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

Lymphatic flow and anatomy can be challenging to study, owing to variable lymphatic anatomy in patients with diverse primary or secondary lymphatic pathologic conditions and the fact that lymphatic imaging is rarely performed in healthy individuals. The primary components of the lymphatic system outside the head and neck are the peripheral, retroperitoneal, mesenteric, hepatic, and pulmonary lymphatic systems and the thoracic duct. Multiple techniques have been developed for imaging components of the lymphatic system over the past century, with trade-offs in spatial, temporal, and contrast resolution; invasiveness; exposure to ionizing radiation; and the ability to obtain information on dynamic lymphatic flow. More recently, dynamic contrast-enhanced (DCE) MR lymphangiography (MRL) has emerged as a valuable tool for imaging both lymphatic flow and anatomy in a variety of congenital and acquired primary or secondary lymphatic disorders. The authors provide a brief overview of lymphatic physiology, anatomy, and imaging techniques. Next, an overview of DCE MRL and the development of an MRL practice and workflow in a hybrid interventional MRI suite incorporating cart-based in-room US is provided, with an emphasis on multidisciplinary collaboration. The spectrum of congenital and acquired lymphatic disorders encountered early in an MRL practice is provided, with emphasis on the diversity of imaging findings and how DCE MRL can aid in diagnosis and treatment of these patients. Methods such as DCE MRL for assessing the hepatic and mesenteric lymphatic systems and emerging technologies that may further expand DCE MRL use such as three-dimensional printing are introduced. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Back to the Future II-A Comprehensive Update on the Rapidly Evolving Field of Lymphatic Imaging and Interventions.

ABSTRACT: Lymphatic imaging and interventional therapies of disorders affecting the lymphatic vascular system have evolved rapidly in recent years. Although x-ray lymphangiography had been all but replaced by the advent of cross-sectional imaging and the scientific focus shifted to lymph node imaging (eg, for detection of metastatic disease), interest in lymph vessel imaging was rekindled by the introduction of lymphatic interventional treatments in the late 1990s. Although x-ray lymphangiography is still the mainstay imaging technique to guide interventional procedures, several other, often less invasive, techniques have been developed more recently to evaluate the lymphatic vascular system and associated pathologies. Especially the introduction of magnetic resonance, and even more recently computed tomography, lymphangiography with water-soluble iodinated contrast agent has furthered our understanding of complex pathophysiological backgrounds of lymphatic diseases. This has led to an improvement of treatment approaches, especially of nontraumatic disorders caused by lymphatic flow abnormalities including plastic bronchitis, protein-losing enteropathy, and nontraumatic chylolymphatic leakages. The therapeutic armamentarium has also constantly grown and diversified in recent years with the introduction of more complex catheter-based and interstitial embolization techniques, lymph vessel stenting, lymphovenous anastomoses, as well as (targeted) medical treatment options. The aim of this article is to review the relevant spectrum of lymphatic disorders with currently available radiological imaging and interventional techniques, as well as the application of these methods in specific, individual clinical situations.

Lymphatic Intervention, the Frontline of Modern Lymphatic Medicine: Part I. History, Anatomy, Physiology, and Diagnostic Imaging of the Lymphatic System.

Recent advances in lymphatic imaging have provided novel insights into the lymphatic system. Interventional radiology has played a significant role in the development of lymphatic imaging techniques and modalities. Radiologists should be familiar with the basic physiology and anatomy of the lymphatic system to understand the imaging features of lymphatic disorders, which reflect their pathophysiology. This study comprehensively reviews the physiological and anatomical aspects of the human lymphatic system as well as the latest lymphatic imaging techniques.

Dynamic Contrast-Enhanced Magnetic Resonance Lymphangiography and Lymphatic Interventions for Pediatric Patients with Various Lymphatic Diseases.

