Pulmonary Angiography- Beautiful 128 Slice CT images

An elderly male with clinically possible pulmonary embolism with wells score of 6.0,  undergoes Perfusion scan in nuclear medicine  which suspects underperfused apices possibly thrombotic . MDCT angio with 128 slices machine, shows attenuated and patent upper lobar arteries due to large bullous disease on account of COPD and that explains clinical breathlessness with MPA and the main branches completely patent. Case submitted by Dr MGK Murthy and Mr Shekhar (CT technologist)

Teaching points :

·         Definition of  Pulmonary embolism= Blockage of MPA or one of its branches

·         Incidence increases  with age and reaches about 300 cases per 100,000 population/yr in western world by 8th decade

·         Mortality in untreated reaches about 30% even today

·         D-Dimer test( a protein fragment found in blood after blood clot is degraded by thrombolysis)can practically rule out thrombus if negative

·         Nuclear medicine  role is reducing nowadays with  increased number of false positives  due to interlobar fissure, COPD, pneumonia, and atelectasis

·         MDCT angio with specific acquisition of images before the contrast reaches aorta(as in our case ), by placing  the bolus chase in Right ventricle , highly specific and sensitive  even in segmental branches

·         Radiation doses have significantly decreased over time  with average of 23-119 CXR equivalent , depending on the  No of slices machine and body habitus deciding the factors

·         False negative of MDCT is usually due to septic emboli(peripherally) and subsegmental defects

·         In our case 60 ml (serum creatinine was  marginally elevated and  test was done in view of positive perfusion scan and clinical  suspicion) of omnipaque at 5ml/ sec was injected with bolus chase in Right ventricle with saline chase of 30mlwith 4 ml/sec rate .