Jump to comment:

• Single- or multi-detector row CT in diagnosing PE: a never ending debate?
  Mathilde Nijkeuter
  Published on: 3 April 2006

• Published on: 3 April 2006

  Single- or multi-detector row CT in diagnosing PE: a never ending debate?

  • Mathilde Nijkeuter, Physician
  • Other Contributors:
    • Menno V.Huisman

  Dear Editor,

  We would like to comment to the limitations of the Christopher-study (JAMA 2006;295) mentioned by Dr. Bari. He states that “the limitations of this study include the use of two different kinds of CT scanner (multi- detector and single-detector) with potentially different pick up rates”. The other limitation stated is: “the prevalence of PE of 23.2% in the ‘clinically unlikely PE and abnormal D-dimer’...

  Show More

  Dear Editor,

  We would like to comment to the limitations of the Christopher-study (JAMA 2006;295) mentioned by Dr. Bari. He states that “the limitations of this study include the use of two different kinds of CT scanner (multi- detector and single-detector) with potentially different pick up rates”. The other limitation stated is: “the prevalence of PE of 23.2% in the ‘clinically unlikely PE and abnormal D-dimer’ group shows that a clinical scoring system alone is inadequate”.

  It is commonly suggested that multi-detector row CT is more likely to detect subsegmental PE in comparison to single-detector row CT. However, whether subsegmental PE is clinically relevant and needs to be treated with anticoagulants is uncertain(Eyer, Am J Roentgenol 2005;184, Goodman, Radiology 2005;234). Because we used multi-detector row CT, there’s a potential for overdiagnosis of subsegmental PE that are not clinically important. The limitation of our study was that patients did not undergo confirmatory pulmonary angiography and thus, our study design did not permit assessing the rate of false-positive CT-scans. Because only 10% of patients underwent single-detector row CT, a meaningful comparison of both techniques was not possible. However, as we have mentioned in the discussion section, the prevalence of PE in our study (20%) compares well with the prevalence of PE in a previous study (24%, van Strijen, Ann Int Med 2003;138) that used solely single-detector row CT and does not support a concern that multi-detector row CT leads to a high number of overdiagnosis of subsegmental PE.

  Concerning the other limitation mentioned by Bari, we think that a clinical scoring system is not designed to adequately diagnose PE, but to categorize patients into groups with low and high risks of PE. The clinical scoring system we used, showed that patients categorized as ‘PE unlikely’ can be safely left untreated if the D-dimer test is normal. In this way, we were able to prevent performing a CT-scan to exclude PE in 32% of our study population.

  Show Less

  Conflict of Interest:
  None declared.

  • Back to top