Background: To demonstrate the magnetic resonance lymphangiography (MRL) imaging findings of lymphatic diseases and the clinical outcomes of lymphatic embolization in pediatric patients. Methods and Results: This retrospective study included 10 consecutive pediatric patients who underwent MRL for lymphatic diseases between June 2017 and June 2021. Nine patients underwent dynamic contrast-enhanced MRL with bilateral inguinal lymph node injection of diluted gadolinium, and one patient underwent nonenhanced MRL with a heavily T2-weighted image. The etiology of lymphatic disease was classified into three categories based on the magnetic resonance findings. The resolution of chylous fluid and weight-adjusted amounts of chylous fluid collected from a drainage tube were evaluated as outcomes. Patients were classified as postoperative lymphatic leak (n = 3), pulmonary lymphatic perfusion syndrome (n = 3), central lymphatic flow disorder (CLFD; n = 3), and primary lymphatic dysfunction (Gorham-Stout syndrome; n = 1). Three patients underwent radiological lymphatic intervention, and one CLFD patient underwent surgical intervention. In patients with postoperative lymphatic leak, the median chest tube drainage decreased significantly after the intervention [from 87.9 to 12.4 mL/(kg·d); p = 0.02]. However, in one CLFD patient, the amount of chylous fluid did not decrease until 7 days after intervention. Conclusion: The etiology of lymphatic disease in pediatrics can be recognized on MRL, and lymphatic intervention can be performed for cessation of lymphatic leak, even though the treatment outcomes may differ according to the underlying etiology. MRL can play an important role in classifying lymphatic disease, and in planning treatment on the basis of the lymphatic anatomy and underlying etiology.

Intranodal Glue Embolization for Postoperative Lymphatic Leaks in the Groin and Pelvis: Comparison with Sclerotherapy.

PURPOSE: To compare the effectiveness of and adverse events related to intranodal glue embolization (IGE) with those of intracavitary sclerotherapy for the treatment of postoperative groin and pelvic lymphatic leaks. MATERIALS AND METHODS: From November 2015 to July 2021, IGE for postoperative pelvic or groin lymphocele or lymphorrhea was performed in 33 patients. From January 2010 to July 2021, 28 patients with postoperative pelvic or groin lymphocele were treated with sclerosis alone. Clinical success was defined as resolution of drainage within 3 weeks of the last intervention performed without recurrence. Patients presenting >1 year after surgery or with <30 days of follow-up were excluded. Patients with lymphorrhea treated with IGE were not statistically compared with those in the sclerosis group because they were not eligible for sclerosis. RESULTS: Clinical success was similar between the groups (lymphocele IGE, 15/18, 83.3%, vs sclerosis, 15/23, 65.2% [P = .29]; lymphorrhea IGE, 8/9, 88.9%). The mean number of interventions performed to successfully treat a lymphocele was significantly higher in the sclerosis group (2.5 for sclerosis vs 1.3 for IGE; P = .003; lymphorrhea IGE, 1.0). The mean time to resolution was significantly longer for sclerosis than for IGE (27 vs 7 days; P = .002; 4 days for lymphorrhea IGE). There were no sclerosis-related adverse events and 2 IGE-related adverse events: (a) 1 case of mild lymphedema and (b) 1 case of nontarget embolization resulting in deep vein thrombosis. CONCLUSIONS: For treatment of postoperative pelvic and groin lymphoceles, IGE results in faster resolution with fewer interventions compared with sclerosis. IGE is also an effective treatment for postoperative groin lymphorrhea.

State-of-the-art imaging for lymphatic evaluation in children.

The lymphatic system has been poorly understood and its importance neglected for decades. Growing understanding of lymphatic flow pathophysiology through peripheral and central lymphatic flow imaging has improved diagnosis and treatment options in children with lymphatic diseases. Flow dynamics can now be visualized by different means including dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL), the current standard technique to depict central lymphatics. Novel imaging modalities including intranodal, intrahepatic and intramesenteric DCMRL are quickly evolving and have shown important advances in the understanding and guidance of interventional procedures in children with intestinal lymphatic leaks. Lymphatic imaging is gaining importance in the radiologic and clinical fields and new techniques are emerging to overcome its limitations.

Interventional Management of Acquired Lymphatic Disorders.

