High sensitivity and specificity of 4D-CTA in the detection of cranial arteriovenous shunts

Eur Radiol. 2019 Nov;29(11):5961-5970. doi: 10.1007/s00330-019-06234-4. Epub 2019 May 14.

Abstract

Purpose: In a prospective cohort study, we evaluated the diagnostic accuracy of time-resolved CT angiography (4D-CTA) compared to digital subtraction angiography (DSA) for detecting cranial arteriovenous shunts.

Material and methods: Patients were enrolled if a DSA had been ordered querying either a dural arteriovenous fistula (dAVF) or a cerebral arteriovenous malformation (bAVM). After enrolment, both a DSA and a 4D-CTA were performed. Both studies were evaluated using a standardized form. If a dAVF or bAVM was found, its classification, angioarchitectural details, and treatment options were recorded.

Results: Ninety-eight patients were enrolled and 76 full datasets were acquired. DSA demonstrated a shunting lesion in 28 out of 76 cases (prevalence 37%). 4D-CTA demonstrated all but two of these lesions (sensitivity of 93%) and produced one false positive (specificity of 98%). These numbers yielded a positive predictive value (PPV) of 96% and a negative predictive value (NPV) of 96%. Significant doubt regarding the 4D-CTA diagnosis was reported in 6.6% of all cases and both false-negative 4D-CTA results were characterized by such doubt.

Conclusions: 4D-CTA has very high sensitivity and specificity for the detection of intracranial arteriovenous shunts. Based on these results, 4D-CTA may replace DSA imaging as a first modality in the diagnostic workup in a large number of patients suspected of a cranial dAVF or bAVM, especially if there is no doubt regarding the 4D-CTA diagnosis.

Key points: • 4D-CTA was shown to have a high diagnostic accuracy and is an appropriate, less invasive replacement for DSA as a diagnostic tool for cranial arteriovenous shunts in the majority of suspected cases. • Doubt regarding the 4D-CTA result should prompt additional DSA imaging, as it is associated with false negatives. • False-positive 4D-CTA results are rare, but do exist.

Keywords: Angiography; Arteriovenous malformations; Brain imaging; Dural arteriovenous fistula; Four-dimensional computed tomography.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Angiography, Digital Subtraction / methods
  • Arteriovenous Anastomosis / diagnostic imaging
  • Central Nervous System Vascular Malformations / diagnostic imaging*
  • Computed Tomography Angiography / methods
  • Computed Tomography Angiography / standards*
  • Female
  • Four-Dimensional Computed Tomography / standards
  • Humans
  • Intracranial Arteriovenous Malformations / diagnostic imaging*
  • Male
  • Middle Aged
  • Prospective Studies
  • Sensitivity and Specificity