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HowHow cancan wewe improveimprove ourourWBCT WBCT protocolprotocol ??

Bertil Leidner, Bertil Leidner, MDMDTMC, Stockholm, SwedenTMC, Stockholm, Sweden

Overview

WBCT today WBCT - today

Technological advancements» Dose reduction measures

WBCT protocols» different choices» different choices

Radiation & cost/benefit analysis

Suggestions WBCT protocol

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Presentation & Reference list

myesr org & nordictraumarad commyesr.org & nordictraumarad.comReferences - PubMed link:

http://www.ncbi.nlm.nih.gov/sites/myncbi/1VMdlCqjfAnAs/collections/49689102/public/

WBCT vs selective CT

WBCT in literature» Time saving +

» Diverging results for mortality– RCT (due soon), registry data, metaanalysis

» Questionable but Possible mortality reduction~ 20 %

Healy DA, Emerg Med J 2014;31; Jiang L, Scand J Trauma Resusc Emerg Med 2014;22; Caputo ND, J Trauma Acute Care Surg. 2014 Oct;77(4); Sierink JC, BMC Emerg Med. 2012 Huber-Wagner S, Lancet. 2009 Apr 25;373

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Clinical recommendations

No universal consensus» WBCT indicated/recommended UK

for major (life-threating) trauma• Royal College of Radiologists, UK

• NICE guidelines for major trauma, UK

» No standpoint WBCT vs selective CT USA & DE• American Congress of Radiology (ACR)

• Eastern American Society of Trauma (EAST)

• German Trauma Society

http://guidelines.irefer.org.uk/adult/#Tpc241; https://acsearch.acr.org/list; 012-019e_S3_Severe_and_Multiple_Injuries_2015-01 English Version of theGerman Guideline S3 – Leitlinie Polytrauma/Schwerverletzten-Behandlung; (AWMF-Registry No. 012/019)https://www.nice.org.uk/guidance/ng39/chapter/recommendations#whole-body-ct-of-multiple-injuries

Abdomen - normal clinical status

Selective CT request Selective CT request Excl abd

Liver injury shock;

Emboliz; packing

WBCT is here to stay

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Surgeon´s Traditional View

WBCT - Who to scan?

Haemodynamically stable patients

Borderline stable Unstable?» Retrospect, multicenter study – German Trauma Reg

» WBCT independent predictor for survival

» in 4280 patients in moderate shock (OR = 0.73);

i 1821 ti t i h k (OR 0 67)» in 1821 patients in severe shock (OR = 0.67)

Structure protocol to Save Time

Huber-Wagner S et al TraumaRegisterDGU. PLoS One. 2013 Jul 24;8(7)

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CT technologic development

Technology moves fast, academics moves slow» > 20 years for RCT WBCT

» VOMIT– Victims of Medical Information Technology

Stress the importance of clinical exam/observation

Technology increases diagnostic power Technology increases diagnostic power– 1990 incremental CT 5 scans/minMDCT slices >300/rot

» MPR – ax, cor, sag – VRT

Increased possibilities

Faster, more coverage, more powerful x-ray tube

More series» balanced by new dose redux measures

Tech advances – never ending story » Act based on previous experience & logic reasoning

» Important with follow-up studies

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Dose reduction measures

1 Attenuation based tube current modulation (AEC) 1 Attenuation based tube current modulation (AEC)

2 Automatic tube voltage selection (ATVS)

3 Iterative reconstruction (IR)

Dose reduction in % (40%) Dose reduction in % (40%)» From what level?

– 2515 mSv possible; true for 63.6 mSv?

