P multi-echo MRSI with low B dual-band refocusing RF pulses.

P magnetic resonance spectroscopy (MRS) can spectrally resolve metabolites involved in phospholipid metabolism whose levels are altered in many cancers. Ultra-high field facilitates the detection of phosphomonoesters (PMEs) and phosphodiesters (PDEs) with increased SNR and spectral resolution. Utilizing multi-echo MR spectroscopic imaging (MRSI) further enhances SNR and enables T information estimation per metabolite.

Indirect H-[C] MRS of the human brain at 7 T using a C-birdcage coil and eight transmit-receive H-dipole antennas with a 32-channel H-receive array.

The neuronal tricarboxylic acid and glutamate/glutamine (Glu/Gln) cycles play important roles in brain function. These processes can be measured in vivo using dynamic H-[C] MRS during administration of C-labeled glucose. Proton-observed carbon-edited (POCE) MRS enhances the signal-to-noise ratio (SNR) compared with direct C-MRS.

Measurement of metabolite levels and treatment-induced changes in hepatic metastases of gastro-esophageal cancer using 7-T phosphorus magnetic resonance spectroscopic imaging.

Methods for early treatment response evaluation to systemic therapy of liver metastases are lacking. Tumor tissue often exhibits an increased ratio of phosphomonoesters to phosphodiesters (PME/PDE), which can be noninvasively measured by phosphorus magnetic resonance spectroscopy (P MRS), and may be a marker for early therapy response assessment in liver metastases. However, with commonly used P surface coils for liver P MRS, the liver is not fully covered, and metastases may be missed.

P MR Spectroscopy in the Pancreas: Repeatability, Comparison With Liver, and Pilot Pancreatic Cancer Data.

Background: Non-invasive evaluation of phosphomonoesters (PMEs) and phosphodiesters (PDEs) by 31-phosphorus MR spectroscopy (P MRS) may have potential for early therapy (non-)response assessment in cancer. However, P MRS has not yet been applied to investigate the human pancreas in vivo.

Purpose: To assess the technical feasibility and repeatability of P MR spectroscopic imaging (MRSI) of the pancreas, compare P metabolite levels between pancreas and liver, and determine the feasibility of P MRSI in pancreatic cancer.

Metabolic profiling of colorectal cancer organoids: A comparison between high-resolution magic angle spinning magnetic resonance spectroscopy and solution nuclear magnetic resonance spectroscopy of polar extracts.

Patient-derived cancer cells cultured in vitro are a cornerstone of cancer metabolism research. More recently, the introduction of organoids has provided the research community with a more versatile model system. Physiological structure and organization of the cell source tissue are maintained in organoids, representing a closer link to in vivo tumor models.

In vivo phosphorus magnetic resonance spectroscopic imaging of the whole human liver at 7 T using a phosphorus whole-body transmit coil and 16-channel receive array: Repeatability and effects of principal component analysis-based denoising.

Quantitative three-dimensional (3D) imaging of phosphorus ( P) metabolites is potentially a promising technique with which to assess the progression of liver disease and monitor therapy response. However, P magnetic resonance spectroscopy has a low sensitivity and commonly used P surface coils do not provide full coverage of the liver. This study aimed to overcome these limitations by using a P whole-body transmit coil in combination with a 16-channel P receive array at 7 T.

Prospective of P MR Spectroscopy in Hepatopancreatobiliary Cancer: A Systematic Review of the Literature.

Background: The incidence of liver and pancreatic cancer is rising. Patients benefit from current treatments, but there are limitations in the evaluation of (early) response to treatment. Tumor metabolic alterations can be measured noninvasively with phosphorus ( P) magnetic resonance spectroscopy (MRS).

Comparison of 2-Hydroxyglutarate Detection With sLASER and MEGA-sLASER at 7T.

The onco-metabolite 2-hydroxyglutarate (2HG), a biomarker of IDH-mutant gliomas, can be detected with H MR spectroscopy (H-MRS). Recent studies showed measurements of 2HG at 7T with substantial gain in signal to noise ratio (SNR) and spectral resolution, offering higher specificity and sensitivity for 2HG detection. In this study, we assessed the sensitivity of semi-localized by adiabatic selective refocusing (sLASER) and J-difference MEsher-GArwood-semi-LASER (MEGA-sLASER) for 2HG detection at 7T.

SNR optimized P functional MRS to detect mitochondrial and extracellular pH change during visual stimulation.

Unlabelled: Energy metabolism of the human visual cortex was investigated by performing P functional MRS.

