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Diagnostic yield of delayed phase imaging in CT angiography of the head and neck: a retrospective study.

Bennett DL, Hamberg LM, Wang B, Hirsch JA, González RG, Hunter GJ - PLoS ONE (2014)

Bottom Line: Obtaining delayed phase imaging for neurovascular CTA should be an active decision and not the default protocol.This avoids imaging with little, if any value.If delayed images had not been obtained in our cohort, no detriment in patient management would have occurred.

View Article: PubMed Central - PubMed

Affiliation: Massachusetts General Hospital, Department of Radiology, Boston, Massachusetts, United States of America.

ABSTRACT

Purpose: To evaluate how often delayed images, obtained during neurovascular CTA, provide unique information relative to early phase imaging alone.

Materials and methods: Informed consent was waived by the institutional review body for this study. Neurovascular CTAs from January through June 2009 were searched to identify those with delayed phase imaging. Reports were reviewed to identify cases where delayed images provided potentially unique information. The studies with potentially unique information were re-interpreted to determine if the information was indeed unique.

Results: 645 CTAs with delayed phase imaging were identified. There were 324 men and 310 women (median age 67 years; range 20-96 years). 59 studies (59/645: 9.1%) had findings on the delayed images. There were 13 cases with hemorrhage, with 4 showing progression on delayed views. Of the remaining 46 cases, 28 had occlusion of a vessel that did not reconstitute on the delayed images, 6 had occlusion of a vessel that did reconstitute on the delayed images, 7 had a string sign which was unchanged on the delayed views and 5 had no abnormal findings. Thus in 10 cases the findings were unique to the delayed images (10/645: 1.55%). Four showed active bleeding, three showed proximal occlusion with distal internal carotid filling from ophthalmic collaterals, two showed pial vessels filling distal to proximal MCA occlusion, and one showed retrograde vertebral artery filling due to subclavian steal. 95% confidence limits of the expected incidence of unique information from the delayed phase images are 0.6%-2.5%.

Conclusion: Obtaining delayed phase imaging for neurovascular CTA should be an active decision and not the default protocol. This avoids imaging with little, if any value. If delayed images had not been obtained in our cohort, no detriment in patient management would have occurred.

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Example of active bleeding into a hematoma.88 year old male with hypertension and acute stroke-like symptoms. CTA with delayed phase imaging shows a large hematoma in a left temporal/parietal location. Two axial levels are presented; on the left, images are from the initial phase imaging, on the right from the delayed phase. The red arrows indicate development of active extravasation seen only on the delayed views. The size of the hematoma was much larger than 80 ml and surgery was not performed, the presence of active bleeding did not change this patient's management decisions.
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pone-0099020-g001: Example of active bleeding into a hematoma.88 year old male with hypertension and acute stroke-like symptoms. CTA with delayed phase imaging shows a large hematoma in a left temporal/parietal location. Two axial levels are presented; on the left, images are from the initial phase imaging, on the right from the delayed phase. The red arrows indicate development of active extravasation seen only on the delayed views. The size of the hematoma was much larger than 80 ml and surgery was not performed, the presence of active bleeding did not change this patient's management decisions.

Mentions: Of the 10 cases with unequivocally unique, additional information on the delayed images, 3 had active bleeding into a cerebral hematoma (Fig. 1), and 1 had active bleeding around a left AICA aneurysm (Fig. 2). Three demonstrated delayed filling of the distal internal carotid artery from ophthalmic artery collateralization. Two demonstrated delayed filling of pial vessels distal to a proximal MCA occlusion (Fig. 3), and one demonstrated retrograde filling of a vertebral artery due to subclavian steal.


Diagnostic yield of delayed phase imaging in CT angiography of the head and neck: a retrospective study.

Bennett DL, Hamberg LM, Wang B, Hirsch JA, González RG, Hunter GJ - PLoS ONE (2014)

Example of active bleeding into a hematoma.88 year old male with hypertension and acute stroke-like symptoms. CTA with delayed phase imaging shows a large hematoma in a left temporal/parietal location. Two axial levels are presented; on the left, images are from the initial phase imaging, on the right from the delayed phase. The red arrows indicate development of active extravasation seen only on the delayed views. The size of the hematoma was much larger than 80 ml and surgery was not performed, the presence of active bleeding did not change this patient's management decisions.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048294&req=5

pone-0099020-g001: Example of active bleeding into a hematoma.88 year old male with hypertension and acute stroke-like symptoms. CTA with delayed phase imaging shows a large hematoma in a left temporal/parietal location. Two axial levels are presented; on the left, images are from the initial phase imaging, on the right from the delayed phase. The red arrows indicate development of active extravasation seen only on the delayed views. The size of the hematoma was much larger than 80 ml and surgery was not performed, the presence of active bleeding did not change this patient's management decisions.
Mentions: Of the 10 cases with unequivocally unique, additional information on the delayed images, 3 had active bleeding into a cerebral hematoma (Fig. 1), and 1 had active bleeding around a left AICA aneurysm (Fig. 2). Three demonstrated delayed filling of the distal internal carotid artery from ophthalmic artery collateralization. Two demonstrated delayed filling of pial vessels distal to a proximal MCA occlusion (Fig. 3), and one demonstrated retrograde filling of a vertebral artery due to subclavian steal.

Bottom Line: Obtaining delayed phase imaging for neurovascular CTA should be an active decision and not the default protocol.This avoids imaging with little, if any value.If delayed images had not been obtained in our cohort, no detriment in patient management would have occurred.

View Article: PubMed Central - PubMed

Affiliation: Massachusetts General Hospital, Department of Radiology, Boston, Massachusetts, United States of America.

ABSTRACT

Purpose: To evaluate how often delayed images, obtained during neurovascular CTA, provide unique information relative to early phase imaging alone.

Materials and methods: Informed consent was waived by the institutional review body for this study. Neurovascular CTAs from January through June 2009 were searched to identify those with delayed phase imaging. Reports were reviewed to identify cases where delayed images provided potentially unique information. The studies with potentially unique information were re-interpreted to determine if the information was indeed unique.

Results: 645 CTAs with delayed phase imaging were identified. There were 324 men and 310 women (median age 67 years; range 20-96 years). 59 studies (59/645: 9.1%) had findings on the delayed images. There were 13 cases with hemorrhage, with 4 showing progression on delayed views. Of the remaining 46 cases, 28 had occlusion of a vessel that did not reconstitute on the delayed images, 6 had occlusion of a vessel that did reconstitute on the delayed images, 7 had a string sign which was unchanged on the delayed views and 5 had no abnormal findings. Thus in 10 cases the findings were unique to the delayed images (10/645: 1.55%). Four showed active bleeding, three showed proximal occlusion with distal internal carotid filling from ophthalmic collaterals, two showed pial vessels filling distal to proximal MCA occlusion, and one showed retrograde vertebral artery filling due to subclavian steal. 95% confidence limits of the expected incidence of unique information from the delayed phase images are 0.6%-2.5%.

Conclusion: Obtaining delayed phase imaging for neurovascular CTA should be an active decision and not the default protocol. This avoids imaging with little, if any value. If delayed images had not been obtained in our cohort, no detriment in patient management would have occurred.

Show MeSH
Related in: MedlinePlus