Claudio Spick

Diagnostic Utility of Second-Look US for Breast Lesions Identified at MR Imaging: Systematic Review and Meta-Analysis

PURPOSE To evaluate the diagnostic utility of second-look ultrasonography (US) in the assessment of lesions identified at breast magnetic resonance (MR) imaging. MATERIALS AND METHODS A systematic review of the PubMed database for articles published up to January 6, 2013, was performed by using predefined search terms applied in a standardized manner. Second-look US studies for the assessment of breast lesions identified at MR imaging were eligible for this meta-analysis. Two independent reviewers performed the literature review and data extraction. Eligible studies presented data on the number of lesions examined and the number of lesions detected at second-look US. The reference standard for lesion diagnosis was either histopathologic or follow-up examination. Sources of bias were assessed by using the Quality Assessment of Diagnostic Accuracy Studies 2, or QUADAS-2 Quality Assessment of Diagnostic Accuracy Studies 2 , tool. Statistical analysis included data pooling, heterogeneity testing, and meta-regression. RESULTS Seventeen studies that included benign and malignant lesions met the inclusion criteria. The general lesion detection rate at second-look US was very heterogeneous and ranged between 22.6% and 82.1% (pooled rate, 57.5% [1266 of 2201]; 95% confidence interval [ CI confidence interval ]: 50.0%, 64.1% [random-effects model]; I(2) = 90.9%; P < .0001). The highest second-look US detection rates were observed for mass lesions (as opposed to nonmass lesions) and malignant (vs benign) lesions (P < .001 for both). Pooled positive and negative predictive values (positive or negative second-look US correlates of MR imaging-detected malignant or benign lesions) were calculated as 30.7% (95% CI confidence interval : 25.3%, 36.4%; I(2) = 75.4%; P < .0001) and 87.8% (95% CI confidence interval : 82.0%, 92.7%; I(2) = 82.1%; P < .0001), respectively, by using random-effects models. CONCLUSION The results of this study demonstrated variable utility of second-look US in MR imaging-detected lesions, as lesion detection rates were very heterogeneous. Subgroup analysis showed that malignant and mass lesions were more likely to be detected at second-look US. Furthermore, malignancy was not excluded if a lesion was not detected at second-look US.

Quantitative apparent diffusion coefficient as a noninvasive imaging biomarker for the differentiation of invasive breast cancer and ductal carcinoma in situ.

ObjectivesThe objective of this study was to evaluate whether apparent diffusion coefficient (ADC) obtained through diffusion-weighted imaging magnetic resonance imaging at 3 T can be used as an imaging biomarker to differentiate invasive breast cancer from noninvasive ductal carcinoma in situ (DCIS). Materials and MethodsOne hundred seventy-six histopathologically verified primary malignant breast tumors were retrospectively evaluated in 170 patients. All patients had undergone a standardized 3-T magnetic resonance imaging protocol, containing a diffusion-weighted sequence with 2 b values and a series of dynamic contrast-enhanced T1-weighted sequences. Apparent diffusion coefficient was measured manually by a reader blinded to the histopathological results. The ADC values were correlated with histopathological results. Mean ADC values were compared between invasive cancers and DCIS as well as between different tumor grades. Receiver operating characteristics curves were used to calculate diagnostic performance. ResultsThere were 155 invasive cancers and 21 noninvasive DCIS. Mean (SD) values differed significantly between the invasive cancers (0.9 [0.15] ×10−3 mm2/s) and the DCIS (1.24 [0.23] ×10−3 mm2/s, P < 0.001). Area under the receiver operating characteristics curve was 0.895 (95% confidence interval [CI], 0.840–0.936). A threshold of 1.01 ×10−3 mm2/s or less allowed an identification of invasive cancers with a sensitivity of 78.06% (95% CI, 70.7%–84.3%) and a specificity of 90.5% (95% CI, 69.6%–98.8%). No significant ADC differences were found among different tumor grades (P > 0.05). ConclusionsApparent diffusion coefficient could be used as an imaging biomarker for the diagnosis of breast cancer. It seems to be a valuable noninvasive quantitative biomarker to assess breast cancer invasiveness. Thus, ADC measurements provide the potential to reduce overdiagnosis and subsequent overtreatment.

