Professor of Radiology, Szeged, Hungary. University …...Professor of Radiology, Szeged, Hungary....

Professor of Radiology, Szeged, Hungary.

Chairman and head of Radiology Department Szeged

University Medical School

Field of interest: Abdominal Imaging.

Published multiple papers in various fields of Radiology

András Palkó Department of Radiology, University of Szeged, Hungary

MDCT PROTOCOLS FOR POLYTRAUMA PATIENTS

Conflicts of Interest

The authors have no conflicts of interest to declare

Learning objectives

to understand through the clinical implications the need for an accurate imaging diagnostic process supporting appropriate treatment planning in the polytrauma patient group

to become familiar with the imaging diagnostic algorithm, the role of MDCT and the special requirements towards imaging technique to be complied with in this special condition

to understand the various types, role and performance of MDCT imaging protocols in achieving the fastest but at the same time most reliable imaging information

Department of Radiology, University of Szeged, Hungary 5


Definition

Etymology (Greek): poly (multiple) + trauma (injury)

A significant injury in at least two out of the following six body regions:

Head, neck, and cervical spine

Face

Chest and thoracic spine

Abdomen and lumbar spine

Limbs and bony pelvis

External (skin)

Syndrome of multiple injuries of different anatomical regions with consecutive systemic reactions, which may lead to dysfunction of remote organs.

F. Gebhard et al, Langenbecks Arch Surg (2008) 393:825–831 Lecky FE et al, in: H.-C. Pape et al. (eds.), Damage Control Management in the Polytrauma Patient, Springer, 2010

Significance

Injury is a global pandemic and the most frequent

cause of death < 45

16.000 deaths / day worldwide

7 Department of Radiology, University of Szeged, Hungary

http://www.cdc.gov/injury/wisqars. 2007

External injury standardised death rates / 100 000 male


http://www.euro.who.int/eprise/main/WHO/InformationSources/Data/2005117

Mortality

1st peak

• Within minutes (major vascular and CNS injuries)

• Medical intervention is rarely successful

2nd peak

• Within the first (“golden“) hour (intracranial bleeding, major chest/abdominal injury)

• Primary focus of Advanced Trauma Life Support (ATLS)

3rd peak

• After days/weeks (SIRS, MODS)


http://www.google.hu/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=CpiSmc9NGjVMeM&tbnid=9E6bt-VLUV7a7M:&ved=0CAUQjRw&url=http://paulholding.com/2012/07/05/north-west-face-of-laila-peak-6096m-hushe-valley-karakoram-pakistan-8th-22nd-june-2012/&ei=b7LLU-7RH8ivPPvbgIgP&bvm=bv.71198958,d.bGQ&psig=AFQjCNFcIa-GqbaIseeNirTScLQuNlNPWQ&ust=1405944317161106

Patterns of injury and mortality in polytrauma


Lecky FE et al, in: H.-C. Pape et al. (eds.), Damage Control Management in the Polytrauma Patient, Springer, 2010

Patterns of injury and mortality in polytrauma


Lecky FE et al, in: H.-C. Pape et al. (eds.), Damage Control Management in the Polytrauma Patient, Springer, 2010

What is to be done

Patient requires a timely and effective management in

order to avoid the deathly spiral of severe systemic

complications:

prolonged haemorrhagic shock

systemic inflammatory response

syndrome (SIRS)

multiple organ dysfunction

syndrome (MODS)

Department of Radiology, University of Szeged, Hungary 12 F. Gebhard et al, Langenbecks Arch Surg (2008) 393:825–831

Abbreviated Injury Scale (AIS)

Anatomy-based scoring system, considering injuries of all major body regions

Minor 1

Moderate 2

Serious 3

Severe 4

Critical 5

Maximal (currently untreatable) 6


Injury Severity Score

ISS = A2 + B2 + C2, (A, B, C = the AIS scores of the

three most severely injured regions)

Severe > 15

14

Department of Radiology, University of Szeged, Hungary

Injury Severity Score

15


Dilemma

Selective nonsurgical management is safe and cost-effective, if the diagnosis is fast and accurate

BUT

identification of serious pathology is challenging may not manifest during the initial assessment

associated injuries may divert attention

clinical examination is notoriously unreliable

Department of Radiology, University of Szeged, Hungary 16 Soto JA, Anderson SW, Radiology: 265, 2012

Diagnosis


Role of imaging

To provide the fastest possible diagnosis in order to start

therapy ASAP to decrease mortality

To detect:

injuries and their consequences

immediate and late complications


Keep in mind

Triage (NISS, GCS, etc.)

