[Use of contrast-enhanced mammography for diagnosis of breast cancer]. / Einsatz der kontrastmittelverstärkten Mammographie in der Brustkrebsdiagnostik.

BACKGROUND: Contrast-enhanced mammography (CEM) is an imaging method that is able to improve visualization of intramammary tumors after peripheral venous administration of an iodine-containing contrast medium (ICM). OBJECTIVES AND METHODS: The current significance of CEM is discussed. RESULTS: Studies were able to show an advantage of CEM in the diagnosis of breast cancer compared to mammography, especially for women with dense breasts. Indications for CEM currently depend on the availability of magnetic resonance imaging (MRI). If MRI is available, CEM is indicated in those cases when MRI cannot be performed. Use of CEM for breast cancer screening is currently viewed critically. This view can change when results and updated assessments of large CEM studies in Europe and USA become available. Patients must be informed about the use of an ICM. As ICM administration for CEM is carried out in a similar manner to established imaging methods, the authors expect the use of ICM for CEM to be unproblematic as long as general contraindications are adhered to. CONCLUSIONS: In the future, CEM could have greater importance for the diagnosis of breast cancer, as this imaging method has diagnostic advantages compared to conventional mammography. A great advantage of CEM is its availability. For those who use breast MRI, CEM is helpful when MRI is not feasible due to contraindications or other reasons.

Comparison between cone-beam breast-CT and full-field digital mammography for microcalcification detection depending on breast density.

The purpose of this study was to evaluate the impact of breast density on the diagnostic performance of cone-beam breast-CT (CBBCT) in comparison to full-field digital mammography (FFDM) for the detection of microcalcifications. This retrospective IRB-approved study was conducted between December 2015 and March 2017 and enrolled 171 women with Breast Imaging Reporting and Data System category 4 or 5 lesions on FFDM and additional CBBCT; 56 of which were ineligible. The inclusion was restricted to 83 women (90 breasts, 90 lesions) with microcalcifications. All lesions underwent histology or were monitored by FFDM and a clinical examination at least 2 years after enrollment. Two breast radiologists independently read each data set twice. Sensitivity, specificity and area under the curve were compared between the modalities. Thirty-two breasts (35.5%) were grouped as non-dense breasts (American College of Radiology types a/b) and 58 breasts (64.5%) as dense breasts (American College of Radiology types c/d). Histopathological assessment was performed in 61 of 90 breast lesions (32 malignant, 1 high-risk and 28 benign). Area under the curve was larger for FFDM than for CBBCT (P = .085). The sensitivity was significantly higher for FFDM compared to CBBCT (P = .009). The specificity showed no significant differences comparing FFDM (both readers: 0.62) versus CBBCT (reader 1: 0.76, reader 2: 0.60; P = .192). Inter-observer-reliability on BI-RADS readings was almost perfect for FFDM and moderate for CBBCT (κ = 0.84, κ = 0.54, respectively). Intra-observer agreement was substantial to almost perfect for both methods and readers. Compared with FFDM, CBBCT demonstrated non-comparable results for microcalcification detection in dense and non-dense breasts.

Ex Vivo Study of Artifacts Caused by Breast Tissue Markers with Different 1.5 Tesla and 3 Tesla MRI Scanners - A Bicentric Study.