The lymphatic system is a complex network of tissues, vessels, and channels found throughout the body that assists in fluid balance and immunologic function. When the lymphatic system is disrupted related to idiopathic, iatrogenic, or traumatic disorders, lymphatic leaks can result in substantial morbidity and/or mortality. The diagnosis and management of these leaks is challenging. Modern advances in lymphatic imaging and interventional techniques have made radiology critical in the multidisciplinary management of these disorders. The authors provide a review of conventional and clinically relevant variant lymphatic anatomy and recent advances in diagnostic techniques such as MR lymphangiography. A detailed summary of technical factors related to percutaneous lymphangiography and lymphatic intervention is presented, including transpedal and transnodal lymphangiography. Traditional transabdominal access and retrograde access to the central lymph nodes and thoracic duct embolization techniques are outlined. Newer techniques including transhepatic lymphangiography and thoracic duct stent placement are also detailed. For both diagnostic and interventional radiologists, an understanding of lymphatic anatomy and modern diagnostic and interventional techniques is vital to the appropriate treatment of patients with acquired lymphatic disorders. ©RSNA, 2022.

Liver lymphatic anatomy and role in systemic lymphatic disease.

OBJECTIVES: To characterize hepatic to systemic lymphatic connections in patients with systemic lymphatic disease using intra-hepatic lymphangiography and to compare outcomes after lymphatic intervention. METHODS: In this retrospective study, patients with intra-hepatic lymphangiography from May 2014 - April 2019 at our institution were included. Imaging review was performed and hepatic lymphatic connections and flow patterns were characterized. Clinical data were reviewed and comparisons between patients undergoing lymphatic intervention with or without abnormal hepatic lymphatics were performed. RESULTS: During the study period, 105 patients underwent intra-hepatic lymphangiography. Primary clinical presentation included ascites (19/105), chylothorax (27/105), plastic bronchitis (PB) (17/105), and protein losing enteropathy (PLE) (42/105). Five categories of hepatic lymphatic connections and flow patterns were identified (%): normal (25%, 26/105), hepatoperitoneal (12%, 13/105), hepatopulmonary (10.5%, 11/105), hepatomesenteric (7.5%, 8/105), and hepatoduodenal (41%, 43/105) with four patients having more than one abnormal pattern. A comparison between clinical presentation and imaging category revealed an increased likelihood of having ascites with hepatoperitoneal (p < .0001), chylothorax/PB with hepatopulmonary (p = .01), and PLE with hepatoduodenal (p < .001) connections. Seventy-six patients had a lymphatic intervention, 24% with normal, and 76% with abnormal liver lymphatics. There was no difference in length of hospital stay or mortality between the two groups, but there was a prolonged time to symptom resolution (p = .006) and persistent symptoms after 6 months (5% vs 44%, p = .002) in the group with abnormal liver lymphatics. CONCLUSION: We identified five liver lymphatic imaging categories with a substantial correlation to presenting lymphatic disease. Abnormal imaging patterns correlated with increased morbidity. Evaluation of liver lymphatics should be considered in patients with a systemic lymphatic disease if central lymphatic imaging is normal. KEY POINTS: • We identified five liver lymphatic imaging patterns: normal, hepatoperitoneal, hepatomesenteric, hepatopulmonary, and hepatoduodenal. • Imaging patterns were correlated with disease presentation (normal - chylothorax/PB, hepatoperitoneal - ascites/chylothorax, hepatopulmonary - chylothorax/PB, hepatoduodenal - PLE). • Abnormal imaging patterns correlated with increased morbidity.

Pediatric Neck Masses: Imaging Guidelines and Recommendations.

Neck masses commonly present in children and several potential diagnostic and management pathways exist, though with a paucity of evidence-based recommendations. The purpose of this article is to evaluate the current literature and utilization of various diagnostic imaging modalities , with a review of imaging features and management pearls for pediatric neck masses. A comprehensive understanding and practical imaging workflow will guide optimal patient workup and management.

Lymphoscintigraphic Investigations for Axillary Web Syndromes.

