Venous access is a procedure in which a catheter is placed into a vein for medical diagnosis or therapy. The type of device used depends on the patient and the type of illness being treated. There are two main types of venous access devices: peripheral and central catheters. A peripheral catheter is usually placed into a small vein, often in the arm, and is usually used up to 96 hours. A central catheter can be placed into a small or large vein in the body, with the tip located in a large vein close to the heart in the chest, and is used for a longer time.

A broad range of nonatherosclerotic diseases affect the peripheral arteries. The appropriate initial diagnostic imaging studies vary, depending upon the clinical presentation and suspicion of disease. Accurate vascular imaging relies upon visualization of the vessel lumen, vessel wall, and surrounding soft-tissue structures, with some modalities also offering the ability to characterize blood flow direction and velocity. Furthermore, nonvascular findings are often paramount in supporting a suspected clinical syndrome or guiding surgical management. The scenarios discussed in this document include the initial evaluation of suspected popliteal entrapment syndrome, external iliac artery endofibrosis, lower-extremity inflammatory vasculitides, dissection or connective tissue disease, noninflammatory vascular disease, and vascular trauma. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Abdominal aortic aneurysm (AAA) is defined as aneurysmal dilation of the abdominal aorta to 3 cm or greater. A high degree of morbidity and mortality is associated with AAA rupture, and imaging surveillance plays an essential role in mitigating the risk of rupture. Aneurysm size and growth rate are factors associated with the risk of rupture, thus surveillance imaging studies must be accurate and reproducible to characterize aneurysm size. Ultrasound, CT angiography, and MR angiography provide an accurate and reproducible assessment of size, while radiographs and aortography provide limited evaluation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The goal of endovascular angioplasty and of surgical bypass is to restore normal blood flow to the diseased arteries in the legs for individuals with peripheral artery disease. Both procedures need imaging follow-up to check for lesions, typically narrowing of arteries that may come back and cause symptoms. Often, noninvasive testing is done first to help choose the appropriate imaging test. The first test is usually measurement of the ankle-bronchial index (ABI), a noninvasive test where blood pressure cuffs are placed on the legs to measure local pressures. Other noninvasive tests can also be used.

Suspected lower extremity deep venous thrombosis is a common clinical scenario which providers seek a reliable test to guide management. The importance of confidently making this diagnosis lies in the 50% to 60% risk of pulmonary embolism with untreated deep vein thrombosis and subsequent mortality of 25% to 30%, balanced with the risks of anticoagulation. The ACR Appropriateness Criteria Expert Panel on Vascular Imaging reviews the current literature regarding lower extremity deep venous thrombosis and compared various imaging modalities including ultrasound, MR venography, CT venography, and catheter venography. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Mesenteric ischemia is an uncommon condition resulting from decreased blood flow to the small or large bowel in an acute or chronic setting. Acute ischemia is associated with high rates of morbidity and mortality; however, it is difficult to diagnose clinically. Therefore, a high degree of suspicion and prompt imaging evaluation are necessary. Chronic mesenteric ischemia is less common and typically caused by atherosclerotic occlusion or severe stenosis of at least two of the main mesenteric vessels. While several imaging examination options are available for the initial evaluation of both acute and chronic mesenteric ischemia, CTA of the abdomen and pelvis is overall the most appropriate choice for both conditions. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Although the incidence of thoracic aortic aneurysm is on the rise, initial imaging diagnosis can present a challenge for many clinicians. Providers are faced with many imaging choices as part of the initial workup. Considering level of invasiveness, relative radiation level, and quality of associated diagnostic data, CT angiography and MR angiography are believed to be the most appropriate options for radiological diagnosis of suspected thoracic aortic aneurysm. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Renovascular hypertension is the most common type of secondary hypertension and is estimated to have a prevalence between 0.5% and 5% of the general hypertensive population, and an even higher prevalence among patients with severe hypertension and end-stage renal disease, approaching 25% in elderly dialysis patients. Investigation for renal artery stenosis is appropriate when clinical presentation suggests secondary hypertension rather than primary hypertension, when there is not another known cause of secondary hypertension, and when intervention would be carried out if a significant renal artery stenosis were identified. The primary imaging modalities used to screen for renal artery stenosis are CT, MRI, and ultrasound, with the selection of imaging dependent in part on renal function. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Thoracic endovascular aortic repair (TEVAR) has undergone rapid evolution and is now applied to a range of aortic pathologies. Imaging plays a vital role in the pre- and postintervention assessment of TEVAR patients. Accurate characterization of pathology and evaluation for high-risk anatomic features are necessary in the planning phase, and careful assessment for graft stability, aortic lumen diameter, and presence of endoleak are paramount in the follow-up period. CTA is the imaging modality of choice for pre- and postintervention assessment, and MRA is an acceptable alternative depending on patient stability and graft composition. Lifelong imaging follow-up is necessary in TEVAR patients because endoleaks may develop at any time. The exact surveillance interval is unclear and may be procedure and patient specific. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

In patients with penetrating neck injuries with clinical soft injury signs, and patients with hard signs of injury who do not require immediate surgery, CT angiography of the neck is the preferred imaging procedure to evaluate extent of injury. Other modalities, such as radiography and fluoroscopy, catheter-based angiography, ultrasound, and MR angiography have their place in the evaluation of the patient, depending on the specific clinical situation and question at hand. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.