Perfusion MRI

Perfusion in cerebral tissue with normal vasculature is controlled by metaboHc demand, allowing use of regional quantitative perfusion measures to detect neurodegeneration in a variety of diseases. Perfusion measures have been a cornerstone of nuclear medicine (SPECT and PET) studies for characterizing brain regions affected in neurological disease. 

MRI perfusion studies have been used primarily to study perfusion deficits in stroke lesions. The mismatch between DWI and perfusion deficit may represent tissue at risk for damage (Neumann-Haefelin et al., 1999) which may be salvaged using thrombolytic therapy. However this interpretation of mismatch between DWI and perfusion MRI is controversial 

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Hagen T, Bartylla K, Piepgras U. Correlation of regional cerebral blood flow measured by stable xenon CT and perfusion MRI. J Comput Assist Tomogr 1999 23 257-264. 

Karonen JO, Vanninen RL, Liu Y, 0stergaard L, Kuikka JT, Nuutinen J, Vanninen EJ, Partanen PL, Vainio PA, Korbonen K, Perkio J, Roivainen R, Sivenius J, Aronen HJ. Combined diffusion and perfusion MRI with correlation to single-photon emission CT in acute ischemic stroke. Ischemic penumbra predicts infarct growth. Stroke 1999 30 1583-1590. 

Schlaug G, Benfield A, Baird AE, Siewert B, Lovblad KO, Parker RA, Edelman RR, Warach S. The ischemic penumbra operationally defined by diffusion and perfusion MRI. Neurology 1999 53 1528-1537. 

Darby DG, Barber PA, Gerraty RP, Desmond PM, Yang Q, Parsons M, Li T, Tress BM, Davis SM. Pathophysiological topography of acute ischemia by combined diffusion-weighted and perfusion MRI. Stroke 1999 30 2043-2052. 

Speck O, Chang L, DeSilva NM, Ernst T. Perfusion MRI of the human brain with dynamic susceptibility contrast gradient-echo versus spin-echo techniques. J Magn Reson Imaging 2000 12 381-387. 

Fink JN, Kumar S, Horkan C et al (2002) The stroke patient who woke up clinical and radiological features, including diffusion and perfusion MRI. Stroke 33 988-993 Fiorelli M, Bastianello S, von Kummer R et al (1999) Hemorrhagic transformation within 36 hours of a cerebral infarct relationships with early clinical deterioration and 3-month outcome in the European Cooperative Acute Stroke Study I (ECASS I). Stroke 30 2280-2284 Fisher CM (1951) Occlusion ofthe internal carotid artery. Arch Neurol Psychiatry 65 346-377... 

Ostrem JL, Saver JL, Alger JR, Starkman S, Leary MC, Duck-wiler G, Jahan R, Vespa P, Villablanca JP, Gobin YP, Vin-uela F, Kidwell CS (2004) Acute basilar artery occlusion diffusion-perfusion MRI characterization of tissue salvage... 

Busch E, Beaulieu C, de Crespigny A, Kreischer S, Diener HC, Moseley ME (2002) Combined X-ray angiography and diffusion-perfusion MRI for studying stroke evolution after rt-PA treatment in rats. Brain Res 953 112-118... 

Combined diffusion and perfusion MRI with correlation to single-photon emission CT in acute ischemic stroke. Ischemic penumbra predicts infarct growth. Stroke 30 1583-1590... 

Markus HS, Lythgoe DJ, 0stergaard L, O Sullivan M, Williams SC (2000) Reduced cerebral blood flow in white matter in ischaemic leukoaraiosis demonstrated using quantitative exogenous contrast based perfusion MRI. J Neurol Neurosurg Psychiatry 69 48-53... 

Fig. 15.12. An asymptomatic 54-year-old patient suffering from left internal carotid artery occlusion (left) shows excellent collateralization via the posterior communicating artery and a sufficient filling of the ipsilateral middle cerebral artery (middle). As a consequence, perfusion MRI (time-to-peak) detects only a slight asymmetry and delay of contrast agent arrival in the parietal parts of the middle cerebral artery territory (right)...

National Foundation, Grant No. 3100-066348.01 Mapping the ischemic tissue at risk with diffusion and perfusion MRI . 

Chang L, Ernst T, Speck O, Patel H, DeSilva M, Leonido-Yee M, Miller EN. Perfusion MRI and computerized cognitive test abnormalities in abstinent methamphetamine users. Psychiatry Res 2002 114 65-79. 

Perfusion MRI In contrast to diffusion MRI that examines the movement of fluid through tissues, perfusion MRI determines blood flow on the basis of measures of blood volume. Perfusion-weighted imaging (PWI) can determine cerebral tissue... 

Major diagnostic applications of MRI in specialized scans include MRA diffusion MRI perfusion MRI fMRI and MRS. 

Quantitation of the CBF can be an important factor in studies of therapeutic intervention. The method of arterial spin-labeled (ASF) perfusion MRI allows quantitative determination of the perfusion rate in units of ml/100 g tissue/min. However, the technique requires exceptional instrumental stability, as the result depends on accurate determination of the difference between tw o images on the order of a few percent. With the appropriate acquisition parameters to achieve sufficient signal to noise ratio (>100) and current instrument stability, this technique is feasible, especially in high field clinical systems. Currently, arterial spin-tagged perfusion measures are not widely used in clinical settings. 

Arterial spin-tagged perfusion MRI is performed by inverting the v ater protons in the blood of the arteries supplying blood to the tissue of interest. Typically, in brain, the carotid arteries are used as the supply. The original description of the method (Detre et al., 1992 Williams et al., 1992) uses a continuous narrow band RF inversion of the protons in the arterial blood, outside of the imaged slice, before and after excitation to cause a steady-state loss of signal in cerebral tissue. The signal loss is related to tissue perfusion (Detre et al., 1992) by ... 

Holmes TM, Petrella JR, Pi oveiizale JM (2004) Drsdnedon between cerebral abscesses and lirgli-gi ade neoplasms by dynamic suscepdbil-ity contrast perfusion MRI. AJR Am J Roentgenol 183 1247—1252. 

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