Hyperpolarised 13C MRI: a new horizon for non-invasive diagnosis of aggressive breast cancer

Abstract

Hyperpolarised ¹³C MRI (HP-MRI) is a novel imaging technique that allows real-time analysis of metabolic pathways in vivo.¹ The technology to conduct HP-MRI in humans has recently become available and is starting to be clinically applied. As knowledge of molecular biology advances, it is increasingly apparent that cancer cell metabolism is related to disease outcomes, with lactate attracting specific attention. ² Recent reviews of breast cancer screening programs have raised concerns and increased public awareness of over treatment. The scientific community needs to shift focus from improving cancer detection alone to pursuing novel methods of distinguishing aggressive breast cancers from those which will remain indolent. HP-MRI offers the opportunity to identify aggressive tumour phenotypes and help monitor/predict therapeutic response. Here we report one of the first cases of breast cancer imaged using HP-MRI alongside correlative conventional imaging, including breast MRI.

Figure 1.

(a)(Medial Lateral Oblique) MLO and (b) (Cranio-caudal) CC mammographic views of the right breast demonstrating extensive malignant micro calcification (outlined with white arrowheads) and an ill-defined mass (red star) on the MLO view.

Figure 2.

Corresponding sonographic image shows an irregular hypoechoic 2 cm likely malignant mass (a) with likely pathological right axillary lymph node (b).

Figure 3.

MRI of extensive multicentric right-sided breast cancer in the prone position (a) T₁ weighted axial image of upper part of breast (b) 3D MIP sagittal image of the 2 mins contrast enhanced images showing the extent of malignant disease in the breast. (c) 2 min contrast enhanced T1 subtracted axial image of the upper part of the breast (d) T1 post contrast reconstructed coronal image of the tumour. The regions of tumour imaged with HP MRI are highlighted with white arrowheads.

Figure 4.

HP-MRI: Coronal T₂ weighted MRI with rectangular ¹³C metabolite colour map superimposed. Red denotes regions of highest metabolite concentration whereas blue denotes the lowest. (a) T₂ weighted coronal image of the tumour. The regions of tumour are highlighted with white arrowheads. The respective metabolic maps are, (b); pyruvate map, and (c); lactate map. Images are from ¹³C CSI first acquisition.

Figure 5.

HP-MRI: (a) Coronal T₂ weighted image with spectroscopic grid. The black square over the tumour denotes the location of the four spectra presented in (b). (b) Four spectra across the black square in the tumour area acquired 25 sec after injection. (c) Summed spectrum, derived from the addition of the four spectra (b) across the tumour, with the [1-¹³C] pyruvate signal (~171 ppm), the [1-¹³C] pyruvate-hydrate signal (~179 ppm) and [1-¹³C]-lactate signal (~184 ppm).

Figure 6.

(a) Six summed spectra acquired at six different points after the injection: first measurement at 25 sec, second measurement at 35 sec, third measurement at 45 sec, fourth measurement at 55 sec, fifth measurement at 65 sec, sixth measurement 75 sec. (b) The peak areas of lactate and pyruvate over time. The pyruvate peak area was divided by four for ease of view.