Background: Axillary web syndrome (AWS) is a frequent complication after surgery for breast cancer, but its lymphatic involvement is not definitively established. Here we report the results of lymphoscintigraphic investigations in patients with AWS. Methods and Results: We conducted a retrospective, single-center review of lymphoscintigraphic investigations performed in 46 patients with AWS that was either clinically obvious or suspected. Of this group, 23 patients had two investigations with a mean interval of 19 weeks between them (range, 6-98 weeks). Results of the lymphoscintigraphic investigations, which were performed according to a well-standardized protocol, were classified into four patterns: normal; functional lymphatic insufficiency only (no lymphatic vascular morphologic abnormality); lymphovascular blockade without collateralization; and vascular collateralization and/or dermal backflow. Of the 46 patients, on the first lymphoscintigraphic investigation, four (8.6%) had a normal pattern, seven (15.2%) had functional lymphatic insufficiency only, four (8.6%) had lymphovascular blockade without collateralization, and 31 (67.3%) had vascular collateralization and/or dermal backflow. Among patients who underwent two investigations, four of the five who had only functional lymphatic insufficiency at the first investigation had developed vascular collateralization and/or dermal backflow by the second. The three patients who had lymphovascular blockade without collateralization at the first examination had also progressed to collateralization and/or dermal backflow at the second. None of the 15 patients who initially had vascular collateralization and/or dermal backflow showed any reversal at the second examination. Conclusions: Our analysis confirms the lymphatic nature of AWS and shows the lymphoscintigraphic patterns and evolutions of the lymphatic lesions with potential therapeutic implications. The retrospective review of our database is approved by the institutional ethics committee under number 2048.

Real-time next-generation sequencing on shell-vial culture to contribute to diagnosis of lymphatic tuberculosis: a case report.

Lymph node tuberculosis is a of limited clinical suspicion form of Mycobacterium tuberculosis infection. After 15 days incubation in a cellular culture and directly from the supernatant, 11 minutes of Oxford Nanopore MinION sequencing provided a preliminary result of an antibiotic-susceptible M. tuberculosis Indo-Oceanic lineage strain. Oxford Nanopore MinION sequencing is a promising tool for optimising the laboratory diagnosis of lymph node tuberculosis.

Unusual Left Periclavicular Cutaneous Lymphatic Fistula After Port Explantation Without Lymph Vessel Injury: Imaging and Interventional Treatment.

Complex oncological treatment can be associated with lymphatic vascular injury that is burdened by considerable morbidity. Lymphatic imaging and interventional techniques offer new minimally invasive treatment options. We report the case of a 59-year-old woman with an unusual lympho-veno-cutaneous fistula, diagnosed by magnetic resonance lymphangiography and treated by minimally invasive embolization therapy and venous recanalization.

Abdominal Imaging of Children and Young Adults With Fontan Circulation: Pathophysiology and Surveillance.

OBJECTIVE. The Fontan procedure has significantly improved the survival in children with a functional single ventricle, but it is associated with chronically elevated systemic venous pressure that leads to multisystemic complications. Imaging plays an important role in assessing these complications and guiding management. The pathophysiology, imaging modalities, and current surveillance recommendations are discussed and illustrated. CONCLUSION. Significant improvement in survival of patients with Fontan circulation is associated with ongoing cardiac and extracardiac comorbidities and multisystemic complications. The liver and intestines are particularly vulnerable to damage. In addition, this patient population has been shown to be at increased risk of certain malignancies such as hepatocellular carcinoma and neuroendocrine tumors. Familiarity with imaging findings of Fontan-associated liver disease and other abdominal complications of the Fontan circulation is essential for radiologists because we are likely to encounter these patients in our general practice.

Lymphatic Interventional Treatment for Chyluria via Retrograde Thoracic Duct Access.

Chyluria is the leakage of intestinal lymph (chyle) into the urine. Novel lymphatic intervention techniques, such as interstitial lymphatic embolization, proved to be a useful treatment option for chyluria. However, one of the challenges of this approach is the difficulty in identifying connections between the lymphatic system and kidney collecting system. Here, embolization of the abnormal lymphatic connection through retrograde thoracic duct access in 3 chyluria patients is introduced.

Using arterial spin labeling blood flow and its histogram analysis to distinguish early-stage nasopharyngeal carcinoma from lymphoid hyperplasia.

