Quantifizierung von extrakraniellen A. carotis interna (ACI) Stenosen mittels Gefäßultraschall mit FKDS und B-Flow im Vergleich zur 64-Zeilen-Multidetektor-CTA, der MRA und DSA

Zusammenfassung

Ziel: Präinterventionelle Bestimmung des distalen Stenosegrades der extrakraniellen Arteria carotis interna (ACI) durch Gefäßultraschall mittels farbkodierter Duplexsonografie (FKDS) und B-Flow: Vergleich mit kontrastmittelverstärkter 64-Zeilen-CT-Angiografie (CTA), kontrastverstärkter MR-Angiografie (ceMRA) und digitaler Subtraktionsangiografie (DSA). Material und Methoden: Bei 21 Patienten mit symptomatischer ACI-Stenose wurde vor perkutaner stentgestützter PTA eine komplementäre Diagnostik und Stenosenbeurteilung mittels FKDS, B-Flow, CTA, ceMRA und DSA durchgeführt. Die Ultraschalldiagnostik erfolgte mit hochauflösenden Linearschallköpfen (5 - 10 MHz und 9 - 14 MHz). Bei jedem Patienten wurden eine bolusgetriggerte kontrastmittelverstärkte Mehrzeilen-CTA (Kollimation 64 × 0,5 mm) und eine ceMRA (1,5 Tesla) sowie eine selektive DSA durchgeführt. Es erfolgte die Bestimmung des distalen Stenosegrades nach NASCET-Kriterien durch Mittelung aus jeweils 5 Einzelmessungen pro Modalität und Patient. In der CTA und ceMRA wurden die Originalbilder (source images) sowie MPR-Darstellungen und MIP-Rekonstruktionen beurteilt. Mit der FKDS wurden hämodynamische Flussparameter bestimmt. Die Auswertung erfolgte durch zwei erfahrene Radiologen im Konsens. Ergebnisse: Die Stenosegraduierung reichte von 45 - 95 % und lag im Mittel bei 73 % (± 0,13). Zu den Referenzwerten der DSA ergab sich ein hohes Maß an Übereinstimmung mit dem B-Flow (r = 0,9379), der FKDS (r = 0,852), den Messwerten aus den Originaldatensatz der MRA (r = 0,9117) und den Rekonstruktionen der CTA (r = 0,8598) im Pearson-Korrelationstest. Schlussfolgerung: Eine komplementäre Diagnostik aus Gefäßultraschall und wahlweise der CTA und MRA erhöht die diagnostische Sicherheit der Quantifizierung von ACI-Stenosen im Vergleich mit der selektiven DSA.

Abstract

Purpose: To evaluate the value of vascular ultrasound determining the pre-interventional degree of distal stenosis in the extracranial internal carotid artery (ICA) by means of color-coded duplex sonography (CCDS) and B-flow. Comparison with contrast-enhanced 64-line CT angiography (CTA), contrast-enhanced MRA (ceMRA) and digital subtraction angiography (DSA). Materials and Methods: Complementary diagnostics and evaluation of the stenosis by means of CCDS, B-flow, CTA, ceMRA and DSA were performed prior to percutaneous stent-assisted PTA in 21 symptomatic ICA stenosis. Ultrasound diagnostics were carried out with high-resolution linear transducers (5 - 10 MHz and 9 - 14 MHz). A bolus-triggered contrast-enhanced multislice CTA (collimation 64 × 0.5 mm) and a ceMRA (1.5 Tesla) as well as selective DSA were performed in every patient. The degree of distal stenosis was established in accordance to NASCET criteria by averaging 5 single measurements per modality and patient. The source images as well as MPR and MIP reconstructions were evaluated in the CTA and ceMRA. Hemodynamic flow parameters were determined with CCDS and B-flow. The images were assessed by two experienced readers in consensus. Results: The extent of stenosis ranged from 45 to 95 %, averaging 73 % (± 13 %). There was a high degree of agreement between the B-flow results (r = 0.938), the CCDS (r = 0.852), the measurements from the source data of the ceMRA (r = 0.9117) and reconstructions of the CTA (r = 0.8598) compared to quantitative DSA as a reference technique. Conclusion: Compared to selective DSA, vascular ultrasound in combination with CTA and ceMRA increase the reliability of the diagnostic quantification of ICA stenosis.

Schlüsselwörter

B-Flow - CCDS - ceMRA - Multislice-CTA - DSA - ICA-stenosis

Key words

carotid arteries - angiography - ultrasound - CT angiography - MR angiography

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