Dynamic MR angiography of upper extremity vascular disease: pictorial review

Cardiothoracic Magnetic Resonance Angiography

Catheter-based angiography is regarded as the clinical reference imaging technique for vessel imaging; however, it is invasive and is currently used for intervention or physiologic measurements. Contrast enhanced magnetic resonance angiography (MRA) with gadolinium-based contrast agents can be performed as a three-dimensional (3D) MRA or as a time resolved 3D (4D) MRA without physiologic synchronization, in which case cardiac and respiratory motion may blur the edges of the vessels and cardiac chambers. Ferumoxytol has recently been a popular contrast agent for MRA in patients with chronic renal failure. Noncontrast 3D MRA with ECG gating and respiratory navigation are safe and accurate noninvasive cross-sectional imaging techniques for the visualization of great vessels of the heart and coronary arteries in a variety of cardiovascular disorders including complex congenital heart diseases. Noncontrast flow dependent MRA techniques such as time of flight, phase contrast, and black-blood MRA techniques can be used as complementary or primary techniques. Here we review both conventional and relatively new contrast enhanced and non-contrast enhanced MRA techniques including ferumoxytol enhanced MRA, and bright-blood and water-fat separation based noncontrast 3D MRA techniques.

Renal clearable magnetic nanoparticles for magnetic resonance imaging and guided therapy

Magnetic resonance imaging (MRI) is a non-invasive, radiation-free imaging technique widely used for disease detection and therapeutic evaluation due to its infinite penetration depth. Magnetic nanoparticles (MNPs) have unique magnetic and physicochemical properties, making them ideal as contrast agents for MRI. However, the in vivo toxicity of MNPs, resulting from metal ion leakage and long-term accumulation in the reticuloendothelial system (RES), limits their clinical application. To overcome these challenges, there is considerable interest in the development of renal-clearable MNPs that can be completely cleared through the kidney, reducing retention time and potential toxic risks. In this review, we provide an overview of recent advancements in the development of renal-clearable MNPs for disease imaging and treatment. We discuss the factors influencing renal clearance, summarize the types of renal-clearable MNPs, their synthesis methods, and biomedical applications. This review aims to offer comprehensive information for the design and clinical translation of renal-clearable MNPs. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Biosensing.

Magnetic Resonance Angiography of the Hand Vasculature in Patients With Systemic Sclerosis and Systemic Lupus Erythematosus

BACKGROUND

When patients with systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) develop digital ischemia, conventional angiography (CA) is traditionally used to assess hand vasculature. Recently, Chang et al described an angiographic classification system for patients with SSc. Conventional angiography uses intravascular contrast agents that are nephrotoxic and vasoconstrictive. Owing to these limitations, this study assesses the use of contrast-enhanced magnetic resonance angiography (MRA) as an alternative to CA to evaluate hand vasculature in patients with digital ischemia.

METHODS

This retrospective case series reports on 38 contrast-enhanced MRAs of hand vasculature from 30 symptomatic patients with SSc (N = 21) or SLE (N = 9). The radial and ulnar arteries (RA, UA) and the superficial and deep palmar arches were evaluated at standard reference points both quantitatively and qualitatively for their diameter, patency, and Chang classification.

RESULTS

In SSc MRAs (n = 26), the UA was significantly smaller than the RA and was occluded in 46%. In SLE MRAs (n = 12), the UA and RA had no difference in diameter and the UA was occluded in 25%. In SSc, the most common Chang classification was type 2 (UA involvement) in 44%. In SLE, the most common Chang classification was type 4 (UA and RA involvement) in 45%, with 18% classified as type 2.

CONCLUSIONS

Contrast-enhanced MRA used to assess hand vasculature in SSc patients with digital ischemia shows similar patterns of vascular involvement as previously demonstrated by CA. While vascular involvement in SSc predominantly involves the UA, the RA is also frequently involved in SLE.

