PT  - JOURNAL ARTICLE
AU  - Jonas Jögi
AU  - Björn Jonson
AU  - Marie Ekberg
AU  - Marika Bajc
TI  - Ventilation–Perfusion SPECT with <sup>99m</sup>Tc-DTPA Versus Technegas: A Head-to-Head Study in Obstructive and Nonobstructive Disease
AID  - 10.2967/jnumed.109.073957
DP  - 2010 May 01
TA  - Journal of Nuclear Medicine
PG  - 735--741
VI  - 51
IP  - 5
4099  - http://jnm.snmjournals.org/content/51/5/735.short
4100  - http://jnm.snmjournals.org/content/51/5/735.full
SO  - J Nucl Med2010 May 01; 51
AB  - Lung scintigraphy is primarily used to diagnose pulmonary embolism. Ventilation imaging is often performed using 99mTc-DTPA or Technegas, an ultrafine dispersion of 99mTc-labeled carbon. Despite the common use of these radioaerosols, they have not been compared in an intraindividual study, and not with ventilation–perfusion (V/P) SPECT. The aim of the present head-to-head study was to systematically investigate differences in ventilation studies performed with 99mTc-diethylenetriaminepentaacetate (DTPA) and Technegas. Methods: Sixty-three patients, 28 without and 35 with obstructive lung disease, were examined with V/P SPECT using both 99mTc-DTPA and Technegas. V/P SPECT images were randomized and assessed independently by 2 masked physicians according to a predefined scoring system. A paired comparison was performed using the Wilcoxon signed-rank test. Results: In both obstructive and nonobstructive disease, the overall unevenness of radiotracer deposition and the degree of central deposition were more pronounced in 99mTc-DTPA than Technegas studies. Because of better peripheral penetration, the extent of reverse mismatch was less when Technegas was used. Additionally, in obstructive disease, the degree of focal deposition in distal airways was more pronounced with 99mTc-DTPA. Mismatched perfusion defects were more frequently found with Technegas in obstructive disease. Conclusion: This intraindividual comparative study shows that Technegas is the preferred radioaerosol, particularly in obstructive disease.