Ventilation perfusion single photon emission computed tomography: Referral practices and diagnosis of acute pulmonary embolism in the quaternary clinical setting

J Med Imaging Radiat Oncol. 2018 Dec;62(6):777-780. doi: 10.1111/1754-9485.12803. Epub 2018 Sep 20.

Abstract

Introduction: Ventilation perfusion single photon emission computed tomography (V/Q SPECT) and CTPA are the two leading imaging studies used to investigate acute pulmonary embolism. V/Q SPECT is often the first line investigation for pregnant patients and young females. Historically, V/Q Planar studies have high rates of indeterminate findings resulting in a preference for CTPA studies. The purpose of this research is to examine current V/Q SPECT referral practices in the quaternary clinical setting and to confirm V/Q SPECT studies have low rates of equivocal findings.

Methods: Retrospective study of a 6-month period of all completed V/Q SPECT studies (± LDCT) indicated for investigation of acute PE. V/Q SPECT studies were reported using the European Association of Nuclear Medicine guidelines. Patient demographic data and V/Q SPECT findings were recorded. CTPA and Doppler Ultrasound report findings were included if performed 48 hours prior to, or following V/Q SPECT study. Standard descriptive statistical analysis was undertaken.

Results: Ninety-nine percent of V/Q SPECT studies had reports positive or negative for acute PE, with 1% inconclusive. Twenty-two percent of patients had either CTPA or Doppler Ultrasound studies within a 48- hour period prior to, or following V/Q SPECT, with the majority having a negative Doppler ultrasound prior to negative V/Q SPECT. Sixty-eight percent of patients referred for V/Q SPECT were females under the age of 55, 40% of whom were pregnant.

Conclusions: Ventilation perfusion single photon emission computed tomography has low rates of equivocal findings with referral practices indicating pregnant patients and young women are considered to most benefit from V/Q SPECT as a first line investigation for acute PE.

Keywords: V/Q SPECT; female; inconclusive; pregnancy; referral.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pregnancy
  • Pulmonary Embolism / diagnostic imaging*
  • Radiopharmaceuticals
  • Referral and Consultation
  • Retrospective Studies
  • Technetium Tc 99m Aggregated Albumin
  • Tomography, Emission-Computed, Single-Photon / methods

Substances

  • Radiopharmaceuticals
  • Technetium Tc 99m Aggregated Albumin