Everything you need to know about Computed Tomography (CT) & CT Scanning

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Vascular: Trauma Imaging Pearls - Learning Modules | CT Scanning | CT Imaging | CT Scan Protocols - CTisus
Imaging Pearls ❯ Vascular ❯ Trauma
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  • “The superficial femoral artery becomes the popliteal artery as it traverses the adductor hiatus, an opening along the insertion of the adductor magnus muscle, marking the transition from the anterior compartment of the thigh to the popliteal fossa. The vast majority (89–92%) of patients have a classical branching pattern with the popliteal artery bifurcating into an anterior tibial artery and the tibioperoneal trunk. The tibioperoneal trunk divides into the posterior tibial artery and peroneal artery (aka fibular artery), both in the posterior compartment of the leg. Other branching patterns include a two vessel runoff with hypoplastic/aplastic posterior tibial artery (3.5%) and trifurcation of the popliteal artery in the popliteal fossa (2.5%). There are at least ten different branching patterns described, with the rest occurring far less frequently.”

    
Computed Tomography Angiography of the Extremities in Emergencies
Madhuripan N et al.
Seminars in Ultrasound, CT and MRI (in press)
  • Blunt trauma can be secondary to motor
vehicle accidents, falls, athletic injuries and can be associated with fractures of adjacent bones. Penetrating trauma may be secondary to ballistic injury, stab injury, and may or may not be associated with bony injuries. The findings that need to be specifically sought in cases of trauma are as follows.

    
• Active arterial bleeding
•Occlusion/transection
    
• Pseudoaneurysm, traumatic arteriovenous fistula

    • Dissection
    
• Focal narrowing/spasm



    Computed Tomography Angiography of the Extremities in Emergencies
Madhuripan N et al.
Seminars in Ultrasound, CT and MRI (in press)
  • Arterial Trauma: CT Findings
    • active extravasation
    • subcutaneous or intra- muscular hematoma
    • pseudoaneurysm
    • vessel narrowing/stretching
    • occlusion
    • arteriovenous fistula
  • “Examples of anatomic landmarks include the lateral margin of the first rib that demarcates the boundary between the subclavian artery and the axillary artery, and the inferior margin of the tendons of the latissimus dorsi and teres major muscles that delineate the transition between the axillary artery and brachial artery. The normal location of the branch point of the brachial artery into the radial and ulnar arteries is at the level of the antecubital fossa near the coronoid process of the ulna. Conventional branching anatomy is seen in approximately 70% of individuals.”


    Computed Tomography Angiography of the Upper Extremities
Dave RB, Fleischmann D.
Radiol Clin North Am. 2016 Jan;54(1):101-14
  • “Examples of anatomic landmarks include the lateral margin of the first rib that demarcates the boundary between the subclavian artery and the axillary artery, and the inferior margin of the tendons of the latissimus dorsi and teres major muscles that delineate the transition between the axillary artery and brachial artery. The normal location of the branch point of the brachial artery into the radial and ulnar arteries is at the level of the antecubital fossa near the coronoid process of the ulna. Conventional branching anatomy is seen in approximately 70% of individuals.”


    Computed Tomography Angiography of the Upper Extremities
Dave RB, Fleischmann D.
Radiol Clin North Am. 2016 Jan;54(1):101-14
  • “The utility of CTA in the setting of trauma has been recognized. However, it’s less well-known and varied clinical applications in the subacute setting are also important and include presurgical anatomic mapping including identification of variant arterial anatomy, evaluation of connective disorders, vasculitis, overuse syndromes, AV fistula/grafts, vascular malformations, compression syndromes, and assessment of perivascular pathology. Volume- 
rendered, maximum intensity projection, and mul- tiplanar reformat images are indispensable for evaluating the data set.”

    
Computed Tomography Angiography of the Upper Extremities
Dave RB, Fleischmann D.
Radiol Clin North Am. 2016 Jan;54(1):101-14
  • “Indication for total body computed tomography (CT) is based on the presence of signs and symptoms of vascular damage at clinical examination. Patients are immediately transferred in the operating room for surgery if more serious injuries that require immediate surgical care are not diagnosed, or hemostasis may be preliminary reached in the emergency room. Hemodynamically stable patients with no history and clinical examination showing suspected vascular damage are allowed in the radiology department for obtaining a total body CT scan with intravenous contrast medium and then transferred to the surgical ward trauma for observation.”

    Imaging assessment of gunshot wounds.
Reginelli A et al.
Semin Ultrasound CT MR. 2015 Feb;36(1):57-67.
  • “Multi-detector computed tomography angiography (MDCTA) of the lower extremities is an integral part of the decision-making process of lower extremity trauma. MDCTA can be integrated into multiphasic whole-body trauma MDCT and has replaced the traditional gold standard of catheter-based angiography as the preferred technique for the initial assessment of lower extremity trauma in many institutions worldwide. Advances in MDCT technology enable high speed simultaneous evaluation of both complete lower extremities, rapid image reconstruction, and advanced image visualization for the noninvasive and accurate diagnosis of vascular, including hematoma, active extravasation, vasospasm, stenosis, external compression, occlusion, intimal injury and dissection, arteriovenous fistulas, and pseudoaneurysm formation.”

