Susanne Wienbeck

Optimal Systolic and Diastolic Reconstruction Windows for Coronary CT Angiography Using Dual-Source CT

OBJECTIVE The purpose of this study was to determine the position of the optimal systolic and diastolic reconstruction intervals for coronary CT angiography using dual-source CT. SUBJECTS AND METHODS In 90 patients, coronary dual-source CT angiography was performed without beta-blocking agents. Data were reconstructed in 5% steps throughout the R-R interval. Two independent readers selected optimal systolic and diastolic reconstruction windows for each major coronary vessel--the right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCX)--using a 3D viewer and volume-rendering displays. The motion score for each vessel was graded from 1 (no motion artifacts) to 5 (severe motion artifacts over entire vessel). RESULTS The average heart rate of all patients was 68.7 beats per minute (bpm) (range, 43-119 bpm). The median optimal systolic reconstruction windows were at 35%, 30%, and 35% for the RCA, LAD, and LCX, respectively. The median optimal diastolic reconstruction window was at 75% for all vessels. The mean motion scores (+/- SD) in the systolic reconstructions were 1.9 +/- 0.8 (RCA), 1.7 +/- 0.5 (LAD), and 2.0 +/- 0.6 (LCX). The mean motion scores for the diastolic reconstructions were 1.7 +/- 0.9, 1.5 +/- 0.6, and 1.6 +/- 0.7, respectively. In patients with a heart rate of < 70 bpm, motion scores were significantly lower in diastole versus systole (1.3 +/- 0.4 and 1.9 +/- 0.5, respectively; p < 0.01). In most patients with a heart rate of > 80 bpm, motion scores were lower in systolic than in diastolic reconstructions (2.1 +/- 0.6 and 2.6 +/- 0.8, respectively; p < 0.05). CONCLUSION Using dual-source CT, the overall optimal reconstruction window is at 75% of the R-R interval in patients with low or intermediate heart rates. In patients with heart rates of > 80 bpm, systolic reconstructions often yield superior image quality compared with diastolic reconstructions.

Automated Threshold-Based 3D Segmentation Versus Short-Axis Planimetry for Assessment of Global Left Ventricular Function with Dual-Source MDCT

OBJECTIVE The purpose of this study was to evaluate software for threshold-based 3D segmentation of the left ventricle in comparison with traditional 2D short axis-based planimetry (Simpson method) for measurement of left ventricular (LV) volume and global function with state-of-the-art dual-source CT. SUBJECTS AND METHODS Fifty patients with known or suspected coronary artery disease underwent coronary CT angiography. LV end-diastolic, end-systolic, and stroke volumes and ejection fraction were determined from axial images to which 3D segmentation had been applied and from short-axis reformations from 2D planimetry. Interobserver variability was assessed for both approaches. RESULTS Threshold-based 3D LV segmentation had excellent correlation with 2D short-axis results (end-diastolic volume, R = 0.99; end-systolic volume, R = 0.99; stroke volume, R = 0.90; ejection fraction, R = 0.97; p < 0.0001). Bland-Altman analyses revealed systematic underestimation of LV end-diastolic volume (-7.4 +/- 8.9 mL) and LV end-systolic volume (-7.0 +/- 4.4 mL) with the 3D segmentation approach and 2.8 +/- 3.3% overestimation of LV ejection fraction. Interobserver variation with 3D segmentation analysis was significantly (p < 0.001) less (e.g., LV ejection fraction, 0.1 +/- 1.7%) than with the 2D technique, and mean analysis time was significantly shorter (172 +/- 20 vs 248 +/- 29 seconds; p < 0.05). CONCLUSION Automated threshold-based 3D segmentation enables accurate and reproducible dual-source CT assessment of LV volume and function with excellent correlation with results of 2D short-axis analysis. Exclusion of papillary muscles from LV volume results in small systematic differences in quantitative values.

Review of clinical studies and first clinical experiences with a commercially available cone-beam breast CT in Europe

The dedicated cone-beam breast computed tomography (CBBCT) is a new and promising imaging modality which provides isotropic, 3D images of the breast with high spatial and contrast resolution. Non-contrast and contrast-enhanced CBBCT (CE-CBBCT) was superior to mammography for the visualization of breast masses, especially in patients with dense breast tissue. CE-CBBCT accurately detects DCIS and distinguishes it from benign causes of microcalcifications when compared with non-contrast CBBCT and mammography. The purpose of this report is to describe the technology and its possible indications, and to present the first results from recent clinical studies, illustrating these with our own image examples.

The role of cone-beam breast-CT for breast cancer detection relative to breast density

ObjectivesTo evaluate the impact of breast density on the diagnostic accuracy of non-contrast cone-beam breast computed tomography (CBBCT) in comparison to mammography for the detection of breast masses.MethodsA retrospective study was conducted from August 2015 to July 2016. Fifty-nine patients (65 breasts, 112 lesions) with BI-RADS, 5th edition 4 or 5 assessment in mammography and/or ultrasound of the breast received an additional non-contrast CBBCT. Independent double blind reading by two radiologists was performed for mammography and CBBCT imaging. Sensitivity, specificity and AUC were compared between the modalities.ResultsBreast lesions were histologically examined in 85 of 112 lesions (76%). The overall sensitivity for CBBCT (reader 1: 91%, reader 2: 88%) was higher than in mammography (both: 68%, p<0.001), and also for the high-density group (p<0.05). The specificity and AUC was higher for mammography in comparison to CBBCT (p<0.05 and p<0.001). The interobserver agreement (ICC) between the readers was 90% (95% CI: 86-93%) for mammography and 87% (95% CI: 82-91%) for CBBCT.ConclusionsCompared with two-view mammography, non-contrast CBBCT has higher sensitivity, lower specificity, and lower AUC for breast mass detection in both high and low density breasts.Key Points• Overall sensitivity for non-contrast CBBCT ranged between 88%-91%.• Sensitivity was higher for CBBCT than mammography in both density types (p<0.001).• Specificity was higher for mammography than CBBCT in both density types (p<0.05).• AUC was larger for mammography than CBBCT in both density types (p<0.001).

