Computed Tomographic Pulmonary...
Transcript of Computed Tomographic Pulmonary...
Computed Tomographic Pulmonary Angiography[CTPA]
Dr.Reddi Prabhakara Rao MD,DNB,PDCC,
Consultant Radiologist The Aga Khan Hospital
Kisumu
Overview • Aims and Objectives • Materials and Methods • Chest radiograph findings • Diagnostic tests available • CTPA and the technique • Flow charts showing the effective usage of these tests • Results of our cases • Discussion of the cases • Conclusions • Acknowledgements • References • Take home message
Aims and Objectives
• To emphasise the omportance of CTPA in the diagnosis of pulmonary embolism.
• To discuss the effective usage of CTPA along with other diagnostic tests, for the diagnosis of high,intermediate and low probability pulmonary embolism.
Materials and Methods
• 16 patients with clinical suspicion of pulmonary embolism are subjected for CTPA
• Seimens emotion duo spiral CT, Medrad single syringe pressure injector for iv nonionic contrast injection, and 3D reconstruction software.
Chest radiograph findings
• Cardiomegaly • Atelectasis • Infiltrate • Pleural effusion • Elevated hemidiaphragm • Fleishners sign • Hamptons hump • Westermark sign
Diagnostic tests available
• D‐dimer • Doppler ultrasound • CTPA • Ventilation‐perfusion scan • Conventional pulmonary angiography
CTPA and the technique • Preferably overnight fasting for an elective case. • UECs to be within limits. • A patent venous access with atleast a 20g bore cannula is
required. • The syringe pump with contrast is fixed to the iv cannula. • 3.5 to 4 ml/sec speed of injecting the contrast and a 10sec
delay is ideal. • Enough saline flush after the procedure into the in iv line. • Axial images with 3mm width can be aquired in a spiral
mode. • Post processing to be done after the procedure for 3d
images.
Results of our cases
• 10 out of our clinically suspected cases are positive on CTPA
• All of them are effectively treated for pulmonary embolism with follow up.
• One case of Budd Chiari Syndrome was diagnosed
Conclusions
• CTPA is a relatively easily available modality for an effective diagnosis of a clinically suspected pulmonary embolism
• Superior to D‐dimer in the fact that d‐dimer has quite a few false positives
• Superior to VP scan in the fact that lung, mediastinal and bony lesions can also be visualised. Also a relatively available modality.
• Availability of a Doppler ultrasound adds value for the diagnosis of deep vein thrombosis.
Acknowledgements
• Dr. Feroz Allibhoy • Dr.Amos Otedo • Dr.Sanjeev Parmar • Dr.Opio • Dr.Prasad in preparing this paper. • Mr Dickson Olouch for his technical support.
References • Fedullo PF, Tapson VF (2003). "Clinical practice. The evaluation of
suspected pulmonary embolism". N. Engl. J. Med. 349 (13): 1247–56. doi:10.1056/NEJMcp035442. PMID 14507950.
• Anderson DR, Kahn SR, Rodger MA et al. (2007). "Computed tomographic pulmonary angiography vs ventilation‐perfusion lung scanning in patients with suspected pulmonary embolism". JAMA 298 (23): 2743–53. doi:10.1001/jama.298.23.2743. PMID 18165667. http://jama.ama‐assn.org/cgi/content/abstract/298/23/2743.
• Scarsbrook AF, Gleeson FV (2007). "Investigating suspected pulmonary embolism in pregnancy". BMJ 334 (7590): 418–9. doi:10.1136/bmj.39071.617257.80. PMID 17322258. PMC 1804186. http://www.bmj.com/cgi/content/full/334/759
• Schoepf UJ, Goldhaber SZ, Costello P (2004). "Spiral computed tomography for acute pulmonary embolism". Circulation 109 (18): 2160–7. doi:10.1161/01.CIR.0000128813.04325.08. PMID 15136509. http://circ.ahajournals.org/cgi/content/full/109/18/2160.
Take home message
• CTPA accounts for the only diagnostic tool in a place like kisumu,where other modalities are not available.
• CTPA is very fast,relatively easily available and a globally upcoming imaging modality of choice for the diagnosis of pulmonary embolism.
• Doppler ultrasound by picking DVT ,adds value for the diagnosis of PE and VTE.