Emergency CT: Update

Rathachai Kaewlai, MD Division of Emergency Radiology

Department of Radiology, Ramathibodi Hospital, Bangkok, Thailand 31st Annual Scientific Meeting “Update and Future Challenges in Health Care”

Faculty of Medicine, Khon Kaen University, 7 October 2015

Ramathibodi Emergency Radiology

Outline

Trauma pan-scan CT

CTA for active bleeding (ICH, hemoptysis, GI bleed) Stroke multiphase CTA

PAN-SCAN

Trauma CT

Selective or “Pan scan”

Pan scan = scanning from head to pelvis in one shot Pre-contrast head CT

Post-contrast neck, chest, abdomen and pelvis

Trauma Pan-Scan: Indications One of these: RR >30 or <10

PR >120

sBP <100 EBL >500 mL

GCS <13

Abnormal pupil react

Clinically suspicious •  Fractures >2 long bones

•  Flail chest, open chest or multiple rib fractures

•  Severe abdominal injury •  Pelvic fracture

•  Unstable vertebral fractures/spinal cord compression

Injury mechanism •  Fall from height (>3m)

•  Ejection from vehicle

•  Death occupant in same vehicle

•  Severely injured patient in same vehicle

•  Wedged of trapped chest/abdomen

http://www.react2.nl/?id=16&p=14&lng=EN

“Pan Scan”

Indication based on severity of trauma and initial evaluations (clinical exam + FAST)

20-year-old woman, motorcycle vs. car SDH, SAH, midline shift, tonsillar herniation Vitreous hemorrhages, skull base fracture Pulmonary contusions, pneumothorax Gluteal hematoma with active extravasation Hypoperfusion complex

40-year-old man, motorcycle vs. car SDH Thoracic aortic injury Complex acetabular fracture

“Pan Scan”

Should it replace other imaging in the primary survey (CXR, PXR, FAST and selective CT)?

CXR PXR FAST

Selective CT

Pan scan CT V

“Pan Scan”

Caputo ND, et al. J Trauma Acute Care Surg 2014

REACT-2 Trial: Results ���(Presented at ASER2015) RCT comparing standard imaging (x-rays, FAST,

selective CT) and pan-scan CT in 5 European centers 1078 patients (539 per group) included

“Bad” trauma or mechanism of injury (65% ISS>16)

REACT-2 Trial: Results ���(Presented at ASER2015) Similar ISS, TRISS, other background info

In-hospital mortality: 2.4% lower for polytrauma patients in pan-scan, not different overall

Shorter time for imaging (similar direct costs, no difference in radiation exposure)

CTA FOR ACTIVE BLEEDING: ICH, HEMOPTYSIS, GI BLEED

Active Bleeding

Timely localization of active hemorrhage of internal organs possible because of faster CT

Especially true in trauma patients Guiding initial Rx of trauma

Use in non-trauma acute bleeds still limited but gaining attention

“Bleed” Scott Reinwand, YouTube.com

Primary Intracerebral Hemorrhage Hemorrhagic stroke = deadliest stroke

Strongest predictor of mortality = initial hematoma vol Not modifiable

“Hematoma expansion”

Potentially modifiable predictor 30% or >6 mL growth of hematoma ~40% of ICH

Correlated with poor functional outcome and death Attractive target of Rx trials

Primary Intracerebral Hemorrhage “Hematoma expansion”

30% or >6 mL growth of hematoma ~40% of ICH Correlated with poor functional outcome and death

Attractive target of Rx trials

Can We Predict Hematoma Expansion? “CTA spot sign”

Intrahematoma contrast following CTA Represents site of active extravasation in early ICH Spot sign growth =

[spot vol (delayed) – spot vol (initial)] elapsed time

Dowlatshahi D, et al. Stroke 2014;45:277 Image credit: smh.com.au

51yo F, known valvular heart disease S/P valve replacement, on warfarin

1 day 2 days

CTA Post

78yo M, HTN, CKD with AOC for 8 hrs “Multiple spot signs”

CTA Post CTV

CTA Post CTV

CTA Spot Sign

Prevalence of spot sign in primary ICH 13-32%

Predicting hematoma expansion (%) Sensitivity 38-93 Specificity 50-93

PPV 22-77

NPV 78-98 Accuracy 56-90

PLR 1.86-10.99 NLR 0.30-0.73

Giudice AD, et al. Cerebrovasc Dis 2014;37: 268

75%

CTA Spot Sign: Imaging Marker

Hematoma expansion

Active bleeding during surgery Postoperative rebleeding In-hospital death

90-day mortality

May help selecting patients with pICH for specific therapy (medical, surgical hemostasis)

Brouwers HB, et al. Neurology 2014;83: 883 Brouwers HB, et al. Stroke 2015;46: 2498

