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Primum Non Nocere Use of Radiology – Danger/Benefit

Bertil Leidner, MD

Background/Disclaimer

§  Consultant, Dept of Radiology, Karolinska, Huddinge 1998 – 2014 » Emergency radiology » CT » Trauma CT development 1990

§  Free-lance consultant 2014 - present » Swedish radiology dept / Norrköping » Teleradiology – TMC

– On call emergency radiology - Sydney

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General aspects - Inspiration och source 

§  Läkartidningens symposium 15/3 - 17 §  Diagnostiska fel och misstag

»  Åke Andrén Sandberg, Rita Fernholm, Pelle Gustafson, Anders v Heijne, Charlotta Nelsson

Outline I

§  General aspects on mistakes §  Radiology – cost/benefit §  How to avoid mistakes/misdiagnosis

» Focus Teamwork Radiology - Surgery

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Sannolikhet för att göra allt rätt

●  5 steg i processen, vi gör rätt 99 gånger av 100 »  = 5 patienter av 100 får inte

rätt behandling ●  5 steg i processen,

vi gör rätt 95 gånger av 100 »  = 23 patienter av 100 får

inte rätt behandling

●  25 steg i processen, vi gör rätt 99 gånger av 100 »  = 22 patienter av 100 får

inte rätt behandling ●  25 steg i processen,

vi gör rätt 95 gånger av 100 »  = 72 patienter av 100 får

inte rätt behandling

Röntgenundersökning - 10 steg §  Patient - klinisk undersökning §  Röntgenremiss

»  Val av klinisk information & frågeställning »  Val av undersökning (metod)

§  Prioritering & bokning »  Metodval, tidsprio

§  (DT-) undersökning »  Hur struktureras den? Antal faser – N, artär, ven, sen

§  Granskning §  Bedömning/ slutsats/diagnos §  Kommunikation av svar radiolog - kirurg

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Hur begränsar vi felen?

●  Patient - klinisk undersökning

●  Röntgenremiss »  Val av klinisk information &

frågeställning »  Val av undersökning

(metod) ●  Prioritering & bokning

»  Metodval, tidsprio ●  (DT-) undersökning

»  Hur struktureras den? Antal faser – N, artär, ven, sen

●  Granskning ●  Bedömning/ slutsats/

diagnos ●  Kommunikation av svar

radiolog - kirurg

●  10 steg; rätt 99/100 ggr »  10/100 pat får inte optimal

bed ●  Hur begränsar vi ”felen”? ● TEAMWORK ● Lagertänk

Fallskärmar för varandras misstag

Kommunikation

§  Svag länk » Kunskapsöverföring mellan specialiteter » Patientöverföringar mellan kliniker och sjukhus

§  Strukturerat arbetssätt »  tydlig metodik för samtalsprocess » värdering av vitala funktioner » standardiserad kommunikation

– Checklistor

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Vanliga radiologiska fel

§  Glömmer differentialdiagnoser §  SOS – Satisfaction of Search

» Finn Fem Fel §  Negationer dränker patologin

» Strukturerad granskning & svar » Top-bottom granskning » SKA INTE medföra ett top-bottom SVAR

– Fokus på patologi – summariska negationer – Sammanfattning & slutsats ska finnas

Teamwork – kommunikation kirurg - radiolog

§  Klinisk bild vs radiologiskt fynd §  Viktigaste kontrollfrågorna

» Vad kan det vara annars? » Vad talar emot diagnosen? » Mer än ett problem?

§  Teamwork » Kommunicera personligen » Verbalisera / Tänk högt

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Varning! Warning!

Outline II §  Radiology – How to think & cost/benefit §  Choice of modality

»  CT vs US §  ”Evidence based" & fast technical development in radiology/CT §  CT – the diagnostic mainstay & work horse

»  Danger of contrast »  Danger of radiation

»  Danger of non-examination? §  Risk evaluation

»  Age »  Earlier and present disease history?

§  Focus: Trauma-CT - a cost-benefit-analysis

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CT or US

§  53 y o man §  Abdominal pain 2

days, right flank §  Fever 38.4, LPK 16.4 §  Tender dorsal over

kidney + right flank + pain in the scrotum

§  Cholecytistis? Pyelitis? Appendicitis? Rt testis?

§  CT or US? §  CT

§  Radiation + iv contrast

§  Age

§  Your choice?

Aortic ocklusion

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CT vs US

§ What modality/exam to use? §  Small spectrum diagnostics - US §  Young & Slim à US §  Old & renal failure à US §  Broad spectrum diagnostics - CT

» When in doubt à CT

CT optimized

§ Radiation §  iv contrast (iodine)

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Aortic ocklusion

NO contrast = NO diagnosis!

