Medizinische Universität Graz - Research portal
Selected Publication:
Janig, C.
CHARACTERISATION OF RETROGRADE BLOOD-FLOW IN THE MAIN PULMONARY ARTERY IN PATIENTS WITH ELEVATED MEAN PULMONARY ARTERIAL PRESSURE THROUGH CARDIAC MAGNETIC RESONANCE
PHASE-CONTRAST IMAGING
A RETROSPECTIVE STUDY
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2015. pp. 58
[OPEN ACCESS]
FullText
- Authors Med Uni Graz:
- Advisor:
- Fuchsjäger Michael
- Reiter Ursula
- Altmetrics:
- Abstract:
- Pulmonary hypertension (PH) is a life-threatening disease, which is characterised by an elevation of the mean pulmonary artery pressure (mPAP) at rest =25mmHg. According to current guidelines, PH is diagnosed by right heart catheterisation (RHC). Magnetic resonance phase-contrast imaging (MR-PCI) enables to estimate elevated mPAP with physical accuracy by the assessment of the persistence of a characteristic blood flow vortex in the main pulmonary artery (MPA). This vortex causes a retrograde flow whose onset time (“retrograde flow onset time”, ROT) in the cardiac interval can be used as a non-invasive index to diagnose pulmonary arterial hypertension (PAH). The purpose of this study was to investigate if this method can be employed for the diagnosis of PH in general. In the present study 108 patients (n=54 with mPAP=25mmHg / n=54 with mPAP<25mmHg) who underwent RHC due to the clinical suspicion of PH and who un-derwent cardiac magnetic resonance imaging around the time of RHC (11±19 days) were retrospectively enrolled. Global and retrospective blood flow in the MPA was manually evaluated with routine software. ROT was defined as the time difference between the onset of forward and retrograde flow in the MPA, and was determined by different fitting algorithms. Resulting ROTs were compared by 2 sample t-test (non-PH/PH and PAH/non-PAH PH), and analysed by correlation analysis and Receiver-Operating-Characteristic (ROC) curve analysis. Evaluation of ROT by upslope-curve fitting was feasible in all patients without mayor limitations. Mean ROT was significantly shorter in patients with PH compared to patients with normal mPAP (PH: 144±53ms; non-PH: 271±65ms; p<0.0001). PAH and non-PAH PH patients did not show significant differences in ROT (p=0.41). In the present study population, ROT correlated moderately with mPAP (r=-0.67). ROC curve analysis re-vealed high accuracy of ROT for the diagnosis of PAH (PAH: AUC, 0.95; cut-off, 195ms; sensitivity/specificity, 0.88/0.89) and PH (AUC, 0.94; cut-off, 195ms; sensitivity/specificity 0.87/0.89). In conclusion, ROT in the MPA can be determined with routine software from MR-PCI of the MPA. Even though mPAP could not be determined from ROT, early onset of ROT is characteristic for PH and allows non-invasive diagnosis of mPAP=25mmHg with high accuracy.