Skip to main content

Magnetic Resonance as a Tool for Pharmaco-Imaging

  • Chapter
  • First Online:
Pharmaco-Imaging in Drug and Biologics Development

Abstract

Imaging technologies in the nonclinical laboratory have been greatly bolstered by the ever-improving methods available with magnetic resonance (MR) imaging. Small animal systems have been growing in capability even while becoming more amenable to use by biologists, revolutionizing how we can study pathophysiology and follow a drug or biologic therapy. MR’s ability to characterize many anatomical and physiological processes, based on their underlying influence on tissue magnetization properties, has led, for example, to discoveries in the psychopharmacology of attention deficit and cognitive drug therapies and in recording changes of oxygenation, blood flow and vessel permeability in acute studies, or the chronic remodeling of tissue water diffusion following therapy. This is a short and clearly abbreviated discussion of the applications of MRI in the nonclinical (and clinical) drug development laboratory, and it is meant to introduce the reader to the concepts and how this specific imaging modality likely offers the most versatile of all imaging modalities as well as being one with very high resolution.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 139.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 179.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 199.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Notes

  1. 1.

    Refer to Wechsler Intelligence Scale for Children http://www.pearsonassessments.com/HAIWEB/Cultures/en-us/Productdetail.htm?Pid=015-8979-044.

Abbreviations

ADC:

Apparent diffusion coefficient—the diffusion of molecules in tissues is modulated by many mechanisms that restrict or impose tortuosity around obstacles and such as blood flow in small vessels or cerebrospinal fluid in ventricles and other contributions to MR signal attenuation. Images are “weighted” by the “apparent” diffusion processes. Note that the ADC concept has been extremely successful in tumor biology to demonstrate necrosis, especially for clinical applications. The basic ADC approach has been challenged recently, as new, more comprehensive models of diffusion in biological tissues have been introduced. Also, the rADC, or relative ADC, is a ratio of lesions to control brain ROIs

B 0 :

Static main magnetic field provided by the MR system magnet

B 1 :

Secondary magnetic field perpendicular to B 0 transiently created during an experiment by the system’s radiofrequency coils and gradient sets

BOLD:

Blood oxygen level dependent (a particular contrast mechanism)

Chemical shift:

The resonant frequency of nuclei in some chemical environment relative to those in a standard environment (e.g., the protons of benzene)

CNR:

Contrast-to-noise ratio—the CNR is directly linked to statistical measures such as the t-values, but it does not depend on the number of points or runs as do the t-values; in fMRI it is made up of the functional signal change and the temporal signal change as the average signal change (task related) over the non-task-related variability over time (time-series noise)

FT:

Fourier Transform—a mathematical treatment of the FID or echo signal from a modern pulsed MR experiment to convert the recorded time-domain data into usable spatial frequency-domain data and hence images; an MR image consists of a matrix of pixels based on the number of lines filed in “K-space” (phase matrix) and the number of data points in each line (frequency matrix)

FID:

Free induction decay—the signal observed during the process of relaxation that follows an excitation of nuclei induced by a pulse of radiofrequency energy

FOV:

Field of view—physical dimensions of the imaged volume

fMRI:

Functional magnetic resonance imaging—generally for cerebral blood flow

Gradient:

A (relatively small) magnetic field that increases in strength with distance from the center of the image; these are created transiently by pulses from the gradient coils to impart the magnetic spins with frequency and phase information to facilitate image formation

K-space:

A spatial frequency domain where information on the frequencies of a signal and where it comes from (on the gradient) in the patient is located; this information is in radians per cm; often called the chest of drawers for how the data is stored

NMR:

Nuclear magnetic resonance—general term for the analytical chemistry of chemical shift analysis and the former term of MR as “NMR imaging”

phMRI:

Physiologic or pharmacologic imaging using MRI

Pulse sequences:

A programmed sequence of magnetic field pulses and time delays from the radiofrequency coil and the gradient set during the imaging experiment which manipulate the spin behavior of nuclei; changes to the induction and relaxation can be exploited to reveal properties of the tissue of interest

Relaxation:

Process by which a population of excited (high-energy) nuclei give up RF energy and return to their ground (low-energy) state. This emitted energy is detected to form the images

