Differentiation of Hemorrhage from Iodine Using Spectral Detector CT: A Phantom Study

Hedent, Steven Van; Hokamp, Nils Große; Laukamp, Kai Roman; Buls, Nico; Kessner, Rivka; Rose, Brigid M.; Ros, Pablo R.; Jordan, David W.

doi:10.3174/ajnr.a5872

Cited by 19 publications

(14 citation statements)

References 33 publications

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“…5,6 Dual-energy CT (DECT) has been shown effective in accurately differentiating parenchymal hemorrhage from contrast staining. 3,[7][8][9] The presence of parenchymal contrast staining on DECT immediately post-thrombectomy is associated with the development of ICH. 3,7 A retrospective study by Bonatti et al 7 of 85 patients undergoing mechanical thrombectomy showed that the presence of parenchymal hyperdensity with a maximum absolute iodine concentration of .1.35 mg/mL may identify patients developing intracerebral hemorrhage with 100% sensitivity and 67.6% specificity.…”

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confidence: 99%

Prediction of Hemorrhage after Successful Recanalization in Patients with Acute Ischemic Stroke: Improved Risk Stratification Using Dual-Energy CT Parenchymal Iodine Concentration Ratio Relative to the Superior Sagittal Sinus

Byrne

Walsh

Schmiedeskamp³

et al. 2020

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE: Brain parenchymal hyperdensity on postthrombectomy CT in patients with acute stroke can be due to hemorrhage and/or contrast staining. We aimed to determine whether iodine concentration within contrast-stained parenchyma compared with an internal reference in the superior sagittal sinus on dual-energy CT could predict subsequent intracerebral hemorrhage.MATERIALS AND METHODS: Seventy-one patients with small infarct cores (ASPECTS $ 7) and good endovascular recanalization (modified TICI 2b or 3) for anterior circulation large-vessel occlusion were included. Brain parenchymal iodine concentration as per dual-energy CT and the percentage of contrast staining relative to the superior sagittal sinus were recorded and correlated with the development of intracerebral hemorrhage using Mann-Whitney U and Fisher exact tests.RESULTS: Forty-three of 71 patients had parenchymal hyperdensity on initial dual-energy CT. The median relative iodine concentration compared with the superior sagittal sinus was significantly higher in those with subsequent intracerebral hemorrhage (137.9% versus 109.2%, P 4 .007). By means of receiver operating characteristic analysis, a cutoff value of 100% (iodine concentration relative to the superior sagittal sinus) enabled identification of patients going on to develop intracerebral hemorrhage with 94.75% sensitivity, 43.4% specificity, and a likelihood ratio of 1.71.CONCLUSIONS: Within our cohort of patients, the relative percentage of iodine concentration at dual-energy CT compared with the superior sagittal sinus was a reliable predictor of intracerebral hemorrhage development and may be a useful imaging biomarker for risk stratification after endovascular treatment. ABBREVIATIONS: DECT 4 dual-energy CT; ICH 4 intracerebral hemorrhage; SSS 4 superior sagittal sinus

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confidence: 99%

Prediction of Hemorrhage after Successful Recanalization in Patients with Acute Ischemic Stroke: Improved Risk Stratification Using Dual-Energy CT Parenchymal Iodine Concentration Ratio Relative to the Superior Sagittal Sinus

Byrne

Walsh

Schmiedeskamp³

et al. 2020

AJNR Am J Neuroradiol

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“…3,12 Studies focusing on dedicated abdominal protocols, including arterial, portal-venous and/or urographic phase examinations, and/ or phantoms have shown attenuation and image noise in VNC comparable to true unenhanced scans (TNC), but this has not been shown for (SDCT) into a larger patient cohort and/or focus on the liver. 3,[14][15][16] CT examinations prior to transcatheter-aortic-valvereplacements (TAVR) are increasingly applied, including unenhanced scans of the chest and CT angiography (CTA) of chest and abdomen. 17,18 This dedicated cardiac examination also depicts upper abdominal organs, such as the liver, but differs in scan and contrast media injection protocols.…”

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confidence: 99%

Evaluation of the liver with virtual non-contrast: single institution study in 149 patients undergoing TAVR planning

