MRI and¹H MRS of The Breast: Presence of a Choline Peak as Malignancy Marker is Related to k21 Value of the Tumor in Patients with Invasive Ductal Carcinoma

Abstract

To assess which specific morphologic features, enhancement patterns, or pharmacokinetic parameters on breast Magnetic Resonance Imaging (MRI) could predict a false-negative outcome of Proton MR Spectroscopy ( 1 H MRS) exam in patients with invasive breast cancer. Sixteen patients with invasive ductal carcinoma of the breast were prospec-tively included and underwent both, contrast-enhanced breast MRI and 1 H MRS examination of the breast. The MR images were reviewed and the lesions morphologic features, enhancement patterns and pharmacokinetic parameters (k21-value) were scored according to the ACR BI-RADS-MRI lexicon criteria. For the in vivo MRS studies, each spectrum was evaluated for the presence of choline based on consensus reading. Breast MRI and 1 H MRS data were compared to histopathologic findings. In vivo 1 H MRS detected a choline peak in 14/16 (88%) cancers. A false-negative 1 H MRS study occurred in 2/16 (14%) cancer patients. K21 values differed between both groups: the 14 choline positive cancers had k21 values ranging from 0.01 to 0.20/second (mean 0.083/second), whereas the two choline-negative cancers showed k21 values of 0.03 and 0.05/second, respectively (mean 0.040/second). Also enhancement kinetics did differ between both groups; typically both cancers that were choline-negative showed a late phase plateau (100%), whereas this was only shown in 51/4 (36%) of the choline positive cases. There was no difference between both groups with regard to morphologic features on MRI. This study showed that false-negative 1 H MRS examinations do occur in breast cancer patients, and that the presence of a choline peak on 1 H MRS as malignancy marker is related to the k21 value of the invasive tumor being imaged.Keywords breast cancer; k21-value; magnetic resonance imaging; proton MR spectroscopy Contrast-enhanced breast magnetic resonance imaging (MRI) detects breast cancer with almost 100% sensitivity, and plays an increasingly important role in breast cancer detection and staging (1). However, the specificity of breast MRI is rather variable, ranging from 37% to 97%, resulting in moderate false-positive rates and unnecessary biopsies (2-5).To optimize specificity in breast MRI combined high spatial-resolution imaging and rapid dynamic imaging for concurrent evaluation of detailed lesion morphology characteristics and

Combined DCE‐MRI and single‐voxel 2D MRS for differentiation between benign and malignant breast lesions

“…Another study by Baek et al reported that the choline level was found to be significantly higher in lesions presenting as mass type compared to non-mass type diffuse enhancements, and a significant correlation was found between the choline level and pharmacokinetic parameter indicating that tissues with a high choline level have higher wash-out rates in DCE-MRI (17). Our pilot findings from a total of 18 subjects and 24 lesions needs to be treated with caution since another recent study by Geraghty et al reported that choline was detectable only 14 out of 16 cancer subjects resulting in a false negative choline level in two breast cancer subjects (18).…”

“…Similarly, the choline groups contain methylene protons that give rise to J-coupled multiplets in the 3-4 ppm region as described above. Due to significant overlap of these J-coupled multiplets, it is difficult to reliably assign these peaks using 1D MRS. MR spectral editing techniques based on subtraction to unravel the overlapping resonances are limited in use because they rely on J-coupled protons that have well separated multiplets and are limited to selection of one metabolite per measurement (18)(19)(20)(21). Single-shot based multiple-quantum filtered MR spectroscopic sequences have also been implemented on whole body scanners, but signal losses associated with various coherence transfer pathways make it less attractive for human applications (22,23).…”

Determination of Choline Concentration in Breast Lesions: Quantitative Multivoxel Proton MR Spectroscopy as a Promising Noninvasive Assessment Tool to Exclude Benign Lesions

“…There have been single-voxel MR spectroscopic studies proposing quantifimeasurements were previously used for the detection of Cho (ie, detectability or Cho signal-to-noise ratio) (22)(23)(24)(25)27,28 ). In our study, a recently published multivoxel MR spectroscopic method based on quantitative measurement was implemented ( 26 ).…”

“…The single-voxel technique has limitations in terms of lesion coverage, which may affect the sensitivity of the assessment of Cho from just one voxel in view of tumor heterogeneity ( 22,26 ). Multivoxel MR spectroscopy, referred to as spectroscopic imaging or chemical shift imaging, acquires spectroscopic information from a large volume of interest subdivided into an array of voxels measured in a single measurement (22)(23)(24)(25)(26)(27)(28). Therefore, the multivoxel MR spectroscopic technique is suitable for analyzing the regional distribution of tumor metabolites and studying tissue heterogeneity.…”

“…MR spectroscopy can be performed as a single- or multivoxel (22)(23)(24)(25)(26)(27)(28) technique. The single-voxel technique has limitations in terms of lesion coverage, which may affect the sensitivity of the assessment of Cho from just one voxel in view of tumor heterogeneity ( 22,26 ).…”