Phantom-based standardization of CT angiography images for spot sign detection

Andrea Morotti; Javier M. Romero; Michael J. Jessel; Andrew M. Hernandez; Anastasia Vashkevich; Kristin Schwab; Joseph D. Burns; Qaisar A. Shah; Thomas A. Bergman; M. Fareed K. Suri; Mustapha Ezzeddine; Jawad F. Kirmani; Sachin Agarwal; Angela Hays Shapshak; Steven R. Messe; Chitra Venkatasubramanian; Katherine Palmieri; Christopher Lewandowski; Tiffany R. Chang; Ira Chang; David Z. Rose; Wade Smith; Chung Y. Hsu; Chun Lin Liu; Li Ming Lien; Chen Yu Hsiao; Toru Iwama; Mohammad Rauf Afzal; Christy Cassarly; Steven M. Greenberg; Renee’ Hebert Martin; Adnan I. Qureshi; Jonathan Rosand; John M. Boone; Joshua N. Goldstein

doi:10.1007/s00234-017-1857-4

Phantom-based standardization of CT angiography images for spot sign detection

Andrea Morotti, Javier M. Romero, Michael J. Jessel, Andrew M. Hernandez, Anastasia Vashkevich, Kristin Schwab, Joseph D. Burns, Qaisar A. Shah, Thomas A. Bergman, M. Fareed K. Suri, Mustapha Ezzeddine, Jawad F. Kirmani, Sachin Agarwal, Angela Hays Shapshak, Steven R. Messe, Chitra Venkatasubramanian, Katherine Palmieri, Christopher Lewandowski, Tiffany R. Chang, Ira ChangDavid Z. Rose, Wade Smith, Chung Y. Hsu, Chun Lin Liu, Li Ming Lien, Chen Yu Hsiao, Toru Iwama, Mohammad Rauf Afzal, Christy Cassarly, Steven M. Greenberg, Renee’ Hebert Martin, Adnan I. Qureshi, Jonathan Rosand, John M. Boone, Joshua N. Goldstein

Research output: Contribution to journal › Article › peer-review

1 Citation (Scopus)

Abstract

Purpose: The CT angiography (CTA) spot sign is a strong predictor of hematoma expansion in intracerebral hemorrhage (ICH). However, CTA parameters vary widely across centers and may negatively impact spot sign accuracy in predicting ICH expansion. We developed a CT iodine calibration phantom that was scanned at different institutions in a large multicenter ICH clinical trial to determine the effect of image standardization on spot sign detection and performance. Methods: A custom phantom containing known concentrations of iodine was designed and scanned using the stroke CT protocol at each institution. Custom software was developed to read the CT volume datasets and calculate the Hounsfield unit as a function of iodine concentration for each phantom scan. CTA images obtained within 8 h from symptom onset were analyzed by two trained readers comparing the calibrated vs. uncalibrated density cutoffs for spot sign identification. ICH expansion was defined as hematoma volume growth >33%. Results: A total of 90 subjects qualified for the study, of whom 17/83 (20.5%) experienced ICH expansion. The number of spot sign positive scans was higher in the calibrated analysis (67.8 vs 38.9% p < 0.001). All spot signs identified in the non-calibrated analysis remained positive after calibration. Calibrated CTA images had higher sensitivity for ICH expansion (76 vs 52%) but inferior specificity (35 vs 63%) compared with uncalibrated images. Conclusion: Normalization of CTA images using phantom data is a feasible strategy to obtain consistent image quantification for spot sign analysis across different sites and may improve sensitivity for identification of ICH expansion.

Original language	English
Pages (from-to)	1-6
Number of pages	6
Journal	Neuroradiology
Volume	59
Issue number	9
DOIs	https://doi.org/10.1007/s00234-017-1857-4
Publication status	Accepted/In press - Jul 20 2017
Externally published	Yes

Keywords

CT angiography
Intracerebral hemorrhage
Phantom standardization
Spot sign

ASJC Scopus subject areas

Radiology Nuclear Medicine and imaging
Clinical Neurology
Cardiology and Cardiovascular Medicine

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10.1007/s00234-017-1857-4

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Morotti, A., Romero, J. M., Jessel, M. J., Hernandez, A. M., Vashkevich, A., Schwab, K., Burns, J. D., Shah, Q. A., Bergman, T. A., Suri, M. F. K., Ezzeddine, M., Kirmani, J. F., Agarwal, S., Shapshak, A. H., Messe, S. R., Venkatasubramanian, C., Palmieri, K., Lewandowski, C., Chang, T. R., ... Goldstein, J. N. (Accepted/In press). Phantom-based standardization of CT angiography images for spot sign detection. Neuroradiology, 59(9), 1-6. https://doi.org/10.1007/s00234-017-1857-4

