professor of radiology, szeged, hungary. university …...professor of radiology, szeged, hungary....
TRANSCRIPT
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
Department of Radiology, University of Szeged, Hungary 6
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
Department of Radiology, University of Szeged, Hungary 8
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)
Department of Radiology, University of Szeged, Hungary 9
Patterns of injury and mortality in polytrauma
Department of Radiology, University of Szeged, Hungary 10
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
Department of Radiology, University of Szeged, Hungary 11
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
13 Department of Radiology, University of Szeged, Hungary
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
Department of Radiology, University of Szeged, Hungary
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
17 Department of Radiology, University of Szeged, Hungary
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
Department of Radiology, University of Szeged, Hungary 18
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
Department of Radiology, University of Szeged, Hungary 19
Diagnostic algorithm
(clinical examination, triage)
Plain X-ray
abdomen and pelvis
chest
Ultrasound – FAST + diagnostic
Computed tomography
20 Department of Radiology, University of Szeged, Hungary
http://www.acr.org/Quality-Safety/Appropriateness-Criteria, 2012
Department of Radiology, University of Szeged, Hungary 21
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
Department of Radiology, University of Szeged, Hungary
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
Department of Radiology, University of Szeged, Hungary 23
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
Department of Radiology, University of Szeged, Hungary 24
S. Nicolaou et al. / European Journal of Radiology 68 (2008) 398–408
25 Department of Radiology, University of Szeged, Hungary
26 Department of Radiology, University of Szeged, Hungary
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
Department of Radiology, University of Szeged, Hungary 28
Contrast administration protocol - Iodine
Department of Radiology, University of Szeged, Hungary
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
Department of Radiology, University of Szeged, Hungary
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
Department of Radiology, University of Szeged, Hungary 31
Boscak AR et al, Radiology 268:79-88, 2013
Active bleeding
Department of Radiology, University of Szeged, Hungary 32
Boscak AR et al, Radiology 268:79-88, 2013
Contrast administration protocol – GI tract
Department of Radiology, University of Szeged, Hungary
None
Oral only
Rectal only
Oral and rectal
33
?
Contrast administration protocol – GI tract
Department of Radiology, University of Szeged, Hungary
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
Department of Radiology, University of Szeged, Hungary 35
Challenges in polytrauma CT imaging
Time restraints
Diagnostic errors
Radiation dose
Bridging anatomy and function
Department of Radiology, University of Szeged, Hungary 36
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
Department of Radiology, University of Szeged, Hungary 37
S. Nicolaou et al. / European Journal of Radiology 68 (2008) 398–408
CT protocol – ”wet reading”
Closely monitor the examination
Report all significant findings immediately
Finalize report when time allows
Department of Radiology, University of Szeged, Hungary 38
Diagnostic errors
Occurs in 2-40 %
”Contribution” of imaging (secondary-tertiary
survey)
Department of Radiology, University of Szeged, Hungary 39
S. Nicolaou et al. / European Journal of Radiology 68 (2008) 398–408
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.
Department of Radiology, University of Szeged, Hungary 40
Dose reduction
Automated exposure control and tube potential
selection software
Bearing devices removal
Contiguous scanning decreases DLP by 17 %
Department of Radiology, University of Szeged, Hungary 41
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”)
Department of Radiology, University of Szeged, Hungary 42
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
Department of Radiology, University of Szeged, Hungary 43
Acute polytrauma imaging algorithm
Department of Radiology, University of Szeged, Hungary 44 D Barron Orthopedics and Trauma, 2011, 25:2
Department of Radiology, University of Szeged, Hungary 45
Department of Radiology, University of Szeged, Hungary 46
Department of Radiology, University of Szeged, Hungary 47
Department of Radiology, University of Szeged, Hungary 48
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
Department of Radiology, University of Szeged, Hungary 49
Department of Radiology, University of Szeged, Hungary