (Senographe 2000, GE Medical Systems). CAD sensitivity was assessed in total group of 127 cases and for subgroups based on breast density, mammographic lesion type, mammographic lesion size, histopathology and mode of presentation. RESULTS Overall CAD sensitivity was 91% (115 of 127 cases). There were no statistical differences (p > 0.1) in CAD detection of cancers in dense breasts 90% (53/59) versus non-dense breasts 91% (62/68). There was statistical difference (p < 0.05) in CAD detection of cancers that appeared mammographically as microcalcifications only versus other mammographic manifestations. CAD detected 100% (44/44) of cancers manifesting as microcalcifications, 89% (47/53) as no-calcified masses or asymmetries, 88% (14/16) as masses with associated calcifications, and 71% (10/14) as architectural distortions. CAD sensitivity for cancers 1-10mm was 84% (38/45); 11-20mm 93% (55/59); and >20mm 97% (22/23). CONCLUSION CAD applied to FFDM showed 100% sensitivity in identifying cancers manifesting as microcalcifications only and high sensitivity 86% (71/83) for other mammographic appearances of cancer. Sensitivity is influenced by lesion size. CAD in FFDM is an adjunct helping radiologist in early detection of breast cancers.

Pilot Study of Quantitative Analysis of Background Enhancement on Breast MR Images: Association with Menstrual Cycle and Mammographic Breast Density

PURPOSE To perform semiautomated quantitative analysis of the background enhancement (BE) in a cohort of patients with newly diagnosed breast cancer and to correlate it with mammographic breast density and menstrual cycle. MATERIALS AND METHODS Informed consent was waived after the research ethics board approved this study. Results of 177 consecutive preoperative breast magnetic resonance (MR) examinations performed from February to December 2009 were reviewed; 147 female patients (median age, 48 years; range, 26-86 years) were included. Ordinal values of BE and breast density were described by two independent readers by using the Breast Imaging Reporting and Data System lexicon. The BE coefficient (BEC) was calculated thus: (SI2 · 100/SI1) - 100, where SI is signal intensity, SI2 is the SI enhancement measured in the largest anteroposterior dimension in the axial plane 1 minute after the contrast agent injection, and SI1is the SI before contrast agent injection. BEC was used for the quantitative analysis of BE. Menstrual cycle status was based on the last menstrual period. The Wilcoxon rank-sum or Kruskal-Wallis test was used to compare quantitative assessment groups. Cohen weighted κ was used to evaluate agreement. RESULTS Of 147 patients, 68 (46%) were premenopausal and 79 (54%) were postmenopausal. The quantitative BEC was associated with the menstrual status (BEC in premenopausal women, 31.48 ± 20.68 [standard deviation]; BEC in postmenopausal women, 25.65 ± 16.74; P = .02). The percentage of overall BE was higher when the MR imaging was performed in women in the inadequate phase of the cycle (<35 days, not 7-14 days; mean BEC, 35.7) compared with women in the postmenopausal group (P = .001). Premenopausal women had significantly higher BEC when compared with postmenopausal women (P = .03). There was no significant difference in the percentage of BE between breast density groups. CONCLUSION Premenopausal women with breast cancer, and specifically women in the inadequate phase of the cycle, presented with higher quantitative BE than postmenopausal women. No association was found between BE and breast density.

The effect of acute aromatase inhibition on breast parenchymal enhancement in magnetic resonance imaging: a prospective pilot clinical trial.

ObjectiveThe breast is highly hormonally sensitive especially to the sex steroid hormone estrogen. Both physiological and iatrogenic steroid hormone modifications could affect how the breast tissue may appear in breast imaging techniques. We hypothesized that estrogen deprivation therapy could reduce breast nonspecific enhancement on magnetic resonance imaging (MRI). MethodsThis study was a prospective pilot phase II clinical trial. The study was approved by Health Canada and the institutional research ethics board, and participants signed informed consent forms. Sixteen healthy postmenopausal women were enrolled, and 14 completed the study. Baseline breast MRI was done followed 1 month later by administration of a high-dose aromatase inhibitor (letrozole 12.5 mg/day) for 3 successive days before a second breast MRI. Background breast parenchymal enhancement was compared between the pretreatment and posttreatment studies. ResultsThere was a statistically significant reduction of the average background breast enhancement after treatment with aromatase inhibitors compared with baseline MRI. Of particular interest, specific areas of benign breast enhancement were reduced after aromatase inhibitor treatment. No significant adverse effects were recorded using this relatively high dose of the aromatase inhibitors. ConclusionsThis preliminary study provided evidence that aromatase inhibitors could reduce the parenchymal background enhancement of benign breast tissue during MRI and may improve the specificity of the technique.