Magnetic resonance imaging findings of intramammary metastases

The purpose of this study was to identify magnetic resonance imaging (MRI) findings of intramammary metastases (IM). We identified 8 cases with IM, which were investigated by breast MRI (1.5T). In every case, the diagnosis of IM was proven histopathologically on breast biopsy specimens. Overall, 187 IM were identified. IM had inconsistent MRI features, which cannot be clearly classify as benign or malignant. IM should be taken into consideration in the differential diagnosis of breast lesions to avoid possible misinterpretations.

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

ObjectivesTo 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).MethodsThis 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.ResultsA 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).ConclusionsCBBCT 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.

Contrast Enhancement on Cone-Beam Breast-CT for Discrimination of Breast Cancer Immunohistochemical Subtypes

PURPOSE: To evaluate whether contrast enhancement on cone-beam breast-CT (CBBCT) could aid in discrimination of breast cancer subtypes and receptor status. METHODS: This study included female patients age >40 years with malignant breast lesions identified on contrast-enhanced CBBCT. Contrast enhancement of malignant breast lesions was standardized to breast fat tissue contrast enhancement. All breast lesions were approved via image-guided biopsy or surgery. Immunohistochemical staining was conducted for expression of estrogen (ER), progesterone (PR), human epidermal growth factor receptor-2 (HER2) and Ki-67 index. Contrast enhancement of breast lesions was correlated with immunohistochemical breast cancer subtypes (Luminal A, Luminal B, HER2 positive, triple negative), receptor status and Ki-67 expression. RESULTS: Highest contrast enhancement was seen for Luminal A lesions (93.6 HU) compared to Luminal B lesions (47.6 HU, P = .002), HER2 positive lesions (83.5 HU, P = .359) and triple negative lesions (45.3 HU, P = .005). Contrast enhancement of HER2 positive lesions was higher than Luminal B lesions (P = .044) and triple negative lesions (P = .039). No significant difference was evident between Luminal B and triple negative lesions (P = .439). Lesions with high Ki-67 index showed lower contrast enhancement than those with low Ki-67 index (P = .0043). ER, PR and HER2 positive lesions demonstrated higher contrast enhancement than their receptor negative counterparts, although differences did not reach statistical significance (P = .1714; P = .3603; P = .2166). CONCLUSIONS: Contrast enhancement of malignant breast lesions on CBBCT correlates with immunohistochemical subtype and proliferative potential. Thereby, CBBCT might aid in selecting individualized treatment strategies for breast cancer patients based on pre-operative imaging.

Cone-beam Breast Computed Tomography: CT Density Does Not Reflect Proliferation Potential and Receptor Expression of Breast Carcinoma.

PURPOSE: Recently, cone-beam breast computed tomography (CBCT) is established for the breast investigation. The purpose of the present study was to investigate possible associations between CBCT findings and histopathological features in breast cancer. METHODS: Overall, 59 female patients, mean age of 64.6 years with histological proven breast cancer were included into the study. In all cases, non-contrast CBCT examination was done. The diagnosis of the identified lesions was confirmed histologically by biopsy. Immunohistochemical staining against estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 was performed for every lesion. Collected data were evaluated by means of descriptive statistics. Spearmans correlation coefficient was used to analyze the association between CT density and Ki-67 values. P values <0.05 were taken to indicate statistical significance in all instances. RESULTS: The size of the lesion varied from 2.7 to 90.0, mean size, 15.88 ± 13.0 mm. The mean value of CT density of the lesions was 63.95 ± 38.18 HU. The density tended to be higher in tubular carcinoma. Correlation analysis identified no significant correlations between CT density and Ki-67 level (r = −0.031, P = .784). There were no statistically significant differences of CT density between tumors with different receptor status. CONCLUSIONS: No significant associations between CT density and receptor status in breast cancer. Tubular carcinoma tended to have higher CT density in comparison to other subtypes of breast carcinomas.

Radiological imaging characteristics of intramammary hematological malignancies: results from a german multicenter study

To assess radiological procedures and imaging characteristics in patients with intramammary hematological malignancies (IHM). Radiological imaging studies of histopathological proven IHM cases from ten German University affiliated breast imaging centers from 1997–2012 were retrospectively evaluated. Imaging modalities included ultrasound (US), mammography and magnetic resonance imaging (MRI). Two radiologists blinded to the histopathological diagnoses independently assessed all imaging studies. Imaging studies of 101 patients with 204 intramammary lesions were included. Most patients were women (95%) with a median age of 64 years. IHM were classified as Non Hodgkin lymphoma (77.2%), plasmacytoma (11.9%), leukemia (9.9%), and Hodgkin lymphoma (1%). The mean lesion size was 15.8 ± 10.1 mm. Most IHM presented in mammography as lesions with comparable density to the surrounding tissue, and a round or irregular shape with indistinct margins. On US, most lesions were of irregular shape with complex echo pattern and indistinct margins. MRI shows lesions with irregular or spiculated margins and miscellaneous enhancement patterns. Using US or MRI, IHM were more frequently classified as BI-RADS 4 or 5 than using mammography (96.2% and 89.3% versus 75.3%). IHM can present with miscellaneous radiological patterns. Sensitivity for detection of IHM lesions was higher in US and MRI than in mammography.