Figure 109f

Qualitative scoring of lung 201Tl activity. Anterior 201Tl images depict myocardial and lung activity. Lung activity can be qualitatively evaluated by comparing it to peak myocardial activity. If the left lung borders are not clearly defined it is grade 0. If the borders of the lung are well defined, but the activity is substantially less than that of peak myocardial activity, it is graded at 1+. If lung activity is equivalent to peak myocardial activity, it is grade 2+. Abnormally increased lung activity can be seen in either left-sided heart failure or chronic obstructive lung disease. In congestive left-sided heart failure, lung activity decreases substantially on the delayed image, while in chronic lung disease it usually persists.

Johnson, L.L., MD, Pohost, G.M., MD, Nuclear Cardiology, Hurst's The Heart, 8th edition, p 2281-2295.