Correlation among the Indices of High-Resolution Computed Tomography, Pulmonary Function Tests, Pulmonary Perfusion Scans and Exercise Tolerance in Cases of Chronic Pulmonary Emphysema

Abstract

Background: Mismatched distribution of pulmonary blood flow is a common characteristic in emphysematous patients. But few reports have mentioned the relationships between the morphological changes in the lungs as assessed by high-resolution computed tomography (HRCT), pulmonary blood flow (PBF) scan and the indices of exercise tolerance. We investigated these relationships. Objective: Pulmonary function tests (PFT), HRCT, single photon emission computed tomography (^99mSPECT) and treadmill exercise tests were performed on emphysematous patients, and the correlations between these examinations were studied. Methods: We evaluated 20 patients (M 18, F 2, age 66 ± 8.0 years). CT evaluation was performed according to the grade of emphysematous change. ^99mSPECT was performed to evaluate mismatched PBF by the score method. The better flow of the middle lobe was selected to be the standard lobe for the basic PBF. That score was set to 1 when the blood flow was below 60 or above 140%. PBF between 60 and 140% was scored as 0. Results: FEV₁(r = 0.648, p = 0.002) and VC (r = 0.767, p = 0.001) correlated significantly with v̇O₂ peak . FEV₁ (r = 0.667, p = 0.0018) correlated significantly with anaerobic threshold (AT). CT grade did not correlate with PBF mismatch score (r = 0.266, p = 0.3376). %v̇O₂peak did not correlate with CT grade (r = –0.467, p = 0.0689) or with mismatch PBF score (r = –0.327, p = 0.2377). Conclusions: HRCT and ^99mSPECT were advantageous for detecting the progression of disease and emphysematous changes. However, the severity of anatomical emphysematous changes did not necessarily correlate with the indices of exercise tolerance and pulmonary function tests.

Six-Minute Walk Distance Predictors, Including CT Scan Measures, in the COPDGene Cohort

“…31,34,44,45 However, only a few studies examined the association of CT scan fi ndings with exercise tolerance. [14][15][16]18 Two reports studied only 20 subjects with COPD. 15,16 For example, Wakayama et al 16 found that emphysema score correlated significantly with 6MWD ( r 5 2 0.74).…”

“…[14][15][16]18 Two reports studied only 20 subjects with COPD. 15,16 For example, Wakayama et al 16 found that emphysema score correlated significantly with 6MWD ( r 5 2 0.74). In a recent study of The dependent variable is 6-min walk distance, and the independent variables are FEV 1 % predicted, BMI, age, sex, race, % gas trapping, and the interaction of % gas trapping with FEV 1 % predicted.…”

“…13 Despite the association between exercise tolerance and lung hyperinfl ation in COPD, few studies have examined the association between CT scan measures of lung hyperinfl ation, namely emphysema and gas trapping, and exercise tolerance measured by 6MWD. [14][15][16] Further, except for one study, 14 sample sizes were too small (n 5 20) 15,16 to adequately discern Primary inclusion criteria were self-identifi ed racial/ethnic category of either non-Hispanic Caucasian or non-Hispanic African American aged 45 to 80 years with a Ն 10 pack-year smoking history. Key exclusion criteria were pregnancy, a history of other lung disease except asthma, previous excision of one or more lung lobes (or lung volume reduction procedure), metal in the chest, or history of chest radiation therapy.…”

Assessment of lobar perfusion in smokers according to the presence and severity of emphysema: preliminary experience with dual-energy CT angiography

“…Although this technique can provide information on the perfusion pattern in patients with severe emphysema, it suffers from low spatial resolution. SPECT has the potential for superior evaluation, but it is rarely used because the technique is very time-consuming and not widely available [7,8]. MRI appears to be a more promising technique owing to its high diagnostic accuracy in the detection of perfusion abnormalities and the ability to provide lobar and segmental analysis of perfusion defects [9][10][11].…”

Semi-quantitation of pulmonary perfusion heterogeneity on respiratory-gated inspiratory and expiratory perfusion SPECT in patients with pulmonary emphysema

“…The expiratory D index was also closely correlated with K CO in our patients, although the extent of LAA on CT was not signifi cantly correlated. CT has certain limitations in detecting emphysematous lungs because of limited spatial resolution [22][23][24][25][26][27]. The earlier clinical studies showed a relatively low prevalence of LAA on CT, regardless of signifi cant airfl ow limitation in respiratory function test in PE patients [22,24].…”