Peripheral Artery Bypass Graft for the Treatment of Ischemic Ulcer or Severe Pain of Hand in Connective Tissue Diseases

ABSTRACT

Chronic ischemia of the hands and feet is a rare medical condition that requires surgical revascularization. In particular, digital ischemia resulting from connective tissue diseases (CTDs) is among the most important manifestations that negatively affect patients' quality of life. Here, we describe a bypass graft technique for treating digital ischemia. This study aimed to share the considerable benefits of surgical intervention for CTD and present a treatment algorithm. From 2009 to 2020, bypass graft surgery was performed on 10 patients with CTD to relieve their ischemic symptoms or ulceration. Preoperative angiography was performed, and blood distribution patterns were analyzed in detail. Based on the angiographic 4-level analysis, bypass graft surgeries were performed accordingly. The postoperative follow-up was 15 to 72 months. Pain in the hands that underwent the bypass graft surgery improved immediately after surgery. All ulcerations healed and the mean time recorded for ulceration healing was 45.7 days. Here, we propose an appropriate surgical treatment algorithm for managing CTD using arterial bypass graft surgery, and its positive long-term results demonstrate that it is an appropriate option for treating digital ischemia. In conclusion, strict measures with precise preoperative planning can provide satisfactory long-term results in patients with CTD.

Simultaneous bilateral distal venous arterialization between redial artery and cephalic vein in dorsal hand for Raynaud's phenomenon in both hands: A case report

Raynaud's phenomenon (RP) is characterized by episodic vasospasm in peripheral vessels and ischemia of the fingers. Venous arterialization is thought to induce neovascularization and increased oxygen tension. In this report, we describe a patient with RP in the fingers of both hands in whom venous arterialization achieved an acceptable result in both hands. The patient was a 62-year-old woman with a 10-year history of worsening pain and cold sensation in the tips of the index, middle, ring, and little fingers on both sides. The venous arterialization procedure was performed on both hands simultaneously at the level of the anatomical snuff box between radial artery and cephalic vein in dorsal hand. There was no need for valvectomy in the level of hands. To prevent development of the steal phenomenon in the arterialized veins, the superficial basilic and median veins of the forearm were ligated via 1 cm skin incisions. The pain and cold sensation in the fingertips of both hands remained decreased, and the nonhealing ulcers on the fingertips healed without the need for amputation. The observation period was 14 months, and the surface temperature of the fingers was increased after venous arterialization, as was the temperature of the palm and forearm. There was no problem when administering intravenous infusion into the forearm on either side postoperatively. The case showed venous arterialization was effective for RP without increasing intravenous pressure in the affected limb, and further investigation is necessary.

Photoplethysmography Analysis with Duffing–Holmes Self-Synchronization Dynamic Errors and 1D CNN-Based Classifier for Upper Extremity Vascular Disease Screening

Common upper limb peripheral artery diseases (PADs) are atherosclerosis, embolic diseases, and systemic diseases, which are often asymptomatic, and the narrowed arteries (stenosis) will gradually reduce blood flow in the right or left upper limbs. Upper extremity vascular disease (UEVD) and atherosclerosis are high-risk PADs for patients with Type 2 diabetes or with both diabetes and end-stage renal disease. For early UEVD detection, a fingertip-based, toe-based, or wrist-based photoplethysmography (PPG) tool is a simple and noninvasive measurement system for vital sign monitoring and healthcare applications. Based on time-domain PPG analysis, a Duffing–Holmes system with a master system and a slave system is used to extract self-synchronization dynamic errors, which can track the differences in PPG morphology (in amplitudes (systolic peak) and time delay (systolic peak to diastolic peak)) between healthy subjects and PAD patients. In the preliminary analysis, the self-synchronization dynamic errors can be used to evaluate risk levels based on the reflection index (RI), which includes normal condition, lower PAD, and higher PAD. Then, a one-dimensional convolutional neural network is established as a multilayer classifier for automatic UEVD screening. The experimental results indicated that the self-synchronization dynamic errors have a positive correlation with the RI (R2 = 0.6694). The K-fold cross-validation is used to verify the performance of the proposed classifier with recall (%), precision (%), accuracy (%), and F1 score.

