PURPOSE: Hyperdense artery sign is the earliest sign of ischemic stroke on non-enhanced computed tomography and it can be visible long before parenchymal changes. The aim of our study was to compare diagnostic value of model-based iterative reconstruction algorithm (IMR) with that of iterative reconstruction algorithm (iDose4) in identifying hyperdense artery sign. METHODS: We selected 56 consecutive patients suspected for ischemic stroke, who underwent a NCCT and that demonstrated a vessel occlusion at angio-CT or developed ischemic lesion at follow-up CT. Two readers randomly analyzed images of NCCT reconstructed both with iDose4 (4 mm) and IMR (2 mm), reporting presence of hyperdense artery sign (0: no; 1: yes; 2: not sure). They rated image quality on a 4-point scale (1: unacceptable; 4: more than average) and recorded HU values of clot and of normal vessel and measured noise index, CNR and SNR. RESULTS: Mean values of CTDI, DLP, and ED were respectively of 43 mGy, 819.7 mGy cm, and 1.72 mSv. By analyzing the IMR reconstruction, both readers were able to recognize hyperdense vessel sign in 55/56 patients, while only in 12/56 patients were identified with iDose. IMR obtained better rating of image quality (mean score for IMR 3.32 vs 2.53 for iDose), higher clot density (57.2 vs 46.7 HU), lower noise index (5 vs 2), higher CNR and SNR (respectively 4.2 vs 2 and 16.8 vs 8.5). CONCLUSIONS: Model-based approach significantly increases sensitivity in detecting hyperdense artery sign, offering higher SNR and CNR in brain CT images in comparison with standard hybrid reconstruction algorithm.
PURPOSE: Hyperdense artery sign is the earliest sign of ischemic stroke on non-enhanced computed tomography and it can be visible long before parenchymal changes. The aim of our study was to compare diagnostic value of model-based iterative reconstruction algorithm (IMR) with that of iterative reconstruction algorithm (iDose4) in identifying hyperdense artery sign. METHODS: We selected 56 consecutive patients suspected for ischemic stroke, who underwent a NCCT and that demonstrated a vessel occlusion at angio-CT or developed ischemic lesion at follow-up CT. Two readers randomly analyzed images of NCCT reconstructed both with iDose4 (4 mm) and IMR (2 mm), reporting presence of hyperdense artery sign (0: no; 1: yes; 2: not sure). They rated image quality on a 4-point scale (1: unacceptable; 4: more than average) and recorded HU values of clot and of normal vessel and measured noise index, CNR and SNR. RESULTS: Mean values of CTDI, DLP, and ED were respectively of 43 mGy, 819.7 mGy cm, and 1.72 mSv. By analyzing the IMR reconstruction, both readers were able to recognize hyperdense vessel sign in 55/56 patients, while only in 12/56 patients were identified with iDose. IMR obtained better rating of image quality (mean score for IMR 3.32 vs 2.53 for iDose), higher clot density (57.2 vs 46.7 HU), lower noise index (5 vs 2), higher CNR and SNR (respectively 4.2 vs 2 and 16.8 vs 8.5). CONCLUSIONS: Model-based approach significantly increases sensitivity in detecting hyperdense artery sign, offering higher SNR and CNR in brain CT images in comparison with standard hybrid reconstruction algorithm.
Authors: Eric P Tamm; X John Rong; Dianna D Cody; Randy D Ernst; Nancy E Fitzgerald; Vikas Kundra Journal: Radiographics Date: 2011-10-03 Impact factor: 5.333
Authors: Christian H Riedel; Ulf Jensen; Axel Rohr; Marc Tietke; Karsten Alfke; Stephan Ulmer; Olav Jansen Journal: Stroke Date: 2010-07-01 Impact factor: 7.914
Authors: Michael T Froehler; Satoshi Tateshima; Gary Duckwiler; Reza Jahan; Nestor Gonzalez; Fernando Vinuela; David Liebeskind; Jeffrey L Saver; J Pablo Villablanca Journal: J Neurointerv Surg Date: 2012-05-22 Impact factor: 5.836
Authors: David S Liebeskind; Nerses Sanossian; William H Yong; Sidney Starkman; Michael P Tsang; Antonio L Moya; David D Zheng; Anna M Abolian; Doojin Kim; Latisha K Ali; Samir H Shah; Amytis Towfighi; Bruce Ovbiagele; Chelsea S Kidwell; Satoshi Tateshima; Reza Jahan; Gary R Duckwiler; Fernando Viñuela; Noriko Salamon; J Pablo Villablanca; Harry V Vinters; Victor J Marder; Jeffrey L Saver Journal: Stroke Date: 2011-03-10 Impact factor: 7.914