Magnetic Resonance Angiography of the Arteries of the Upper and Lower Extremities

Time-Resolved Imaging of Contrast Kinetics for Canine Hindlimb Angiography: A Comparison With CT Angiography and Noncontrast Magnetic Resonance Angiography

This study aimed to evaluate the feasibility of time-resolved imaging of contrast kinetics (TRICKS) for visualizing hindlimb vasculature in normal dogs and to compare it with CT angiography (CTA) and noncontrast magnetic resonance angiography (MRA). In a method-comparison prospective study, CTA and MRA, including three-dimensional time-of-flight (TOF), phase-contrast, and TRICKS sequences, were performed on the bilateral hindlimbs of six healthy beagles. Vascular distinction, delineation, connectivity, visualization, and image quality were qualitatively assessed. The relative signal intensity and acquisition time were measured. TRICKS provided better vascular distinction, delineation, and connectivity in both the proximal and distal regions compared with phase-contrast and TOF, and its image quality was comparable to that of CTA. TRICKS also demonstrated excellent differentiation between arteries and veins, which was attributable to the use of contrast agents and high temporal resolution, allowing for detailed visualization of both large and small vessels. Although artifacts were occasionally observed in TRICKS, they did not affect the overall image quality. Although the phase-contrast sequence performed well in visualizing larger vessels, it showed significant limitations in smaller branches and vessel connectivity. TOF suffers from artifacts and long acquisition times, rendering it less effective for the peripheral vasculature. These findings suggest that TRICKS is a feasible and valuable tool for detailed hindlimb vasculature imaging, offering improved visualization and rapid acquisition compared with noncontrast MRA techniques.

Predictive value of magnetic resonance angiography combined with serum ischemia-modified albumin for secondary cerebral infarction after transient ischemic attack

OBJECTIVE

This study investigated the diagnostic value of magnetic resonance angiography (MRA) combined with serum ischaemia-modifier albumin (IMA) testing in predicting secondary cerebral infarction (CI) following transient ischemic attack (TIA).

METHODS

All TIA patients underwent MRA and IMA level assessments, along with ABCD2 scoring (a TIA risk stratification tool). Patients were categorized into secondary CI and non-CI groups based on the occurrence of CI within a 90-day follow-up period. Vessel stenosis, serum IMA levels, the predictive value of MRA and IMA levels for secondary CI after TIA, and the independent factors associated with secondary CI in TIA patients were analyzed.

RESULTS

The high-risk and intermediate-risk groups showed a higher proportion of moderate-severe vessel stenosis and elevated IMA levels compared to the low-risk group, with IMA levels significantly higher in the high-risk group than in the intermediate-risk group (P < 0.05). The secondary CI group exhibited a greater proportion of moderate-severe vessel stenosis and higher IMA levels compared to non-CI group (P < 0.05). The combined predictive model using MRA and IMA demonstrated a significantly higher area under the curve (AUC = 0.908) compared to MRA alone (AUC = 0.798; z = 3.083, P = 0.002), but only slightly higher than IMA alone (AUC = 0.875; z = 1.226, P = 0.220). Independent factors associated with secondary CI included advanced age, moderate-severe vessel stenosis, ABCD2 scores, and elevated IMA levels (OR > 1, P < 0.05).

CONCLUSION

Changes in MRA and IMA levels were correlated with disease severity in TIA patients. MAR combined with serum IMA demonstrated high predictive efficacy for secondary CI after TIA, making it a valuable tool for CI risk assessment. Independent factors associated with secondary CI included advanced age, moderate-severe vessel stenosis, intermediate-high-risk ABCD2 scores, and elevated IMA levels.

Added value of pre-procedural magnetic resonance angiography in transarterial embolization for refractory musculoskeletal pain

Background

Transarterial microembolization (TAME) is a minimally invasive treatment for chronic musculoskeletal disorders. Identifying angiogenesis and the supplying vessels of the target joint is important but challenging. Although magnetic resonance imaging (MRI) is commonly used to diagnose musculoskeletal diseases, it typically excludes vascular imaging. Dynamic contrast-enhanced magnetic resonance angiography (DCE-MRA) has the ability to visualize lesion angiogenesis, identify supplying vessels, and evaluate the vasculature anatomy. We propose that incorporating DCE-MRA into pre-procedural assessments can help identify the culprit vessels, arterial anatomy, and variant assessment of the target joint before TAME.