1. Attenuation basedtube current modulation

CT software AEC– Automat Exp Control

– Different vendors, different solutions

» topogram + previous rotation

Reduction exposure dose

» 35–60 %» 35 60 %

Image (part) fromLoewenhardt B, et al. Injury. 2012 Jan;43(1):67-72; Söderberg M, Acta Radiol. 2010 Jul;51

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AEC & Arms positioning

Image from:Brink M, Radiology. 2008 Nov;249(2)

Optimize for arms down scans Consult your vendor Different AEC solutions

AEC vs fixed low dose

No AEC fixed low dose (for torso)

+ Big boy protocol w increased radiation

» Karolinska Huddinge; Karolinska Solna, trauma center

CTDIvol DLP

Trauma center, 

Uppsala with AEC 13 987Uppsala, with AEC 13 987

Karolinska,Huddinge

fixed dose 5,4 407

Trauma Karolinska 

Solna; fixed dose 2,9 500 Leidner, unpubl data;Beckman, unpubl data

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2. Attenuation based tube voltageselection (ATVS)

Lower the tube voltageI i l t th k d f I (33 2 k V)– Imaging closer to the k-edge of I (33,2 keV)

– attenuation of iodine +; keeping CNR/ dose redux

» ATVS vs fixed kV dose redux 16-56%

192 ch vs 128 ch dual source CT– Extended range 70 -150 kV at smaller (10 kV) steps

» Dose redux 19.2 %– 5.9 4.9 mSv (in CTA)

– Subjective image quality, mean aortic attenuation and CNR higher

Siegel MJ, Invest Radiol. 2013 Aug;48(8); Schwarz F, AJR Am J Roentgenol. 2013 Jun;200(6)Winklehner A, Eur Radiol. 2015 Aug;25(8)

3. Iterative reconstructions (IR)

Vendor specific IR calculations to reduce noise» Multiple steps: image compared to initial raw data

» @ different strengths

» advanced with ”model” or knowledge based calculations

Reduced noise reduce radiation equal noise

D b k ” l i / i il d” i l k Drawback ”plastic/pixilated” image look

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3. IR

Changed image look?» No diff IR (ADMIRE) cf. FBP

– lower image noise, improved image quality

– allows for dose reduction

Knowledgebased IR – pediatric phantom

» 75 % dose redux; FBP @3.64 mSv cf. IR (IMR) @0.92 mSv

» Similar image quality

Gordic S, Br J Radiol. 2015 Mar;88(1047);Ryu YJ, Pediatr Radiol. 2015 Nov 6

IR: Noise reduxCaution – the whole truth?

Liver phantom with artificial lesions» 5 different IR from 4 vendors FBP vs IR

– Only two algorithms improved lesion detection• Only one improved at the lowest dose level

» 2 different scanners/detectors (one vendor)– IR lesion conspicuity+ with 33% dose redux

– only for the new scanner @ 10mGy cf. 15mGy FBP

Jensen K, Eur Radiol. 2014 Dec;24(12) Jensen K, Curr Probl Diagn Radiol. 2015 Dec 15.

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Clinical studies: FBP vs ASIR

~25% dose redux 2518 or 1713 mSv

– 23% redux – 16.6 12,7 mSv • 122 trauma patients randomized FBP vs IR (ASIR)

» SNR/CNR & subjective image quality – no signif diff

– 22-31% redux – 25 19.7 17.5 mSv 18 traumapatients• 18 traumapatients

» No diff in image noise/contrast & overall interpret.

» For FBP vs IR 30% vs IR 40%

Kahn J, Acta Radiol. 2016 Mar;57(3)Grupp U, Emerg Med Int. 2013

Optimal WBCT protocol

Blunt trauma

One size fits all?» Adapt to individual patients/suspected injuries

» Local situation– Trauma volume & severity

Y l l f ti– Your level of expertise

– Teamwork - with clinicians

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Optimal WBCT Scan/phases

Standard» Head non-C

» C-spine non-C

» Torso +C (non-C cannot exclude injuries)

Optionsf Bl t C b V l I j (BCVI)» screen for Blunt CerebroVascular Injury (BCVI)

• c-spine included in torso contrast scan

» Torso – single/dual pass; single/split contrast bolus

» Extremities -/+ C for fx/vascular injury

BCVICT # 1 - 2 h post injury

Car accidentCar accident» Conscious all time» Alert, temporal

wound, neck pain

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@2h @4h @16h

BCVI - considerations

Do we need to scan the cerebrovasculature? – ~2% of blunt trauma patients, stroke rate up to 20%.