    State-of-the-art 3DCT angiography assessment of lower extremity trauma: typical findings, pearls, and pitfalls.
Fritz J, Efron DT, Fishman EK.
Emerg Radiol. 2013 Jun;20(3):175-84
  • “Advances in MDCT technology enable high speed simultaneous evaluation of both complete lower extremities, rapid image reconstruction, and advanced image visualization for the noninvasive and accurate diagnosis of vascular, including hematoma, active extravasation, vasospasm, stenosis, external compression, occlusion, intimal injury and dissection, arteriovenous fistulas, and pseudoaneurysm formation.”

    State-of-the-art 3DCT angiography assessment of lower extremity trauma: typical findings, pearls, and pitfalls.
Fritz J, Efron DT, Fishman EK.
Emerg Radiol. 2013 Jun;20(3):175-84
  • “The subclavian artery continues as the axillary artery after crossing the lateral margin of the first rib. Its major branches include the superior thoracic, thoracoacromial, lateral thoracic, subscapular, and anterior and posterior humer- al circumflex arteries. These branches supply muscles of the shoulder girdle, humerus, scap- ula, and chest wall. After coursing beyond the inferior lateral margin of the teres major mus- cle, the axillary artery becomes the brachial artery.” 
CT Angiography of the Upper Extremity Arterial System: Part 1—Anatomy, Technique, and Use in Trauma Patients 
Bozlar U et al.
AJR 2013; 201:745–752
  • “The brachial artery courses along the medial aspect of the upper arm and gives rise to the deep brachial artery and smaller arteries around the elbow joint. Anteriorly in the antecubital fossa, the brachial artery divides into the radial and ulnar arteries. The radial recurrent artery and the posterior and anterior ulnar recurrent arteries arise immediately beyond the origins of their respective arteries to form anastomoses with branches of the brachial and deep brachial arteries. The radial artery courses along the radial side of the forearm to the wrist, traverses the snuffbox, and turns medially to give rise to the deep palmar arch.” 


    CT Angiography of the Upper Extremity Arterial System: Part 1—Anatomy, Technique, and Use in Trauma Patients 
Bozlar U et al.
AJR 2013; 201:745–752
  • “Arterial injuries of the upper extremities occur in the setting of both blunt and penetrating trauma. Posttraumatic vascular abnormalities include spasm, external compression, dissection , occlusion or transection , arteriovenous fistula (AVF) development , pseudoaneurysm formation, rupture, and transection.” 


    CT Angiography of the Upper Extremity Arterial System: Part 1—Anatomy, Technique, and Use in Trauma Patients 
Bozlar U et al.
AJR 2013; 201:745–752
  • “In difficult cases, pseudoaneurysms can easily be differentiated from extravasation if late phase imaging is performed. Pseudoaneurysms maintain their shape and follow opacification characteristics of the aorta, whereas in arterial extravasation, contrast material spreads along tissue planes and has increased attenuation compared with parent arteries on delayed images.”

    CT Angiography of the Upper Extremity Arterial System: Part 1—Anatomy, Technique, and Use in Trauma Patients 
Bozlar U et al.
AJR 2013; 201:745–752
  • “CTA is an important diagnostic imaging modality for the evaluation of upper extremity arterial abnormalities. High-quality CTA of the upper extremities is feasible on modern CT scanners using optimized scanning and con- trast injection technique. Its 24-hour availabil- ity, rapid acquisition, minimal invasiveness, and display of both vascular and musculoskeletal structures makes it particularly attrac- tive for the evaluation of patients with blunt or penetrating trauma to the upper extremity. .” 


    CT Angiography of the Upper Extremity Arterial System: Part 1—Anatomy, Technique, and Use in Trauma Patients 
Bozlar U et al.
AJR 2013; 201:745–752
  • “Arterial injuries included transection (24.3%), occlusion (17.3%), partial transection/flow limiting defect (24.5%), pseudoaneurysm (9.0%), and other injuries including intimal defects (22.7%). Nonoperative management was undertaken in 276 (50.9%), with failure in 4.0%. Definitive endovascular and open repair were used in 40 (7.4%) and 126 (23.2%) patients, respectively.”

