MR Lymphangiography in Lymphatic Disorders: Clinical Applications, Institutional Experience, and Practice Development

MR lymphangiography in the pediatric population: 10-year single institution experience

The purpose of this study is to demonstrate the feasibility of magnetic resonance (MR) lymphangiography in the pediatric population, as well as assess patient risk factors which may impact procedural success. A total of 57 MR lymphangiograms (MRL) were performed over a 10-year period at a single stand-alone pediatric hospital. Patients with known or suspected pathology related to central lymphatic flow were enrolled. The study revealed a procedural success rate of 98.2 % for MR lymphangiography in the pediatric population, with visualization of the central lymphatics on MRI in 91.1 %. Patient age, body mass, and lymph node length did not have a statistically significant influence on the success of the procedure or MRI visualization of lymphatic channels. In the pediatric population, MRL has a high technical success rate and is a safe tool for assessing lymphatic abnormalities.

Clinical value of contrast-enhanced magnetic resonance lymphatic vessel imaging for precise localization of lymphatic vessels in patients with lymphaticovenous anastomosis

BACKGROUND

Magnetic resonance lymphangiography (MRL) is crucial for preoperative localization of lymphatic vessels for lymphaticovenous anastomosis (LVA), improving surgical success and treating limb lymphoedema. This study was performed to investigate the accuracy of indocyanine green (ICG) lymphography assisted by contrast-enhanced MRL (CE-MRL) in microsurgical incision planning and to evaluate the efficacy of LVA.

METHODS

From August 2023 to October 2024, 35 patients with secondary upper or lower extremity lymphoedema who underwent LVA were selected. All patients underwent preoperative ICG angiography and CE-MRL imaging. After ICG angiography, lymphatic vessels were marked and re-evaluated using MRL images. The accuracy of CE-MRL-assisted ICG angiography in detecting lymphatic vessels and the efficacy of LVA were assessed, and accuracy was compared with ICG angiography alone.

RESULTS

The 35 patients comprised 34 women and 1 man, with a mean age of 63.83 ± 11.89 years. Preoperative CE-MRL imaging identified 151 lymphatic vessels, of which 150 were accurately located and anastomosed during surgery, resulting in an accuracy rate of 99% (95% CI 0.980-1.00) for CE-MRL-assisted ICG angiography. Compared with ICG angiography alone, CE-MRL increased the number of identified lymphatic vessels by 12%. The effective rate of LVA was 94% (95% CI 0.857-1.00). Four weeks postoperatively, the limb circumferential difference improved by 14% ± 8.32%, while the circumferential reduction rate reached 49% ± 19%.

CONCLUSION

Contrast-enhanced MRL serves as a valuable complementary tool to ICG angiography in microsurgical LVA, enhancing the precision of lymphatic vessel localization. Lymphaticovenous anastomosis demonstrates a high effective cure rate, offering significant clinical benefits for patients with lymphoedema.

Important Anatomy in Lymphatic Interventions: A Practical Review

New understanding of the lymphatic system as well as increasing recognition of its importance in various pathologies have increased the opportunity to perform lymphatic interventions. Advancement in our understanding of the lymphatic system anatomy, including variations, combined with improved imaging has renewed interest in both surgical and interventional management of a wide range of complex lymphatic pathologies. It is important for the proceduralist to recognize the anatomy, variability, and physiology of the lymphatic system, including lower extremity lymphatic drainage, cisterna chyli location, and thoracic duct drainage. The purpose of this study is to convey the practical aspects of performing lymphatic interventions in an effort to improve the speed and reliability of these procedures.

Highlights of the society for magnetic resonance angiography 2024 conference

The 36th Annual International Meeting of the Society for Magnetic Resonance Angiography (SMRA), held from November 12-15, 2024, in Santiago de Chile, marked a milestone as the first SMRA conference in Latin America. Themed "The Ever-Changing Landscape of MRA", the event highlighted the rapid advancements in magnetic resonance angiography (MRA), including cutting-edge developments in contrast-enhanced MRA, contrast-free techniques, dynamic, multi-parametric, and multi-contrast MRA, 4D flow, low-field solutions and artificial intelligence (AI)-driven technologies, among others. The program featured 174 attendees from 15 countries, including 43 early-career scientists and 30 industry representatives. The conference offered a rich scientific agenda, with 12 plenary talks, 24 educational talks, 98 abstract presentations, a joint SMRA-MICCAI challenge on intracranial artery lesion detection and segmentation and a joint session with the Society for Cardiovascular Magnetic Resonance (SCMR) emphasizing accessibility, low-field MRI, and AI's transformative role in cardiac imaging. The meeting's single-track format fostered engaging discussions on interdisciplinary research and highlighted innovations spanning various vascular beds. This paper summarizes the conference's key themes, emphasizing the collaborative efforts driving the future of MRA, while reflecting on SMRA's vision to advance research, education, and clinical practice globally.

