Assessing Pulmonary Perfusion in Emphysema Automated Quantification of Perfused Blood Volume in Dual-Energy CTPA

Objectives: The objective of this study was to determine whether automated quantification of lung perfused blood volume (PBV) in dual-energy computed tomographic pulmonary angiography (DE-CTPA) can be used to assess the severity and regional distribution of pulmonary hypoperfusion in emphysema. Materials and Methods: We retrospectively analyzed 40 consecutive patients (mean age, 67 13] years) with pulmonary emphysema, who have no cardiopulmonary comorbidities, and a DE-CTPA negative for pulmonary embolism. Automated quantification of global and regional pulmonary PBV was performed using the syngo Dual Energy application (Siemens Healthcare). Similarly, the global and regional degrees of parenchymal hypodensity were assessed automatically as the percentage of voxels with a computed tomographic density less than -900 Hounsfield unit. Emphysema severity was rated visually, and pulmonary function tests were obtained by chart review, if available. Results: Global PBV generated by automated quantification of pulmonary PBV in the DE-CTPA data sets showed a moderately strong but highly significant negative correlation with residual volume in percentage of the predicted residual volume (r = -0.62; P = 0.002; n = 23) and a positive correlation with forced expiratory volume in 1 second in percentage of the predicted forced expiratory volume in 1 second (r = 0.67; P < 0.001; n = 23). Global PBV values strongly correlated with diffusing lung capacity for carbon monoxide (r = 0.80; P < 0.001; n = 15). Pulmonary PBV values decreased with visual emphysema severity (r = -0.46, P = 0.003, n = 40). Moderate negative correlations were found between global PBV values and parenchymal hypodensity both in a per-patient (r = -0.63; P G 0.001; n = 40) and per-region analyses (r = -0.62; P < 0.001; n = 40). Conclusions: Dual-energy computed tomographic pulmonary angiography allows simultaneous assessment of lung morphology, parenchymal density, and pulmonary PBV. In patients with pulmonary emphysema, automated quantification of pulmonary PBV in DE-CTPA can be used for a quick, reader-independent estimation of global and regional pulmonary perfusion, which correlates with several lung function parameters

Penumbra Pattern Assessment in Acute Stroke Patients: Comparison of Quantitative and Non-Quantitative Methods in Whole Brain CT Perfusion - Table 2

<p>* CBF perfusion deficit ≥50 mL, N = 14.</p>†<p>CBF perfusion deficit <50 mL, N = 15.</p><p>** statistically significant.</p><p>ICC: intraclass correlation coefficient.</p><p>doi:10.1371/journal.pone.0105413.t002</p><p>Inter- and intrareader agreement for quantitative methods of mismatch assessment, depending on perfusion deficit volume of the patient, N = 29.</p

ASPECTS for mismatch assessment in CT perfusion.

<p>C, caudate head; I, insular ribbon; IC, internal capsule; L, lentiform nucleus; M1-M6, MCA region 1–6; CBF, cerebral blood flow; CBV, cerebral blood volume.</p

Whole brain CTP mismatch assessment in a 79 yrs old female who presented with a mild left-sided hemiparesis and facial paresis.

<p>NIHSS on admission was 2. WB-CTP was performed 185 min after symptom onset. Concerning MM_ASPECTS, all readers rated for both CBF and CBV ASPECTS regions M1 and M4 in the right hemisphere as the only affected ones. Therefore, in none of the four readings, an ASPECTS mismatch was considered present (MM_ASPECTS = CBF_ASPECTS - CBV_ASPECTS = 8 - 8 = 0). However, volumetric assessment revealed an extensive mismatch of 59.9%. MM_EST varied from 30 to 80% (mean 57.5±26.3%). ASPECTS, Alberta Stroke Programme Early CT Score; CBF, cerebral blood flow; CBV, cerebral blood volume; NIHSS, National Institutes of Health Stroke Scale.</p