    The American Association for the Surgery of Trauma PROspective Observational Vascular Injury Treatment (PROOVIT) registry: multicenter data on modern vascular injury diagnosis, management, and outcomes.
DuBose JJ et al.
J Trauma Acute Care Surg. 2015 Feb;78(2):215-22
  • “A total of 542 injuries from 14 centers (13 American College of Surgeons-verified Level I and 1 American College of Surgeons-verified Level II) have been captured since February 2013. The majority of patients are male (70.5%), with an Injury Severity Score (ISS) of 15 or greater among 32.1%.”


    The American Association for the Surgery of Trauma PROspective Observational Vascular Injury Treatment (PROOVIT) registry: multicenter data on modern vascular injury diagnosis, management, and outcomes.
DuBose JJ et al.
J Trauma Acute Care Surg. 2015 Feb;78(2):215-22
  • “Arterial injuries were categorized into 116 penetrating (73.0%) and 43 blunt (27.0%) mechanisms. Arterial distribution involved was as follows: 13 axillary (8.2%), 40 brachial (25.2%), 52 radial (32.7%), 51 ulnar (32.1%), and 3 other (1.9%). The types of arterial injuries were as follows: 69 transection (43.4%), 68 laceration (42.8%), 16 occlusion (10.1%), 3 avulsion (1.9%), and 3 entrapment (1.9%).”


    A five-year review of management of upper-extremity arterial injuries at an urban level I trauma center.
Franz RW et al.
Ann Vasc Surg. 2012 Jul;26(5):655-64
  • “One patient (0.7%) required a primary above-elbow amputation. The majority of injuries (96.8%) receiving vascular management underwent surgical intervention--76 primary repair (49.7%), 41 ligation (26.8%), 31 bypass (20.3%), and 5 endovascular (3.3%). Conservative treatment was the primary strategy for five arterial injuries (3.3%). Of the patients receiving vascular intervention, three (2.2%) required major and three (2.2%) required minor amputations during hospitalization and no patients expired.”


    A five-year review of management of upper-extremity arterial injuries at an urban level I trauma center.
Franz RW et al.
Ann Vasc Surg. 2012 Jul;26(5):655-64
  • “The current multidisciplinary team management approach with prompt surgical management resulted in successful outcomes after upper-extremity arterial injuries. No outcome differences between penetrating and blunt or between proximal and distal arterial injuries were calculated. This management approach will continue to be used.”


    A five-year review of management of upper-extremity arterial injuries at an urban level I trauma center.
Franz RW et al.
Ann Vasc Surg. 2012 Jul;26(5):655-64
  • “CT is the procedure of choice to identify hemorrhage, air, bullet, bone fragments, hemothorax, nerve lesion, musculoskeletal lesions, and vessels injuries and is useful for assessing medicolegal aspects as trajectory and the anatomical structures at risk.”

    Imaging assessment of gunshot wounds.
Reginelli A et al.
Semin Ultrasound CT MR. 2015 Feb;36(1):57-67.
  • “Indication for total body computed tomography (CT) is based on the presence of signs and symptoms of vascular damage at clinical examination. Patients are immediately transferred in the operating room for surgery if more serious injuries that require immediate surgical care are not diagnosed, or hemostasis may be preliminary reached in the emergency room. Hemodynamically stable patients with no history and clinical examination showing suspected vascular damage are allowed in the radiology department for obtaining a total body CT scan with intravenous contrast medium and then transferred to the surgical ward trauma for observation.”


