Rajan Jain1, Hassan Bagher-Ebadian2,3,
Jayant Narang1, Siamak Pourabdollah Nejad-Davarani2,
Sona Sakesna1, Lonni Schultz4, Mohammad H. Asgari2,
James R. Ewing2,3
1Radiology, Henry Ford Hospital,
Detroit, MI, United States; 2Neurology, Henry Ford Hospital,
Detroit, MI, United States; 3Physics, Oakland University,
Rochester, MI, United States; 4Biostatistics and Research
Epidemiology, Henry Ford Hospital, Detroit, MI, United States
In
Patlak analysis, contrast agent transport is assumed to be unidirectional
(from plasma space into extracellular extravascular space). Although this
model has the advantage of simplicity, it is important to note that it will
give inaccurate results when this assumption is incorrect as in leaky brain
tumors. Using longer acquisition fit-times will probably yield overestimates
of fV and underestimates of Ktrans in the leaky regions as these will fall
into the non-linear part of the Patlak plot. Hence, understanding of the
optimal fit-times as well as proper modeling used for Patlak analysis is
important for measuring the physiologic parameters accurately.