Magnetic resonance lymphography findings across different clinical stages of lower limb lymphedema.

OBJECTIVE: To investigate the findings on lower limb lymphedema using magnetic resonance lymphography (MRL). METHODS: MRL was used to record the lymphatic vessel morphology, distribution of lymphatic vessels, dermal backflow (DBF), and morphology of inguinal lymph nodes in 112 patients (175 affected limbs) with lower limb lymphedema at different clinical stages (according to the International Society of Lymphology staging criteria 2020). RESULTS: The lymphatic vessel morphology significantly differed at different clinical stages (X2 =59.306; P = 0.000). ISL stage I is dominated by "scattered beads" and "branch-like" distribution, ISL stage Ⅱ has tree branch or "capillary-like" distribution, and ISL stage Ⅲ primarily has a capillary pattern and contrast agent accumulation in the foot. There were statistically significant differences in the distribution of lymphatic vessels and DBF in different clinical stages. Distribution of the enhanced lymphatic vessels was distal to the knee in ISL stage I, involved areas below the knee joint or the whole limb in ISL stage II, and involved the whole limb in ISL stage III (X2 =44.591; P = 0.000). With the progression of edema, DBF severity increased (X2 =76.416; P = 0.000). CONCLUSION: MRL revealed the morphology and distribution of lymphatic vessels and detected abnormal inguinal lymph nodes in patients at different stages of lymphedema, which can be used as reference information for surgical treatment.

Three-dimensional non-contrast magnetic resonance lymphography severity stage for upper extremity lymphedema.

PURPOSES: Non-contrast magnetic resonance lymphography (NMRL) has recently shown the capability of evaluating anatomical fluid distribution in upper extremity lymphedema (UEL). However, there is still a lack of knowledge about the correlation between the characteristic three-dimensional (3D) NMRL findings and the indocyanine green lymphography (ICG-L) findings. Our goal was to clarify the relationship between the 3D NMRL findings and the ICG-L findings. METHODS: Medical charts of patients with secondary UEL who underwent NMRL and ICG-L between January 2018 to October 2021 were reviewed. The upper extremities were divided into 6 regions; the hand, elbow, and the radial and ulnar aspects of the forearm and the upper arm. We investigated the prevalence of characteristic 3D NMRL patterns (Mist/Spray/Inky) in each region based on the ICG-L stage. We also examined the association between the 3D NMRL stage which we proposed and the ICG-L stage, and other clinical factors. RESULTS: A total of 150 regions of 25 patients with upper extremities lymphedema were enrolled in the study. All of the characteristic patterns increased significantly as the ICG-L stage advanced (p < 0.001, < 0.001, and < 0.001, respectively). The predominant NMRL patterns changed significantly from the Early pattern (Mist pattern) to the Advanced pattern (Inky/Spray pattern) as the ICG-L stage progressed (p < 0.001). The higher Stage of 3D NMRL was significantly associated with the progression of the ICG-L stage (rs = 0.80, p < 0.001). CONCLUSIONS: Characteristic 3D NMRL patterns and the 3D NMRL Stage had a significant relationship with the ICG-L stage and other clinical parameters. This information may be an efficient tool for a more precise and objective evaluation of various treatments for UEL patients.

Adipose tissue-derived microvascular fragments promote lymphangiogenesis in a murine lymphedema model.

Chronic lymphedema after cancer treatment is common and there is still no cure for this disease. We herein investigated the lymphangiogenic capacity of adipose tissue-derived microvascular fragments (MVF), which contain stem cells and lymphatic vessel fragments. Secondary lymphedema was induced in the hindlimbs of C57BL/6J mice. Green fluorescence protein (GFP)+ MVF were isolated from transgenic C57BL/6Tg (CAG-EGFP)1Osb/J mice, suspended in collagen hydrogel, and injected in the lymphadenectomy defect of wild-type animals. This crossover model allowed the detection of MVF-derived blood and lymphatic vessels after transplantation. The MVF group was compared with animals receiving collagen hydrogel only or a sham intervention. Lymphangiogenic effects were analyzed using volumetry, magnetic resonance (MR) lymphography, histology, and immunohistochemistry. MVF injection resulted in reduced hindlimb volumes when compared to non-treated controls. MR lymphography revealed lymphatic regeneration with reduced dermal backflow after MVF treatment. Finally, MVF transplantation promoted popliteal angiogenesis and lymphangiogenesis associated with a significantly increased microvessel and lymphatic vessel density. These findings indicate that MVF transplantation represents a promising approach to induce therapeutic lymphangiogenesis.

