Comparative Analysis of CEM and Breast MRI: A Retrospective Study

Breast cancer is a prevalent malignancy where accurate preoperative assessment is crucial for treatment planning. Breast MRI is a highly sensitive imaging modality for breast cancer detection. It is widely used preoperatively and can assist with local staging, tumour size assessment, detection of additional tumour foci and assessment of treatment response in patients receiving neoadjuvant chemotherapy. Contrast-enhanced spectral mammography (CEM) is an emerging alternative with comparable diagnostic performance and shorter examination times. This study retrospectively compares CEM and MRI in measuring breast cancer extent.

In this retrospective study conducted at Imperial College Healthcare NHS Trust, 58 patients with histologically confirmed breast cancer who underwent both CEM and MRI between January 2020 and July 2023 were included. Lesion sizes were evaluated on both modalities and compared with the postoperative histopathology specimen using the Wilcoxon signed-rank test and Pearson correlation.

There was no statistically significant difference in average tumour size between CEM and MRI (28.8 mm (SD = 22.8) on CEM and 31.8 mm (SD = 24.2) on MRI; p = 0.1058). Both imaging modalities demonstrated similar measurement precision when compared with the surgical specimen (12.9 mm vs. 12.2 mm absolute mean difference between histopathological and radiological measurement - MRI and CEM respectively). Pearson analysis demonstrated a good correlation with postoperative histopathology in size measurement, with CEM showing slightly stronger correlation (r = 0.7858, p < 0.0001, n = 45) compared with MRI (r = 0.6726, p < 0.0001, n = 46).

CEM appears to be a viable alternative to MRI. This study demonstrates high sensitivity of CEM and MRI for breast cancer detection, with no statistically significant difference in maximum diameter of enhancing abnormalities. Both modalities strongly correlate with histopathology. Further studies are required to validate the role of CEM in clinical practice.