CT & Evidence based radiology

§  1992 spiral 60 images/minute §  2005 MDCT 64 channels 9.000 images/minute

§  2010 320 channels 45.000

§  Abdomen in a second scan

§  1992 à today = x1000 images capacity

§  Scientific articles – to form evidence base »  What CT capacity in the articles; what do YOU have ??!

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The Strength of CT

§  Less risk for mistakes cf US §  Covers the whole abdomen

» NOT ”FA –focused assessment” » Lateral viewing – find 5 errors/diagnosis

§  Comparison to previous exams §  Full value second reading is always possible

New CT Paradigm

Virtual & Functional

Laparoscopy

§  Thin slices – higher diagnostic quality

§  Multi Planar Reformat - MPR §  3D - Volume Rendering Technique -

VRT

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64 ch abd

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Focus: The acute abdomen

§  Ileus §  Ischemia §  Bleeds

Female 57 y - MS

§  2 days abdominal pain, vomiting, peritoneal status

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CT @ 24 h

Necrotic intestine

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GI ischemia

MDCT / CTA in ischemia

§  Gold standard §  Sensitivity 82% - 96%; specificity 94% §  Reginelli et al.: Mesenteric ischemia: the importance of differential diagnosis

for the surgeon. BMC Surgery 2013 13(Suppl 2):S51.

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Female 66 y o

§  Diarrhea, vomiting + abd pain 2 days §  KOL, longstanding Mb Crohn

§  Exam without iv contrast » due to non-defined ”allergy towards

contrast media”

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§  Dilated small bowel loops; distal obstruction?

§  Oedema in mesentary & distal ileal wall – inflammmatory reaction??

§  Air in intrahepatic bilary ducts or in peripheral portal branches but not in central porta. No air in bowel walls

§  Status post ERCP/papillotomy? §  Follow-thru exam started……

12 h later 2nd exam + iv contrast

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2nd radiology report (iv contrast +)

§  Thrombus in proximal a mes sup & coeliac trunc.

§  Air in portal vein + intestinal wall §  Patchy hepatic necrosis §  Acute laparotomy reveals

» no pulsation in these arteries » extensive tissue necrosis

§  No further actions. » Patient dies in ICU

Ischemia

§  85 year old man §  Advanced cardiovascular disease,

claudicatio §  5 h severe abd pain w acute onset, no

peritonitis §  Lactate up 6.8

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SMA– ocklusion

Ischemia

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Discussion

§  Limits of non-contrast exam » Diagnostic hesitation, delay!

§  Make it easy to diagnose » = iv contrast ! » Even the super stressed specialist » & least experienced resident

Bleeds (GI)

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Acute Bleed - Clincial Workup

§  Stabilize the patient » stabilization of BP/pulse »  restoration of volume before diagnostics » Most complications from hypo-perfusion

Sensitivity & specificity CTA

§  (Problem of intermittent bleeding) §  Metaanalys 1995-2009

•  Wu et al, World J Gastroenterol, Aug 2010

§  9 studies, 198 patients §  CTA acute GI bleeding

» Ref standard: endoskopy, angio or surgery §  Sens 89%, specif 85% §  My comment:

» Better performance w MDCT 64 ch+

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Bleeding rate for detection

§  RBC scintigraphy 0.1- 0.2 ml/min §  Convent mesent angio 0.5 ml/min

§  CTA 0.2-0.3 ml/min

§  Kuhle et al Radiology 2003 228:743-752 (CTA -swine model)

70 y old woman

§  3 months earlier » Small bowel GIST tumor with intussuception

(invagination) §  Now: Abd pain, dark vomiting, diarrhea with

fresh blood §  Clinically unstable – Do we dare do CT? §  à Multiphase CT

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Native – non-contrast

(Late) Arterial

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CTA vs Angio §  Unstable patient?

» CT-angio? » Angio?

§  CT + » During preparation time for angio » more sensitive for bleed »  roadmap for intervention

– Saves intervention time

§  CT - » CT + intervention à More iv contrast (?)

Cost/Benefit Contrast & Radiation vs Diagnosis

§  Iv contrast § Old age

§  Radiation » Young & Pregnancy

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Questions/problems iv contrast

§  Breast feeding – OK §  Allergy

» Premedicate »  If severe - anestesiologist present

Renal function & iv contrast

§  Older patients » Higher risk for premorbid renal dysfuncition

§  Cost-benefit analysis » severity of clinical situation

§  Don´t save the kidneys and loose the patient

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Case discussion: iv contrast complication

32 year old female; 4 h post partum

§  Abdominal pain §  Tachycardia, low blood pressure §  P-krea 150 §  DIC injury to liver + kidneys §  CT PROTOCOL

» 160 ml Visipaque 320 @ 6 ml/s §  + pending intervention w contrast

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Roadmap

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Follow up

§  Dialysis 6 weeks » Anuria 2 weeks » Polyuria phase

§  Rescanned twice w iv contrast » abscess?

