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