High-resolution T1 MRI via renally clearable dextran nanoparticles with an iron oxide shell

Contrast agents for magnetic resonance imaging (MRI) improve anatomical visualizations. However, owing to poor image resolution in whole-body MRI, resolving fine structures is challenging. Here, we report that a nanoparticle with a polysaccharide supramolecular core and a shell of amorphous-like hydrous ferric oxide generating strong T₁ MRI contrast (with a relaxivity coefficient ratio of ~1.2) facilitates the imaging, at resolutions of the order of a few hundred micrometres, of cerebral, coronary and peripheral microvessels in rodents and of lower-extremity vessels in rabbits. The nanoparticle can be synthesized at room temperature in aqueous solution and in the absence of surfactants, has blood circulation and renal clearance profiles that prevent opsonization, and leads to better imaging performance than Dotarem (gadoterate meglumine), a clinically approved gadolinium-based MRI contrast agent. The nanoparticle's biocompatibility and imaging performance may prove advantageous in a broad range of preclinical and clinical applications of MRI.

CT angiography and MRI of hand vascular lesions: technical considerations and spectrum of imaging findings

Vascular lesions of the hand are common and are distinct from vascular lesions elsewhere because of the terminal vascular network in this region, the frequent hand exposure to trauma and microtrauma, and the superficial location of the lesions. Vascular lesions in the hand may be secondary to local pathology, a proximal source of emboli, or systemic diseases with vascular compromise. In most cases, ischaemic conditions are investigated with Doppler ultrasonography. However, computed tomography angiography (CTA) or dynamic contrast-enhanced magnetic resonance angiography (MRA) is often necessary for treatment planning. MR imaging is frequently performed with MRA to distinguish between vascular malformations, vascular tumours, and perivascular tumours. Some vascular tumours preferentially affect the hand, such as pyogenic granulomas or spindle cell haemangiomas associated with Maffucci syndrome. Glomus tumours are the most frequent perivascular tumours of the hand. The purpose of this article is to describe the state-of-the-art acquisition protocols and illustrate the different patterns of vascular lesions and perivascular tumours of the hand.

Techniques for Imaging Vascular Supply of Peripheral Nerves

Few studies have been developed to map the vascular structures feeding peripheral nerves, with the majority using cadaveric models and inadequate sample sizes. Preliminary evidence, while limited, indicates that the mapping of these vessels may allow or preclude certain procedures in nerve reconstruction due to the location of essential arterial inflow to the vasa nervorum. This review evaluates the evidence regarding historical, current, and emerging techniques for visualizing these vascular structures in vivo and considers their potential application in peripheral nerve vasculature.

An overview of the findings of dynamic upper limbs’ arterial and venous duplex in cases of vascular thoracic outlet syndrome

Background

To describe the findings of the dynamic upper limb arterial and venous duplex in the assessment of vascular compression in cases of VTOS. This study was conducted on 58 patients with VTOS; they were evaluated by dynamic duplex examination.

Results

Vascular compression was subdivided into a venous compression that was detected in (84.4%,n = 49), arterial compression that was seen in (1.7%,n = 1), and combined arterial and venous compression that was present in (13.7%,n = 8); bilateral compression was existing in (94.4%,n = 55), compression at the scalene triangle was seen in (1.7%,n = 1), at the costo-clavicular space was seen in (91.3%,n = 53), and at the retro-pectoral space was depicted in (8.6%,n = 5).

Complicated arterial compression was detected in (1.7%,n = 1), whereas venous complications were seen in (6.8%,n = 4).

Conclusion

Dynamic duplex ultrasound offered a simple, noninvasive, and quick technique that can help in the evaluation of the vascular thoracic outlet syndrome without exposure to ionizing radiation or contrast media administration like that in CT; nevertheless, it is done with the patient in the upright position, thus avoiding the high false-negative results associated with the supine position that is used in the CT and MRI studies.