§  Judged to regain renal & liver function §  2 years later – limited renal impairment

» Creatinine 120

Discussion

§  Amount of iv contrast high » Lower dose vs find the bleeding source

§  Several instances of iv contrast use §  Lifesaving procedures §  BOTTOM LINE

» A woman has got to do, what a woman has to do

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Cost/Benefit Contrast & Radiation vs Diagnosis

§  Radiation » Young & Pregnancy

§  iv- contrast

Cost: Radiation

§  Radiation Dose §  Adult medium size

» 6-7 mSv » 2 years Swedish background radiation

§  5 mo child » 0,5 mSv

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CT Abdomen radiation

§  Continous radiation reduction with technology

§ New image reconstruction – iterative recons » 50 kg female » 1.5 – 2 mSv » Compare to lumbar spine X-ray

Radiation §  Cost vs Benefit §  Old vs young §  Risk comparison -- CT abd 10 mSv

» 2 months work travel Stockholm-Gävle (before highway north of Uppsala)

» 500 cigarettes » 5 months construction work

§  What happens if you miss a serious diagnosis?

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Pregnancy & radiation

§  < 10 days » Any damage à abortion

§  week 3-8 » border dose: 100-200 mGy

§  week 8-15 » border dose 200 mGy

§  Trauma CT Huddinge » 25 mGy

Approximate fetal doses Examination Mean dose

(mGy) Maximum dose (mGy)

Abdomen 1,5 5 Pelvis (one image) 0,5 1 Abdomen CT 15 35 Pelvis CT (low dose) 5 10 Pelvis CT (normal dose) 12 32 Chest CT 0,02 <0,1 Head CT ~0 ~0

Theoretical approximate fetal doses calculated from non pregnant patients at Karolinska University Hospital

Courtesy Physicist Jon Holm, GE

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Probability of bearing healthy child

Dose to conceptus (mGy)

Probability of no malformation

Probability of no cancer (0-19yrs)

0 97 99,7 1 97 99,7 5 97 99,7 10 97 99,6 50 97 99,4 100 97 99,1 >100 Possible

Courtesy Physicist Jon Holm, GE

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Primum Non Nocere Select the RIGHT patient to

CT

§ Clinical selection – the ill patient §  Uncertain diagnosis

» This patient is seriously ill, but I don´t know why » Differential diagnostics

§  Preoperative mapping »  Ileus - cause & location » Bleed roadmap

Which patient should NOT go to CT??

§  When you are confident in your clinical diagnosis

§  No serious clinical suspicion of disease » Rule out pathology » Lack of hospital beds !?

§  Clinical evalutation » Could you ask an older and/or wiser clinical

colleague for advice?

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For the radiologist: Don´t forget

§  YOU have to make a medical decision »  If there is an indication to scan » How to structure and individualize the CT exam

– radiation & contrast

§  No patient comes to radiology in order to » get a low dose of radiation » get a low dose of contrast media

§  The patient comes for a diagnostic exam

Take home messages

§ Diagnosis of the ill patient is the goal !!

§ Make the full diagnosis » one stop shop

§ Make the diagnosis max visible » For the SSS (Super Stressed Specialist)

» For the junior doc

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Trauma Radiology before CT Surgeon´s Viewpoint

X-ray = X-time

What injuries?

Image from trauma.org

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Trauma CT

§  iv contrast (iodine) § Radiation

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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)

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Renal function & iv contrast

§  Renal insuffiency » Calculate GFR » Omnivis – re: achieve a diagnostic

examination » kV adjustment

– 80 -100 kV

§  Cost-benefit analysis » severity of clinical situation

§  Don´t save the kidneys and loose the patient

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Dose

● CT Dose » head 2.0 mSv (1,8-2,4) » c-spine 3.5 mSv (0,8-1,8) » body 9.0 mSv (7,6-18,4)

●  Total dose ~14.5 mSv (10,2-22,6) ●  4-6 (3,5-7,5) years Swedish background

radiation

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

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Cost/benefit WBCT §  Contrast media consequenses

– marginal life loss (1/500.000)

§  Radiation death toll (linear radiation theory) – 1/1000 lethal cancers/13.3 mSv – Today´s average 13-26 mSv à 1-2/1000 scans

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

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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)

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

§  Pregnancy – Don´t hesitate: radiation/contrast OK – Save the mother, save the child

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

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Friends, not enemies

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Take home messages

§ Diagnosis of the (critically) ill patient is the goal !!

§ Love but Respect our Prime tools: Radiation & Contrast

§ TEAM: The Radiologist is a Doctor » Not merely an image interpreter!

In the struggle to save lives TEAMWORK ......

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Thank you for your attention! leidnerimaging.se