Improved Carotid Stenosis Quantification on Novel 4D/3D-Doppler Ultrasonography Indexing to the Common Carotid Artery

Purpose The accuracy of internal carotid artery stenosis (ICAS) quantification depends on the method of stenosis measurement, impacting therapeutic decisions and outcomes. The NASCET method references the stenotic to the distal ICAS lumen, the ECST method to the local outer and the common carotid artery (CC) method to the CC diameter. Direct morphometric stenosis measurement with four-dimensionally guided three-dimensional ultrasonography (4D/3DC-US) demonstrated good validity for the commonly used NASCET method. The NASCET definition has clinically relevant drawbacks. Our purpose was to investigate the validity of the ECST and CC methods. Materials and Methods 4D/3DC-US percent-stenosis measures of 103 stenoses (80 patients) were compared to quantitative catheter angiography and duplex ultrasonography (DUS) in a blinded fashion. Results The 4D/3DC-US versus angiography intermethod standard deviation of differences (SDD, n = 103) was lower for the CC method (5.7 %) compared to the NASCET (8.1 %, p < 0.001) and ECST methods (9.1 %, p < 0.001). Additionally, it was lower than the NASCET angiography interrater SDD of 52 stenoses (SDD 7.2 %, p = 0.047) and non-inferior for the ECST method (p = 0.065). Interobserver analysis of equivalent grading methods showed no differences for the SDDs between angiography and 4D/3DC-US observers (p > 0.076). Binary comparison to angiography showed equal Kappa values > 0.7 and an accuracy ≥ 85 % for the NASCET and CC methods, higher than for the ECST method. The binary accuracy of ICAS grading did not differ from DUS for all methods. Conclusion The new 4D/3DC-US CC method is an accurate and well reproducible alternative to the NASCET and ECST methods and offers potential for clinical application.

Detailed Precision of Computed Tomography Angiography Compared to Invasive Angiography in Different Coronary Vessels: Overestimate, Underestimate, or Concordance?

Background: Quantitative analysis of stenosis lesions by Computed Tomography angiography (CTA) show good correlation with Invasive Coronary Angiography (ICA) examination. However, detailed precision whether CTA overestimate or underestimate have not been explored thoroughly. Objectives: This research is performed to analyze the precision of CTA compared to ICA. Materials & Methods: There are 195 patients examined by both CTA and ICA from October 2014 until December 2015 in our hospital. CTA was analyzed by a team of cardiovascular imaging cardiologists. Quantitative grading of stenosis was determined visually using 2014 Society of Cardiovascular Computed Tomography (SCCT) guidelines classification. Quantitative measurement of stenosis during ICA was classified with the same criteria so that it can be comparable. The final comparison of both tests was clas­sified as concordance, overestimate and underestimate. Results: Lesion of stenosis was found in 573 coronary vessels. Coronary vessels are significantly associated with detailed precision of quantitative analysis comparison in CTA and ICA. LM coronary stenosis quantification from CTA is predominantly overestimate (concordance in 6% vessels and overestimate in 75.9% vessels), while stenosis analysis by CTA in other major coronary vessels is spread without conspicuous domination (p<0.001). Sensitivity, specificity, PPV, and NPV of CTA to detect obstructive lesion (stenosis ≥ 50%) found by ICA is 81.4%, 80.4%, 73.9%, and 86.3%, respectively (780 vessels). Conclusions: Degree of stenosis in LM is predominantly overestimate by CTA. The precision of stenosis grading in CTA in different coronary vessels is not the same. Abstrak Latar Belakang: Analisis kuantitatif lesi stenosis pada pembuluh koroner menggunakan modalitas Computed Tomography Angiography (CTA) memiliki korelasi yang baik dengan pemeriksaan Invasive Coronary Angiography (ICA). Namun, presisi CTA terhadap ICA masih belum ter­eksplorasi dengan baik. Terutama dari sisi apakah CTA menunjukkan presisi yang overestimate atau underestimate. Tujuan: Penelitian ini dilakukan untuk menganalisis presisi CTA terhadap ICA dalam mendeteksi lesi stenosis pada pembuluh koroner. Metode Penelitian: Terdapat 195 pasien yang diperiksa menggunakan CTA dan ICA sejak Oktober 2014 hingga Desember 2015 di RS Jan­tung dan Pembuluh Darah Harapan Kita, Jakarta. Analisis kuantitatif CTA dilakukan oleh tim kardiolog pencitraan kardiovaskular. Klasifikasi derajat stenosis ditentukan secara visual menggunakan pedoman dari Society of Cardiovascular Computed Tomography (SCCT) 2014. Analisis kuantitatif lesi stenosis dari pemeriksaan ICA diklasifikasikan menggunakan pedoman yang sama sehingga keduanya dapat diperbandingkan. Data hasil perbandingan kedua modalitas diklasifikasikan sebagai concordance, overestimate dan underestimate. Hasil Penelitian: Lesi stenosis ditemukan pada 573 pembuluh koroner. Pembuluh koroner yang berbeda secara signifikan berhubungan dengan perbandingan klasifikasi analisis semi-kuantitatif CTA dan ICA. Pembuluh koroner LM terutama menunjukkan lesi dengan kategori overestimate (75.9%). Sementara analisis stenosis pada pembuluh koroner lainnya tidak menunjukkan perbedaan yang mencolok (p < 0,001). Sensitivitas, spesifisitas, PPV, dan NPV CTA dalam mendeteksi lesi koroner obstruktif (stenosis ≥50%) terhadap ICA adalah sebesar 81.4%, 80.4%, 73.9%, dan 86.3% (780 pembuluh kroner). Kesimpulan: Analisis stenosis semi-kuantitatif pada LM terutama adalah overestimate berdasarkan pemeriksaan CTA. Presisi analisis perband­ingan derajat stenosis CT angiografi pada setiap pembuluh koroner tidak sama.