Pulmonary blood volume and pulmonary extravascular water volume in men

Multi-slice, breathhold imaging of the lung with submillisecond echo times

The signal from the lungs is heavily attenuated by T2 and T2 decay in standard MR images of the thorax. The authors utilized the capabilities of a prototype fast gradient system to develop a multi-slice gradient echo sequence that can obtain images with an echo time of 0.7 ms. Images acquired in a single breath-hold are free from respiratory motion artifacts and clearly display signal from lung parenchyma. The use of fast gradients makes short echo times possible without the use of nonstandard RF pulses and spatial encoding techniques and their associated limitations.

Extravascular lung water measured with 99mTc-RBC and 99mTc-DTPA is increased in left-sided heart failure

Extravascular lung water (EVLW) was quantitatively measured in 81 patients consisting of 10 subjects with normal cardiac function and 71 patients with left-sided heart diseases, using 99mTc-RBC as a non-diffusible indicator and 99mTc-DTPA as a diffusible indicator in the equilibrium phase. EVLW averaged 3.0 +/- 1.4 (ml/kg, mean +/- SD) in subjects with normal cardiac function (n = 10), 4.3 +/- 1.7 in New York Heart Association functional class I patients (n = 30), 4.8 +/- 2.4 in NYHA functional class II patients (n = 33) and 9.4 +/- 5.4 in NYHA functional class III (n = 8) patients. EVLW was greater in NYHA class III than in normal controls or NYHA classes I or II (p < 0.01). Lung thermal volume (LTV) was also measured in 31 of the 81 patients using a double indicator dilution technique with sodium and heat. LTV averaged 6.0 +/- 1.2 (ml/kg) in normal subjects (n = 4), 8.6 +/- 2.0 in NYHA functional class I patients (n = 11), 9.7 +/- 3.0 in NYHA functional class II patients (n = 13), and 15.9 +/- 8.2 in NYHA functional class III patients (n = 3). The correlation between EVLW and LTV was significant (EVLW = 0.79 x LTV - 72.8, r = 0.80, p < 0.01). There were significant differences in EVLW/LTV ratio between NYHA class III (0.93 +/- 0.16) and NYHA class I (0.62 +/- 0.22). Thus, it was shown that EVLW was increased in left-sided heart failure and that LTV overestimated the EVLW.