Introduction: The human brain is known to be the main glucose demanding organ of the human body and neuronal activity can increase this energy demand. In this study we investigate whether alterations in pH during activation of the brain can be observed with MRS, focusing on the mitochondrial inorganic phosphate (Pi) pool as potential marker of energy demand.

Contradiction between amide-CEST signal and pH in breast cancer explained with metabolic MRI.

Purpose: Metabolic MRI is a noninvasive technique that can give new insights into understanding cancer metabolism and finding biomarkers to evaluate or monitor treatment plans. Using this technique, a previous study has shown an increase in pH during neoadjuvant chemotherapy (NAC) treatment, while recent observation in a different study showed a reduced amide proton transfer (APT) signal during NAC treatment (negative relation). These findings are counterintuitive, given the known intrinsic positive relation of APT signal to pH.

Early detection of changes in phospholipid metabolism during neoadjuvant chemotherapy in breast cancer patients using phosphorus magnetic resonance spectroscopy at 7T.

The purpose of this work was to investigate whether noninvasive early detection (after the first cycle) of response to neoadjuvant chemotherapy (NAC) in breast cancer patients was possible. P-MRSI at 7 T was used to determine different phosphor metabolites ratios and correlate this to pathological response. P-MRSI was performed in 12 breast cancer patients treated with NAC.

Analysis of chemical exchange saturation transfer contributions from brain metabolites to the Z-spectra at various field strengths and pH.

Chemical exchange saturation transfer (CEST) exploits the chemical exchange of labile protons of an endogenous or exogenous compound with water to image the former indirectly through the water signal. Z-spectra of the brain have traditionally been analyzed for two most common saturation phenomena: downfield amide proton transfer (APT) and upfield nuclear Overhauser enhancement (NOE). However, a great body of brain metabolites, many of interest in neurology and oncology, contributes to the downfield saturation in Z-spectra.

Shortening of apparent transverse relaxation time of inorganic phosphate as a breast cancer biomarker.

Phosphorus MRS offers a non-invasive tool for monitoring cell energy and phospholipid metabolism and can be of additional value in diagnosing cancer and monitoring cancer therapy. In this study, we determined the transverse relaxation times of a number of phosphorous metabolites in a group of breast cancer patients by adiabatic multi-echo spectroscopic imaging at 7 T. The transverse relaxation times of phosphoethanolamine, phosphocholine, inorganic phosphate (P ), glycerophosphocholine and glycerophosphatidylcholine were 184 ± 8 ms, 203 ± 17 ms, 87 ± 8 ms, 240 ± 56 ms and 20 ± 10 ms, respectively.

P T s of phosphomonoesters, phosphodiesters, and inorganic phosphate in the human brain at 7T.

Purpose: To determine the phosphorus-31 T s of phosphomonoesters, phosphodiesters, and inorganic phosphate in the healthy human brain at 7T.

Methods: A 3D chemical shift imaging multi-echo sequence with composite block pulses for refocusing was used to measure one free induction decay (FID) and seven full echoes with an echo spacing of 45 ms on the brain of nine healthy volunteers (age range 22-45 years; average age 27 ± 8 years). Spectral fitting was used to determine the change in metabolic signal amplitude with echo time.

Proton and phosphorus magnetic resonance spectroscopy of the healthy human breast at 7 T.

In vivo water- and fat-suppressed H magnetic resonance spectroscopy (MRS) and P magnetic resonance adiabatic multi-echo spectroscopic imaging were performed at 7 T in duplicate in healthy fibroglandular breast tissue of a group of eight volunteers. The transverse relaxation times of P metabolites were determined, and the reproducibility of H and P MRS was investigated. The transverse relaxation times for phosphoethanolamine (PE) and phosphocholine (PC) were fitted bi-exponentially, with an added short T component of 20 ms for adenosine monophosphate, resulting in values of 199 ± 8 and 239 ± 14 ms, respectively.

Erratum to: Dynamic contrast-enhanced breast MRI at 7T and 3T: an intra-individual comparison study.

[This corrects the article DOI: 10.1186/s40064-015-1654-7.].

Glycerophosphocholine and Glycerophosphoethanolamine Are Not the Main Sources of the In Vivo (31)P MRS Phosphodiester Signals from Healthy Fibroglandular Breast Tissue at 7 T.

Purpose: The identification of the phosphodiester (PDE) (31)P MR signals in the healthy human breast at ultra-high field.

Methods: In vivo (31)P MRS measurements at 7 T of the PDE signals in the breast were performed investigating the chemical shifts, the transverse- and the longitudinal relaxation times. Chemical shifts and transverse relaxation times were compared with non-ambiguous PDE signals from the liver.