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.

Magnetic Resonance Angiography of the Upper Extremity

The magnetic resonance angiography (MRA) toolbox includes a wide array of versatile methods for diagnosis and therapy planning in patients with a variety of upper extremity vascular pathologies. MRA can provide excellent image quality with high spatial and high temporal resolution without the disadvantages of ionizing radiation, iodinated contrast, and operator dependency. Contrast-enhanced techniques are preferred for their robustness, image quality, and shorter scan times. This article provides an overview of the available MRA techniques and a description of the clinical entities that are well suited for evaluation with contrast-enhanced MRA.

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

Upper extremity vasculature can be affected by various traumatic and nontraumatic pathologies; however, the evaluation of these arteries can be challenging for the radiologists as well as for the clinicians. After an accurate history and clinical examination, imaging plays a vital role in the diagnosis and treatment planning of these patients. Depending on the urgency and the indication, upper extremity arteries may be evaluated by ultrasonography with color Doppler, computed tomography (CT), magnetic resonance imaging (MRI), or digital subtraction angiography. This review article discusses relevant imaging anatomy of the upper extremity arteries, presents CT and MRI protocols, briefly describes the state-of-the-art CT and MRI of various pathologies affecting the upper extremity arteries, and summarizes the important pearls needed for busy practicing radiologist.

Historical perspective: eponyms of vascular radiology

Eponyms are ubiquitous throughout the medical literature, especially the radiology lexicon. In particular, vascular radiology is replete with dozens of eponyms named after pathologic and anatomic features and various medical devices. Several disease processes are known exclusively by their eponyms or by both their eponyms and their descriptive names. Although some authors advocate abandoning eponyms in favor of more descriptive terms, the established history and common use of eponyms make it unlikely that they will disappear from the vocabulary. Radiologists should be familiar with both the eponymous and descriptive names of disease processes to ensure effective communication and prevent erroneous identification. Study of these eponyms provides information about these disease processes and other medical knowledge for use in daily practice. In addition, biographic information about the pertinent physicians can yield insights into the sometimes surprising origins of these eponyms. The authors provide biographic sketches of these physicians and discuss the clinical relevance of the anatomic features, malformations, and syndromes that bear their names.

Interpretation of upper extremity arteriography: vascular anatomy and pathology [corrected]

Understanding the utility and interpretation of upper extremity angiography is critical for the hand surgeon treating vaso-occlusive diseases of the hand. Although invasive and requiring the use of contrast dye, it remains the gold standard for imaging of the vascular system of the upper extremity. Angiography may detect numerous variants of the upper limb arterial system which may contribute to surgical pathology. Extensive vascular collateralization helps to maintain perfusion to the hand and facilitates reconstruction of the upper extremity. It is paramount to remember that angiography is a dynamic study and should represent a "flexible roadmap" for surgical reconstruction.

Management of acute and chronic vascular conditions of the hand

Management of acute and chronic vascular disorders of the hand in patients with vasospastic and vaso-occlusive disorders is a complex problem and requires a multidisciplinary approach. The ischemia-related pain, skin ulcerations, and ultimately the threat of digital gangrene require a concerted effort to improve perfusion using a combination of medications and surgery. The purpose of this work is to review our experience over the past 2 decades with this cohort of patients including the variability of the clinical presentation, a method of classification, and a practical treatment philosophy.

CT angiography of the upper extremity arterial system: Part 2- Clinical applications beyond trauma patients

OBJECTIVE

CT angiography using modern MDCT scanners has evolved into a highly accurate noninvasive diagnostic tool for the evaluation of patients with pathologic abnormalities of the upper extremity arterial system.

CONCLUSION

Here we focus on the use of this modality in patients with nontraumatic vascular pathologic abnormalities.