Relaxivity:

The ability of magnetic compounds to increase the relaxation rates of the surrounding water proton spins. Relaxivity is used to improve the contrast of the image and to study tissue-specific areas where the contrast agent better diffuses; view http://www.youtube.com/watch?v=Osx8Ced9Eyw

RF:

Radiofrequency—the resonant frequency of protons at commonly used magnetic field strengths is in the radiofrequency range, e.g., 64 MHz at 1.5 Tesla

SNR:

Signal-to-noise ratio

T1 :

Longitudinal relaxation occurs when a population of excited nuclei give up their extra energy to the surrounding electronic environment; the time constant “T1” (63 % of the longitudinal magnetization to recover) for this process is also known as the “spin–lattice” relaxation time constant. T1 values are typically on the order of a second

T2 :

Transverse relaxation occurs when a population of excited nuclei exchange energy with their neighbors; the time constant “T2” (63 % of the longitudinal magnetization to recover) for this process is also known as the “spin–spin relaxation” time constant. In biological tissues T2 values are typically on the order of tenths of a second

T2*:

The observed decay of the FID signal following the RF excitation pulse; it is faster than T2 as it is the combination of the T2 decay superimposed on dephasing phenomena such as magnetic field inhomogeneity

Tesla:

One weber per meter squared; the SI unit of magnetic field strength

TOF:

Time of flight—flowing nuclei present in a slice of interest which has an excitation pulse applied; more or less signal is recovered depending on their velocity; useful in magnetic resonance angiography

A full listing of definitions is available at

http://cis.rit.edu/htbooks/mri/gloss.html (8 pages of glossary terms)

References

  • ACR practice guideline: performing and interpreting MRI, ACR technical standard for performing and interpreting magnetic resonance imaging (MRI), 1992 (Res 14), amended 1995, 96, 2000, 2001, 2002, effective 1/1/2003, pp 29–33

    Google Scholar 

  • ACR technical standard: MRI equipment, ACR technical standard for diagnostic medical physics performance monitoring of magnetic resonance imaging (MRI) equipment, 1999 (Res 19), revised 2004 (Res 17b), pp 743–745

    Google Scholar 

  • Becerra L, Upadhyay J, Chang P-C et al (2013) Parallel buprenorphine phMRI responses in conscious rodents and healthy human subjects. J Pharmacol Exp Ther 345:41–51

    Article  PubMed  CAS  Google Scholar 

  • Buxton RB (2002) Introduction to functional magnetic resonance imaging: principles and techniques. Cambridge University Press, Cambridge. Second revised edition published in October 2009

    Google Scholar 

  • Buxton RB (2010) Interpreting oxygenation-based neuroimaging signals: the importance and the challenge of understanding brain oxygen metabolism. Front Neuroenergetics 2:8

    PubMed  Google Scholar 

  • Cory DA, Schwartzentruber DJ, Mock BH (1987) Ingested manganese chloride as a contrast agent for magnetic resonance imaging. Magn Reson Imaging 5(1):65–70

    Article  PubMed  CAS  Google Scholar 

  • Damadian R, Goldsmith M, Minkoff L (1977) NMR in cancer: XVI. FONAR image of the live human body. Physiol Chem Phys 9:97–100

    Article  PubMed  Google Scholar 

  • D’Esposito M, Deouell LY, Gazzaley A (2003) Alterations in the BOLD fMRI signal with ageing and disease: a challenge for neuroscience. Nat Rev Neurosci 4:863–872

    Article  PubMed  Google Scholar 

  • Faulkner W (2008) Gadolinium based contrast agents. SMRT Educ Sem 11(2):5–10

    Google Scholar 

  • Ferrari L, Turrini G, Crestan V, Bertani S, Cristofori P, Bifone A, Gozzi A (2012) A robust experimental protocol for pharmacological fMRI in rats and mice. J Neutrosci Methods 204:9–18

    Article  Google Scholar 

  • Friedman L, Glover GH (2006) Report on a multicenter fMRI quality assurance protocol. J Magn Reson Imaging 23:827–839