Algorithm and technique of imaging depend on haemodynamic stability and associated injuries

Timing: lifesaving interventions should not be impeded


Diagnostic algorithm

(clinical examination, triage)

Plain X-ray

abdomen and pelvis

chest

Ultrasound – FAST + diagnostic

Computed tomography


http://www.acr.org/Quality-Safety/Appropriateness-Criteria, 2012


Diagnostic algorithm

(clinical examination, triage)

Plain X-ray

abdomen and pelvis

chest

Ultrasound – FAST + diagnostic

Computed tomography

21

http://www.acr.org/Quality-Safety/Appropriateness-Criteria, 2012

Indications of MDCT

Haemodynamic instability

Suspicion of occult, severe injury by clinical examination, plain film

Abdominal fluid by FAST

Obvious severe injury on clinical assessment

Whole body contrast-enhanced MDCT is the default procedure of choice in the severely injured patient


22 Standards of practice and guidance of trauma radiology in the severely injured patient (RCR)

Whole body MDCT

Standard procedure for providing rapid and accurate diagnosis

within the narrow therapeutic window

Demonstrates all potentially injured organs, as well as vascular

and bone structures, from the circle of Willis to the symphysis

pubis with a single continuous acquisition

The large volume of information inherent to whole-body CT is

a new challenge to radiologists in providing efficient and

timely interpretation


Non-contrast primary survey

Haemodynamically instable pt

Scan directly: thigh to head – reconstruct 3-5 mm axials

Immediate monitor reading

A, B, C A – airway

B – breathing, brain

C – circulation / source of bleeding

Transform the scanner room into a Trauma Bay Zero


S. Nicolaou et al. / European Journal of Radiology 68 (2008) 398–408



Single pass vs segmental WBCT

WBCT should cover head, C spine, chest, abdomen and pelvis

Single pass:

Pro: no time lost by arm repositioning

Con: arm causes beam hardening and photon starvation artefacts

Segmental:

Pro: allows for changing arm position

Con: repositioning is time consuming

Department of Radiology, University of Szeged, Hungary 27 Nguyen D et al: AJR 2009; 192:3–10

Scanning protocol @ 64

Patient position: supine, hands up/down

Scanning direction: cephalocaudal

Tube voltage: 120 – 140 kVp w. AEC

Auto mA range: 100 – 700

Collimation : 0.625 – 1.25 mm

Pitch: 1.375

Primary reconstruction:

Slice thickness: 3/5 mm (+ 0,625 for 3D, MPR)

FOV: adjusted to body habitus


Contrast administration protocol - Iodine


Concentration: 350 – 400 mg/mL

Volume (extracellular enhancement):

80 – 150 mL

Flow (bolus geometry – vessels):

Biphasic 6 mL/sec + 4 mL/sec

Monophasic 2.5 – 4 mL/sec

+ saline flush

29

Contrast administration protocol – scan delay


Single vs. double vs. triple phase

Single phase delay:

Fixed (pt < 50) vs. bolus triggering (pt > 50)

Angio / arterial bleeding: 18 sec or 90 HU @ aortic arch

General: 35 sec or 100 HU @ AA

Parenchymal organ / veins: 60 – 75 sec or 70 HU @ liver

Delayed scans: 3 – 5 min

30

Pseudoaneurysm


Boscak AR et al, Radiology 268:79-88, 2013

Active bleeding


Boscak AR et al, Radiology 268:79-88, 2013

Contrast administration protocol – GI tract


None

Oral only

Rectal only

Oral and rectal

33

?

Contrast administration protocol – GI tract


None

Oral only

Rectal only

Oral and rectal

34

CT protocol – as we do it…

Plain head, neck – arms down

Plain and CE (arterial + venous) chest, abdomen and pelvis – arms up

Iodine: 100 mL (+ saline flush), 350 mg/mL, 4 mL/sec, 18/60 sec delay or bolus triggering

Delayed scan if necessary

No GI contrast

Routine scanning protocol

The examination is supervised by the radiologist – allows for real-time adaptation


Challenges in polytrauma CT imaging

Time restraints

Diagnostic errors

Radiation dose

Bridging anatomy and function


Time restraints – the „golden hour”

Primary diagnostic evaluation is to be completed

within the shortest possible time frame

Time restraints:

stabilization + transfer + positioning

scanning

data manipulation/interpretation



CT protocol – ”wet reading”

Closely monitor the examination

Report all significant findings immediately

Finalize report when time allows


Diagnostic errors

Occurs in 2-40 %

”Contribution” of imaging (secondary-tertiary

survey)



Radiation dose

A lifetime excess cancer mortality risk of 0.08 %

is estimated in patients younger than 45 years

old who undergo panscanning

Indiscriminate use of CT without obvious injuries

or a severe injury mechanism may not be

justified.


Dose reduction

Automated exposure control and tube potential

selection software

Bearing devices removal

Contiguous scanning decreases DLP by 17 %


Frellesen C et al: Eur Radiol (2014) 24:1725–1734

Keep in mind

A scenario where a clearly indicated CT

examination is held back because of excessive

and disproportionate fear of radiation-induced

cancer must be avoided

A life-threatening injury may be missed and the

appropriate treatment may be delayed,

potentially leading to a worse clinical outcome

and survival (“second risk of radiation”)


Hendee WR et al: Radiology 2012, 264(2):312–321

Trauma and pregnancy - principles

Any female patient in childbearing age must be considered pregnant until proved otherwise

There is no foetal survival without maternal survival –(the possible exception is third-trimester trauma with poor prognosis for the mother – caesarean section may be necessary to save the foetus)

In lifesaving trauma care one should not hesitate to perform the needed tests


Acute polytrauma imaging algorithm

Department of Radiology, University of Szeged, Hungary 44 D Barron Orthopedics and Trauma, 2011, 25:2





Take home…

Patients with abdominal injuries require fast and

appropriate treatment to reduce

morbidity/mortality

Diagnostic imaging is the most accurate tool for

reliable diagnosis

CT is the single best diagnostic modality in

polytrauma



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Professor of Radiology, Szeged, Hungary. University …...Professor of Radiology, Szeged, Hungary....

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