Breast MRI used as a problem-solving tool reliably excludes malignancy

PURPOSE To evaluate the diagnostic performance of breast MRI if used as a problem-solving tool in BI-RADS 0 cases. MATERIAL AND METHODS In this IRB-approved, single-center study, 687 women underwent high-resolution-3D, dynamic contrast-enhanced breast magnetic resonance imaging (MRI) between January 2012 and December 2012. Of these, we analyzed 111 consecutive patients (mean age, 51 ± 12 years; range, 20-83 years) categorized as BI-RADS 0. Breast MRI findings were stratified by clinical presentations, conventional imaging findings, and breast density. MRI results were compared to the reference standard, defined as histopathology or an imaging follow-up of at least 1 year. RESULTS One hundred eleven patients with BI-RADS 0 conventional imaging findings revealed 30 (27%) mammographic masses, 57 (51.4%) mammographic architectural distortions, five (4.5%) mammographic microcalcifications, 17 (15.3%) ultrasound-only findings, and two palpable findings without imaging correlates. There were 15 true-positive, 85 true-negative, 11 false-positive, and zero false-negative breast MRI findings, resulting in a sensitivity, specificity, PPV, and NPV of 100% (15/15), 88.5% (85/96), 57.7% (15/26), and 100% (85/85), respectively. Breast density and reasons for referral had no significant influence on the diagnostic performance of breast MRI (p>0.05). CONCLUSION Breast MRI reliably excludes malignancy in conventional BI-RADS 0 cases resulting in a NPV of 100% (85/85) and a PPV of 57.7% (15/26).

Rate of Malignancy in MRI-Detected Probably Benign (BI-RADS 3) Lesions

OBJECTIVE The purpose of this study was to evaluate the malignancy rate in MRI-detected probably benign (BI-RADS 3) lesions in women without a history of breast cancer. MATERIALS AND METHODS In this study, 1265 patients underwent breast MRI during a 7-year period. One hundred and eight (8.5%) patients with a nonpalpable breast lesion classified as BI-RADS 3 at MRI and with a needle biopsy or adequate follow-up of at least 24 months were included. Statistical analysis included calculation of the negative predictive value with its 95% CI. RESULTS Of 108 lesions, 107 (99.1%) were correctly assessed as probably benign, resulting in a negative predictive value of 99.1% (95% CI, 94.99-99.98%). Histopathology was requested by the patient or referring physician in 44 patients. Of these, 43 (39.8%) lesions were classified as benign and one (0.9%) as malignant. There were no changes evident in any of the remaining 64 (59.2%) lesions during follow-up (range, 2-9 years). CONCLUSION In MRI-detected probably benign (BI-RADS 3) lesions, the malignancy rate is low and within the accepted cancer rate for mammographically or sonographically detected BI-RADS 3 lesions. Short-term follow-up MRI at intervals of 6, 12, and 24 months in MRI BI-RADS 3 lesions remains a strong tool with which to detect suspicious lesions. Interval changes in size, morphology, or enhancement are regarded as indicative of malignancy.

Quantitative apparent diffusion coefficient measurements obtained by 3-Tesla MRI are correlated with biomarkers of bladder cancer proliferative activity.

Purpose To investigate the association between Apparent Diffusion Coefficient (ADC) values and cell cycle and proliferative biomarkers (p53, p21, Ki67,) in order to establish its potential role as a noninvasive biomarker for prediction of cell cycle, proliferative activity and biological aggressiveness in bladder cancer. Materials and Methods Patients with bladder cancer who underwent 3,0 Tesla DW-MRI of the bladder before TUR-B or radical cystectomy were eligible for this prospective IRB-approved study. Histological specimen were immunohistochemically stained for the following markers: p53, p21 and ki67. Two board-certified uropathologists reviewed the specimens blinded to DW-MRI results. Histological grade and T-stage were classified according to the WHO 2004 and the 2009 TNM classification, respectively. Nonparametric univariate and multivariate statistics including correlation, logistic regression and ROC analysis were applied. Results Muscle invasive bladder cancer was histologically confirmed in 10 out of 41 patients. All examined tissue biomarkers were significantly correlated with ADC values (p<0.05, respectively). Based on multivariate analysis, p53 and ADC are both independent prognostic factors for muscle invasiveness of bladder cancer (>/ = T2). (p = 0.013 and p = 0.018). Conclusion ADC values are associated with cell cycle and proliferative biomarkers and do thereby reflect invasive and proliferative potential in bladder cancer. ADC and p53 are both independent prognostic factors for muscle invasiveness in bladder cancer.

