How can we improve our WBCT protocol ?

Bertil Leidner, MD TMC, Stockholm, Sweden

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

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 the German 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 §  Excl abd

§  Liver injury à shock; §  Emboliz; packing

§  WBCT is here to stay

Surgeon´s Traditional View

WBCT - Who to scan?

§  Haemodynamically stable patients §  Borderline stable à Unstable?

» Retrospect, multicenter study – German Trauma Reg » WBCT independent predictor for survival »  in 4280 patients in moderate shock (OR = 0.73); »  in 1821 patients in severe shock (OR = 0.67)

§  Structure protocol to Save Time

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

Optimal WBCT Scan/phases

§  Standard » Head non-C » C-spine non-C » Torso +C (non-C cannot exclude injuries)

§  Options » 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

BCVI CT # 1 - 2 h post injury

§  Car accident »  Conscious all time »  Alert, temporal

wound, neck pain

@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

BCVI - considerations §  Is WBCT good enough?

» 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 BCVI

•  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% in Nordic countries §  In your practice

» Hospital Trauma group decision – Ready to treat?

§  How to scan? »  Include in body scan

– start circle of Willis » Arms up » Recon soft + bone algorithms

Wiklund E, Acta Radiol. 2015 Aug 12

WBCT – torso protocols

§ No consensus §  We want

» High HU in art. & organs » Low radiation level & low contrast dose

§  Different alternatives » References & comparison chart

WBCT – torso protocols – alternatives §  Dual scan

»  ”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

§  Single scan »  ”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 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-

WBCT – torso protocols – alternatives

Yaniv G, Clin Radiol. 2013 Jul;68(7) Beenen LF, Acta Radiol. 2015 Jul;56(7) Leidner B, Emergy Rad 2001 8; + unpubl data Nguyen D, Am J Roentg. 2009 Jan;192(1)

Focus: Single scan – enhancement

Yaniv(40pat) Benen(10pat) Leidner(20pat) Nguyen(30pat) YoursiteA,B,C64chD16ch

Asinglescan,splitbolus

Bsinglescan,splitbolus

Csinglescansinglebolus

Dsinglescan,singlebolus

Yourprotocol

WBCT – single scan - enhancement

Yaniv(40pat) Benen(10pat) Leidner(20pat) Nguyen(30pat) YoursiteA,B,C64chD16ch

Asinglescan,splitbolus

Bsinglescan,splitbolus

Csinglescansinglebolus

Dsinglescan,singlebolus

Yourprotocol

Aorticarch 215 276 246 217

Abdaorta 208 241 238

Femoralart (iliacart)209 221gIcontrast 45,5 42 38,4 44

WBCT – single scan - enhancement

Yaniv(40pat) Benen(10pat) Leidner(20pat) Nguyen(30pat) YoursiteA,B,C64chD16ch

Asinglescan,splitbolus

Bsinglescan,splitbolus

Csinglescansinglebolus

Dsinglescan,singlebolus

Yourprotocol

Aorticarch 215 276 246 217

Abdaorta 208 241 238

Liver 110 78 109 118Spleen 131 120 137 126

Femoralart (iliacart)209 221gIcontrast 45,5 42 38,4 44

WBCT – single scan - enhancement

Yaniv(40pat) Benen(10pat) Leidner(20pat) Nguyen(30pat) YoursiteA,B,C64chD16ch

Asinglescan,splitbolus

Bsinglescan,splitbolus

Csinglescansinglebolus

Dsinglescan,singlebolus

Yourprotocol

Aorticarch 215 276 246 217Pulmtrunc 232Abdaorta 208 241 238IVC 148 139Portalvein 156 169Liver 110 78 109 118Spleen 131 120 137 126Kidney 204 177 164 190Femoralart (iliacart)209 221gIcontrast 45,5 42 38,4 44

Extremity coverage & delayed series

» Arterial phase/single scan to feet, or

»  1. legs@25 s 2. chest @30-35 s 3. abd@ 70 s 100 ml 370mgI/ml @4-5 ml/s + 30 ml saline flush

» Delayed series (5-10 min)

– Low dose abd scan (-50%) –  parenchymal & urological

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

Radiation §  Radiation dose today (WBCT dose often excl head)

» 8 – 12 – 16 – 24 mSv » Generation scanner

– 16 vs 64 ch Siemens à25% radiation redux » # of scan phases;

– extra abd scan à ~ 3-7 mSv+

CT radiation dose report

WBCT dose comparison chart

Hospital#cases Head

CTDIvolHeaddlp

C-spineCTDIvol

C-spinedlp

TorsoCTDIvol

Torsodlp

C-spine+torsodlp

totaldlp

Traumacenter 300 50,6 926 12 235 13 987 1222 2148yourhospitalconvfactor,Huda 0,0024 0,0053 0,0186mSv

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

WBCT dose comparison chart

Hospital#casesorhospit

HeadCTDIvol

Headdlp

C-spineCTDIvol

C-spinedlp

TorsoCTDIvol

Torsodlp

C-spine+torsodlp

Totaldlp

CentralhospitalNorrköping 100 54,7 989 6,1 148 13,7 954 1102 2091TraumacenterUppsala 300 50,6 926 12 235 13 987 1222 2148UniversityhospHuddinge 100 42,3 766 14,6 339 5,4 407 746 1556Trauma/UniversCharité(ASIR) 798 843Querynordic 56hosp 1838Querynon-nordic 8hosp 2200convfactor,Huda,IRCP103 0,0024 0,0053 0,0186

mSvmin 1,8 0,8 7,6mSvmax 2,4 1,8 18,4

WBCT

§  Cost/benefit analysis

Radiation

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

•  Tien - dosimetry 22.7 mSv à 1.9/1000 •  Brenner 12 mSv à 1/1250 •  0.84 alt 0.67/1000 per 10 mSv

§  45-year adult » x annual WBCT of 12 mSv until 75-years age » à 1.9% extra cancer mortality risk

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

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

» Life savings? – Early detection of tumor/aneurysm 1%? – of these 10% life saving = 0,1% à 1/1000?

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

Contrast media reactions » Adverse reactions

•  Allergic reactions

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

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

Contrast media reactions §  CIN: CT with contrast vs no contrast exposure

» 3 studies à 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)

– 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 registries/

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

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

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

http://rcsyd.se/swetrau/dokument

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

– 1/1000 lethal cancers/13.3 mSv – Today´s average 13-26 mSv à 1-2/1000 scans

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

§  Radiation toll & incidental findings may balance §  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% - 1-2

» 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 h

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

WBCT protocol -my suggestions

§  Include BCVI-screening §  Make several protocols (torso scan)

Ø 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)

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

Ø 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 § > 100 HU in liver/spleen

» Check radiation level § < 20 mSv; aim for < 10 mSv

§  Adjust

Friends, not enemies

Thank you for your attention!

leidnerimaging@gmail.com

Recommended reading

§  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.

Dose reduction measures

§  1 Attenuation based tube current modulation (AEC) §  2 Automatic tube voltage selection (ATVS) §  3 Iterative reconstruction (IR)

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

– 25à15 mSv possible; true for 6à3.6 mSv?

Radiation: Ongoing study

§  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