RPS 1002a - Contrast-enhanced x-ray imaging of the breast

Purpose:

Comparative diagnostic efficiency of digital mammography, Ultrasound, and contrast-enhanced digital mammography (CEDM) in breast cancer detection among women with dense breast with histopathological diagnosis as the gold standard.

Methods and materials:

A prospective study on consecutive women >40 years with dense breast on conventional imaging who underwent CEDM and biopsy at our centre were included. Women with h/o pregnancy, renal insufficiency, or prior allergic reaction to iodinated contrast agent were excluded. On mammography and ultrasound, lesions were categorised based on ACR BI-RADS fifth edition. On CEDM, lesions were categorised based on the intensity and dynamic patterns of contrast enhancement. Moderate to intense enhancement with wash-out in delayed phase were considered malignant and lesions with no enhancement or progressive enhancement were considered benign lesions. Statistical analysis was done using SPSS software version 21.

Results:

A total of 156 lesions, 87 malignant and 69 benign lesions, were included. For mammogram, US, mammogram and US combined, and CEDM, sensitivity was 89.7%, 71.3%, 93.1%, and 96.6%; specificity 52.2%, 75%, 82.6%, and 83%; and accuracy 73%, 76.9%, 85.7%, and 92%, respectively.

Conclusion:

CEDM is an emerging tool with significantly better diagnostic efficiency and accuracy than the mammogram and ultrasound alone or combined, therefore it may play a promising role in early detection, diagnosis, staging, and follow-up of breast cancer in women with dense breast at lesser cost and short examination time compared to MRI.

Limitations:

Radiation exposure 1.2 to 1.5 times of conventional digital mammography. CEDM cannot be performed in women with renal insufficiency and a history of allergy to iodinated contrast. Depth of the lesion and chest wall invasion cannot be assessed as accurately as MRI.

Ethics committee approval

Approved from an ethics committee.

Funding:

No funding was received for this work.

Purpose:

To compare the role of contrast-enhanced spectral mammography and dynamic contrast-enhanced MRI in the preoperative diagnosis of suspicious breast lesions detected on sonomammography and evaluation of disease extension of the proved breast cancer.

Methods and materials:

This study included 171 lesions in 82 patients. All patients underwent digital mammography, breast ultrasound, CESM, and contrast-enhanced MRI breast. Results were correlated to histopathological details.

Results:

Histological analysis: 51/171 (29.8 %) lesions were benign while 120/171 (70.2 %) were malignant.

The accuracy measures of CESM and DCE-MRI were higher than that of sonomammography. DCE-MRI sensitivity and NPV were significantly higher than CESM (p-value 0.014 and 0.013). The overall accuracy of MRI was better than CESM, however, no statistically significant difference was detected.

Axillary lymph nodes were assessed by SM, CESM, and MRI in cases with malignant lesions and their sensitivities were 93.8 %, 50 %, and 87.5 %, respectively, and their specificities were 90.3%, 93.5 %, and 93.5%, respectively.

Regarding multiplicity, both DCE-MRI and CESM were better than SM in their detection, with DCE-MRI superior to CESM.

Regarding size assessment, we found no correlation between SM and postoperative size, with weak agreement, high correlation, and agreement between CESM and postoperative size, slightly higher correlation and agreement between DCE- MRI and postoperative, with high correlation and agreement between CESM and DCE-MRI.

Conclusion:

MRI is still the best study in preoperative diagnosis and management decision of breast cancer, however, contrast-enhanced spectral mammography is a feasible comparable technique with promising results.

Limitations:

Different biological subtypes of included breast cancer patients.

Ethics committee approval

Approved by ethical committee of faculty of medicine at Cairo University. Written consent was obtained from all patients.

Funding:

No funding was received for this work.

Purpose:

To assess the performance of the delayed image in CESM to diagnose breast cancer in BI-RADS 4 findings detected by mammography.

Methods and materials:

Between May 2018 and May 2019, 150 women with BI-RADS 4 after standard mammography were performed CESM. CESM technique: image acquisition began at a 2-minute delay after the start of the contrast injection and was completed within 6 minutes after initiation of contrast administration. On 8-12 minutes, a set of additional bilateral (lesions of both breast) or monolateral (lesions of one breast) craniocaudal (CC) or mediolateral-oblique (MLO) views was acquired. All the lesions were histologically verified.

Results:

160 lesions were identified, 89 of which were malignant and 71 benign. Malignancy rates were 22.7% (10/44 BI-RADS 4a), 47.5% (29/61 BI-RADS 4b), and 90.9% (50/55 BI-RADS 4c). There were 86 true-positive, 63 true-negative, 8 false-positive, and 3 false-negative (one invasive cancer, two DCIS) CESM findings, effecting a sensitivity, specificity, PPV, and NPV of 96.9% (95%-CI 90.9–99.2%), 92.9% (95%-CI 86.5–97.9%), 92.2% (95%-CI 85.6–96.9%), and 97.2% (95%-CI 92.2–99.5%), respectively.

Conclusion:

CESM is an accurate tool to further diagnose BI-RADS 4a and 4b lesions and may be helpful to avoid unnecessary biopsies. BI-RADS 4c lesions should be biopsied irrespective of CESM findings. Delayed image increases the specificity of the method by 10%.

Limitations:

Small number of patients.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To assess the added value of contrast-enhanced digital mammography (CEDM) in the evaluation of microcalcifications.