Added cancer yield of breast magnetic resonance imaging screening in women with a prior history of chest radiation therapy

Recommendation for breast magnetic resonance imaging (MRI) screening for women with a prior history of chest radiation is currently based on expert opinion, because existing data are very scant. The objective of this study was to evaluate added cancer yield of screening breast MRI in this population.

The evolving role of axillary lymph node fine‐needle aspiration in the management of carcinoma of the breast

Image‐guided fine‐needle aspiration (FNA) studies of axillary lymph nodes (LN) to evaluate breast carcinoma have shown high specificity but variable sensitivity. The purposes of this study were to evaluate the performance of axillary LN FNA depending on clinicoradiologic findings and to document how treatment varied according to FNA results.

Sensitivity of a Direct Computer-aided Detection System in Full-field Digital Mammography for Detection of Microcalcifications Not Associated with Mass or Architectural Distortion

Purpose The purpose of this study was to evaluate the sensitivity of a direct computer-aided detection (CAD) system (d-CAD) in full-field digital mammography (FFDM) for the detection of microcalcifications not associated with mass or architectural distortion. Materials and Methods A database search of 1063 consecutive stereotactic core biopsies performed between 2002 and 2005 identified 196 patients with Breast Imaging-Reporting and Data System (BI-RADS) 4 and 5 microcalcifications not associated with mass or distortion detected exclusively by bilateral FFDM. A commercially available CAD system (Second Look, version 7.2) was retrospectively applied to the craniocaudal and mediolateral oblique views in these patients (mean age, 59 years; range, 35–84 years). Breast density, location and mammographic size of the lesion, distribution, and tumour histology were recorded and analysed by using χ2, Fisher exact, or McNemar tests, when applicable. Results When using d-CAD, 71 of 74 malignant microcalcification cases (96%) and 101 of 122 benign microcalcifications (83%) were identified. There was a significant difference (P < .05) between CAD sensitivity on the craniocaudal view, 91% (68 of 75), vs CAD sensitivity on the mediolateral oblique view, 80% (60 of 75). The d-CAD sensitivity for dense breast tissue (American College of Radiology [ACR] density 3 and 4) was higher (97%) than d-CAD sensitivity (95%) for nondense tissue (ACR density 1 and 2), but the difference was not statically significant. All 28 malignant calcifications larger than 10 mm were detected by CAD, whereas the sensitivity for lesions small than or equal to 10 mm was 94%. Conclusions D-CAD had a high sensitivity in the depiction of asymptomatic breast cancers, which were seen as microcalcifications on FFDM screening, with a sensitivity of d-CAD on the craniocaudal view being significantly better. All malignant microcalcifications larger than 10 mm were detected by d-CAD.

Impact of Early Breast Cancer Screening on Mortality Among Young Survivors of Childhood Hodgkin’s Lymphoma

BACKGROUND Female survivors treated with thoracic radiation therapy (RT) for childhood cancer experience increased risks of breast cancer (BC). There are currently no data quantifying the potential mortality gains of early BC screening among such survivors. METHODS A mathematical model of BC development was used to evaluate the marginal benefit of early-initiated screening of female survivors of adolescent Hodgkins lymphoma (HL) starting at age 25 years on BC mortality compared with screening initiated at age 40 years. Sensitivity analyses were performed to evaluate the robustness of the estimates over a plausible range of conditions. RESULTS For survivors treated at age 15 years, the absolute risk of BC mortality by age 75 years was predicted to decrease from 16.65% with no early screening to 16.28% (annual mammography), 15.40% (annual MRI), 15.38% (same-day annual mammography and MRI), and 15.37% (alternating mammography and MRI every six months). Approximately 80 patients would need to be invited to MRI-based screening to prevent one BC death. In sensitivity analyses, the number needed to invite to MRI-based screening to prevent one BC death ranged from 71 to 333. Combinations of MRI plus mammography were predicted to produce 99.52 false positives per 1000 screenings done between age 25 to 39 years. CONCLUSIONS These findings are the first to indicate that early MRI-based screening should reduce BC mortality among women treated with RT for adolescent HL. The magnitude of this benefit is superior to that described for other accepted screening indications although MRI can produce a substantial rate of false-positive results.

Sonographic Findings of Palpable Isoechoic Breast Fat Necrosis Look for Skin Integrity

Fat necrosis is a cause of palpable breast lesions. Sonography is commonly used before mammography in young patients with palpable lumps. We describe a case of isoechoic breast fat necrosis that was detected because of extension to the skin. We are unaware of other reports of an isoechoic appearance of fat necrosis.