Chao Ren

Reliable assessment of liver iron concentration (LIC) is important for diagnosing and monitoring iron overload disorders. We used a spin exchange relaxation free (SERF) atomic magnetometer to record magnetic relaxation signals from resected human liver tissue. A total of 23 specimens from 20 patients, including normal, fatty, cirrhotic, and hepatocellular carcinoma (HCC) liver, were polarized with a Helmholtz coil inside a magnetic shield, and the field decay after switch off was recorded. For each specimen, a water-referenced, mass-normalized relaxation amplitude ΔB (pT/g) was derived. ΔB was compared with the HISTO-derived water transverse relaxation rates, $R_2^{\mathit{water}}$, from the patients’ clinical MRI. For HCC, SERF measurements were made on resected tumor tissue, whereas MRI sampled non-cancerous liver parenchyma in the same patient. Within each category, ΔB increased with $R_2^{\mathit{water}}$ and rank order agreed fully in three of the four categories. Slope differences between categories were significant with conventional standard errors but not with heteroscedasticity-consistent (HC3) standard errors and are therefore regarded as exploratory. These measurements establish a SERF workflow for comparing post-polarization magnetic relaxation amplitudes across resected human liver specimens.