Diffusion-weighted imaging of breast lesions: Region-of-interest placement and different ADC parameters influence apparent diffusion coefficient values

ObjectivesTo investigate the influence of region-of-interest (ROI) placement and different apparent diffusion coefficient (ADC) parameters on ADC values, diagnostic performance, reproducibility and measurement time in breast tumours.MethodsIn this IRB-approved, retrospective study, 149 histopathologically proven breast tumours (109 malignant, 40 benign) in 147 women (mean age 53.2) were investigated. Three radiologists independently measured minimum, mean and maximum ADC, each using three ROI placement approaches:1 – small 2D-ROI, 2 – large 2D-ROI and 3 – 3D-ROI covering the whole lesion. One reader performed all measurements twice. Median ADC values, diagnostic performance, reproducibility, and measurement time were calculated and compared between all combinations of ROI placement approaches and ADC parameters.ResultsMedian ADC values differed significantly between the ROI placement approaches (p < .001). Minimum ADC showed the best diagnostic performance (AUC .928–.956), followed by mean ADC obtained from 2D ROIs (.926–.94). Minimum and mean ADC showed high intra- (ICC .85–.94) and inter-reader reproducibility (ICC .74–.94). Median measurement time was significantly shorter for the 2D ROIs (p < .001).ConclusionsROI placement significantly influences ADC values measured in breast tumours. Minimum and mean ADC acquired from 2D-ROIs are useful for the differentiation of benign and malignant breast lesions, and are highly reproducible, with rapid measurement.Key Points• Region of interest placement significantly influences apparent diffusion coefficient of breast tumours.• Minimum and mean apparent diffusion coefficient perform best and are reproducible.• 2D regions of interest perform best and provide rapid measurement times.

Diffusion-weighted MRI of breast lesions: a prospective clinical investigation of the quantitative imaging biomarker characteristics of reproducibility, repeatability, and diagnostic accuracy.

Diffusion‐weighted MRI (DWI) provides insights into tissue microstructure by visualization and quantification of water diffusivity.

A simple classification system (the Tree flowchart) for breast MRI can reduce the number of unnecessary biopsies in MRI-only lesions

AbstractObjectivesTo assess whether using the Tree flowchart obviates unnecessary magnetic resonance imaging (MRI)-guided biopsies in breast lesions only visible on MRI.MethodsThis retrospective IRB-approved study evaluated consecutive suspicious (BI-RADS 4) breast lesions only visible on MRI that were referred to our institution for MRI-guided biopsy. All lesions were evaluated according to the Tree flowchart for breast MRI by experienced readers. The Tree flowchart is a decision rule that assigns levels of suspicion to specific combinations of diagnostic criteria. Receiver operating characteristic (ROC) curve analysis was used to evaluate diagnostic accuracy. To assess reproducibility by kappa statistics, a second reader rated a subset of 82 patients.ResultsThere were 454 patients with 469 histopathologically verified lesions included (98 malignant, 371 benign lesions). The area under the curve (AUC) of the Tree flowchart was 0.873 (95% CI: 0.839–0.901). The inter-reader agreement was almost perfect (kappa: 0.944; 95% CI 0.889–0.998). ROC analysis revealed exclusively benign lesions if the Tree node was ≤2, potentially avoiding unnecessary biopsies in 103 cases (27.8%).ConclusionsUsing the Tree flowchart in breast lesions only visible on MRI, more than 25% of biopsies could be avoided without missing any breast cancer.Key Points• The Treeflowchart may obviate >25% of unnecessary MRI-guided breast biopsies.• This decrease in MRI-guided biopsies does not cause any false-negative cases. • The Treeflowchart predicts 30.6% of malignancies with >98% specificity. • The Tree’shigh specificity aids in decision-making after benign biopsy results.