Imaging appearances of Buerger's disease complications in the upper and lower limbs

Thromboangiitis obliterans (Buerger's disease) is a rare, non-atherosclerotic, segmental, inflammatory vasculitis that most commonly involves small and medium-sized arteries, veins and nerves of the extremities and affects tobacco smokers between the ages of 25 and 45 years. The manifestations of Buerger's disease can be extremely variable and, therefore, awareness of the condition is important for both general and musculoskeletal radiologists. This paper presents the radiological appearance of the sequelae of Buerger's disease involving the upper and lower limbs.

Assessment of vascular disorders of the upper extremity with contrast-enhanced magnetic resonance angiography: pictorial review

We reviewed the role of contrast magnetic resonance angiography (MRA) in patients with vascular disorders of the upper extremity. MRA accurately defines stenoocclusive lesions in patients with atherosclerosis and embolus. It helps to diagnose thoracic outlet syndrome, vascular malformations, and vasculitis. It demonstrates vascular injuries after blunt or occupational trauma, corkscrew collaterals in Burger's disease, and pathological vessels in malignant tumors. Also, it detects the cause of hemodialysis fistula dysfunction. We concluded that contrast MRA is a noninvasive imaging modality that can be used for planning the treatment of vascular disorders of the upper extremity.

Incorporation of an apoE-derived lipopeptide in high-density lipoprotein MRI contrast agents for enhanced imaging of macrophages in atherosclerosis

Magnetic resonance (MR) imaging is becoming a pivotal diagnostic method to identify and characterize vulnerable atherosclerotic plaques. We previously reported a reconstituted high-density lipoprotein (rHDL) nanoparticle platform enriched with Gd-based amphiphiles as a plaque-specific MR imaging contrast agent. Further modification can be accomplished by inserting targeting moieties into this platform to potentially allow for improved intraplaque macrophage uptake. Since studies have indicated that intraplaque macrophage density is directly correlated to plaque vulnerability, modification of the rHDL platform may allow for better detection of vulnerable plaques. In the current study we incorporated a carboxyfluoresceine-labeled apolipoprotein E-derived lipopeptide, P2fA2, into rHDL. The in vitro macrophage uptake and in vivo MR efficacy were demonstrated using murine J774A.1 macrophages and the apolipoprotein E knock-out (apoE(-/-)) mouse model of atherosclerosis. The in vitro studies indicated enhanced association of murine macrophages to P2fA2 enriched rHDL (rHDL-P2A2) nanoparticles, relative to rHDL, using optical techniques and MR imaging. The in vivo studies showed a more pronounced and significantly higher signal enhancement of the atherosclerotic wall 24 h after the 50 micromol Gd/kg injection of rHDL-P2A2 relative to administration of rHDL. The normalized enhancement ratio for atherosclerotic wall of rHDL-P2A2 contrast agent injection was 90%, while that of rHDL was 53% 24 h post-injection. Confocal laser scanning microscopy revealed that rHDL-P2A2 nanoparticles co-localized primarily with intraplaque macrophages. The results of the current study confirm the hypothesis that intraplaque macrophage uptake of rHDL may be enhanced by the incorporation of the P2fA2 peptide into the modified HDL particle.

Venous malformations: classification, development, diagnosis, and interventional radiologic management

Venous malformations are categorized as low-flow vascular malformations within the domain of vascular anomalies and are the most common vascular malformation encountered clinically. Venous malformations are by definition present at birth, undergo pari passu growth, and present clinically because of symptoms related to mass effect or stasis. Although diagnosis can usually be made by clinical history and examination, differentiation from other vascular and nonvascular entities often requires an imaging work-up that includes ultrasound, CT, MR imaging, and diagnostic phlebography. All decisions regarding imaging work-up and decision to treat must be coordinated though referral and discussions with a multidisciplinary team and be based on clearly defined clinical indications. Percutaneous image-guided sclerotherapy has become the mainstay of treatment for venous malformations and involves the introduction of any one of a number of endothelial-cidal sclerosants into the vascular spaces of the lesion, with each sclerosant possessing its own unique spectrum of advantages and disadvantages.