Imaging Pearls ❯ Musculoskeletal ❯ Vascular
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- “The inguinal region, specifically the femoral vasculature, is a commonly used site of injection for intravenous drug users (IVDU). Repeated puncture of the vessel wall results in breakdown and subsequent arterial pseudoaneurysm- dilatations or outpouching of blood vessels, which, if left untreated, can result in fatal complications such as rupture with hemorrhage, sepsis, or even limb loss. The current modalities for arterial pseudoaneurysms include Doppler ultrasound and computed tomography (CT) angiography, both of which play important roles in management and surgical planning. However, 3D cinematic rendering (CR), a novel CT post-processing technique, offers timely, highly detailed photorealistic images that more clearly display the relation of anatomical structures, allowing for greater diagnostic confidence and precise surgical planning, particularly useful in the emergency setting.”
3D Cinematic rendering for evaluating femoral pseudoaneurysms in injection drug users
Mohammad Yasrab · Ryan C. Rizk · Linda C. Chu· Elliot K. Fishman
Emergency Radiology https://doi.org/10.1007/s10140-024-02237-x - “The inguinal region, specifically the femoral vasculature, is a The inguinal region is frequently used as a primary injection site in IVDU, therefore the femoral artery (or its branches) are the most common site where infected pseudoaneurysms develop. They can rapidly progress and often present as a surgical emergency, potentially leading to fatal consequences including rupture with hemorrhage, sepsis, and even limb-loss. Color doppler ultrasound (US) and multidetector computed tomography (CT) angiography are the most common investigations of choice for femoral pseudoaneurysms. Doppler US can swiftly confirm diagnosis by providing a dynamic view of blood flow in and out of the pseudoaneurysm sac and rule out associated venous thrombosis. On the other hand, CT imaging provides greater definition of the pseudoaneurysm and surrounding soft tissue anatomy, vasculature, and abscesses, and thus plays an important role in determining appropriate management and surgical planning.”
3D Cinematic rendering for evaluating femoral pseudoaneurysms in injection drug users
Mohammad Yasrab · Ryan C. Rizk · Linda C. Chu · Elliot K. Fishman
Emergency Radiology https://doi.org/10.1007/s10140-024-02237-x 
3D Cinematic rendering for evaluating femoral pseudoaneurysms in injection drug users
Mohammad Yasrab · Ryan C. Rizk · Linda C. Chu · Elliot K. Fishman
Emergency Radiology https://doi.org/10.1007/s10140-024-02237-x
3D Cinematic rendering for evaluating femoral pseudoaneurysms in injection drug users
Mohammad Yasrab · Ryan C. Rizk · Linda C. Chu · Elliot K. Fishman
Emergency Radiology https://doi.org/10.1007/s10140-024-02237-x- “Postprocessing after CT acquisition includes the generation of select MIP, VR, and 3D CR images. 3D CR is performed at a dedicated, independent workstation that using a proprietary rendering technique developed by Siemens (syngo.via VB40 [Siemens Healthineers, Erlangen, Germany]). An NVIDIA RTX A4000 GPU powers the station. Whereas VR utilizes a local lighting model, CR employs a global illumination model, and thus Monte Carlo techniques form the basis of complex calculations and algorithms involved in determining direct and indirect paths of light rays and simulating realistic interactions with the reconstructed data. This results in a better 3D perspective, particularly at tissue interfaces. Numerous presets are available based on clinical applications, and can be further fine-tuned by various display settings, optimizing parameters, setting HU thresholds, and leveling, depending on the need of the imager and anatomic region of interest.”
3D Cinematic rendering for evaluating femoral pseudoaneurysms in injection drug users
Mohammad Yasrab · Ryan C. Rizk · Linda C. Chu · Elliot K. Fishman
Emergency Radiology https://doi.org/10.1007/s10140-024-02237-x - “By adjusting display parameters, including windowing and transparency there is greater control over which structures to emphasize or subtract. Vascular mapping with 3D CR allows for a closer inspection and characterization of the pseudoaneurysm anatomy, internal blood flow, as well as its spatial relationships with the surrounding vasculature. Evaluation of high-risk features, including subtle irregularities in texture, communication with the native vessel such as a narrow neck, as well as projections and lobulations are captured with improved depth perception in 3D, which helps ascertain the instability or imminent risk of rupture with greater confidence and thus plays a vital role in determining surgical approach and management, as alluded to in prior applications of 3D CR. For instance, a smaller pseudoaneurysm that abuts off the larger pseudoaneurysm in Fig. 6 is depicted clearly in 3D CR owing to the realistic shadowing, which wasotherwise difficult to appreciate.”