    Imaging assessment of gunshot wounds.
Reginelli A et al.
Semin Ultrasound CT MR. 2015 Feb;36(1):57-67.
  • “ CT angiography findings indicative of arterial injury were observed in 24 patients (30%) and a total of 43 arterial injuries were noted; the most common form was focal narrowing/spasm (n?=?16, 37.2%); the most common artery involved was the superficial femoral artery (n?=?12, 50%). In qualitative assessment of images based on a 4-point grading system, both readers considered CT angiography diagnostically excellent (grade 4) in most cases. Surgical findings were consistent with CT angiography and follow-up of patients' medical records showed no arterial injuries in patients with normal findings on initial imaging.”
    Computed tomography angiography of lower extremities in the emergency room for evaluation of patients with gunshot wounds.
    Adibi A et al.
    Eur Radiol. 2014 Jul;24(7):1586-93
  • “Our findings demonstrate that CT angiography is an effective imaging modality for evaluation of lower extremity gunshot wounds and could help limit more invasive procedures such as catheter angiography to a select group of patients.”
    Computed tomography angiography of lower extremities in the emergency room for evaluation of patients with gunshot wounds.
    Adibi A et al.
    Eur Radiol. 2014 Jul;24(7):1586-93
  • Vascular Emergencies of the Chest Post Trauma
    - Aortic rupture (complete and incomplete)
    - Traumatic aortic dissection
    - Aortic dissection and rupture
    - Traumatic acute intramural hematoma
    - Pseudoaneurysm
    - Catheter related injuries
    - Foreign body embolization
  • “ Multirow CT angiography is a fast,safe and noninvasive imaging technique. In combination with two and three dimensional postprocessing techniques, it often clarifies complex vascular and nonvascular anatomy.”
    Vascular Emergencies of the Thorax after Blunt and Iatrogenic Trauma: Multidetector Row CT and Three Dimensional Imaging
    Alkadhi H et al.
    RadioGraphics 2004:24:1239-1255
  • Aortic Transection: Facts
    - 10-20% of patients survive the initial event
    - Occurs most commonly at aortic isthmus (space between brachiocephalic trunk and that of the ligamentum arteriosus)
    - Mediastinal hematoma (anterior of posterior mediastinum) is common but not diagnostic of aortic injury
    - Hematoma of interest most commonly around the aorta
  • Aortic Transection: Facts
    - The direct signs of aortic transection include;
    - Vessel caliber change
    - Pseudoaneurysm
    - Intramural flap
  • Cardiac Trauma: Differential Diagnosis
    - Aortic transection
    - Valvular rupture
    - Hemopericardium
    - Cardiac tamponade
  • Hypovolemic Shock: CT Findings
    - Bright adrenals
    - Diffuse fluid filled dilated small bowel
    - Hyperenhancement of the small bowel
    - Hyperenhancement of the gall bladder mucosa
    - Reduced splenic perfusion
    - Intense enhancement of the kidneys
    - Peripancreatic edema
  • Clinical Signs of Vascular Injury
    Soft signs
    - Significant hemorrhage found on history
    - Decreased pulse compared to the contralateral extremity
    - Bony injury or proximity to penetrating wound
    - Neurologic abnormality
  • Arterial Injury: Patterns of Injury
    - Hematoma
    - Active extravasation
    - Vasospasm
    - Stenosis
    - External compression
    - Occlusion
    - Intimal injury and dissection
    - Arteriovenous fistulas
    - Pseudoaneurysm formation
  • “ An advantage of 3D mapping is the ability to display the information in a format that not only simulates a classic catheter angiogram (digital subtraction), but also the capability to display tissue in addition to the vasculature,
    including muscle, soft tissues, and bone. MIP
    and VRT imaging may require segmentation with bone removal, especially when the extremities are involved. VRT is especially valuable when opaque foreign
    matter is present.”
    State of the art 3DCT angiography assessment of lower extremity trauma: typical findings, pearls and pitfalls
    Fritz J, Efron DT, Fishman EK
    Emerg Radiol (epub November 2012)
  • “A variety of factors may obscure or mimic vascular injury on MDCTA including inadequate arterial enhancement due to timing of the contrast injection, motion artifacts, inadequate positioning, streak artifacts, dense calcifications, and similar density of vessels and bone. Venous injuries may be missed on a single phase study or in the absence of late phase images.”
    State of the art 3DCT angiography assessment of lower extremity trauma: typical findings, pearls and pitfalls
    Fritz J, Efron DT, Fishman EK
    Emerg Radiol (epub November 2012)
  • AVFs or Arteriovenous Fistulas: Definition
    -Arteriovenous Fistulas are abnormal communications with shunting of blood from am artery to a vein that mainly involve the peripheral vascular system but can affect virtually any organ or system in the body
  • Vascular Trauma: CT Findings Arterial injuries
    - Pseudoaneurysm
    - Active arterial hemorrhage
    - AV fistulae
    - Occlusion
    - Intimal injury vasospasm
  • "The use of multiphasic images affords more definitive characterization of areas of “contrast blush” as to the underlying etiologies of contained vascular injuries or active hemorrhage."

    CT of Blunt Abdominal and Pelvic Vascular Injury
    Vi M et al.
    Emerg Radiol (2010) 17;21-29

  • "Multiphasic imaging also allows for the definitive differentiation between arterial and venous sources of hemorrhage."

    CT of Blunt Abdominal and Pelvic Vascular Injury
    Vi M et al.
    Emerg Radiol (2010) 17;21-29

  • CT Angiography: Potential Limitations in Extremity Trauma
    - Inadequate arterial enhancement
    - Motion artifact
    - Inadequate positioning
    - Streak artifact
  • " By demonstrating the extent, location, and type of injury, CT angiography aids in the decision making process to determine the appropriate management for each injury in each patient."

    Use of 64-Row Multidetector CT Angiography in Blunt and Penetrating Trauma of the Upper and Lower Extremities
    Pieroni S et al.
    RadioGraphics 2009; 29:863-876

  • Sixty-four-row multidetector CT angiography of the extremities has the ability to demonstrate a variety of vascular injuries such as occlusion, pseudoaneurysm, active extravasation, and intimal dissection."

    Use of 64-Row Multidetector CT Angiography in Blunt and Penetrating Trauma of the Upper and Lower Extremities
    Pieroni S et al.
    RadioGraphics 2009; 29:863-876

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