RATIONALE AND OBJECTIVES: The purpose of our study was to evaluate magnetic resonance (MR) artifacts related to breast tissue markers in breast imaging procedures. MATERIALS AND METHODS: In this bicentric prospective ex vivo study 10 different commercially available markers were measured in self-made breast phantoms. Breast tissue markers varying in marker size, composition, and shape were evaluated. MR imaging (MRI) scans were performed on 1.5 Tesla (T) and 3 T scanners from 2 different vendors, using dedicated breast coils. Three different sequences (T1-weighted images with and without fat saturation, T2-weighted images) were acquired in axial and coronal view. Three blinded readers electronically measured the artifact length. RESULTS: All markers caused artifacts in MRI. The largest median artifact length was 10.4 mm, interquartile range (IQR 9.4-11.0 mm), the smallest 4.8 mm (IQR 4.5-5.2 mm). Relative artifact length (quotient artifact length in mm/real physical length of the marker) ranged between 0.9 (IQR 0.9-1.2) and 3.0 (IQR 2.8-3.4). Mean artifact length was higher for metallic markers (10.2 mm; IQR 8.7-11.5 mm) compared to metallic markers with nonmetallic coating (7.7 mm; IQR 6.3-10.2 mm) and nonmetallic marker (7.6 mm; IQR 5.9-10.0 mm); all p < 0.0001. Artifact size was higher in coronal in comparison to axial view; p < 0.05. The results were comparable between the different field strengths, the sites and sequences; p > 0.05. Interobserver agreement was excellent (ntraclass correlation coefficient = 0.83). CONCLUSION: Artifacts are necessary in the detection and localization of breast tissue markers, but could also limit the interpretation of MRI due to the possibility of masking the residual tumor after biopsy. This artifact size varies among the different clips evaluated. It depends on marker composition and scan direction but is not influenced by image sequence, field strength or scanner type.

Comparison of propagation-based CT using synchrotron radiation and conventional cone-beam CT for breast imaging.

OBJECTIVES: To evaluate and compare the image quality of propagation-based phase-contrast computed tomography (PB-CT) using synchrotron radiation and conventional cone-beam breast computed tomography (CBBCT) based on various radiological image quality criteria. METHODS: Eight excised breast tissue samples of various sizes and containing different lesion types were scanned using PB-CT at a synchrotron facility and using CBBCT at a university-affiliated breast imaging centre. PB-CT scans were performed at two different mean glandular dose (MGD) levels: standard (5.8 mGy) and low (1.5 mGy), for comparison with CBBCT scans at the standard MGD (5.8 mGy). Image quality assessment was carried out using six quality criteria and six independent medical imaging experts in a reading room with mammography workstations. The interobserver agreement between readers was evaluated using intraclass correlation coefficient (ICC), and image quality was compared between the two breast imaging modalities using the area under the visual grading characteristic curve (AUCVGC). RESULTS: Interobserver agreement between the readers showed moderate reliability for five image criteria (ICC: ranging from 0.488 to 0.633) and low reliability for one criterion (image noise) (ICC 0.307). For five image quality criteria (overall quality, perceptible contrast, lesion sharpness, normal tissue interfaces, and calcification visibility), both standard-dose PB-CT images (AUCVGC 0.958 to 1, p ≤ .05) and low dose PB-CT images (AUCVGC 0.785 to 0.834, p ≤ .05) were of significantly higher image quality than standard-dose CBBCT images. CONCLUSIONS: Synchrotron-based PB-CT can achieve a significantly higher radiological image quality at a substantially lower radiation dose compared with conventional CBBCT. KEY POINTS: • PB-CT using synchrotron radiation results in higher image quality than conventional CBBCT for breast imaging. • PB-CT using synchrotron radiation requires a lower radiation dose than conventional CBBCT for breast imaging. • PB-CT can help clinicians diagnose patients with breast cancer.

Clinical and imaging features of myeloid sarcoma: a German multicenter study.

