Upper Extremity Runoff: Pearls and Pitfalls in Computed Tomography Angiography and Magnetic Resonance Angiography

CT Angiography of the Upper Extremities: Review of Acute Arterial Entities

Historically, evaluation of the upper extremity vasculature was performed using digital subtraction angiography. With the advancement of cross-sectional imaging and submillimeter isotropic data acquisition, CT angiography (CTA) has become an excellent noninvasive diagnostic tool for evaluation of the vasculature of the upper extremities. CTA allows quick evaluation of vessel patency and irregularity and achievement of the anatomic detail needed in preoperative planning. When interpreting CTA of the upper extremities, radiologists must be familiar with the normal vascular anatomy, common vascular anomalies, and pitfalls or artifacts that may mimic or mask abnormality. In this review, the authors provide an overview of the utility of CTA of the upper extremities. Also discussed are CTA techniques and the use of several newer technologies including dual-energy and photon-counting detector CT. The utility of CTA in patients with upper extremity trauma is explored, with a focus on assessing vascular injury. Other vascular abnormalities including infection, acute limb ischemia, and vasculitis are discussed. It is imperative for radiologists to be accustomed to CTA of the upper extremities in diagnosing acute vascular abnormalities and to recognize common pitfalls and mimics of these abnormalities. ©RSNA, 2025 Supplemental material is available for this article.

Upper limb computed tomography (CT) angiography in the emergency department

A range of abnormalities may acutely affect the upper limb (UL) extremity vasculature including trauma, peripheral vascular disease, and inflammatory conditions. Significant technical advances in computed tomography angiography (CTA) have led to the widespread adoption of this noninvasive modality for rapid evaluation of UL arterial abnormalities in the emergency department setting. A key advantage of CTA over traditional digital subtraction angiography (DSA) is the ability to evaluate concurrent osseous and soft tissue injuries. Accurate identification of pathology requires knowledge of normal UL arterial anatomy in addition to a high-quality study, which may be achieved with a robust CTA protocol. We describe the spectrum of imaging findings on upper limb CTA associated with various acute presentations. Traumatic vascular injuries may occur secondary to penetrating and blunt aetiologies appearing on CTA as contrast extravasation, pooling, pseudoaneurysm, occlusion, and arteriovenous fistula. Peripheral vascular disease manifests as atherosclerotic plaques with thready downstream opacification, and these may precipitate acute thromboembolic events. Inflammatory conditions affecting the UL vasculature includes large and small vessel vasculitides characterised by arterial mural thickening. The use of modalities, including ultrasound and magnetic resonance angiography (MRA), should be considered for further characterisation where appropriate.

Applications of Vascular Imaging and Interventional Radiology Modalities in the Upper Extremity: A Review

Hand and upper extremity (HUE) vascular disorders are encountered frequently by hand surgeons in clinical practice. A wide array of imaging and vascular interventional radiology modalities exists for the diagnosis and treatment of HUE vascular disorders, some of which may not be familiar to the HUE surgeons. In this review article, we summarize the vascular imaging and vascular interventional radiology modalities and their relative advantages, disadvantages, and indications with respect to HUE pathology. We aim to familiarize HUE surgeons with the available types of diagnostic and therapeutic options for HUE vascular pathologies and aid interdisciplinary communication with vascular interventional radiology specialists during the clinical decision-making process.

Imaging primer for CT angiography in peripheral vascular trauma

The use of computed tomography angiography (CTA) for the evaluation of peripheral vascular trauma has become increasingly prevalent in the past decade with the development of multidetector CT (MDCT) and multiple studies subsequently demonstrating high sensitivity, specificity, and diagnostic accuracy when compared with conventional angiography. Additional benefits of MDCT include the ability to rapidly acquire the images, perform multiplanar and 3D reconstructions, and assess the adjacent soft tissues and bones. Rapid intravenous injection of iodinated contrast material is required for optimal arterial enhancement. CTA manifestations of an arterial injury may be direct, and include active contrast extravasation, pseudoaneurysm, arteriovenous fistula (AVF), intimal injury, dissection, or occlusion. There are also indirect signs which have a high association with vascular injury, and should raise suspicion, when present. Pitfalls related to image acquisition or patient factors can be mitigated with appropriate planning and post-processing techniques.

Imaging of the aortic root on high-pitch non-gated and ECG-gated CT: awareness is the key!