– Early treatment decreases mortality & stroke rate (by 5–10 x)

– Treatment is cost-effective in high risk group

Screening by risk factors or all patients?– Ex. facial/skullbase/c-spine fx, GCS < 8, focal neuro defecit

– Will miss ~20% of injuries

» Stroke prevention– 4/1250 patients screening by risk factors;

– 1 extra prevented stroke by screening ALL

Laser A, Surgery. 2015 Sep;158(3)Kaye D, J Trauma. 2011 May;70(5)Bruns BR, J Trauma Acute Care Surg. 2014 Mar;76(3)www.nordictraumarad.com/guidelines/bcvi-cerebrovasc-injury-13397469

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BCVI - considerations Is WBCT good enough?

DSA/ th i h CTA 64 h» DSA/cath angiography ~ CTA 64 ch• 64 ch CTA per patient sensitivity 84%

• DSA complications = calculated morbidity by missed injuries

» but WBCT (-)– WBCT sensitivity rates > 90% to detect BCVIy

• WBCT indeterminate 18%; false pos 23%

» Follow-up of positive findings– CTA < 24 h

Paulus EM, J Trauma Acute Care Surg. 2014 Feb;76(2)Laser A, Surgery. 2015 Sep;158(3)

BCVI – decision point Regional differences Europe/US

24% i N di t i» 24% in Nordic countries

In your practice» Hospital Trauma group decision

– Ready to treat?

How to scan?How to scan?» Include in body scan

– start circle of Willis

» Arms up

» Recon soft + bone algorithmsWiklund E, Acta Radiol. 2015 Aug 12

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WBCT – torso protocols

No consensus We want

» High HU in art. & organs

» Low radiation level & low contrast dose

Different alternatives Different alternatives» References & comparison chart

WBCT – torso protocols – alternatives Dual scan

” ” C» ”Whole body” CTA

» Abd/pelvis – venous phase

» Split contrast bolus– 1st phase – high flow; (2nd phase – reduced flow)

» Gunn

» Single contrast bolus» Schueller; Geyer

Pro/con• Pos: arterial HU+; splenic aneurysm+

• Neg: radiation+, image no+

Gunn ML, Radiol Clin North Am. 2015 Jul;53(4)Schueller G, Radiol Med. 2015 Jul;120(7)Geyer LL, Acta Radiol. 2013 Jun;54(5)Boscak AR, Radiology. 2013 Jul;268(1)Atluri S, Emerg Radiol. 2011 Aug;18(4

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Single scan» ”whole body” / thorax abd/pelvis

WBCT – torso protocols – alternatives

» whole body / thorax-abd/pelvis– combined art/venous phase

» Split contrast bolus– 2nd phase – high flow; (1st phase – reduced flow)

• A. Yaniv; B. Beenen

» Single contrast bolusYaniv G, Clin Radiol.

» Single contrast bolus• C. Leidner; 120 ml 320mgI/ml@2.5ml/s

• D. Nguyen

» No diff single vs split (16 ch)

Pro/con• Pos: radiation- image no- Neg: arterial HU-(?); splenic aneurysm-

2013 Jul;68(7)Beenen LF, Acta Radiol. 2015 Jul;56(7)Leidner B, Emergy Rad2001 8; + unpubl dataNguyen D, Am J Roentg. 2009 Jan;192(1)

Focus: Single scan – enhancement

Yaniv(40 pat) Benen(10 pat) Leidner(20 pat) Nguyen(30 pat) Your site

h l l l lA,B,C 64 ch 

D 16 ch

A single scan,

split bolus

B single scan,

split bolus

C single scan

single bolus

D single scan,

 single bolus 

Your

protocol

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WBCT – single scan - enhancement

