Perfusion assessment with bolus differentiation: a technique applicable to hyperpolarized tracers

Area of Science:

• Physiology
• Medical Imaging
• Biochemistry

Background:

• Assessing tissue blood flow is crucial for diagnosing and monitoring various medical conditions.
• Existing methods for blood flow assessment often face challenges with arterial delay and dispersion, complicating accurate quantification.
• Hyperpolarized tracers offer a promising avenue for advanced physiological measurements.

Purpose of the Study:

• To describe and validate a new technique for assessing tissue blood flow using hyperpolarized tracers.
• To quantify renal cortical blood flow, arterial transit time, and dispersion in rabbits.
• To demonstrate the technique's insensitivity to arterial delay and dispersion.

Main Methods:

• Utilized a novel technique based on the permanent destruction of hyperpolarized tracer magnetization.
• Employed a 13C-labeled compound (2-hydroxyethylacrylate) polarized via parahydrogen-induced polarization (PHIP).
• Studied renal cortical blood flow in six rabbits.

Main Results:

• Estimated renal cortical blood flow was 5.7/5.4 +/- 1.6/1.3 ml/min per milliliter of tissue (right/left kidney).
• Determined mean transit time in renal arteries to be 1.47/1.42 +/- 0.07/0.07 s.
• Quantified dispersion in renal arteries as 1.78/1.93 +/- 0.40/0.42 s2.

Conclusions:

• The described technique enables accurate assessment of tissue blood flow using hyperpolarized tracers.
• This method overcomes limitations related to arterial delay and dispersion.
• The study successfully quantified renal cortical blood flow and arterial dynamics in a rabbit model.