BACKGROUND: Myeloid sarcoma (MS), also known as chloroma, is an extramedullary manifestation of malignant primitive myeloid cells. Previously, only small studies investigated clinical and imaging features of MS. The purpose of this study was to elucidate clinical and imaging features of MS based upon a multicenter patient sample. METHODS: Patient records of radiological databases of 4 German university hospitals were retrospectively screened for MS in the time period 01/2001 and 06/2019. Overall, 151 cases/76 females (50.3%) with a mean age of 55.5 ± 15.1 years and 183 histopathological confirmation or clinically suspicious lesions of MS were included into this study. The underlying hematological disease, localizations, and clinical symptoms as well as imaging features on CT and MRI were investigated. RESULTS: In 15 patients (9.9% of all 151 cases) the manifestation of MS preceded the systemic hematological disease. In 43 cases (28.4%), first presentation of MS occurred simultaneously with the initial diagnosis of leukemia, and 92 (60.9%) patients presented MS after the initial diagnosis. In 37 patients (24.5%), the diagnosis was made incidentally by imaging. Clinically, cutaneous lesions were detected in 35 of 151 cases (23.2%). Other leading symptoms were pain (n = 28/151, 18.5%), neurological deficit (n = 27/151, 17.9%), swelling (n = 14/151, 9.3%) and dysfunction of the affected organ (n = 10/151, 6.0%). Most commonly, skin was affected (n = 30/151, 16.6%), followed by bone (n = 29/151, 16.0%) and lymphatic tissue (n = 21/151, 11.4%). Other localizations were rare. On CT, most lesions were homogenous. On T2-weighted imaging, most of the lesions were hyperintense. On T1-weighted images, MS was hypointense in n = 22/54 (40.7%) and isointense in n = 30/54 (55.6%). A diffusion restriction was identified in most cases with a mean ADC value of 0.76 ± 0.19 × 10- 3 mm2/s. CONCLUSIONS: The present study shows clinical and imaging features of MS based upon a large patient sample in a multicenter design. MS occurs in most cases meta-chronous to the hematological disease and most commonly affects the cutis. One fourth of cases were identified incidentally on imaging, which needs awareness of the radiologists for possible diagnosis of MS.

Breast lesion size assessment in mastectomy specimens: Correlation of cone-beam breast-CT, digital breast tomosynthesis and full-field digital mammography with histopathology.

To compare the accuracy of breast lesion size measurement of cone-beam breast-CT (CBBCT), digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM).Patients scheduled for mastectomy due to at least 1 malignant breast lesion were included. Mastectomy specimens were examined by CBBCT, DBT, FFDM, and histopathology.A total of 94 lesions (40 patients) were included. Histopathological analyses revealed 47 malignant, 6 high-risk, and 41 benign lesions. Mean histopathological lesion size was 20.8 mm (range 2-100). Mean absolute size deviation from histopathology was largest for FFDM (5.3 ±â€Š6.7 mm) and smallest for CBBCT 50 mA, high-resolution mode (4.3 ±â€Š6.7 mm). Differences between imaging modalities did not reach statistical significance (P = .85).All imaging methods tend to overestimate breast lesion size compared to histopathological gold standard. No significant differences were found regarding size measurements, although in tendency CBBCT showed better lesion detection and cT classification over FFDM.

Pre- and post-contrast versus post-contrast cone-beam breast CT: can we reduce radiation exposure while maintaining diagnostic accuracy?

OBJECTIVES: To evaluate whether post-contrast cone-beam breast CT (CBBCT) alone is comparable to the current standard of combined pre- and post-contrast CBBCT regarding diagnostic accuracy and superior regarding radiation exposure. MATERIAL AND METHODS: This study included 49 women (61 breasts) with median age 57.9 years and BI-RADS 4/5 lesions diagnosed on mammography/ultrasound in density type c/d breasts. Two radiologists rated post-contrast CBBCT and pre- and post-contrast CBBCT with subtraction images on the BI-RADS scale separately for calculation of inter- and intra-observer agreement and in consensus for diagnostic accuracy assessment. Sensitivity, specificity, and area under the curve (AUC) were compared via McNemar test and DeLong method, respectively. Subtraction imaging misregistration were measured from 1 (no artifacts) to 4 (artifacts with width > 4 mm). RESULTS: A total of 100 lesion (51 malignant; 6 high risk; 43 benign) were included. AUC, sensitivity, and specificity showed no significant differences comparing post-contrast CBBCT alone versus pre- and post-contrast CBBCT (AUC 0.84 vs. 0.83, p = 0.643; sensitivity 0.89 vs. 0.85, p = 0.158; specificity 0.73 vs. 0.76, p = 0.655). Inter- and intra-observer agreement was excellent (intra-class correlation coefficient ICC = 0.76, ICC = 0.83, respectively). Radiation dose was significantly lower for post-contrast CBBCT alone versus pre- and post-contrast CBBCT (median average glandular radiation dose 5.9 mGy vs. 11.7 mGy, p < 0.001). High-degree misregistrations were evident in the majority of subtraction images (level 1/2/3/4 16.9%/27.1%/16.9%/39%), in particular for bilateral exams (3.2%/29.2%/8.3%/58.3%). CONCLUSION: Diagnostic accuracy of post-contrast CBBCT alone is comparable to pre- and post-contrast CBBCT in type c/d breasts, while yielding a significant twofold radiation dose reduction. KEY POINTS: • The diagnostic accuracy of post-contrast CBBCT alone is comparable to dual acquisition of pre- and post-contrast CBBCT. • Acquisition of the post-contrast CBBCT scan alone reduces radiation exposure compared to pre- and post-contrast CBBCT, thus countering one of the main limitations of CBBCT. • High-degree misregistration artifacts limit the interpretation of subtraction images from pre- and post-contrast CBBCT studies.

