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Screening for High‐grade Carotid Stenosis Using a Portable Ultrasonography Instrument
Author(s) -
Schminke Ulf,
Motsch Lillian,
Lien LiMing,
Tan TengYeow,
Bond M. Gene,
Toole James F.,
Tegeler Charles H.
Publication year - 2006
Publication title -
journal of neuroimaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.822
H-Index - 64
eISSN - 1552-6569
pISSN - 1051-2284
DOI - 10.1111/j.1552-6569.2006.00044.x
Subject(s) - medicine , carotid arteries , stenosis , receiver operating characteristic , radiology , doppler effect , duplex ultrasonography , prospective cohort study , ultrasound , sonographer , nuclear medicine , common carotid artery , ultrasonography , astronomy , physics
Background and Purpose. We investigated the diagnostic performance of a brief Power Doppler Imaging (PDI) screening examination for carotid artery stenoses using a newly developed portable instrument. Methods . A highly experienced sonographer screened in total 152 carotid arteries by either continuous wave (cw) Doppler ( n = 50) or a lightweight (2.4 kg) portable duplex device ( n = 102) in a prospective study of 76 high‐risk patients. The screening protocols included either spectrum analysis and frequency shift measurement in both internal carotid arteries with cw‐Doppler or determination of area and diameter ratios in transverse and longitudinal views of both carotid arteries in B‐mode and with PDI, but without velocity measurement. Both protocols were evaluated against a complete routine duplex ultrasonography examination. Results. According to the complete examination, stenoses were <50% in 73 of 102 (71.6%), 50–75% in 19 of 102 (18.6%), 75–95% in 7 of 102 (6.9%), and occluded in 3 of 102 (2.9%) arteries (PDI cohort), and <50% in 39 of 50 (78%), 50–75% in 8 of 50 (16%), 75–95% in 2 of 50 (4%), and occluded in 1 of 50 (2%) artery (cw‐Doppler cohort). Mean screening time was 8.8 ± 2.5 minute (PDI) and 9.4 ± 2.6 minute (cw‐Doppler). For stenoses >75%, A z values (area under the receiver operating characteristics curve) were 0.897 for area ratios, 0.843 for diameter ratios (PDI protocol) and 1.0 for the cw‐Doppler protocol. Conclusions. The diagnostic performance of the cw‐Doppler protocol was superior to the PDI protocol. Nevertheless, both protocols appear suitable as inexpensive screening strategies to identify subjects with >75% stenosis measured by carotid Doppler ultrasound. However, these preliminary data need further verification.