<sup>31</sup>P MR spectroscopic imaging of the human prostate at 7 T: T<sub>1</sub>relaxation times, Nuclear Overhauser Effect, and spectral characterization

Lagemaat, Miriam W.; Maas, Marnix C.; Vos, Eline K.; Bitz, Andreas K.; Orzada, Stephan; Weiland, Elisabeth; Uden, Mark J. van; Kobus, Thiele; Heerschap, Arend; Scheenen, Tom W. J.

doi:10.1002/mrm.25209

Cited by 28 publications

(41 citation statements)

References 51 publications

(127 reference statements)

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“…Using the NOE, through 1 H RF-irradiation during the 31 P inter-pulse delay, the detection sensitivity for 31 P can be increased up to about 80% at lower fields in skeletal muscle [30]. The reported increase of up to 44% in brain [31] and prostate [32] in 31 P-MR signal at ultra-high fields cannot be directly transferred to skeletal muscle or liver, due to the NOE dependence on the tissue of interest. It is also important to note that the effect is metabolite-specific, and therefore, individual correction factors must be applied for reliable quantification.…”

Section: Introductionmentioning

confidence: 99%

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

Valkovič

Chmelík

Krššák

2017

Analytical Biochemistry

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In addition to direct assessment of high energy phosphorus containing metabolite content within tissues, phosphorus magnetic resonance spectroscopy (31P-MRS) provides options to measure phospholipid metabolites and cellular pH, as well as the kinetics of chemical reactions of energy metabolism in vivo. Even though the great potential of 31P-MR was recognized over 30 years ago, modern MR systems, as well as new, dedicated hardware and measurement techniques provide further opportunities for research of human biochemistry. This paper presents a methodological overview of the 31P-MR techniques that can be used for basic, physiological, or clinical research of human skeletal muscle and liver in vivo. Practical issues of 31P-MRS experiments and examples of potential applications are also provided. As signal localization is essential for liver 31P-MRS and is important for dynamic muscle examinations as well, typical localization strategies for 31P-MR are also described.

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Section: Introductionmentioning

confidence: 99%

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

Valkovič

Chmelík

Krššák

2017

Analytical Biochemistry

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“…As these have chemical shifts similar to that for GPE and GPC, the signals will overlap, making T 1 assessments of these pools questionable. The measured T 1 values of 2.1 ± 0.1 s and 1.5 ± 0.1 s for GPtE + GPC and GPtC, respectively, are two‐ to four‐fold lower than that reported for GPC and GPE in calf muscle, prostate, and brain at 7T and 3T . Note that the T 1 value for the GPtE + GPC signal is larger than for GPtC, possibly partially due to the longer T 1 value for GPC, but the T 1 value of GPtE could be longer than for GPtC.…”

Section: Discussionmentioning

confidence: 55%

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

et al. 2015

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“…31 P MRSI was performed using a 3D phase‐encoded pulse‐acquire sequence with a nonselective BIR‐4 excitation pulse (see Table for further imaging and spectroscopy details). The nuclear Overhauser effect was used with continuous low‐power irradiation of the water resonance to enhance 31 P SNR . 31 P MRSI data was fitted using Metabolite Report (Siemens Healthineers Erlangen, Germany).…”

Section: Methodsmentioning

confidence: 99%

“…Since an endorectal coil is needed for 31 P, this ERC can also be equipped with 1 H receive capabilities to enhance 1 H imaging and spectroscopy of the prostate, increasing SNR for 1 H spectroscopy and spatial resolution for T 2 W imaging and DWI. Moreover, the 1 H transmit capabilities of the external body array allow the use of the nuclear Overhauser effect for an extra increase in 31 P SNR …”

Section: Introductionmentioning

confidence: 99%

A multitransmit external body array combined with a ¹H and ³¹P endorectal coil to enable a multiparametric and multimetabolic MRI examination of the prostate at 7T

et al. 2019

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Purpose In vivo 1H and 31P magnetic resonance spectroscopic imaging (MRSI) provide complementary information on the biology of prostate cancer. In this work we demonstrate the feasibility of performing multiparametric imaging (mpMRI) and 1H and 31P spectroscopic imaging of the prostate using a 31P and 1H endorectal radiofrequency coil (ERC) in combination with a multitransmit body array at 7 Tesla (T).MethodsAn ERC with a 31P transceiver loop coil and 1H receive (Rx) asymmetric microstrip (31P/1H ERC) was designed, constructed and tested in combination with an external 8‐channel 1H transceiver body array coil (8CH). Electromagnetic field simulations and measurements and in vivo temperature measurements of the ERC were performed for safety validation. In addition, the signal‐to‐noise (SNR) benefit of the 1H microstrip with respect to the 8CH was evaluated. Finally, the feasibility of the setup was tested in one volunteer and three patients with prostate cancer by performing T2‐weighted and diffusion‐weighted imaging in combination with 1H and 31P spectroscopic imaging.ResultsElectromagnetic field simulations of the 31P loop coil showed no differences in the E‐ and B‐fields of the 31P/1H ERC compared with a previously safety validated ERC without 1H microstrip. The hotspot of the specific absorption rate (SAR) at the feed point of the 31P/1H ERC loop coil was 9.42 W/kg when transmitting on 31P at 1 W. Additional in vivo measurements showed a maximum temperature increase at the SAR hotspot of 0.7°C over 6 min on 31P at 1.9 W transmit (Tx) power, indicating safe maximum power levels. When transmitting with the external 1H body array at 40W for 2:30 min, the temperature increase around the ERC was < 0.3°C. Up to 3.5 cm into the prostate the 1H microstrip of the ERC provided higher SNR than the 8CH. The total coil combination allowed acquisition of an mpMRI protocol and the assessment of 31P and 1H metabolites of the prostate in all test subjects.ConclusionWe developed a setup with a 31P transceiver and 1H Rx endorectal coil in combination with an 8‐channel transceiver external body array coil and demonstrated its safety and feasibility for obtaining multiparametric imaging and 1H and 31P MRSI at 7T in patients with prostate cancer within one MR examination.

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³¹P MR spectroscopic imaging of the human prostate at 7 T: T₁relaxation times, Nuclear Overhauser Effect, and spectral characterization

Cited by 28 publications

References 51 publications

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

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

A multitransmit external body array combined with a ¹H and ³¹P endorectal coil to enable a multiparametric and multimetabolic MRI examination of the prostate at 7T

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31P MR spectroscopic imaging of the human prostate at 7 T: T1relaxation times, Nuclear Overhauser Effect, and spectral characterization

Cited by 28 publications

References 51 publications

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

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

A multitransmit external body array combined with a 1H and 31P endorectal coil to enable a multiparametric and multimetabolic MRI examination of the prostate at 7T

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³¹P MR spectroscopic imaging of the human prostate at 7 T: T₁relaxation times, Nuclear Overhauser Effect, and spectral characterization

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

A multitransmit external body array combined with a ¹H and ³¹P endorectal coil to enable a multiparametric and multimetabolic MRI examination of the prostate at 7T