Research

Arterial Spin Labeling

We are developing arterial spin labeling (ASL) based non-contrast perfusion techniques for quantitative blood flow measurements.

Blood flow, which supplies the essential oxygen and nutrients, increases in certain conditions such as cancer through angiogenesis and gets disrupted in other conditions such as chronic lung disease. Non-invasive measurement of blood flow often guides the disease evaluation, treatment choice, and therapeutic monitoring of disease progression. We are currently exploring two major aspects of ASL based studies specifically using pseudo-continuous ASL (pCASL) for 1) pulmonary physiology and 2) tumor angiogenesis.

Proton-density weighted image
Proton-density weighted image (a), perfusion-weighted image (b) and perfusion-quantified image (c) of the kidneys of a normal human volunteer acquired on a Philips 3 T Ingenia scanner. Prolonged labeling (1.5 seconds) afforded by pCASL on a clinical scanner combined with efficient background signal suppression provided increased signal to noise ratio (SNR).

With pCASL, arterial blood is magnetically labeled in a feeding artery (e.g. abdominal aorta), which is later acquired when the labeled blood perfuse to the organ of interest (e.g. kidneys). With this approach, the perfused blood can be quantitated in physiological values (ml/100g/min), using a proton-density weighted image. Absolute quantification in physiological values offers robust means for therapeutic monitoring, regardless of the scanner on which the data were acquired.

Proton-density weighted image (2 of 2)
Proton-density weighted image (a), perfusion-weighted image (b) and perfusion-quantified image (c) of the lungs of a normal human volunteer acquired on a Philips 3 T Ingenia scanner. Prolonged labeling (1.5 seconds) afforded by pCASL on a clinical scanner enables higher SNR.