Severe Hemoptysis

Life-threatening

Without bleeding control – mortality >50% Indications for intervention (bronchial embolization) Volume >200 mL/24-48h

Acute respiratory failure Erosion of pulmonary artery

Clinical Bedside Evaluation vs. CTA

Clinical CTA Lateralization 93.1 87.4

Lobar location 82.7 85.0

Etiology 70.1 86.2

Rx change -  Medical -  Embo -  Pulm a. occlusion

21.8

Comparing bedside eval vs. CTA in 87 patients with severe hemoptysis

Those needing emergent FOB excluded

67% bronchiectasis 92% bronchial systemic

bleeds

Chalumeau-Lemoine L, et al. Eur J Radiol 2013

CTA in Severe Hemoptysis

Bleeding site

Bleeding vessels (PA involved or not) Bronchial artery network (normotopic, atypical,

ectopic, non-bronchial systemic arteries)

Etiology

CTA: Site of The Bleed

Bleeding side and precise localization of hemoptysis essential for Rx (airway protection, embo, surgery)

Parenchymal bleed

Consolidation GGO

PA pseudoaneurysm

CTA: Bleeding Vessels

90% systemic arteries (BA, and non-bronchial systemic)

10% pulmonary arteries Direct signs of bleeding from pulmonary artery Pulmonary artery aneurysms

Lung consolidation with necrosis and irregular PA

Bronchial Artery Network

By excluding PA as a source, hemoptysis likely from systemic artery

CTA more accurate than angiography for identifying BA and NBSA Anatomical variants

Catheterization difficulties a/w age atherosclerosis Except: middle anterior spinal artery of high T-cord

76yo F hemoptysis during PA pressure measurement

Bleeding site: RML Bleeding vessel: Pulmonary artery BA network: N/A Etiology: Traumatic pseudoaneurysm of PA branch

69yo M

Bleeding site: RUL Bleeding vessel: Pulmonary artery BA network: N/A Etiology: TB Rasmussen pseudoaneurysm

67yo F

Bleeding site: RUL Bleeding vessel: Bronchial systemic BA network: as in picture Etiology: bronchiectasis

54yo M, Bleeding site: RUL

Bleeding vessel: Bronchial systemic BA network: as in picture

Etiology: TB

CTA Algorithm for Severe Hemoptysis

Bleeding Site

Bronchoscopy

No Yes

BA Network

BA -  Normotopic

-  Atypical -  Ectopic

NBSA

Bleeding Vessels

PA involvement?

PA embolization

Systemic artery

embolization

No Yes

Khalil A, et al. Diagn Interv Imaging 2015;96: 775

Etiology

Cancer Bronchiectasis

TB Mycetoma

Others Cryptogenic

Overt Lower GI Bleeding

GI bleeding visible: melena, hematochezia

UGIB more common but prevalence is changing Mortality 2-20% (40% if hemodynamically unstable) Colonoscopy often not helpful

Identify source of bleed in only 13-40% of cases Limited therapeutic advantage over endovascular Rx

Overt Lower GI Bleeding: Etiology

Colonic diverticulosis

Angioectasia Colonic or small bowel neoplasm Meckel’s diverticulum

Rectal ulcers and hemorrhoids Rare: hemobilia (liver biopsy, bleeding hepatic tumors),

hemosuccus pancreaticus, aorto-enteric fistula

Scintigraphy, ���Catheter Angiography and CTA

Scintigraphy Catheter Angiography

CTA

Minimum rate of bleeding (mL/min)

0.05 0.5 0.3*

Type of bleed Intermittent Active Active

Location of bleed Limited Yes Yes

Etiology of bleed Limited Limited Probable

Soto JA, et al. Abdom Imaging 2015;40: 993 *Kuhle WG, et al. Radiology 2003;228: 743

CTA: Overt LGIB

90% source in colon and rectum

Accuracy for identifying source of bleed 80-90% Non-contrast, CTA, venous phase. No enteric contrast

CTA: Findings of Overt LGIB

Hyperattenuating focus (blush) of variable size in arterial phase (jet may be present if arterial source)

Change morphology and location on venous phase

Move distally and larger

78yo M with abdominal distension, SMA branch active contrast extravasation

CTA Venous

43yo M, HIV with lymphoma, dropped Hct

Venous Plain Delayed

CTA: Diagnostic Performance

Systematic review and meta-analysis, 672 patients in 22 studies with reference standards of endoscopy, angiography and surgery

494 positive cases (prevalence 74%) Sensitivity 85.2 %

Specificity 92.1% Accuracy 93.5%

PLR 10.8% NLR 0.16%

Garcia-Blazquez V, et al. Eur Radiol 2013;23: 1181

STROKE “MULTIPHASE” CTA:���A NEW TOOL FOR ACUTE STROKE

Acute Ischemic Stroke

Newer mechanical devices – rapid/successful recanalization possible and now standard

