I enjoyed reading the paper of Pacheco-Torres et al.Reference Pacheco-Torres, Lopez-Larrubia, Ballesteros and Cerdan1 The authors have provided pO2 values of some human organs and a few cancerous tissues. Using pO2 values, a new perspective can be assessed.
In Figure 1, we plotted the T1 against the pO2 in six healthy tissue and three neoplastic tissue (Table 1) and yielded a good correlation (R 2 = 0.74). The T1 values are abstracted from Damadian et alReference Damadian, Zaner, Hor and and DiMaio2. The neoplastic tissue not only has low pO2 values but also has higher T1 value. This is consistent with the findings of AkberReference Akber3 and O’Connor et alReference O’Connor, Naish and Parker4.
Figure 1. Correlation between water proton spin lattice relaxation time and median oxygen tension
Table 1. Median pO2 values along with organ weight, and spin lattice relaxation time (T1) in normal and neoplastic tissues
In Figure 2, we plotted the pO2 values with organ weight and yielded a good correlation of 0.72. AkberReference Akber5 showed that T1 correlates well with organ weight in human organs as well as in animal organs.
Figure 2. Correlation between median oxygen tension and organ weight.
It is indeed interesting to note that T1 and pO2 yield a linear relationshipReference Akber3. The T1 value of the whole organ would provide a base value of pO2. Changes in T1 value in an organ would provide a sensitive index of the onset of hypoxia. For example, in normal breast tissue, the T1 value is 367 ms and pO2 value is 52 mm Hg, whereas in neoplastic breast tissue the T1 value is 1,080 ms and pO2 value is 9 mm Hg. In three cancerous tissues (Table 1), they yielded higher T1 value than any normal organs. It is also interesting to note that as the organ weight increases by assembling many cells of different functions, pO2 decreases (Figure 2).
Respectfully submitted
Syed F. Akber, PhD, DABR
Radiological Physicist
Cleveland, Ohio, USA