Methods and materials:

We retrospectively screened 1233 women who performed CEDM from September 2016 to August 2018. Inclusion criteria were the presence of microcalcifications on a mammogram, biopsy-proven histological diagnosis, and the absence of an associated mass. CEDM performed with no residual microcalcifications after biopsy were excluded. CEDM sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. Microcalcifications morphology and associated enhancement were independently reviewed by 2 radiologists with 6 and 24 months of CEDM experience, respectively. Interobserver agreement was calculated with Cohen’s kappa test.

Results:

The final population included 138 women (52.99±9.92 years old). 87 microcalcifications presented enhancement: 45 out of 50 (90.0%) were carcinomas (B5), 26 out of 34 (76.5%) lesions with uncertain malignant potential (B3), and 16 out of 54 (29.6%) benign lesions (B2). All 5 B5 without enhancement were carcinomas in situ. Carcinoma in situ presented as mild to moderate progressive non-mass enhancement, invasive carcinoma as moderate to intense wash-out mass enhancement. Out of 8 B3 without enhancement, only 1 (12.5%) upgraded to carcinoma in situ. All morphologically different types of microcalcification presented high NPV and included rounded/punctiform calcification (VPN=94.4%). The overall diagnostic sensitivity of CEDM was 89.5%, with 57.0% specificity, 60.0% PPV, 88.2% NPV, and 70.6% accuracy. AUC was 0.81 according to ROC curve. Substantial agreement was observed between the two observers (K=0.71).

Conclusion:

CEDM represents a novel technique with good ability in detecting and characterising microcalcifications. Morphology and distribution still play the most important role in the decision planning, however, CEDM can help when rounded/punctiform microcalcifications or B3 lesions are found.

Limitations:

A retrospective study, small sample, and CEDM performed after biopsy.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

One of the most important indications for contrast-enhanced breast imaging is the pre-surgical breast cancer (BC) staging. This is the large-scale single-centre experience evaluating the role of CEDM in pre-surgical staging. The aims of this retrospective study were to define the diagnostic performance of CEDM in the pre-surgical setting and to identify which type of patient may have a greater advantage of having CEDM.

Methods and materials:

We selected 326 patients with BC who performed CEDM as preoperative staging and had breast cancer-related surgery at our institution. We analysed when CEDM led to additional imaging or biopsy and when it changed the type of surgery that was planned according to conventional breast imaging (CI) techniques (digital mammography, tomosynthesis, and ultrasound). CEDM diagnostic performance in the correct preoperative staging of BC of the whole population and into various subgroups were calculated.

Results:

CEDM sensitivity for the index lesion was 98.8%, which led to additional breast imaging in 23.6% and additional biopsies in 17.5%. CEDM changed the type of surgery in 18.4%. In the preoperative BC staging, CEDM sensitivity, specificity, PPV, and NPV and accuracy resulted in 93%, 98%, 90%, 98%, and 98%, respectively. CEDM performance was better in patients with palpable lesions.

Conclusion:

CEDM has an excellent diagnostic performance in the pre-surgical staging of BC. Symptomatic patients with palpable lesions benefitted most from CEDM, with a statistically significant difference.

Limitations:

The most important limitations are the patient population we selected i.e. patients with histological-proven BC, not a screening population, which may have influenced the high rate of surgical change and the retrospective nature of the study.

Ethics committee approval

The local institutional review board (IRB) approved this retrospective analysis.

Funding:

No funding was received for this work.

Purpose:

Optimising the settings of a photon-counting breast CT (pcBCT) for spectral contrast-enhanced imaging from a single scan and evaluating the accuracy according to iodine quantification and the creation of virtual-unenhanced images (VNC).

Methods and materials:

The settings of a pcBCT with 100µm detector element size and integrated charge‑sharing correction were adapted to maximize the signal to noise ratio (SNR) between the contrast agent and soft tissue. Therefore, the energy threshold separating the x-ray spectrum was swept from 23.1keV to 50.6keV. Validation measurements were performed with contrast agent samples (2.5 to 25mg Iodine/ml) in phantoms with a 7.5 cm and 12 cm diameter. Iodine maps and VNC images were generated from a single scan using image-based material decomposition. Iodine concentrations and CT values were measured and compared to the known concentrations and reference CT values.

Results:

Spectral single-scan contrast-enhanced pcBCT was feasible. Maximal SNRs were found at a threshold position of 32.5keV. Accurate iodine quantification (average RMSE of 0.56mg/ml) was possible down to 2.5 mg Iodine/ml. Minor changes of CT values compared to non-enhanced CT scans were observed in the VNC images -1.2±21.6HU and 4.9±67.4HU (7.5 and 12 cm phantom). The noise was increased by the decomposition by a factor of 2.62 and 4.87 (7.5 and 12 cm phantom) but did not compromise accurate iodine quantification.

Conclusion:

Accurate iodine quantification and the creation of VNC images can be achieved using contrast-enhanced pcBCT from a single CT scan under the complete absence of temporal or spatial misalignment. Using iodine maps and VNC images, pcBCT has the potential to reduce dose, shorten examination and reading time, and to increase cancer detection rates.

Limitations:

The CT scans presented were performed on a bench testing model of a commercially available pcBCT system.

Ethics committee approval

n/a

Funding:

No funding was received for this work.