3D Cinematic rendering for evaluating femoral pseudoaneurysms in injection drug users
Mohammad Yasrab · Ryan C. Rizk · Linda C. Chu · Elliot K. Fishman
Emergency Radiology https://doi.org/10.1007/s10140-024-02237-x - “3D Cinematic Rendering (CR), an important development in CT postprocessing after traditional VR, can help thoroughly evaluate acutely developing femoral artery pseudoaneurysms in IVDU. An intuitive, photorealistic rendering of the complex spatial relationships with accurate textures, shadowing, and improved depth adds to diagnostic confidence and preoperative planning as demonstrated in the cases we present. Moving forwards, prospective studies can further evaluate its accuracy by directly comparing CR to other imaging modalities or renderingtechniques, as well as explore its utility in areas outside of diagnostic and surgical planning, such as medical education and patient counselling.”
3D Cinematic rendering for evaluating femoral pseudoaneurysms in injection drug users
Mohammad Yasrab · Ryan C. Rizk · Linda C. Chu · Elliot K. Fishman
Emergency Radiology https://doi.org/10.1007/s10140-024-02237-x
- BACKGROUND: Retroperitoneal and rectus sheath hematomas can occur spontaneously. There is a lack of research about the disease progression, optimal treatment strategies and the need for surgical intervention. Our study investigated their outcomes and management.
RESULTS: 99 patients were included; median age was 73-years (IQR 61-80). 88 patients were on an anticoagulant or antiplatelet agent. Warfarin and intravenous heparin being the most commonly utilized agents (42% and 36.4%, respectively). All 99 patients were diagnosed by CT scan. 79 patients received some sort of blood product (79.8% PRBC, 43.4% FFP, 17% platelets), and 26 patients were in hemorrhagic shock. 17 patients underwent angiography and/or angioembolization. Neither anticoagulation in general nor any specific agent was associated with the need for blood product transfusion or angiography. 13 patients died but none were attributable to the hematoma.
CONCLUSION: Both hematomas are usually self-limiting and rarely require surgical intervention. A subset may require angioembolization.
Contemporary management of spontaneous retroperitoneal and rectus sheath hematomas.
Warren MH et al.
Am J Surg. 2019 May 14. pii: S0002-9610(19)30097-2. doi: 10.1016/j.amjsurg.2019.05.002. [Epub ahead of print} - “A rectus sheath hematoma (RSH), or bleeding into the rectus abdominis muscles, is usually secondary to damage to the epigastric arteries or the muscle itself. Like SRH, these hemorrhages can be difficult to diagnose, as patients present with abdominal pain and often an abdominal mass that can imitate many other conditions. While trauma is a common etiology, spontaneous RSH can occur.”
Contemporary management of spontaneous retroperitoneal and rectus sheath hematomas.
Warren MH et al.
Am J Surg. 2019 May 14. pii: S0002-9610(19)30097-2. doi: 10.1016/j.amjsurg.2019.05.002. [Epub ahead of print} - “One of the main objectives was to determine how clinicians are currently diagnosing these cases. In this study, all cases were diagnosed by CT scan. This is not surprising since patients often present with vague, non-specific symptoms that make organ specific imaging difficult to use. Also detecting retroperitoneal pathology can be limited by other imaging modalities. CT scan with contrast also provides additional information as evidence of active contrast extravasation may direct the clinician toward angioembolization.”
Contemporary management of spontaneous retroperitoneal and rectus sheath hematomas.
Warren MH et al.
