Low-Field Nuclear Magnetic Resonance and Magnetic Resonance Imaging Using a High-${\rm T}_{\rm c}$ SQUID for Tumor Detection

In this work, a study of hepatocellular carcinoma and normal livers in rats using nuclear magnetic resonance (NMR) based on superconducting quantum interference devices (SQUIDs) was presented. The time domain free induction decay signals,
${\rm S}_{\rm y}({\rm t})$
, of cancerous liver tissue and control liver tissue of rats were measured to study the respective longitudinal relaxation rate
${\rm T}_{1}^{-1}$
. The NMR data were fitted to
$[1-\exp(-{\rm T}_{\rm Bp}/{\rm T}_{1})]$
to derive the longitudinal relaxation times
${\rm T}_{1}$
for cancerous liver tissue and control liver tissue. It is found that
${\rm T}_{1}$
, cancer of cancerous liver tissues is 2.3 times higher than
${\rm T}_{1}$
, control of control liver tissues. Statistically the data suggest that
${\rm T}_{1, {\rm cancer}}/{\rm T}_{1}$
, control can be used to discriminate cancerous liver tissue from control tissue. Furthermore, differentiating cancerous tissues from control tissues was demonstrated using magnetic fluid phantoms as phantoms for cancerous and control tissues. The SQUID-detected NMR/MRI exhibits potential applications in clinical research.