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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