title: Clinical Breast MR Using MRS or DWI: Who Is the Winner?
abstract: Magnetic resonance imaging (MRI) of the breast gained a role in clinical practice thanks to the optimal sensitivity of contrast-enhanced (CE) protocols. This approach, first proposed 30 years ago and further developed as bilateral highly spatially resolved dynamic study, is currently considered superior for cancer detection to any other technique. However, other directions than CE imaging have been explored. Apart from morphologic features on unenhanced T2-weighted images, two differentnon-contrastmolecular approaches were mainly runin vivo: proton MR spectroscopy (1H-MRS) and diffusion-weighted imaging (DWI). Both approaches have shown aspects of breast cancer (BC) hidden to CE-MRI: 1H-MRS allowed for evaluating the total choline peak (tCho) as a biomarker of malignancy; DWI showed that restricted diffusivity is correlated with high cellularity and tumor aggressiveness. Secondary evidence on the two approaches is now available from systematic reviews and meta-analyses, mainly considered in this article: pooled sensitivity ranged 71-74% for 1H-MRS and 84-91% for DWI; specificity 78-88% and 75-84%, respectively. Interesting research perspectives are opened for both techniques, including multivoxel MRS and statistical strategies for classification of MR spectra as well as diffusion tensor imaging and intravoxel incoherent motion for DWI. However, when looking at a clinical perspective, while MRS remained a research tool with important limitations, such as relatively long acquisition times, frequent low quality spectra, difficult standardization, and quantification of tCho tissue concentration, DWI has been integrated in the standard clinical protocols of breast MRI and several studies showed its potential value as a stand-alone approach for BC detection.
authors.affiliation: Utà di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy; Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sardanelli
authors.affiliation: Utà di Radiologia, IRCCS Policlinico San Donato , San Donato Milanese, Milan , Italy.
authors.forename: Luca Alessandro
authors.initials: LA
authors.lastname: Carbonaro
authors.affiliation: Dipartimento di Radiologia, Azienda Ospedaliera Universitaria Integrata , Verona , Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Montemezzi
authors.affiliation: Dipartimento di Fisica Sanitaria, Azienda Ospedaliera Universitaria Integrata , Verona , Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Cavedon
authors.affiliation: Utà di Radiologia, IRCCS Policlinico San Donato , San Donato Milanese, Milan , Italy.
authors.forename: Rubina Manuela
authors.initials: RM
authors.lastname: Trimboli
keywords: breast cancer; diffusion-weighted imaging; magnetic resonance imaging; proton MR spectroscopy; systematic reviews and meta-analyses