Technical limits in transcranial Doppler recording: Inadquate acoustic windows

Marinoni, Marinella; Ginanneschi, A.; Forleo, Paolo; Amaducci, L.

doi:10.1016/s0301-5629(97)00077-x

Cited by 153 publications

(138 citation statements)

References 9 publications

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“…Indeed, many groups (Bruno et al 1988;Marinoni et al 1997;Postert et al 1997;Dominguez-Roldan et al 2004) have noted difficulties in clinical TCD studies via the temporal window. Insufficient penetration of TCD has been noted in elderly people, especially women and non Caucasian groups (Itoh et al 1993;Hoksbergen et al 1999;Shambal et al 2003).…”

Section: Discussionmentioning

confidence: 99%

Characterization of Ultrasound Propagation Through Ex-vivo Human Temporal Bone

Ammi

Mast

Huang³

et al. 2008

The Journal of the Acoustical Society of America

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Adjuvant therapies that lower the thrombolytic dose or increase its efficacy would represent a significant breakthrough in the treatment of patients with ischemic stroke (Eggers 2006;Tsivgoulis and Alexandrov 2007). The objective of this study was to perform intracranial measurements of the acoustic pressure field generated by 0.12, 1.03 and 2.00 MHz ultrasound transducers to identify optimal ultrasound parameters that would maximize penetration and minimize aberration of the beam. To achieve this goal, in vitro experiments were conducted on five human skull specimens. In a water-filled tank, two unfocused transducers (0.12 and 1.03 MHz) and one focused transducer (2.00 MHz) were consecutively placed near the right temporal bone of each skull. A hydrophone, mounted on a micropositioning system, was moved to an estimated location of the middle cerebral artery (MCA) origin and measurements of the surrounding acoustic pressure field were performed. For each measurement, the distance from the position of maximum acoustic pressure to the estimated origin of the MCA inside the skulls was quantified. The -3 dB depth of field and beam width in the skull were also investigated as a function of the three frequencies. Results show that the transducer alignment relative to the skull is a significant determinant of the detailed behavior of the acoustic field inside the skull. For optimal penetration, insonation normal to the temporal bone was needed. The shape of the 0.12-MHz intracranial beam was more distorted than those at 1.03 and 2.00 MHz due to the large aperture and beam width. However, lower ultrasound pressure reduction was observed at 0.12 MHz (22.5%). At 1.03 and 2.00 MHz two skulls had an insufficient temporal bone window and attenuated the beam severely (up to 96.6% pressure reduction). For all frequencies, constructive and destructive interference patterns were seen near the contralateral skull wall at various elevations. The 0.12-MHz ultrasound beam depth of field was affected the most when passing Corresponding Address: Christy K. Holland, Ph.D., Department of Biomedical Engineering, Colleges of Medicine and Engineering, University of Cincinnati, Medical Science Building, Rm. 6167, 231 Albert Sabin Way, Cincinnati, Ohio 45267-0586, USA, Phone: +1 (513) 558-5675, Fax: +1 (513) 558-5958, Christy.Holland@uc.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. HHS Public Access Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript through the temporal bone and showed a decrease in size of more than 55% on average. The speed of sound in the temporal...

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Section: Discussionmentioning

confidence: 99%

Characterization of Ultrasound Propagation Through Ex-vivo Human Temporal Bone

Ammi

Mast

Huang³

et al. 2008

The Journal of the Acoustical Society of America

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“…The lack of an agreed definition for LMF on TCD, absence of direct collateral visualization, and difficulty in finding acoustic windows are limitations of TCD, though these are offset by the lack of radiation and contrast requirements. 90 Flow diversion on TCD, defined as increased flow velocity in ipsilateral ACA/ PCA, did correlate with angiographic collateral grade when methods were compared, suggesting a possible role for TCD to measure LMF. 35 When collaterals were measured by using DSA, CTA, and MR imaging, CTA compared favorably, but the methods used for grading LMF on CTA were not clearly stated, so this finding must be interpreted with caution.…”

Section: Discussionmentioning

confidence: 99%

Systematic Review of Methods for Assessing Leptomeningeal Collateral Flow

McVerry¹,

Liebeskind²,

Muir³

2011

AJNR Am J Neuroradiol

194

162

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“…Sonographic contrast-enhancing agents were not applied. Categorized variables were compared by using the 2 …”