    Article  PubMed  Google Scholar 

  • Gavin PR, Bagley RS (eds) (2009) Practical small animal MRI. Wiley-Blackwell, Ames, IA

    Google Scholar 

  • Geva T (2006) Magnetic resonance imaging: historical perspective. J Cardiovasc Magnet Reson 8:573–580

    Google Scholar 

  • Geissler A, Gartus A, Foki T, Tahamtan AR, Beisteiner R, Barth M (2007) Contrast-to-Noise ratio (CRN) as a quality parameter in fMRI. J Magn Reson Imaging 25:1263–1270

    Article  PubMed  Google Scholar 

  • Hustvedt SO, Grant D, Southon TE, Zech K (1997) Plasma pharmacokinetics, tissue distribution and excretion of MnDPDP in the rat and dog after intravenous administration. Acta Radiol 38(4 Pt 2):690–699

    PubMed  CAS  Google Scholar 

  • Jensen JH, Helpern JA, Ramani A, Lu H, Kaczynski K (2005) Diffusional kurtosis imaging: the quantification of non-gaussian water diffusion by means of magnetic resonance imaging. Magn Reson Med 53:1432–1440

    Article  PubMed  Google Scholar 

  • Kanal E (2008) Nephrogenic syndrome fibrosis. SMRT Educ Sem 11(2):11–14

    Google Scholar 

  • Kanal E, Expert Panel on MR Safety et al (2013) ACR guidance document on MR safe practices. J Magn Reson Imaging 37:501–530

    Article  PubMed  Google Scholar 

  • Kirchin MA, Runge VM (2008) Contrast agents for magnetic resonance imaging: safety update. SMRT Educ Sem 11(2):15–23

    Google Scholar 

  • Krupnick AS, Tidwell VK, Engelbach JA, Alli VV, Nehori A, You M, Vikis HG, Gelman AE, Kreisel D, Garbow JR (2012) Quantitative monitoring of mouse lung tumors by magnetic resonance imaging. Nat Protoc 7(1):128–142

    Article  PubMed  CAS  Google Scholar 

  • Lauterbur PC (1973) Image formation by induced local interactions: examples employing nuclear magnetic resonance. Nature 242:190–191

    Article  CAS  Google Scholar 

  • Logothetis NK, Wandell BA (2004) Interpreting the BOLD Signal. Annu Rev Physiol 66:735–769

    Article  PubMed  CAS  Google Scholar 

  • Matthews PM, Honey GD, Bullmore ET (2006) Applications of fMRI in translational medicine and clinical practice. Nat Rev Neurosci 7:732–744

    Article  PubMed  CAS  Google Scholar 

  • Mendonca-Dias MH, Gaggelli E, Lauterbur PC (1983) Paramagnetic contrast agents in nuclear magnetic resonance medical imaging. Semin Nucl Med 13(4):364–376

    Article  PubMed  CAS  Google Scholar 

  • Miller KL, Luh WM, Liu TT, Martinez A, Obata T, Wong EC, Frank LR, Buxton RB (2001) Nonlinear temporal dynamics of the cerebral blood flow response. Hum Brain Mapp 13:1–12

    Article  PubMed  CAS  Google Scholar 

  • Mittal S, Wu Z, Neelavalli J, Haacke EM (2009) Susceptibility-weighted imaging: technical aspects and clinical applications, part 2. AJNR Am J Neuroradiol 30:232–252

    Article  PubMed  CAS  Google Scholar 

  • Mitterschiffthaler MT, Ettinger U, Mehta MA, Mataix-Cols D, Williams SCR (2006) Applications of functional magnetic resonance imaging in psychiatry. J Magn Reson Imaging 23:851–861

    Article  PubMed  Google Scholar 

  • Moseley ME, Liu C, Rodriguez S, Brosnan T (2009) Advances in magnetic resonance neuroimaging. Neuro Clin 27:1–19

    Article  PubMed  Google Scholar 

  • Neil JJ (2008) Diffusion imaging concepts for clinicians. J Magn Reson Imaging 27:1–7

    Google Scholar 

  • Paschal CB, Morris HD (2004) K-space in the clinic. J Magn Reson Imaging 19:145–159