Clinical outcome depends on

Salvageable brain at presentation Early recanalization

Ideal imaging selection tool should enable one to detect salvageable brain quickly, reliably, and widely available

Factors Determining Potential Rx

Brain parenchyma – infarct core (size)

Large vessel – occlusion (presence) Collateral circulation (grading)

MRI-DWI

CTA

Multiphase CTA

NCCT, CTA-SI

CTA: Cerebral Vasculature

Sensitivity 97-100% and specificity 98-100% to detect proximal intracranial occlusions and stenosis

Proximal occlusion results in large infarcts, which have high likelihood of hemorrhagic transformation but greatest benefit from IA Rx

Evaluation of Collateral Circulation Good leptomeningeal/pial collaterals beneficial in stroke

Repeated acquisitions after routine CTA = multiphase “Multiphase CTA”

Degree and extent of pial arterial filling of whole brain in a time-resolved manner

Assess collaterals better than one phase Avoid pitfalls of false occlusion on CTA

Multiphase CTA - Interpretation

Score Delayed Filling

Prominence Extent

Good 5 No Normal or increased Symmetric

4 1 phase Normal Symmetric

Intermediate 3 2 phases Normal Normal

1 phase Decreased Decreased

2 2 phases Decreased Decreased

1 phase No vessels in some areas

No vessels in some areas

Poor 1 3 phases A few vessels visible A few vessels visible

0 3 phases No vessels visible No vessels visible

Menon BK, et al. Radiology 2015;275: 510

For MCA territory occlusion Comparing with contralateral asymptomatic side

Multiphase CTA

147 patients

Interrater reliability n=30, k=0.81, P<.001

Menon BK, et al. Radiology 2015;275: 510

Multiphase CTA

Predicting clinical outcome at 24 hours

Best = baseline infarct volume (<80 vs. >80 mL) 2nd best = multiphase CTA (score >3 vs. <3)

Predicting clinical outcome at 90 days

Best = multiphase CTA (score >3 vs. <3) 2nd best = single-phase CTA (score >2 vs. <2)

Better than CTP mismatch ratio

Menon BK, et al. Radiology 2015;275: 510

47yo F, NIHSS 20, Rt hemispheric symptoms 2 hrs ASPECTS score = 7

mCTA: Rt M1 occlusion Delayed collaterals filling 2 phases with decreased prominence/extent Collaterals score = 2 (Intermediate) IA Rx not recommended

Images from Menon BK, et al. Radiology 2015;275: 510

CTP: Blue = infarct core = 100 mL IA Rx not recommended

Congruent mCTA and CTP No IA Rx

87yo F, NIHSS 15, Lt hemispheric symptoms 2 hrs ASPECTS score = 6

mCTA: Lt M1 occlusion Delayed collaterals 1 phase at worst Collaterals score = 4 (Good) IA Rx recommended

CTP: Blue = infarct core = 0 mL (no blue) IA Rx recommended

Congruent mCTA and CTP IA Rx performed by not successful

Images from Menon BK, et al. Radiology 2015;275: 510

Images from Menon BK, et al. Radiology 2015;275: 510

78yo F, NIHSS 18, Rt hemispheric symptoms 1.5 hrs ASPECTS score = 8

mCTA: Rt M1 occlusion Delayed collaterals 1 phase Collaterals score = 4 (Good) IA Rx recommended

CTP: Blue = infarct core = 113 mL IA Rx not recommended

Incongruent mCTA and CTP IA Rx performed with success

ASPECTS score = 8

mCTA: Left M1 occlusion Delayed collaterals 1 phase Decreased prominence Collaterals score = 3 (intermediate)

5 days

IA Rx not recommended and was not performed

1 day

49yo M ASPECTS score = 8

mCTA: Partial right M1 occlusion Delayed collateral 1 phase Normal prominence/extent Collaterals score = 4 (Good)

IA Rx recommended but not performed

Summary: Pan-scan CT

Good to go esp. high-severity trauma

Not inferior to standard of care (CXR, PXR, FAST + selective CT)

Trauma Centers: please set up protocols and indications

Summary: CTA for active bleeding

Primary intracerebral hemorrhage

CTA spot sign Predictive of hematoma expansion and outcome

Severe hemoptysis evaluation

Bleeding site, vessels, BA network, etiology LGIB Useful for pre-embolization

Summary: Multiphase CTA in acute stroke evaluation NCCT-mCTA is a new paradigm for acute stroke

imaging Collaterals evaluation valuable for IA Rx decision,

probably better than CTP Stroke onset, NIHSS, ASPECTS, Collaterals score (+/- DWI)

THANK YOU VERY MUCH FOR YOUR ATTENTION

Rathachai Kaewlai, MD