Dynamic contrast-enhanced breast MRI at 7T and 3T: an intra-individual comparison study.

The aim of this study is to compare the current state of lesion identification, the BI-RADS classification and the contrast-enhancement behavior at 7T and 3T breast MRI in the same patient group. Twenty-seven patients with thirty suspicious lesions were selected for this prospective study and underwent both 7T and 3T MRI. All examinations were rated by two radiologists (R1 and R2) independently on image quality, lesion identification and BI-RADS classification.

Proton observed phosphorus editing (POPE) for in vivo detection of phospholipid metabolites.

The purpose of this article was to compare the sensitivity of proton observed phosphorus editing (POPE) with direct (31) P MRS with Ernst angle excitation for (1) H-(31) P coupled metabolites at 7 T. POPE sequences were developed for detecting phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC), and glycerophosphoethanolamine (GPE) on the (1) H channel, thereby using the enhanced sensitivity of the (1) H nuclei over (31) P detection. Five healthy volunteers were examined with POPE and (31) P-MRS.

2D AMESING multi-echo (31)P-MRSI of the liver at 7T allows transverse relaxation assessment and T2-weighted averaging for improved SNR.

Purpose: Liver diseases are a major global health concern often requiring invasive assessment by needle biopsy. (31)P magnetic resonance spectroscopic imaging (MRSI) allows non-invasive probing of important liver metabolites. Recently, the adiabatic multi-echo spectroscopic imaging sequence with spherical k-space sampling (AMESING) was introduced at 7T, enabling acquisition of T2 information.

Saturation-transfer effects and longitudinal relaxation times of (31) P metabolites in fibroglandular breast tissue at 7T.

Purpose: To investigate longitudinal relaxation times and saturation-transfer effects of phosphorous metabolites in breast fibroglandular tissue in vivo with (31) P MR spectroscopy at 7T.

Methods: Progressive saturation with adiabatic half passage excitation was used to determine T1 values of (31) P metabolites in a group of six healthy volunteers. Saturation-transfer experiments were performed in seven healthy volunteers by saturating at 0 ppm and 10 ppm with sinc-Gaussian pulses (90 ms; 10-ms pulse interval; B1 = 17 μT) prior to excitation.

Multiparametric MRI With Dynamic Contrast Enhancement, Diffusion-Weighted Imaging, and 31-Phosphorus Spectroscopy at 7 T for Characterization of Breast Cancer.

Objectives: To describe and to correlate tumor characteristics on multiparametric 7 tesla (T) breast magnetic resonance imaging (MRI) with prognostic characteristics from postoperative histopathology in patients with breast cancer.

Materials And Methods: Institutional review board approval and written informed consent of 15 women (46-70 years) with 17 malignant lesions were obtained. In this prospective study (March 2013 to March 2014), women were preoperatively scanned using dynamic contrast-enhanced MRI, diffusion-weighted imaging, and 31-phosphorus spectroscopy (¹³P-MRS).

Radiofrequency configuration to facilitate bilateral breast (31) P MR spectroscopic imaging and high-resolution MRI at 7 Tesla.

Purpose: High-resolution MRI combined with phospholipid detection may improve breast cancer grading. Currently, configurations are optimized for either high-resolution imaging or (31) P spectroscopy. To be able to perform both imaging as well as spectroscopy in a single session, we integrated a (1) H receiver array into a (1) H-(31) P transceiver at 7T.

1H/31P polarization transfer at 9.4 Tesla for improved specificity of detecting phosphomonoesters and phosphodiesters in breast tumor models.

Purpose: To assess the ability of a polarization transfer (PT) magnetic resonance spectroscopy (MRS) technique to improve the detection of the individual phospholipid metabolites phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC), and glycerophosphoethanolamine (GPE) in vivo in breast tumor xenografts.

Materials And Methods: The adiabatic version of refocused insensitive nuclei enhanced by polarization transfer (BINEPT) MRS was tested at 9.4 Tesla in phantoms and animal models.

MRI and (31)P magnetic resonance spectroscopy hardware for axillary lymph node investigation at 7T.

Purpose: Neoadjuvant treatment response in lymph nodes predicts patient outcome, but existing methods do not track response during therapy accurately. In this study, specialized hardware was used to adapt high-field (7T) (31) P magnetic resonance spectroscopy (MRS), which has been shown to track treatment response in small breast tumors, to monitor axillary lymph nodes.

Method: A dual-tuned quadrature coil that is a (31) P (120 MHz) transceiver and a (1) H (300 MHz) receiver was designed using a novel detune circuit.