Morotti, A, Romero, JM, Jessel, MJ, Hernandez, AM, Vashkevich, A, Schwab, K, Burns, JD, Shah, QA, Bergman, TA, Suri, MFK, Ezzeddine, M, Kirmani, JF, Agarwal, S, Shapshak, AH, Messe, SR, Venkatasubramanian, C, Palmieri, K, Lewandowski, C, Chang, TR, Chang, I, Rose, DZ, Smith, W, Hsu, CY, Liu, CL, Lien, LM, Hsiao, CY, Iwama, T, Afzal, MR, Cassarly, C, Greenberg, SM, Martin, RH, Qureshi, AI, Rosand, J, Boone, JM & Goldstein, JN 2017, 'Phantom-based standardization of CT angiography images for spot sign detection', Neuroradiology, vol. 59, no. 9, pp. 1-6. https://doi.org/10.1007/s00234-017-1857-4

@article{3a23197890c44d928c86689bfdf1feef,

title = "Phantom-based standardization of CT angiography images for spot sign detection",

abstract = "Purpose: The CT angiography (CTA) spot sign is a strong predictor of hematoma expansion in intracerebral hemorrhage (ICH). However, CTA parameters vary widely across centers and may negatively impact spot sign accuracy in predicting ICH expansion. We developed a CT iodine calibration phantom that was scanned at different institutions in a large multicenter ICH clinical trial to determine the effect of image standardization on spot sign detection and performance. Methods: A custom phantom containing known concentrations of iodine was designed and scanned using the stroke CT protocol at each institution. Custom software was developed to read the CT volume datasets and calculate the Hounsfield unit as a function of iodine concentration for each phantom scan. CTA images obtained within 8 h from symptom onset were analyzed by two trained readers comparing the calibrated vs. uncalibrated density cutoffs for spot sign identification. ICH expansion was defined as hematoma volume growth >33%. Results: A total of 90 subjects qualified for the study, of whom 17/83 (20.5%) experienced ICH expansion. The number of spot sign positive scans was higher in the calibrated analysis (67.8 vs 38.9% p < 0.001). All spot signs identified in the non-calibrated analysis remained positive after calibration. Calibrated CTA images had higher sensitivity for ICH expansion (76 vs 52%) but inferior specificity (35 vs 63%) compared with uncalibrated images. Conclusion: Normalization of CTA images using phantom data is a feasible strategy to obtain consistent image quantification for spot sign analysis across different sites and may improve sensitivity for identification of ICH expansion.",

keywords = "CT angiography, Intracerebral hemorrhage, Phantom standardization, Spot sign",

author = "Andrea Morotti and Romero, {Javier M.} and Jessel, {Michael J.} and Hernandez, {Andrew M.} and Anastasia Vashkevich and Kristin Schwab and Burns, {Joseph D.} and Shah, {Qaisar A.} and Bergman, {Thomas A.} and Suri, {M. Fareed K.} and Mustapha Ezzeddine and Kirmani, {Jawad F.} and Sachin Agarwal and Shapshak, {Angela Hays} and Messe, {Steven R.} and Chitra Venkatasubramanian and Katherine Palmieri and Christopher Lewandowski and Chang, {Tiffany R.} and Ira Chang and Rose, {David Z.} and Wade Smith and Hsu, {Chung Y.} and Liu, {Chun Lin} and Lien, {Li Ming} and Hsiao, {Chen Yu} and Toru Iwama and Afzal, {Mohammad Rauf} and Christy Cassarly and Greenberg, {Steven M.} and Martin, {Renee{\textquoteright} Hebert} and Qureshi, {Adnan I.} and Jonathan Rosand and Boone, {John M.} and Goldstein, {Joshua N.}",

note = "Publisher Copyright: {\textcopyright} 2017, Springer-Verlag Berlin Heidelberg.",

year = "2017",

month = jul,

day = "20",

doi = "10.1007/s00234-017-1857-4",

language = "English",

volume = "59",

pages = "1--6",

journal = "Neuroradiology",

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TY - JOUR

T1 - Phantom-based standardization of CT angiography images for spot sign detection

AU - Morotti, Andrea

AU - Romero, Javier M.

