| Objective:Idiopathic pulmonary arterial hypertension (IPAH) is a progressive disease with a poor prognosis. The non-uniform distributions of lung perfusion scans are a well-know feature of pulmonary hypertension. The aim of this study was to assess the value of lung perfusion scan in quantitative analysis of idiopathic pulmonary arterial hypertension (IPAH)Methods:Both lung perfusion scans and right heart catheterization were performed in thirty patients with IPAH. Lung perfusion images were analyzed and Perfusion index (P index) was obtained using quantitative software provided by NIH. Twelve age-matched control subjects were also underwent lung perfusion scans for drawing PAR curve. A Pearson correlation coefficient was determined between the P index and hemodynamic parameters. The patients were divided into three groups. The differences of P index among the groups were assessed by Student's t test.Results:The P index was significantly correlated with mPAP and TPR (R=0.541 for mPAP, P<0.01 and R=0.573 for TPR, P<0.01). Significant differences of P index were showed in three groups divided by three typical characters in lung perfusion scan(Student's t test, t value:-2.83,-5.68,-2.65, all P<0.05). The mPAP and TPR showed no significant differences for these 3 groups.Conclusion:The P index is a useful indicator for quantifying the non-uniform distributions of lung perfusion scan. Quantitative assessment of lung perfusion could provide useful information about the severity of IPAH. Objective:The non-uniform distributions of lung perfusion scans are a well-know feature of pulmonary hypertension. The aim of this study was to assess the value of lung perfusion scan in quantitative analysis of various forms of pulmonary arterial hypertension(PAH), including idiopathic pulmonary arterial hypertension (IPAH), pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) and chronic thromboembolic pulmonary hypertension (CTEPH).Methods:Eighty-three patients who had pulmonary hypertension were enrolled prospectively between February and December in 2009. Six patients were excluded for meeting exclusion criteria and six patients were excluded for their situation not suitable for the study protocol. Lung perfusion scans, right heart catheterization and Doppler echocardiography were all performed in thirty patients with PAH. Lung perfusion images were analyzed and Perfusion index (P index) was obtained using quantitative software provided by NIH. Twelve age-matched control subjects were also underwent lung perfusion scans for drawing PAR curve. A Pearson correlation coefficient was determined between the P index and hemodynamic parameters. Bland altman method was used to assess the agreement between right heart catheterization and Doppler echocardiography.Results:Among the 71 patients with PAH,34 patients were IPAH,17 patients were PAH-CHD, and 20 patients were CTEPH.1. The P index was significantly correlated with mPAP and TPR (R=0.550 for mPAP, P<0.01 and R=0.495 for TPR, P<0.01) in IPAH patients. There was no correlation between P index and sPAP(R=0.329, P>0.05).2. The P index was significantly correlated with sPAP, mPAP and TPR (R=0.0.631 for sPAP, P<0.01,R=0.641 for mPAP, P<0.01 and R=0.730 for TPR, P<0.01) in PAH-CHD patients. 3. The P index shows no correlation with sPAP, mPAP and TPR (R=-0.376 for sPAP, R=-0.135 for mPAP and R=-0.334 for TPR, all P<0.01) in CTEPH patients.4. The Doppler echocardiography shows good correlation and consistency with right heart catheterization, whereas sPAP and mPAP were underestimated by Doppler echocardiography comparing with right heart catheterization.Conclusion:The P index is a useful indicator for quantifying the non-uniform distributions of lung perfusion scan. Quantitative assessment of lung perfusion could provide useful information about the severity of IPAH and CTEPH. Objective:To investigate the added value of the Wells score and D-dimer assay as adjunct to pulmonary perfusion imaging for the diagnosis of acute pulmonary embolism(APE).Methods:From January,2006 to December 2008,121 consecutive patients with suspected APE were studied. All patients underwent the assessment of clinical probability (the Wells score), a quantitative D-dimer assay, chest X-ray and pulmonary perfusion imaging. The sensitivity, specificity, positive predictive value and negative predictive value were calculated to assess the diagnostic accuracy of pulmonary perfusion imaging combining with Wells score and D-dimer.Results:Of 121 patients,41.3%(51/121) had APE, and APE was excluded in 58.7%(71/121) patients. Pulmonary perfusion imaging combining with chest radiography (Q/X scan) showed positive results in 49 patients. The sensitivity, specificity, positive predictive value and negative predictive value of the Q/X scan were 86.0%,91.5%,87.3% and 90.2%, respectively. Combined with Wells score>4 and D-dimer≥0.5mg/L, Q/X scan had a positive predictive value (PPV) of 100%, for patients with Wells score≤4 and D-dimer<0.5mg/L, the negative predictive value (NPV)for Q/X scan was 100%.Conclusion:The assessment of clinical probability and D-dimer assay may offer improved PPV and NPV for Q/X scan in the diagnosis of APE. |
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