    Article  PubMed  CAS  Google Scholar 

  • Rivkin MJ (2000) Developmental neuroimaging of children using magnetic resonance techniques. Ment Retard Dev Disabil Res Rev 6:68–80

    Article  PubMed  CAS  Google Scholar 

  • Roe AW, Chen LM (2008) High resolution fMRI maps of cortical stimulation in nonhuman primates: correlation with intrinsic signal optical images. ILAR J 49(1):116–123

    Article  PubMed  CAS  Google Scholar 

  • Schepkin VD, Brey WW, Gor’kov PL, Grant SC (2010) Initial in vivo rodent sodium and proton MR imaging at 21.1 T. Magn Reson Imaging 28:400–407

    Article  PubMed  CAS  Google Scholar 

  • Schlaug G, Stewart B, Benfield A, Edelman RR, Warach S (1997) Time course of the apparent diffusion coefficient (ADC) abnormality in human stroke. Neurology 49(1):113–119

    Article  PubMed  CAS  Google Scholar 

  • Sorenson AG (2006) Future prospects for fMRI in the clinic. J Magn Reson Imaging 23:941–944

    Article  Google Scholar 

  • Stolzmann P et al (2013) Detection rate, location, and size of pulmonary nodules in trimodality PET/CT-MR. Invest Radiol 48:241–246

    Article  PubMed  Google Scholar 

  • Thomsen HS, Loegager V, Noerrgaard H, Chabanova E, Moller J, Sonne J (2005) Oral manganese for liver and bile imaging. Acad Radiol 12(Suppl 1):S21–S23

    Article  PubMed  Google Scholar 

  • Toft KG, Hustvedt SO, Grant D et al (1997) Metabolism and pharmacokinetics of MnDPDP in man. Acta Radiol 38(4 Pt 2):677–689

    PubMed  CAS  Google Scholar 

  • UCSD, Center for Functional MRI, why is the MR signal sensitive to changes in brain activity? http://fmri.ucsd.edu/Research/whatisfmri.html. Accessed 13 May 2013

  • UK (2005) (now in 4th edition, 2011: http://www.westbrookmriinpractice.com/)

  • Westbrook C, Roth CK, Talbot J (2011) MRI in practice, 3rd edn. Blackwell, Oxford

    Google Scholar 

  • Williams TM et al (2013) DW-MRI as a predictive biomarker of radiosensitization of GBM through targeted inhibition of checkpoint kinases. Transl Oncol 6:133–142

    PubMed  Google Scholar 

  • Wise RG, Tracey I (2006) The role of fMRI in drug discovery. J Magn Reson Imaging 23: 862–876

    Article  PubMed  Google Scholar 

  • Wolf RL et al (2005) Grading of CNS neoplasms using continuous arterial spin labeled perfusion MR imaging at 3 Tesla. J Magn Reson Imaging 22:475–482

    Article  PubMed  Google Scholar 

  • Yang GY, Betz AL (1994) Reperfusion-induced injury to the blood-brain barrier after middle cerebral artery occlusion in rats. Stroke 25:1658–1664

    Article  PubMed  CAS  Google Scholar 

  • Young RJ, Knopp EA (2007) Brain MRI: tumor evaluation, in, update: MRI of the brain. SMRT Educat Sem 10(4):23–38

    Google Scholar 

  • Yurgelun-Todd DA, Coyle JT, Gruber SA, Renshaw PF, Silveri MM, Amico E, Cohen B, Goff DC (2005) Functional magnetic resonance imaging studies of schizophrenic patients during word production: effect of D-cycloserine. Psychiatry Res 138:23–31

    Article  PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Brian R. Moyer M.S. (Pharm), M.S. (Tox), C.N.M.T. .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2014 American Association of Pharmaceutical Scientists

About this chapter

Cite this chapter

Moyer, B.R., Hu, T.CC., Williams, S., Morris, H.D. (2014). Magnetic Resonance as a Tool for Pharmaco-Imaging. In: Moyer, B., Cheruvu, N., Hu, TC. (eds) Pharmaco-Imaging in Drug and Biologics Development. AAPS Advances in the Pharmaceutical Sciences Series, vol 8. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-8247-5_11

Download citation

Publish with us

Policies and ethics