Reliability of the Diagnosis of Cerebral Vasospasm Using Catheter Cerebral Angiography: A Systematic Review and Inter- and Intraobserver Study

BACKGROUND AND PURPOSE

Conventional angiography is the benchmark examination to diagnose cerebral vasospasm, but there is limited evidence regarding its reliability. Our goals were the following: 1) to systematically review the literature on the reliability of the diagnosis of cerebral vasospasm using conventional angiography, and 2) to perform an agreement study among clinicians who perform endovascular treatment.

MATERIALS AND METHODS

Articles reporting a classification system on the degree of cerebral vasospasm on conventional angiography were systematically searched, and agreement studies were identified. We assembled a portfolio of 221 cases of patients with subarachnoid hemorrhage and asked 17 raters with different backgrounds (radiology, neurosurgery, or neurology) and experience (junior ≤10 and senior >10 years) to independently evaluate cerebral vasospasm in 7 vessel segments using a 3-point scale and to evaluate, for each case, whether findings would justify endovascular treatment. Nine raters took part in the intraobserver reliability study.

RESULTS

The systematic review showed a very heterogeneous literature, with 140 studies using 60 different nomenclatures and 21 different thresholds to define cerebral vasospasm, and 5 interobserver studies reporting a wide range of reliability (κ = 0.14-0.87). In our study, only senior raters reached substantial agreement (κ ≥ 0.6) on vasospasm of the supraclinoid ICA, M1, and basilar segments and only when assessments were dichotomized (presence or absence of ≥50% narrowing). Agreement on whether to proceed with endovascular management of vasospasm was only fair (κ ≤ 0.4).

CONCLUSIONS

Research on cerebral vasospasm would benefit from standardization of definitions and thresholds. Dichotomized decisions by experienced readers are required for the reliable angiographic diagnosis of cerebral vasospasm.

Reliability of CT Angiography in Cerebral Vasospasm: A Systematic Review of the Literature and an Inter- and Intraobserver Study

BACKGROUND AND PURPOSE

Computed tomography angiography offers a non-invasive alternative to DSA for the assessment of cerebral vasospasm following subarachnoid hemorrhage but there is limited evidence regarding its reliability. Our aim was to perform a systematic review (Part I) and to assess (Part II) the inter- and intraobserver reliability of CTA in the diagnosis of cerebral vasospasm.

MATERIALS AND METHODS

In Part I, articles reporting the reliability of CTA up to May 2018 were systematically searched and evaluated. In Part II, 11 raters independently graded 17 arterial segments in each of 50 patients with SAH for the presence of vasospasm using a 4-category scale. Raters were additionally asked to judge the presence of any moderate/severe vasospasm (≥ 50% narrowing) and whether findings would justify augmentation of medical treatment or conventional angiography ± balloon angioplasty. Four raters took part in the intraobserver reliability study.

RESULTS

In Part I, the systematic review revealed few studies with heterogeneous vasospasm definitions. In Part II, we found interrater reliability to be moderate at best (κ ≤ 0.6), even when results were stratified according to specialty and experience. Intrarater reliability was substantial (κ > 0.6) in 3/4 readers. In the per arterial segment analysis, substantial agreement was reached only for the middle cerebral arteries, and only when senior raters' judgments were dichotomized (presence or absence of ≥50% narrowing). Agreement on the medical or angiographic management of vasospasm based on CTA alone was less than substantial (κ ≤ 0.6).

CONCLUSIONS

The diagnosis of vasospasm using CTA alone was not sufficiently repeatable among observers to support its general use to guide decisions in the clinical management of patients with SAH.

Inter- and Intrarater Agreement on the Outcome of Endovascular Treatment of Aneurysms Using MRA

BACKGROUND AND PURPOSE

Patients treated with coiling are often followed by MR angiography. Our objective was to assess the inter- and intraobserver agreement in diagnosing aneurysm remnants and recurrences by using multimodality imaging, including TOF MRA.