Laukamp

Lennartz

et al. 2020

The British Journal of Radiology

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Objective: To evaluate accuracy of virtual-non-contrast images (VNC) compared to true-unenhanced-images (TNC) for evaluation of liver attenuation acquired using spectral-detector CT (SDCT). Methods: 149 patients who underwent multiphase transcatheter-aortic-valve-replacement (TAVR) SDCT-examinations [unenhanced-chest (TNC), CT-angiography chest (CTA-chest, early arterial-phase) and abdomen (CTA-abdomen, additional early arterial-phase after a second injection of contrast media)] were retrospectively included. VNC of CTA-chest (VNC-chest) and CTA-abdomen (VNC-abdomen) were reconstructed and compared to TNC. Region of interest-based measurement of mean attenuation (Hounsfield unit, HU) was applied in the following regions: liver, spleen, abdominal aorta and paraspinal muscle. Results: VNC accuracy was high in the liver, spleen, abdominal aorta and muscle for abdomen-scanning. For the liver, average attenuation was 59.0 ± 9.1 HU for TNC and 72.6 ± 9.5 HU for CTA-abdomen. Liver attenuation in VNC-abdomen (59.1 ± 6.4 HU) was not significantly different from attenuation in TNC (p > 0.05). In contrast, VNC was less accurate for chest-scanning: Due to the protocol, in CTA-chest no contrast media was present in the liver parenchyma as indicated by the same attenuation in TNC (59.0 ± 9.1 HU) and CTA-chest (58.8 ± 8.9 HU, p > 0.05). Liver attenuation in VNC-chest (56.2 ± 6.4 HU, p < 0.05) was, however, significantly lower than in TNC and CTA-chest implying an artificial reduction of attenuation. Conclusion: VNC performed well in a large cohort of TAVR-examinations yielding equivalent mean attenuations to TNC; however, application of this technique might be limited when no or very little contrast media is present in parenchyma, more precisely in an early arterial-phase of the liver. Advances in knowledge: This study showed that VNC can be reliably applied in cardiac protocols when certain limitations are considered

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“…This is not a study validating the spectral CT data. While phantom studies have shown the potential of SDCT for differentiating iodine from hemorrhage [30], without verification with MRI or neuropathology we cannot completely rule out any blood extravasation on SDCT images classified as no ICH. Dual energy CT material decomposition is usually successful in neuroradiology [21].…”

Section: Limitationsmentioning

confidence: 82%

Initial experience with dual-layer detector spectral CT for diagnosis of blood or contrast after endovascular treatment for ischemic stroke

et al. 2021

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Purpose To determine whether spectral detector CT (SDCT) with a plain non-enhanced monochromatic CT, a water-weighted image after iodine removal, an iodine map, and Mono energetic images changes the diagnosis and classification of intracranial hemorrhage based on single energy CT after endovascular treatment (EVT) for ischemic stroke. Methods Two readers evaluated single energy and SD CT data collected from 63 patients within one week after EVT. They diagnosed ICH or contrast staining, and graded ICH according to the Heidelberg and Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) classification. Differences in diagnosis between single energy and SD CT were tested with Pearson's chi-squared test. Diagnostic values of single energy CT were calculated. Interrater agreement was based on Cohen's Kappa. Results When spectral data were added to single energy CT, the diagnosis of ICH changed in 8 CT scans (13%): in 4, the diagnosis of ICH was rejected and in 4, initially undetected ICH was diagnosed. In an additional 3 patients, the ICH grade was modified. CT alone had 88% sensitivity, 87% specificity, 88% positive diagnostic value, 87% negative diagnostic value, and 87% overall accuracy for ICH compared to SDCT. Interreader agreement on the presence of ICH was 0.84 (95% CI 0.51-0.86) for spectral CT and 0.84 (95% CI 0.73-0.97) for single energy CT. Conclusion SD CT after endovascular treatment contributes to the distinction between intracranial hemorrhage and contrast staining. KeywordsStroke • Endovascular treatment • Computed tomography • Spectral computed tomography • Intracerebral hemorrhage (ICH)

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Differentiation of Hemorrhage from Iodine Using Spectral Detector CT: A Phantom Study

Cited by 19 publications

References 33 publications

Prediction of Hemorrhage after Successful Recanalization in Patients with Acute Ischemic Stroke: Improved Risk Stratification Using Dual-Energy CT Parenchymal Iodine Concentration Ratio Relative to the Superior Sagittal Sinus

Prediction of Hemorrhage after Successful Recanalization in Patients with Acute Ischemic Stroke: Improved Risk Stratification Using Dual-Energy CT Parenchymal Iodine Concentration Ratio Relative to the Superior Sagittal Sinus

Evaluation of the liver with virtual non-contrast: single institution study in 149 patients undergoing TAVR planning

Initial experience with dual-layer detector spectral CT for diagnosis of blood or contrast after endovascular treatment for ischemic stroke

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