Section: Techniquementioning

confidence: 99%

“…Although a proper bone window for TCCS is essential for detecting intracranial vascular lesions, the acoustic property of the standard approach via the temporal bone window (TBW) is limited in elderly and female patients. 1,2 In particular, an optimal TBW is difficult to apply in Asians. 3,4 Improving the detection rate of the anterior cerebral artery (ACA) by TCCS will increase the opportunity for such patients to undergo noninvasive and real-time evaluations at the bedside in general practice.…”

mentioning

confidence: 99%

Frontal Bone Window Improves the Ability of Transcranial Color-Coded Sonography to Visualize the Anterior Cerebral Artery of Asian Patients with Stroke: Fig 1.

Yoshimura¹,

Koga²,

Toyoda³

et al. 2009

AJNR Am J Neuroradiol

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SUMMARY:The frontal bone window (FBW) is a promising approach in evaluating the anterior cerebral artery. The goal of the present study was to determine the rates of detection of the basal cerebral arteries by using the FBW alone and a combination of the FBW with the temporal bone window (TBW) in 163 patients. The combined application improved detection rates of A1 (58.6% versus 46.0%, P ϭ .001) and A2 (43.6% versus 6.7%, P Ͻ .001) compared with the TBW alone.T ranscranial color-coded sonography (TCCS) is an established tool for evaluating intracranial cerebral arteries because it can identify and focus a sonographic beam on occluded sites. Although a proper bone window for TCCS is essential for detecting intracranial vascular lesions, the acoustic property of the standard approach via the temporal bone window (TBW) is limited in elderly and female patients.1,2 In particular, an optimal TBW is difficult to apply in Asians. 3,4 Improving the detection rate of the anterior cerebral artery (ACA) by TCCS will increase the opportunity for such patients to undergo noninvasive and real-time evaluations at the bedside in general practice. In particular, Japanese patients will receive considerable benefits from an improved TCCS examination because pathologic changes often arise in the intracranial arteries, including the ACA. 5,6 However, the ACA is more difficult to detect than the middle cerebral artery (MCA) through the TBW.7 Studies of a small cohort have indicated that this limitation could be overcome by an approach through the frontal bone window (FBW) to evaluate the postcommunicating segment (A2) of the ACA from a single center. 8 However, the utility of the FBW for Asian patients with stroke has not been determined. For Asians, TCCS via the FBW and the TBW might be equally disadvantageous.The present study determined the rate of detecting the basal cerebral arteries, including the ACA via the FBW alone and via the FBW combined with the TBW in Japanese patients with stroke. TechniqueA total of 163 consecutive Japanese patients (46 women; mean age, 69.5 Ϯ 11.4 years) with cerebrovascular disease were recruited. The detection rates of the main trunk of the MCA (M1), the precommunicating segment (A1) and A2 of the ACA, the precommunicating (P1) and the postcommunicating (P2) segments of the posterior cerebral artery (PCA) by TCCS through the FBW and TBW were evaluated by using a Sonos 5500 equipped with an S3 transducer (1.0 -3.0 MHz; Philips Medical Systems, Tokyo, Japan) or an iE33 with an S5-1 transducer (1.0 -5.0 MHz; Philips Medical Systems). Patients were randomly examined with 1 examination from each scanner. The TBW is located upward and forward of the earhole. The FBW consists of the lateral FBW located above the lateral aspect of the eyebrow and the paramedian FBW slightly lateral to the midline of the forehead (Fig 1). The most prominent vascular structure identified via the lateral FBW is A2 with blood flowing toward the probe. The ipsilateral A1 is color-coded with flow moving away from the probe, and ...

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Technical limits in transcranial Doppler recording: Inadquate acoustic windows

Cited by 153 publications

References 9 publications

Characterization of Ultrasound Propagation Through Ex-vivo Human Temporal Bone

Characterization of Ultrasound Propagation Through Ex-vivo Human Temporal Bone

Systematic Review of Methods for Assessing Leptomeningeal Collateral Flow

Frontal Bone Window Improves the Ability of Transcranial Color-Coded Sonography to Visualize the Anterior Cerebral Artery of Asian Patients with Stroke: Fig 1.

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