Identifying the heterogeneity of COPD by V/P SPECT: a new tool for improving the diagnosis of parenchymal defects and grading the severity of small airways disease

Figures & data

Table 1 Characteristics of the patients

94 COPD patients	Mean ± SD	Range
Age (years)	68±9	43–86
Height (cm)	164±7	146–178
Weight (kg)	66±11	38–98
BMI (kg/m^2)	24±4	16–35
Pack years	33±21	0–104
Number of exacerbations within the past 12 months	1.1±1.3	0–6
Spirometry
– Post-bronchodilatation FEV1	50%±18% pred	21%–108% pred
– Post-bronchodilatation FVC	82%±22% pred	28%–125% pred
– Post-bronchodilatation FEV1/FVC	51%±15%	25%–86%
– Acute bronchodilatation response	6.3%±7.8%	−9%–43%

Abbreviations: BMI, body mass index; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; SD, standard deviation.

Figure 1 V/P SPECT of a patient with a severe COPD (GOLD 3).

Notes: On the frontal slice, uneven distribution of ventilation and absent ventilation are seen, as is perfusion in the upper lobe (blue arrows indicating emphysema). Hot spots represent changes in small airway disease (dotted blue arrow on sagittal slice).

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; V/P SPECT, ventilation/perfusion single-photon emission computed tomography.

Figure 2 Correlation between Vgrade and TPLF% and GOLD stages.

Note: Pearson correlation coefficients and linear regression lines with best-fit values (continuous line) and 95% confidence intervals (dotted lines) are presented.

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; TPLF%, total preserved lung function; SPECT, single-photon emission computed tomography; Vgrade, penetration grade of Technegas in V SPECT.

Figure 3 Correlation between Vgrade and TPLF% and results of the technically accepted and reproducible pulmonary lung function tests.

Note: Pearson’s correlation coefficients and linear regression lines with best-fit values (continuous line) and 95% confidence intervals (dotted lines) are presented.

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; TPLF%, total preserved lung function; SPECT, single-photon emission computed tomography; Vgrade, penetration grade of Technegas in V SPECT.

Figure 4 Vgrade 1, 2, and 3 in relation to the technically accepted and reproducible lung function test results (n=75).

Note: The plots of measurements with the mean and the 95% confidence intervals are shown.
Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; SPECT, single-photon emission computed tomography; Vgrade, penetration grade of Technegas in V SPECT.

Figure 5 V/P SPECT of a patient with a severe COPD (GOLD 3).

Note: Uneven distribution of ventilation with hot spots (indicating obstructive small airways disease), area with absent ventilation and perfusion in the upper lobe (blue arrows indicating emphysema), as well as area with absent perfusion and preserved ventilation (mismatch – red arrows indicating pulmonary embolism).
Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; V/P SPECT, ventilation/perfusion single-photon emission computed tomography.