The aortic pathologies are well recognized on imaging. However, conventionally cardiac and proximal aortic abnormalities were only seen on dedicated cardiac or aortic studies due to need for ECG gating. Advances in CT technology have allowed motionless imaging of the chest and abdomen, leading to an increased visualization of cardiac and aortic root diseases on non-ECG-gated imaging. The advances are mostly driven by high pitch due to faster gantry rotation and table speed. The high-pitch scans are being increasingly used for variety of clinical indications because the images are free of motion artifact (both breathing and pulsation) as well as decreased radiation dose. Recognition of aortic root pathologies may be challenging due to lack of familiarity of radiologists with disease spectrum and their imaging appearance. It is important to recognize some of these conditions as early diagnosis and intervention is key to improving prognosis. We present a comprehensive review of proximal aortic anatomy, pathologies commonly seen at the aortic root, and their imaging appearances to familiarize radiologists with the diseases of this location.

Vascular magnetic resonance angiography techniques

Magnetic resonance angiography (MRA) denotes a unique option for the evaluation of peripheral vasculature due to its noninvasive nature, lack of ionizing radiation exposure, potential for non-contrast examination, and ability for generating volumetric representations that showcase vascular pathology. The constant evolution of the available MRA techniques, however, makes understanding and determining an optimal imaging protocol difficult. Here we present a brief overview of the major MRA sequence options, their major weaknesses and strengths, and related imaging considerations. Understanding the technical underpinnings of the various MRA methods helps with recognition of common imaging issues and artifacts and rendering clinically relevant interpretations.

CT and MR imaging of the upper extremity vasculature: pearls, pitfalls, and challenges

Imaging is needed for diagnosis, treatment planning, and follow-up of patients with pathologies affecting upper extremity vasculature. With growth and evolution of imaging modalities [especially CT angiography (CTA) and MR angiography (MRA)], there is need to recognize the advantages and disadvantages of various modalities and obtain the best possible imaging diagnostic test. Understanding various limitations and pitfalls as well as the best practices to minimize and manage these pitfalls is very important for the diagnosis. This article reviews the upper extremity arterial vascular anatomy, discusses the CTA and MRA imaging, various pitfalls, and challenges and discuss imaging manifestations of upper extremity arterial pathologies.

Multimodality Imaging Approaches for Evaluating Traumatic Extremity Injuries: Implications for Military Medicine

Significance: Military service members are susceptible to traumatic extremity injuries that often result in limb loss. Tremendous efforts have been made to improve medical treatment that supports residual limb function and health. Despite recent improvements in treatment and novel prosthetic devices, many patients experience a wide range of clinical problems within residual limbs that can negatively impact the progress of rehabilitation programs while also impairing functional capacity and overall quality of life. Recent Advances: In addition to existing standard imaging modalities that are used for clinical evaluation of patients suffering from traumatic extremity injury, novel noninvasive imaging techniques are in development that may facilitate rapid and sensitive assessment of various aspects of traumatic extremity injuries and residual limb health. Critical Issues: Despite recent advances, there remains a clinical need for noninvasive quantitative imaging techniques that are capable of providing rapid objective assessments of residual limb health at the time of initial presentation as well as after various forms of medical treatment. Future Directions: Ongoing development of imaging techniques that allow for assessment of anatomical and physiological characteristics of extremities exposed to traumatic injury should greatly enhance the quality of patient care and assist in optimizing clinical outcomes.

Evaluation of the diagnostic value of a venous phase in CT angiography of the extremities in the setting of trauma: is vein imaging in vain?

PURPOSE

This study examined the value of including a venous phase in addition to the initial arterial phase in the CT angiography evaluation of extremity trauma.

METHODS

CT studies from 157 patients (average age 38 years, age range 18-89 years, male 83%, female 17%) were obtained for trauma to the upper or lower extremity with both arterial and venous phases and retrospectively reviewed. The detection rate and type of vascular injury were evaluated by using the arterial phase alone and compared to the detection rate when interpreting the arterial and venous phases together.

RESULTS

Arterial injury was identified in 35 cases (22%), and venous injury was identified in seven cases (5%). Four cases of discrepant diagnoses were identified between image interpretation of the arterial phase alone and interpretation using both phases, all of which were venous injuries that were visible only on the venous phase. None of the four cases of venous injury required a change in surgical management. Overall, no significant difference in diagnosis between the two methods of image interpretation (arterial phase alone, arterial and venous phases) was discovered (p > 0.125; CI 95%).

CONCLUSIONS

The use of a venous phase in the CT angiography evaluation of extremity trauma does not add significant arterial diagnostic or clinical management value despite its potential of increasing the diagnostic detection rate of venous injury.