MR Lymphangiography: Congenital Lymphatic Flow Disorders

ABSTRACT

Congenital lymphatic flow disorders collectively refer to a heterogeneous group of diseases that manifest as chylothorax, chylous ascites, intestinal lymphangiectasia, protein-losing enteropathy, and peripheral extremity or genital lymphedema, all in the absence of identifiable injury to the lymphatic system. We have only recently begun to understand congenital lymphatic flow disorders through the ability to image lymph flow dynamically. Intranodal dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) is a crucial technique for imaging lymphatic flow in pediatric patients with congenital lymphatic flow disorders. However, as lymphatic imaging is still a nascent discipline with many uncertainties regarding optimal imaging and treatment, effective patient management requires a comprehensive understanding of imaging techniques, disease pathophysiology, and multidisciplinary treatment approaches. Above all, a fundamental understanding of the physiological lymphatic flow of the central conducting lymphatics is essential for the correct interpretation of DCMRL images. This knowledge helps to avoid unnecessary examinations, erroneous diagnoses, and potentially harmful treatment approaches. This review provides an overview of the methods, advantages, and precautions for interpreting the DCMRL examination, a state-of-the-art lymphatic system imaging technique, and shares various case studies.

Contrast-enhanced CT Lymphangiography for Various Central Lymphatic Disorders

Lymphatic leakage, manifesting as chylothorax or chylous ascites, arises from traumatic or nontraumatic causes and poses severe risks such as malnutrition and increased infection susceptibility. Accurate diagnosis and an effective treatment strategy necessitate comprehensive lymphatic imaging. Conventional lymphangiography and dynamic contrast-enhanced MR lymphangiography (DCMRL) have been widely used and studied as effective lymphatic imaging methods. Recently, CT lymphangiography (CTL) has been successfully implemented in animal studies and some patients, and the authors' institution now prioritizes CTL over DCMRL. Contrast-enhanced CTL offers a promising alternative, with advantages such as better accessibility and faster imaging. These advantages of CTL over traditional methods highlight its superior accessibility and fast acquisition time. Moreover, to reduce and optimize radiation dose, the stepwise propagation scanning method in CTL could be used, which is especially beneficial in pediatric patients. In this review, the authors suggest the protocol for CTL and interpretation methods for evaluation and therapeutic planning of central lymphatic disorders, focusing on the condition of lymphatic leakage. ©RSNA, 2024 The slide presentation from the RSNA Annual Meeting is available for this article.

A look inside the gut as a clue to nutritional status

PURPOSE OF REVIEW

Malabsorption and malnutrition are common gastrointestinal manifestations clinicians face, requiring diagnostic workup for effective diagnosis and management of the underlying cause. This review discusses recent advances in diagnostic approaches to malabsorption and maldigestion of macronutrients - lipids, proteins, and carbohydrates. We highlight underrecognized causes, available testing modalities, and ongoing diagnostic unmet needs.

RECENT FINDINGS

Innovations in the diagnostic landscape are enhancing our understanding of malabsorption syndromes. Stool collection and handling is uncomfortable and commonly avoided. The objective quantification of stool lipids, bile acids, and gut enzymes is therefore underused in the diagnosis and management of common disorders such as exocrine pancreatic insufficiency, bile acid diarrhea, protein-losing enteropathy, and more. We review the recent advancements in spot quantification of stool fat and bile acid content, endoscopic imaging techniques such as endocytoscopy, confocal laser endomicroscopy, and optical coherence tomography and the future place in clinical practice.

SUMMARY

Malabsorption and maldigestion represent significant challenges in clinical nutrition and gastroenterology. Through the integration of advanced diagnostic techniques, clinicians will be better equipped to tailor therapy and monitor treatment response, ultimately improving patient health outcomes. This review underscores the critical role of innovative diagnostic tools in accurately detecting and effectively managing gastrointestinal disorders linked to nutritional status.