Diagnostic accuracy of cone-beam breast computed tomography: a systematic review and diagnostic meta-analysis.

PURPOSE: To review the published evidence on cone-beam breast computed tomography (CBBCT) and summarize its diagnostic accuracy for breast lesion assessment. MATERIALS AND METHODS: A systematic literature search was conducted using the EMBASE, MEDLINE and CENTRAL libraries. Studies were included if reporting sensitivity and specificity for discrimination of benign and malignant breast lesions via breast CT. Sensitivity and specificity were jointly modeled using a bivariate approach calculating summary areas under the receiver-operating characteristics curve (AUC). All analyses were separately performed for non-contrast and contrast-enhanced CBBCT (NC-CBBCT, CE-CBBCT). RESULTS: A total of 362 studies were screened, of which 6 with 559 patients were included. All studies were conducted between 2015 and 2018 and evaluated female participants. Four of six studies included dense and very dense breasts with a high proportion of microcalcifications. For NC-CBBCT, pooled sensitivity was 0.789 (95% CI: 0.66-0.89) and pooled specificity was 0.697 (95% CI: 0.471-0.851), both showing considerable significant between-study heterogeneity (I2 = 89.4%, I2 = 94.7%, both p < 0.001). Partial AUC for NC-CBBCT was 0.817. For CE-CBBCT, pooled sensitivity was 0.899 (95% CI: 0.785-0.956) and pooled specificity was 0.788 (95% CI: 0.709-0.85), both exhibiting non-significant moderate between-study heterogeneity (I2 = 57.3%, p = 0.0527; I2 = 53.1%, p = 0.0738). Partial AUC for CE-CBBCT was 0.869. CONCLUSION: The evidence available for CBBCT tends to show superior diagnostic performance for CE-CBBCT over NC-CBBCT regarding sensitivity, specificity and partial AUC. Diagnostic accuracy of CE-CBBCT was numerically comparable to that of breast MRI with meta-analyses reporting sensitivity of 0.9 and specificity of 0.72. KEY POINTS: • CE-CBBCT rather than NC-CBBCT should be used for assessment of breast lesions for its higher diagnostic accuracy. • CE-CBBCT diagnostic performance was comparable to published results on breast MRI, thus qualifying CE-CBBCT as a potential imaging alternative for patients with MRI contraindications.

The "rapid atrial swirl sign" for assessing central venous catheters: Performance by medical residents after limited training.

RATIONALE: Central venous catheter (CVC) placement is a standard procedure in critical care. Ultrasound guidance during placement is recommended by current guidelines, but there is no consensus on the best method for evaluating the correct CVC tip position. Recently, the "rapid atrial swirl sign" (RASS) has been investigated in a limited number of studies. OBJECTIVES: We performed a prospective diagnostic accuracy study of focused echocardiography for the evaluation of CVC tip position in our medical ICU and IMC units. METHODS: We performed a prospective diagnostic accuracy study in 100 patients admitted to the Intensive Care Unit and Intermediate Care Unit at our center. The first 10 subjects were assessed by one staff physician investigator (reference cohort), the remaining 90 patients by different residents (test cohort). All patients received a post-procedural chest radiograph (CXR) as gold standard. CVC placement was assessed with focused echocardiography performed by residents after a short training session. A rapid opacification of the right atrium (RASS) after injection of 10 mL of normal saline was regarded as "positive", flush after more than two seconds was defined as "delayed", no flush was a "negative" test result. MEASUREMENTS AND MAIN RESULTS: Overall sensitivity of the RASS was 100% (95% CI 73.54-100%), specificity was 94.32% (CI 87.24-98.13%). Positive and negative predictive values were 70.59% (CI 44.04-89.09%) and 100% (CI 95.65-100%), respectively. Median time for echocardiographic testing was 5 minutes (1-28) in the whole cohort, CXRs were available after 49.5 minutes (13-254). Interrater agreement of the RASS was 0.77 (Cohen's kappa), Measurement of CVC tip position was not different between two observers. Test characteristics were similar among differently experienced residents. CONCLUSIONS: Presence of the RASS by focused echocardiography showed excellent sensitivity and specificity and was equally performed by residents after minimal training. In patients with a positive RASS, routine CXR can be safely omitted, reducing time, costs and radiation exposure. A negative RASS should lead to a search for misplaced catheters. CLINICAL TRIAL REGISTRATION: The study was registered with www.clinicaltrials.gov (NCT02661607).