Yaniv(40 pat) Benen(10 pat) Leidner(20 pat) Nguyen(30 pat) Your site

A B C 64 h A i l B i l C i l D i l YA,B,C 64 ch 

D 16 ch

A single scan,

split bolus

B single scan,

split bolus

C single scan

single bolus

D single scan,

 single bolus 

Your

protocol

Aortic arch 215 276 246 217

Abd aorta  208 241 238

Femoral art (iliac art)  209 221

g I contrast  45,5 42 38,4 44

WBCT – single scan - enhancement

Yaniv(40 pat) Benen(10 pat) Leidner(20 pat) Nguyen(30 pat) Your site

A B C 64 h A i l B i l C i l D i l YA,B,C 64 ch 

D 16 ch

A single scan,

split bolus

B single scan,

split bolus

C single scan

single bolus

D single scan,

 single bolus 

Your

protocol

Aortic arch 215 276 246 217

Abd aorta  208 241 238

Liver  110 78 109 118

Spleen 131 120 137 126

Femoral art (iliac art)  209 221

g I contrast  45,5 42 38,4 44

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WBCT – single scan - enhancement

Yaniv(40 pat) Benen(10 pat) Leidner(20 pat) Nguyen(30 pat) Your site

A B C 64 h A i l B i l C i l D i l YA,B,C 64 ch 

D 16 ch

A single scan,

split bolus

B single scan,

split bolus

C single scan

single bolus

D single scan,

 single bolus 

Your

protocol

Aortic arch 215 276 246 217

Pulm trunc 232

Abd aorta  208 241 238

IVC 148 139

Portal vein  156 169

Liver  110 78 109 118

Spleen 131 120 137 126

Kidney  204 177 164 190

Femoral art (iliac art)  209 221

g I contrast  45,5 42 38,4 44

Extremity coverage& delayed series

» Arterial phase/single scan to feet orfeet, or

» 1. legs@25 s 2. chest @30-35 s 3. abd@ 70 s100 ml 370mgI/ml @4-5 ml/s + 30 ml saline flush

» Delayed series (5-10 min)– Low dose abd scan (-50%)

– parenchymal & urologicalinjuries; (+ cystogram)

Foster BR, Radiology. 2011 Dec;261(3)Gunn ML, Radiol Clin North Am. 2015 Jul;53

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Arms positioning: down +/-

+ Save time by not changing arms position y g g» 2-4 minutes

- Arms down» Increases radiation 16 - 45% +

» Artifacts liver/spleen» Artifacts liver/spleen

Beenen LF, Acta Radiol. 2015 Jul;56(7)Loewenhardt B, Injury. 2012 Jan;43(1Brink M, Radiology. 2008 Nov;249(2)

Arms positioningPosition C

Images from:Gunn ML, Radiol Clin North Am. 2015 Jul;53(4)

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Patient positioning

Patient centering in gantry Patient centering in gantry» 3 cm off z-axis

– 6%+ image noise;

– 12-18%+ radiation dose surf/periph

Trauma bearing devices» Metal-free - avoid artifacts

» 4/9 showed 2.5-4.5% + radiation dose

Li J, Am J Roentgenol. 2007 Feb;188(2)Loewenhardt B, Injury. 2014 Jan;45(1)

No i.v. access

Intraosseus needle in tibia or prox humerusIntraosseus needle in tibia or prox humerus» Power injector; 2-5 ml/s

» standard trauma injection & scan protocol» If needle in proximal humerus (keep arm by side!)

Plancade D, Ann Fr Anesth Reanim. 2012 Dec;31(12)Knuth TE, Ann Emerg Med. 2011 Apr;57(4)Ahrens KL, J Emerg Med. 2013 Aug;45(2)http://www.nordictraumarad.com/guidelines/intraosseus-contrast-inj-ct-29043303

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Radiation

Radiation dose today (WBCT dose often excl head)

» 8 – 12 – 16 – 24 mSv

» Generation scanner – 16 vs 64 ch Siemens 25% radiation redux

» # of scan phases; – extra abd scan ~ 3-7 mSv+

CT radiation dose report

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WBCT dose comparison chart

Hospital

# cases Head 

CTDIvol

Head 

dlp

C‐spine 

CTDIvol

C‐spine 

dlp

Torso 

CTDIvol

Torso

dlp

C‐spine+

torso dlp

total 

dlp

Trauma 

center 300 50,6 926 12 235 13 987 1222 2148

your 

hospital

conv factor, 

Huda 0,0024 0,0053 0,0186

mSv

Huda W, Med Phys. 2011 Mar;38(3)