MATERIALS AND METHODS

A portfolio composed of 120 selected images from 56 patients was sent to 15 neuroradiologists from 10 institutions. For each case, raters were asked to classify angiographic results (3 classes) of 2 studies (32 MRA-MRA and 24 DSA-MRA pairs) and to provide a final judgment regarding the presence of a recurrence (no, minor, major). Six raters were asked to independently review the portfolio twice. A second study, restricted to 4 raters having full access to all images, was designed to validate the results of the electronic survey.

RESULTS

The proportion of cases judged to have a major recurrence varied between 16.1% and 71.4% (mean, 35.0% ± 12.7%). There was moderate agreement overall (κ = 0.474 ± 0.009), increasing to nearly substantial (κ = 0.581 ± 0.014) when the judgment was dichotomized (presence or absence of a major recurrence). Agreement on cases followed-up by MRA-MRA was similarly substantial (κ = 0.601 ± 0.018). The intrarater agreement varied between fair (κ = 0.257 ± 0.093) and substantial (κ= 0.699 ± 0.084), improving with a dichotomized judgment concerning MRA-MRA comparisons. Agreement was no better when raters had access to all images.

CONCLUSIONS

There is an important variability in the assessment of angiographic outcomes of endovascular treatments. Agreement on the presence of a major recurrence when comparing 2 MRA studies or the MRA with the last catheter angiographic study can be substantial.

Traumatic intracranial hematomas: prognostic value of contrast extravasation

BACKGROUND AND PURPOSE

Contrast extravasation within spontaneous intracranial hemorrhage is a well-described predictor of hematoma growth, poor clinical outcome, and mortality. The purpose of this study was to assess the prognostic value of contrast extravasation in acute traumatic intracranial hematomas.

MATERIALS AND METHODS

In our institution, CTA (including PCCT) is the primary screening technique for cervical vascular injuries. Sixty consecutive patients with at least 1 acute intracranial hematoma (ICH, subdural hematoma, and/or epidural hematoma) meeting predefined size criteria, with CTA/PCCT performed within 24 hours of admission and follow-up CT within 72 hours of admission, were retrospectively evaluated for CE by 2 observers. The predictive value of CE for a composite outcome (hematoma expansion, need for hematoma evacuation, in-hospital mortality) was evaluated on a per-patient basis. Interobserver agreement for CE and the association between baseline variables and outcome were also examined. Different patterns of extravasation were evaluated on a per-lesion basis, with outcomes including hematoma expansion and evacuation.

RESULTS

CE was present in 30 (50%) patients with almost perfect interobserver agreement (κ=0.87; 95% CI, 0.74-0.99). The per-patient multivariate analysis showed independent association of midline shift (P=.020), Glasgow Coma Scale score≤8 (P=.024), and CE (P=.017), with poor outcome and demonstrated a trend toward poor outcome prediction for age 65 years or older (P=.050). In the per-lesion analysis, only extravasation identified on CTA (active and contained extravasation) was associated with hematoma expansion and evacuation.

CONCLUSIONS

Contrast extravasation within intracranial hematomas predicts poor in-hospital outcome in the setting of acute traumatic intracranial injuries.

Simultaneous arteriovenous shunting and venous congestion identification in dural arteriovenous fistulas using susceptibility-weighted imaging: initial experience

In this short report, we describe the potential contribution of SWI in the noninvasive evaluation of DAVFs. SWI images were compared with DSA for the identification of the location of the fistulous point, the presence of CVR, and the presence of the PPP. In 5 of 6 patients, it was possible to identify the fistulous locations depicted as hyperintensity within venous structures. Cortical venous reflux was underestimated on SWI in 3 cases of robust CVR and not identified in 2 cases of less severe CVR. The PPP seen on angiograms correlated anatomically with increased number, caliber, and tortuosity of hypointense veins seen on SWI. Furthermore, SWI was superior to conventional MR imaging in the detection of these dilated veins. These preliminary results suggest an important role for SWI in the detection and assessment of the complex hemodynamics associated with DAVFs.