Novel Breast Imaging and Machine Learning: Predicting Breast Lesion Malignancy at Cone-Beam CT Using Machine Learning Techniques.

OBJECTIVE: The purpose of this study is to evaluate the diagnostic performance of machine learning techniques for malignancy prediction at breast cone-beam CT (CBCT) and to compare them to human readers. SUBJECTS AND METHODS: Five machine learning techniques, including random forests, back propagation neural networks (BPN), extreme learning machines, support vector machines, and K-nearest neighbors, were used to train diagnostic models on a clinical breast CBCT dataset with internal validation by repeated 10-fold cross-validation. Two independent blinded human readers with profound experience in breast imaging and breast CBCT analyzed the same CBCT dataset. Diagnostic performance was compared using AUC, sensitivity, and specificity. RESULTS: The clinical dataset comprised 35 patients (American College of Radiology density type C and D breasts) with 81 suspicious breast lesions examined with contrast-enhanced breast CBCT. Forty-five lesions were histopathologically proven to be malignant. Among the machine learning techniques, BPNs provided the best diagnostic performance, with AUC of 0.91, sensitivity of 0.85, and specificity of 0.82. The diagnostic performance of the human readers was AUC of 0.84, sensitivity of 0.89, and specificity of 0.72 for reader 1 and AUC of 0.72, sensitivity of 0.71, and specificity of 0.67 for reader 2. AUC was significantly higher for BPN when compared with both reader 1 (p = 0.01) and reader 2 (p < 0.001). CONCLUSION: Machine learning techniques provide a high and robust diagnostic performance in the prediction of malignancy in breast lesions identified at CBCT. BPNs showed the best diagnostic performance, surpassing human readers in terms of AUC and specificity.

Contrast-enhanced cone-beam breast-CT (CBBCT): clinical performance compared to mammography and MRI.

OBJECTIVES: To evaluate the diagnostic accuracy of contrast-enhanced (CE) cone-beam breast computed tomography (CBBCT) in dense breast tissue and compare it to non-contrast (NC) CBBCT, mammography (MG) and magnetic resonance imaging (MRI). METHODS: This prospective institutional review board-approved study included 41 women (52 breasts) with American College of Radiology (ACR) density types c or d and Breast Imaging Reporting and Data System (BI-RADS) 4 or 5 assessments in MG or ultrasound (US). Imaging modalities were independently evaluated by two blinded readers. RESULTS: A total of 100 lesions (51 malignant, 6 high-risk, and 43 benign) were identified. For readers 1/2, respectively, and p values comparing CE-CBBCT to other modalities: diagnostic accuracy (AUC) for CE-CBBCT was 0.83/0.77, for MRI 0.88/0.89 (p = 0.2272/0.002), for NC-CBBCT 0.73/0.66 (p = 0.038/ 0.0186) and for MG 0.69/0.64 (p = 0.081/0.0207). CE-CBBCT sensitivity (0.88/0.78) was 37-39% higher in comparison to MG (0.49/0.41, p < 0.001 both) but inferior to MRI (0.98/0.96, p = 0.0253/0.0027). CE-CBBCT specificity (0.71/0.71) was numerically higher compared to MRI (0.61/0.69, p = 0.0956/0.7389). CONCLUSIONS: CBBCT diagnostic performance varied with the respective reader and experience. CE-CBBCT improved AUC and sensitivity in comparison to MG and NC-CBBCT, and was comparable to MRI in dense breast tissue. In tendency, specificity was higher for CE-CBBCT than MRI. KEY POINTS: • CE-CBBCT diagnostic accuracy (AUC) was comparable to MRI in dense breasts. • CE-CBBCT improved sensitivity and AUC in comparison to MG and NC-CBBCT. • CE-CBBCT has inferior sensitivity but higher specificity than MRI. • CE-CBBCT is a potential imaging alternative for patients with MRI contraindications.