Am J Surg. 2019 May 14. pii: S0002-9610(19)30097-2. doi: 10.1016/j.amjsurg.2019.05.002. [Epub ahead of print} - ”Spontaneous retroperitoneal and rectus sheath hematomas are serious complications for patients and require close monitoring. As they closely correlate with age and anticoagulation, clinicians will continue to see more of these cases. These patients rarely require surgical intervention and are primarily managed without an intervention. Larger multicenter studies are needed to establish guidelines.”
Contemporary management of spontaneous retroperitoneal and rectus sheath hematomas.
Warren MH et al.
Am J Surg. 2019 May 14. pii: S0002-9610(19)30097-2. doi: 10.1016/j.amjsurg.2019.05.002. [Epub ahead of print} - ” First described almost 70 years ago, retroperitoneal hematomas are relatively rare conditions with a reported incidence in anticoagulated patients as low as 0.1% and as high as 0.6%. While most commonly seen after procedures such as femoral artery catheterizations or blunt abdominal trauma, a subgroup of these bleeds occurs without associated trauma or medical instrumentation thus classified as spontaneous retroperitoneal hematomas (SRH). Patients with SRH often present in the emergency department with vague complaints, such as abdominal and back pain, which increase the likelihood of a delayed or missed diagnosis.”
Contemporary management of spontaneous retroperitoneal and rectus sheath hematomas.
Warren MH et al.
Am J Surg. 2019 May 14. pii: S0002-9610(19)30097-2. doi: 10.1016/j.amjsurg.2019.05.002. [Epub ahead of print}
- CT Angiography of the Upper Extremities: Applications
- Atherocsclerotic disease
- Thromboembolic disease
- Aortic dissection
- Vasculitis
- Small artery vasculitis
- Fibromuscular dysplasia
- Extrinsic compression syndrome
- Connective tissue disorders
- Preprocedural planning and postprocedural evaluation - “ Takayasu arteritis, giant cell arteritis and thromboangitis obliterans are the most common types of vasculitides that affect upper extremity vessels.”
CT Angiography of the Upper Extremity Arterial System: Part 2-Clinical Applications Beyond Trauma Patients
Bozlar U et al.
AJR 2013; 201:753-763 - “ Thoracic outlet syndrome (TOS) refers to compression of the neurovascular bundle as it crosses through the thoracic inlet.”
CT Angiography of the Upper Extremity Arterial System: Part 2-Clinical Applications Beyond Trauma Patients
Bozlar U et al.
AJR 2013; 201:753-763 - Thoracic Outlet Syndrome: Facts
- Clinical presentation is pain, tingling, weakness, or other symptoms of the ipsilateral upper extremity
- The syndrome may be caused by neurogenic, arterial, venous or combined causes although the neurogenic cause is most common
- Arterial involvement can be diagnosed by CT with arm in both abduction and the neutral position - “ CTA plays a significant role in the planning of complex arterial surgical reconstructions where upper extremity arterial mapping is needed.”
CT Angiography of the Upper Extremity Arterial System: Part 2-Clinical Applications Beyond Trauma Patients
Bozlar U et al.
AJR 2013; 201:753-763 - “ Traditionally, vascular mapping is performed with duplex ultrasound, but CTA and MRA may be performed for more anatomic imaging.”
CT Angiography of the Upper Extremity Arterial System: Part 2-Clinical Applications Beyond Trauma Patients
Bozlar U et al.
AJR 2013; 201:753-763 - “ Complications of dialysis access are typically diagnosed with DSA and ultrasound. However, CTA has also been shown to reveal complications such as arterial steal,aneurysm formation, stenoses, and occlusions.”
CT Angiography of the Upper Extremity Arterial System: Part 2-Clinical Applications Beyond Trauma Patients
Bozlar U et al.
AJR 2013; 201:753-763 - “ CT angiography has become an important diagnostic imaging modality for the evaluation of upper extremity vascular pathologic abnormalities. The attractiveness of upper extremity is 24 hour availability, rapid acquisition, minimal invassiveness, and the display of both vascular and musculoskeletal structures.”
CT Angiography of the Upper Extremity Arterial System: Part 2-Clinical Applications Beyond Trauma Patients
Bozlar U et al.
AJR 2013; 201:753-763