ABSTRACT: To investigate the feasibility of arterial spin labeling (ASL) blood flow (BF) and its histogram analysis to distinguish early-stage nasopharyngeal carcinoma (NPC) from nasopharyngeal lymphoid hyperplasia (NPLH).Sixty-three stage T1 NPC patients and benign NPLH patients underwent ASL on a 3.0-T magnetic resonance imaging system. BF histogram parameters were derived automatically, including the mean, median, maximum, minimum, kurtosis, skewness, and variance. Absolute values were obtained for skewness and kurtosis (absolute value of skewness [AVS] and absolute value of kurtosis [AVK], respectively). The Mann-Whitney U test, receiver operating characteristic curve, and multiple logistic regression models were used for statistical analysis.The mean, maximum, and variance of ASL BF values were significantly higher in early-stage NPC than in NPLH (all P < 0.0001), while the median and AVK values of early-stage NPC were also significantly higher than those of NPLH (all P < 0.001). No significant difference was found between the minimum and AVS values in early-stage NPC compared with NPLH (P = 0.125 and P = 0.084, respectively). The area under the curve (AUC) of the maximum was significantly higher than those of the mean and median (P < 0.05). The AUC of variance was significantly higher than those of the other parameters (all P < 0.05). Multivariate analysis showed that variance was the only independent predictor of outcome (P < 0.05).ASL BF and its histogram analysis could distinguish early-stage NPC from NPLH, and the variance value was a unique independent predictor.

Research Priorities in Lymphatic Interventions: Recommendations from a Multidisciplinary Research Consensus Panel.

Recognizing the increasing importance of lymphatic interventions, the Society of Interventional Radiology Foundation brought together a multidisciplinary group of key opinion leaders in lymphatic medicine to define the priorities in lymphatic research. On February 21, 2020, SIRF convened a multidisciplinary Research Consensus Panel (RCP) of experts in the lymphatic field. During the meeting, the panel and audience discussed potential future research priorities. The panelists ranked the discussed research priorities based on clinical relevance, overall impact, and technical feasibility. The following research topics were prioritized by RCP: lymphatic decompression in patients with congestive heart failure, detoxification of thoracic duct lymph in acute illness, development of newer agents for lymphatic imaging, characterization of organ-based lymph composition, and development of lymphatic interventions to treat ascites in liver cirrhosis. The RCP priorities underscored that the lymphatic system plays an important role not only in the intrinsic lymphatic diseases but in conditions that traditionally are not considered to be lymphatic such as congestive heart failure, liver cirrhosis, and critical illness. The advancement of the research in these areas will lead the field of lymphatic interventions to the next level.

Dynamic contrast-enhanced magnetic resonance lymphangiography in pediatric patients with central lymphatic system disorders.

Central conducting lymphatics (CCLs) disorders represent a broad spectrum of clinical entities ranging from self-limiting traumatic leaks treated by conservative strategies, to complex lymphatic circulation abnormalities that are progressive and unresponsive to currently available treatments. Dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) performed by intranodal injection of gadolinium-based contrast material is a recently developed technique which allows a minimally invasive evaluation of the CCL abnormalities providing a dynamic assessment of lymph flow and its pathways. In our institution, DCMRL is performed after bilateral cannulation of inguinal lymph nodes, using a MR protocol which includes volumetric 3D T2-SPACE (sampling perfection with application-optimized contrasts using different flip-angle evolution) and free-breathing respiratory navigated sequence and TWIST (time-resolved angiography with Interleaved stochastic trajectories) MR angiography sequence, during intranodal injection of paramagnetic contrast medium. Although DCMRL applications in clinical practice are still improving, a minimally invasive assessment of lymphatic pathways is particularly important both in pediatric patients with primitive lymphatic system disorders and in children with complex congenital heart disease associated with CCL impairment.

Ultrasound Monitoring of Thymus Involution in Septic Mice.

Thymus involution is characterized by a progressive regression of thymus size and contributes to immunosuppression in sepsis. High-frequency ultrasonography is a non-invasive monitoring system in multiple organs, including the thymus, in mice. However, thymus involution has not been studied using ultrasonography in septic mice. This study reports ultrasound approaches to monitoring septic thymus involution in mice. Sepsis was induced by cecum ligation and puncture (CLP). Mice were euthanized at three time points: baseline and days 3 and 10 after CLP. Thymus areas and volumes were measured using 2-D and 3-D ultrasound approaches. Thymus weights were measured ex vivo. Compared with values at baseline, both thymus area and volume decreased significantly at days 3 and 10. In addition, thymus areas and volumes correlated positively with thymus weights. In conclusion, ultrasonography provides reliable thymus measurements and is an optimal technique for monitoring thymus involution in septic mice.