Clinical application of Acoustic Radiation Force Impulse Imaging with Virtual Touch IQ in breast ultrasound: diagnostic performance and reproducibility of a new technique

Background Virtual Touch IQ (VTIQ) is a novel technique of quantitative sonoelastography that applies acoustic radiation force impulse (ARFI). Purpose To evaluate breast ARFI imaging with VTIQ in the clinical setting, with regard to reproducibility and diagnostic performance, and to specify cutoff limits for the differentiation of benign and malignant lesions. Material and Methods This retrospective study included 83 patients with 85 breast lesions (51 benign, 34 malignant) who received ARFI imaging with VTIQ. Two independent ARFI measurements of each lesion were performed and shear wave velocities (SWV) of the lesion and the adjacent tissues were measured. A lesion-to-fat velocity ratio (L/F Ratio) was calculated for each lesion. Diagnostic performance of SWV measurements and L/F Ratios was evaluated with receiver operating curve (ROC) analysis. The intraclass correlation coefficient and Bland–Altman plots were used to evaluate measurement reproducibility. Results All measurements showed equal diagnostic performance, as measured by the area under the ROC curve (0.853 for SWV, 0.882 for the L/F Ratio). At a cutoff value of 3.23 m/s, sensitivity and specificity were 82.4% and 80.4%, respectively. An L/F Ratio cutoff value of 2.23 revealed a sensitivity and specificity of 89.7% and 76.5%. The reproducibility of the SWV measurements was moderate (limits of agreement, 40.3–44.4%) and higher than that of the L/F Ratios (54.5–60.2%). Conclusion ARFI imaging with VTIQ is a novel, moderately reproducible, quantitative elastography technique, which provides useful information for the differentiation of benign and malignant breast lesions in the clinical setting.

MR arthrography of the shoulder: Do we need local anesthesia?

PURPOSE To assess pain intensity with and without subcutaneous local anesthesia prior to intraarticular administration of contrast medium for magnetic resonance arthrography (MRa) of the shoulder. MATERIALS AND METHODS This single-center study was conducted after an IRB waiver of authorization, between January 2010 and December 2012. All patients provided written, informed consent for the procedure. Our prospectively populated institutional database was searched, based on our inclusion criteria. There were 249 outpatients (178 men and 71 women; mean age, 44.4 years ± 14.6; range, 15-79) who underwent MRa and were enrolled in this study. Patients were excluded if they had received surgery of the shoulder before MRa, had undergone repeated MRa of the same shoulder, and/or had undergone MRa of both shoulders on the same day. Patients were randomly assigned into one of three groups. Patients in group A (n=61) received skin infiltration with local anesthesia. Patients in control group B (n=92) and group C (n=96) did not receive local anesthesia. Pain levels were immediately assessed after the injection for MRa using a horizontal visual analog scale (VAS) that ranged from 0 to 10. To compare the pain scores of the three groups for male and female patients, a two-way analysis of variance was used. A p-value equal to or less than 0.05 was considered to indicate a significant result. RESULTS Patients who received local anesthesia (group A) showed a mean pain level on the VAS of 2.6 ± 2.3. In patients who did not receive local anesthetics (groups B and C), a mean pain level on the VAS of 2.6 ± 2.2 and 2.7 ± 2.4 were detected, respectively. Between the three groups, no statistically significant difference in pain intensity was detected (p=.960). There were significant differences in subjective pain perception between men and women (p=.009). Moreover, the sex difference in all three groups was equal (p=.934). CONCLUSION Local anesthesia is not required to lower a patients pain intensity when applying intra-articular contrast media for MR arthrography of the shoulder. This could result in reduced costs and a reduced risk of adverse reactions, without an impact on patient comfort.