Redundant Neurovascular Imaging: Who Is to Blame and What Is the Value?

Multisystem factors contributing to redundant intracranial vascular imaging in the ED

PURPOSE

To evaluate the multisystem factors contributing to redundant neurovascular orders in the ED.

METHODS

This was an IRB-approved, retrospective study, performed at a single institution examining a 5-year history of redundant CTA/MRA head and neck (HN) exams performed in the ED for patients with no documented clinical change in mental status/neurological exam necessitating additional imaging. Factors contributing to redundant ordering including provider experience, synchronous order placement, and radiologist recommendations were examined. Additionally, the impact of duplicative imaging in terms of medical cost and ED length of stay was evaluated.

RESULTS

250 patients met inclusion criteria with both CTA/MRA of the HN performed during a single ED encounter (total 500 exams). 190 (76%) redundant exams were not recommended by a radiologist and contributed to an added ED length of stay of 3.6 h on average. Provider experience was not a significant contributing factor. 60 (24%) of redundant exams were recommended by a radiologist and were most frequently CTAs needed to clarify an area of artifact/high-grade stenosis/occlusion on a primary MRA exam.

CONCLUSION

Evaluation of contributing factors to redundant CTA/MRA HN exams ordering has highlighted multiple associated factors including provider experience, recommendations by radiologists for clarification of MRA findings, as well as systems processes related to synchronous CTA/MRA order placement.

Redundant Imaging in Transient Ischemic Attack: Evidence From the Nationwide Emergency Department Sample

PURPOSE

Increasing emergency department (ED) compliance with transient ischemic attack (TIA) imaging guidelines has previously been demonstrated, along with a substantial rise in imaging utilization over the past decade. The purpose of this study was to characterize the most commonly used combinations of imaging studies during ED workup of TIA and to quantify prevalence of redundant imaging (RI).

METHODS

TIA discharges from EDs in the United States from 2006 to 2017 were identified in the Nationwide Emergency Department Sample. Brain and neurovascular imaging obtained during the encounter was identified using Current Procedural Terminology codes. RI was defined as an ED encounter with any duplicate cross-sectional brain, brain-vascular, or neck-vascular imaging. Patient demographics and hospital characteristics were incorporated into a multivariable logistic regression analysis to identify significant associations with RI.

RESULTS

There were 184,870 discharges with TIA from EDs in 2017. RI (brain) was observed in 55,513 (30%) of encounters. RI (brain-vascular) and RI (neck-vascular) imaging was identified in 5,149 (2.8%) and 1,325 (0.7%) of encounters, respectively. Decreased odds of obtaining RI was observed in Medicaid patients(odds ratio [OR: 0.72, 95% confidence interval [CI]: 0.64-0.81), non-trauma centers(OR: 0.49, 95% CI: 0.26-0.93), rural hospital locations(OR: 0.18, 95% CI: 0.11-0.29), and weekend encounters(OR: 0.9, 95% CI: 0.85-0.96). Trend analysis from 2006 to 2017 demonstrated a rise in RI (brain) from 2.3% of encounters in 2006 to 30% of encounters in 2017. RI for patients discharged from EDs with TIA in 2017 resulted in additional charges of approximately US $8,670,832.

CONCLUSION

Increased imaging utilization for TIA workup across EDs in the United States is associated with rising use of redundant imaging. We identify imaging practices that could be targeted to mitigate health care expenditures, while adhering to TIA imaging guidelines.

Vascular imaging in the initial evaluation of embolic stroke source

PURPOSE

During acute ischemic stroke evaluations, neurovascular imaging is commonly performed to localize the source of a thromboembolus and to identify vascular stenoses. In this study, we aimed to analyze 1) the usefulness of intracranial and/or cervical CTA and MRA and carotid doppler ultrasound (DUS) for identifying the stroke source and 2) the incidence of vascular stenoses across stroke etiologies.

METHODS

We retrospectively reviewed intracranial and/or cervical CTA, DUS and MRA studies to identify the source of the acute stroke by Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria for 200 consecutive patients admitted with a stroke to our tertiary hospital. Stroke etiologies were ascertained and the rates of intracranial and cervical vascular stenoses were stratified by stroke type.

RESULTS

Of 200 patients, the most probable sources of stroke were small vessel disease (29%), cardioembolic (26.0%) and atheroembolic (23.5%). Across all groups, 27.5% of patients had ≥70% stenosis on neurovascular imaging. The rate of ≥70% vascular stenosis in the neck was 6.9% and 5.8% in the small vessel and cardioembolic categories, respectively.

CONCLUSIONS

The TOAST etiologies of strokes were nearly equally distributed. Neurovascular imaging was of high utility for identifying large vessel intracranial stenoses in patients presenting with acute stroke across all etiologies, although neck CTA/MRA had a lower rate of positive studies with cardiogenic and small vessel strokes. These findings have implications on the use of CTA/MRA in acute stroke work-up.