Materials and methods

We investigated six cases, each presenting pain in different body parts: shoulder adhesive capsulitis, trapezius myalgia, combined tennis and golf elbow, knee osteoarthritis, refractory knee pain after osteotomy, and plantar fasciitis. All patients underwent MRI with DCE-MRA before undergoing TAME. DCE-MRA was performed using either 1.5 T or 3 T MRI scanners, employing 3D-TRICKS or 4D-TRAK XD techniques. The numerical rating scale for pain was evaluated at one, three, and six months after the procedure, and any adverse events were recorded over the entire six-month follow-up period.

Results

Pre-procedural DCE-MRA helped to visualize angiogenesis at the lesion site in all patients and identify the supplying vessels, arterial vasculature anatomy, and branching variants. These findings corroborated the subsequent digital subtraction angiography (DSA) findings obtained during TAME. All patients experienced pain reduction and functional improvement after TAME without any complications. The average pain score reduced significantly after TAME treatment (p < 0.05). Two patients underwent a second MRI and DCE-MRA at the six-month follow-up and showed a significant reduction in angiogenesis.

Conclusion

DCE-MRA offers a valuable pre-procedural assessment tool for TAME procedures by facilitating the visualization of angiogenesis at the lesion site, supplying vessels, and arterial anatomic variants, including the variable orifice of the supplying branches. This information can potentially improve patient selection and pre-procedural planning, leading to better outcomes and reduced risk of complications.

Under pressure: a head-to-toe review of vascular compression syndromes

Vascular compression syndromes are a group of conditions resulting from mechanical compression of blood vessels by adjacent structures leading to compromised blood flow and various associated symptoms. They frequently affect young, otherwise healthy individuals and are often underdiagnosed due to their rarity and vague clinical manifestations. Achieving an accurate diagnosis depends on the integration of clinical presentation and imaging findings. Imaging modalities including color doppler ultrasound, computed tomography angiography, magnetic resonance angiography, and catheter-directed digital subtraction angiography are essential for diagnosis and management. Dynamic imaging is crucial in eliciting findings due to the positional nature of many of these syndromes. In this paper, we will present a "head-to-toe" overview of vascular compression syndromes including Vascular Eagle Syndrome, Vascular Thoracic Outlet Syndrome, Quadrilateral Space Syndrome, Hypothenar Hammer Syndrome, Median Arcuate Ligament Syndrome, Renal Artery Entrapment Syndrome, Left Renal Vein Compression/Nutcracker Syndrome, May-Thurner Syndrome, Adductor Canal Syndrome, and Popliteal Artery Entrapment Syndrome. Treatment is variable but typically involves a combination of conservative and surgical management. Surgical approaches focus on decompression of affected neurovascular structures. Endovascular treatment alone is rarely recommended. We aim to equip general radiologists with the knowledge needed to accurately diagnose patients with vascular compression syndromes, allowing for timely treatment.

Exploring the Intersection of Geophysics and Diagnostic Imaging in the Health Sciences

To develop diagnostic imaging approaches, this paper emphasizes the transformational potential of merging geophysics with health sciences. Diagnostic imaging technology improvements have transformed the health sciences by enabling earlier and more precise disease identification, individualized therapy, and improved patient care. This review article examines the connection between geophysics and diagnostic imaging in the field of health sciences. Geophysics, which is typically used to explore Earth's subsurface, has provided new uses of its methodology in the medical field, providing innovative solutions to pressing medical problems. The article examines the different geophysical techniques like electrical imaging, seismic imaging, and geophysics and their corresponding imaging techniques used in health sciences like tomography, magnetic resonance imaging, ultrasound imaging, etc. The examination includes the description, similarities, differences, and challenges associated with these techniques and how modified geophysical techniques can be used in imaging methods in health sciences. Examining the progression of each method from geophysics to medical imaging and its contributions to illness diagnosis, treatment planning, and monitoring are highlighted. Also, the utilization of geophysical data analysis techniques like signal processing and inversion techniques in image processing in health sciences has been briefly explained, along with different mathematical and computational tools in geophysics and how they can be implemented for image processing in health sciences. The key findings include the development of machine learning and artificial intelligence in geophysics-driven medical imaging, demonstrating the revolutionary effects of data-driven methods on precision, speed, and predictive modeling.