WBCT dose comparison chart

Hospital

# cases

or hospit

Head 

CTDIvol

Head 

dlp

C‐spine 

CTDIvol

C‐spine 

dlp

Torso 

CTDIvol

Torso

dlp

C‐spine+torso 

dlp

Total 

dlp

Central hospital

Norrköping 100 54,7 989 6,1 148 13,7 954 1102 2091

Trauma center

Uppsala 300 50,6 926 12 235 13 987 1222 2148

University hosp

Huddinge 100 42,3 766 14,6 339 5,4 407 746 1556

Trauma/Univers

Charité (ASIR) 798 843Charité (ASIR) 798 843

Query nordic 56 hosp 1838

Query non‐nordic 8 hosp 2200

conv factor, 

Huda, IRCP 103 0,0024 0,0053 0,0186

mSv min 1,8 0,8 7,6mSv max 2,4 1,8 18,4

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Radiation: Ongoing study

BOTTOM LINE BOTTOM LINE

Diagnostic security vs radiation & contrast

DoReMI prospective study

» Low 12.5 mSv

» vs ultralow dose w IR 6.2 mSv ; – 500 + 500 patients

– single pass 128 ch MDCT

Stengel D, Dose reduction in whole-body computed tomography of multiple injuries (DoReMI):protocol for a prospective cohort study. Scand J Trauma Resusc Emerg Med. 2014 Mar 3

Radiation

Estimation of cancer mortality /1000 patients» mean 1/1000/13.3 mSv

• Tien - dosimetry 22.7 mSv 1.9/1000

• Brenner 12 mSv 1/1250

• 0.84 alt 0.67/1000 per 10 mSv

45-year adult» x annual WBCT of 12 mSv until 75-years age

» 1.9% extra cancer mortality risk

Tien HC, J Trauma. 2007 Jan;62(1)Brenner DJ, Radiology. 2004 Sep;232(3):735-8

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Incidental Findings (IF)

Trauma patient studies» 7- 9% of patients potentially severe

• ie 1 lymph node met/tumor; 1 AAA; 3 pulm masses

» 2.6 – 8.8% High/moderate relevance• Age dependent

• 2.6 % in < 40 y; 6.6% 40-60 y; 8.8% >60 y

Lif i ?» Life savings? – Early detection of tumor/aneurysm 1%?

– of these 10% life saving = 0,1% 1/1000?

Fakler JK, Patient Saf Surg. 2014 Aug 31;8:36Sierink JC, Injury. 2014 May;45(5)Munk MD, J Emerg Med. 2010 Apr;38(3)

Contrast media reactions» Adverse reactions

Allergic reactions• Allergic reactions

– Anaphylaxic deaths• Low osmolar = 1/500.000 (1990-1994)

» CIN 5 - 11%– (Contrast Induced Nephropathy) (S-Cr 25%+ or 44 mol/L +)

– 6.6% CIN, 1 pat dialysis; no mortality increase• 1184 trauma pat (ISS 16; diabetic 8%)

– 5% CIN, all recovered in 5 days • – angioembo 248 ml 320/350 mgI/ml - 100 hypotensive trauma pat

– 11% CIN; 1% severe (outpatients) Idée JM, Fundam Clin Pharmacol. 2005 Jun;19(3)Lasser EC, Radiology. 1997 Jun;203(3)Matsushima K, J Trauma. 2011 Feb;70(2)Vassiliu P, J Am Coll Surg. 2002 Feb;194(2)Mitchell AM, Clin J Am Soc Nephrol. 2010 Jan;5(1)

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Contrast media reactions

CIN: CT with contrast vs no contrast exposure» 3 studies no significant difference

– even in patients with eGFR < 30

» C+ 4% vs C- 5% - CIN in traumapatients

» no difference in rates of acute kidney injury (AKI) y j y ( )– meta-analysis 26,000 patients