AU - Jessel, Michael J.

AU - Hernandez, Andrew M.

AU - Vashkevich, Anastasia

AU - Schwab, Kristin

AU - Burns, Joseph D.

AU - Shah, Qaisar A.

AU - Bergman, Thomas A.

AU - Suri, M. Fareed K.

AU - Ezzeddine, Mustapha

AU - Kirmani, Jawad F.

AU - Agarwal, Sachin

AU - Shapshak, Angela Hays

AU - Messe, Steven R.

AU - Venkatasubramanian, Chitra

AU - Palmieri, Katherine

AU - Lewandowski, Christopher

AU - Chang, Tiffany R.

AU - Chang, Ira

AU - Rose, David Z.

AU - Smith, Wade

AU - Hsu, Chung Y.

AU - Liu, Chun Lin

AU - Lien, Li Ming

AU - Hsiao, Chen Yu

AU - Iwama, Toru

AU - Afzal, Mohammad Rauf

AU - Cassarly, Christy

AU - Greenberg, Steven M.

AU - Martin, Renee’ Hebert

AU - Qureshi, Adnan I.

AU - Rosand, Jonathan

AU - Boone, John M.

AU - Goldstein, Joshua N.

PY - 2017/7/20

Y1 - 2017/7/20

N2 - Purpose: The CT angiography (CTA) spot sign is a strong predictor of hematoma expansion in intracerebral hemorrhage (ICH). However, CTA parameters vary widely across centers and may negatively impact spot sign accuracy in predicting ICH expansion. We developed a CT iodine calibration phantom that was scanned at different institutions in a large multicenter ICH clinical trial to determine the effect of image standardization on spot sign detection and performance. Methods: A custom phantom containing known concentrations of iodine was designed and scanned using the stroke CT protocol at each institution. Custom software was developed to read the CT volume datasets and calculate the Hounsfield unit as a function of iodine concentration for each phantom scan. CTA images obtained within 8 h from symptom onset were analyzed by two trained readers comparing the calibrated vs. uncalibrated density cutoffs for spot sign identification. ICH expansion was defined as hematoma volume growth >33%. Results: A total of 90 subjects qualified for the study, of whom 17/83 (20.5%) experienced ICH expansion. The number of spot sign positive scans was higher in the calibrated analysis (67.8 vs 38.9% p < 0.001). All spot signs identified in the non-calibrated analysis remained positive after calibration. Calibrated CTA images had higher sensitivity for ICH expansion (76 vs 52%) but inferior specificity (35 vs 63%) compared with uncalibrated images. Conclusion: Normalization of CTA images using phantom data is a feasible strategy to obtain consistent image quantification for spot sign analysis across different sites and may improve sensitivity for identification of ICH expansion.

AB - Purpose: The CT angiography (CTA) spot sign is a strong predictor of hematoma expansion in intracerebral hemorrhage (ICH). However, CTA parameters vary widely across centers and may negatively impact spot sign accuracy in predicting ICH expansion. We developed a CT iodine calibration phantom that was scanned at different institutions in a large multicenter ICH clinical trial to determine the effect of image standardization on spot sign detection and performance. Methods: A custom phantom containing known concentrations of iodine was designed and scanned using the stroke CT protocol at each institution. Custom software was developed to read the CT volume datasets and calculate the Hounsfield unit as a function of iodine concentration for each phantom scan. CTA images obtained within 8 h from symptom onset were analyzed by two trained readers comparing the calibrated vs. uncalibrated density cutoffs for spot sign identification. ICH expansion was defined as hematoma volume growth >33%. Results: A total of 90 subjects qualified for the study, of whom 17/83 (20.5%) experienced ICH expansion. The number of spot sign positive scans was higher in the calibrated analysis (67.8 vs 38.9% p < 0.001). All spot signs identified in the non-calibrated analysis remained positive after calibration. Calibrated CTA images had higher sensitivity for ICH expansion (76 vs 52%) but inferior specificity (35 vs 63%) compared with uncalibrated images. Conclusion: Normalization of CTA images using phantom data is a feasible strategy to obtain consistent image quantification for spot sign analysis across different sites and may improve sensitivity for identification of ICH expansion.

KW - CT angiography

KW - Intracerebral hemorrhage

KW - Phantom standardization

KW - Spot sign

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DO - 10.1007/s00234-017-1857-4

M3 - Article

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JO - Neuroradiology

JF - Neuroradiology

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ER -

Phantom-based standardization of CT angiography images for spot sign detection

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