Contrast-enhanced cone-beam breast-CT: Analysis of optimal acquisition time for discrimination of breast lesion malignancy.

OBJECTIVE: To investigate the optimal acquisition time of contrast-enhanced cone-beam breast-CT (CBBCT) for best discrimination of breast lesion malignancy and whether contrast enhancement can aid in classification of tumor histology. MATERIAL AND METHODS: The study included patients with BI-RADS 4 or 5 lesions identified on mammography and/or ultrasound. All patients were examined by non-contrast (NC-CBBCT) and contrast-enhanced CBBCT (CE-CBBCT) at 2 and 3min after contrast media (CM) injection. Lesion enhancement of suspicious breast lesions was evaluated in corresponding CBBCT slices. RESULTS: A total of 31 patients with 57 breast lesions, 30 malignant and 27 benign, were included. Malignant breast lesions demonstrated higher contrast enhancement than benign breast lesions at both 2min and 3min CE-CBBCT (2min: 48.17 vs. 0.3 HU, p<0.001; 3min: 57.38 vs. 15.43 HU, p<0.001). Enhancement differences between malignant and benign breast lesions were largest at 2min CE-CBBCT. Ductal carcinoma in situ (DCIS) showed highest mean contrast enhancement among malignant breast lesions (100.93 HU at 3min CE-CBBCT, p=0.0314) compared to invasive carcinoma of no special type with DCIS component (55.82 HU at 3min CE-CBBCT) and invasive ductal carcinoma (52.31 HU at 3min CE-CBBCT). CONCLUSIONS: The contrast enhancement on CE-CBBCT best discriminates between malignant and benign breast lesions at 2min after CM injection. The enhancement has the potential to differentiate histopathological subtypes, with highest enhancement among malignant lesions seen for DCIS.

The Value of Quality-Assured Magnetic Resonance Imaging of the Breast for the Early Detection of Breast Cancer in Asymptomatic Women.

PURPOSE: The aim of this study was to evaluate the exclusive performance of quality-assured high-resolution breast magnetic resonance imaging (MRI) for early detection of breast cancer in a population of asymptomatic women. MATERIALS AND METHODS: A total of 1189 MRI examinations performed in 789 asymptomatic women (mean age, 51.1 years) were evaluated. All examinations were performed using open bilateral surface coil, dedicated compression device, and high spatial resolution (matrix, 512 × 512). Digital mammography was available for all participants. Assessment included density types, artifact level, and Breast Imaging Reporting and Data System classification. Evaluation was performed by 2 readers. In addition, a computer-assisted diagnosis (CAD) system was used for image assessment. RESULTS: Breast MRI showed density types I and II in 87.6% and artifacts categories III and IV in 3.1%. Study included 32 carcinomas (8 ductal carcinoma in situ, 24 invasive tumors). Both readers detected 29 of 32 correctly (sensitivity 90.6%). The variation between the readers was low (reader 1: specificity, 94.4% and positive predictive value (PPV), 25.7%; reader 2: specificity, 97.6% and PPV, 34.1%). Sensitivity of CAD was 62.5% (specificity, 84.4%; PPV, 5.2%). Digital mammography detected 13 of 32 carcinomas (sensitivity, 56.3%; specificity, 98.4%; PPV, 32.1%). CONCLUSIONS: The exclusive use of quality-assured breast MRI allows the early detection of breast cancer with a high sensitivity and specificity. The CAD analysis of MRI does not give additional information but shows results comparable with digital mammography.