– matched (propensity score) 12 508 patients

Colling KP, J Trauma Acute Care Surg. 2014 Aug;77(2)McDonald JS, Radiology. 2013 Apr;267(1)McDonald JS, Radiology. 2014 Apr;271(1)

Cost/benefit WBCT 20% mortality reduction in

i t i / t l iregistries/metaanalysis

Mortality in SweTrau 2014 (NISS=New Injury Severity Score)

– NISS < 15 0.9% >15 17.4% NISS all 4.4%

» Saved lives/1000 patientsNISS < 15 2 >15 35 NISS all 9

http://rcsyd.se/swetrau/dokument

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Cost/benefit WBCT Radiation death toll (linear radiation theory)

1/1000 l th l /13 3 S– 1/1000 lethal cancers/13.3 mSv

– Today´s average 13-26 mSv 1-2/1000 scans

Incidental findings– life saving findings 1/1000 (?)

Radiation toll & incidental findings may balanceg y

Contrast media consequenses– marginal life loss (1/500.000)

Cost/benefit WBCT mortality/1000 patients

Mortality reduction – extra radiation toll = N:o saved lifes/1000

20% 1 220% - 1-2

» NISS < 15 2 – 1(2) = 1 (0)

» NISS > 15 35 – 1(2) = 34 (33)

» Low risk group – special consideration– Excessive radiation

– Clinical prediction rules

– Clinical observation 8 hLinder F, Scand J Trauma Resusc Emerg Med. 2016 Jan 27;24(1)Kendall JL, West J Emerg Med. 2011 Nov;12(4)

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Special groups:protocol adjustments?

Children– Radiation sensitive; few injured need surgical expl (5%)

> 65 y– Mortality risk x10, radiation risk –; renal risk +

– Protocol change: lower kV; higher radiation

PregnancyPregnancy– Don´t hesitate: radiation/contrast OK

– Save the mother, save the child

Harvey JJ, Clin Radiol. 2013 Sep;68(9)

WBCT diagnostic limitations

Artifacts; foreign material; patient unrest

Delayed & missed diagnosis (375 patients)

» Need treatment 7 %

» Small pancreatic inj and bowel contusions – truly non-detectable

» 3rd read 85 % of missed lesions seen» 3rd read, 85 % of missed lesions seen– 25/48 missed injuries = fractures

Pfeifer R, Patient Saf Surg. 2008 Aug 23;2:20Geyer LL, Acta Radiol. 2013 Jun;54(5)

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WBCT protocol-my suggestions

Include BCVI-screening

Make several protocols (torso scan)

1. Clinically life threatening Arms down in front of chest - saves time

2 scan phases CTA ”whole body” & venous Abd/pelvis

Maximize quality by High radiation dose & increase iv contrast (48 g I)

2. Standard w arms up; single scan phase; single bolus contrast injection

3. Consider clinical observation

Standard protocol for you

Robust!» Secure for every patient; hectic trauma environment

» Changing co-workers

Start analyze your present protocol w comp charts» Check contrast enhancement > 220-250 HU uniformly in arteries> 220 250 HU uniformly in arteries

> 100 HU in liver/spleen

» Check radiation level < 20 mSv; aim for less

Adjust

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Friends, not Friends, not enemiesenemies

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leidnerimaging@gmail.comleidnerimaging@gmail.com

ThankThank you for your you for your attentionattention!!

Presentation & Reference list

myesr org & nordictraumarad commyesr.org & nordictraumarad.comReferences - link to PubMed

http://www.ncbi.nlm.nih.gov/sites/myncbi/1VMdlCqjfAnAs/collections/49689102/public/

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Recommended reading

G ML K l DR L h t BE I i O t i Gunn ML, Kool DR, Lehnert BE. Improving Outcomes in the Patient with Polytrauma: A Review of the Role of Whole-Body Computed Tomography. Radiol Clin North Am. 2015 Jul;53(4):639-56

Harvey JJ, West AT. The right scan, for the right patient, at the right time: the reorganization of major trauma service provision in England and its implications for radiologists. Clin Radiol. 2013 Sep;68(9):871-86.