Sentinel lymph node biopsy with a handheld cordless magnetic probe following preoperative MR lymphography using superparamagnetic iron oxide for clinically N0 early oral cancer: A feasibility study.

PURPOSE: Radioisotope (RI) tracers are generally used for preoperative mapping of sentinel lymph node (SLN) and intraoperative detection with a portable γ probe. However, the use of RI has several limitations. Therefore, a method without RI is required for the widespread application of SLN biopsy. The purpose of this study was to evaluate the feasibility of SLN biopsy with a handheld cordless magnetic probe following magnetic resonance lymphography (MRL) using superparamagnetic iron oxide (SPIO) and for clinically N0 early oral cancer. MATERIALS AND METHODS: MRL using SPIO and SLNB with the handheld cordless magnetic probe were performed for 27 patients with clinically N0 early oral cancer. RESULTS: In all 27 patients (100%), SLNs were detected by MRL, and the total and mean number of SLNs were 73 and 2.7, respectively. All SLNs identified by MRL were detectable using the magnetic probe in all patients. CONCLUSIONS: SLNB with handheld cordless magnetic probe following preoperative SLN mapping by MRL using SPIO is feasible, without RI use, for neck management in cases of clinically N0 early oral cancer.

Visualization of Both the Superficial and Deep Lymphatic System of the Upper Extremity Using Magnetic Resonance Lymphography.

Background: The lymphatic system consists of the superficial and deep lymphatic system. Several diagnostic methods are used to assess the lymphatic system. Lymphoscintigraphy and indocyanine green lymphography are widely applied, both showing disadvantages, such as a poor resolution and lack of field of view. Magnetic resonance lymphography (MRL) shows satisfactory temporal and spatial resolution. The aim of this study was to assess both the superficial and deep lymphatic system in the upper extremity of healthy subjects, using an MRL protocol. Methods and Results: Ten healthy volunteers underwent an MRL examination, using a three Tesla MRI unit. Water-soluble gadolinium was used as a contrast agent. MRL images were evaluated by an experienced radiologist on image quality, enhancement of veins and lymphatic vessels, and characteristics of the latter. Overall image quality was good to excellent. In all subjects, veins and lymphatic vessels could be distinguished. Superficial and deep lymphatic vessels were seen in 9 out of 10 subjects. Lymphatic vessels with a diameter between 0.9 and 4.3 mm were measured. Both veins and lymphatic vessels showed their characteristic appearance. Enhancement of veins was seen directly after contrast agent injection, which decreased over time. Lymphatic vessel enhancement slowly increased over time. Mean total MRL examination (room) time was 110 minutes (81 minutes scan time). Conclusions: The MRL protocol accurately visualizes both deep and superficial lymphatic vessels showing their characteristic appearances with high spatial resolution, indicating the MRL can be of value in diagnosing and staging peripheral lymphedema.

Non-contrast magnetic resonance lymphography (NCMRL) in cancer-related secondary lymphedema: acquisition technique and imaging findings.

Cancer-related secondary lymphedema (LE) is a widespread issue, which markedly affects patients' quality of life. Its diagnosis is mainly clinical since there is no consensus on the best imaging technique that should be used to assess this pathology. Even if lymphedema treatment has been traditionally conservative and mainly based on compressive bandages and decongestive therapy, new surgical techniques are proving their effectiveness in the management of the disease and made proper assessment and characterization of lymphedema necessary. In this scenario, non-contrast magnetic resonance lymphography (NCMRL) is acquiring an increasing role, as a non-invasive imaging technique, useful for the analysis of LE. NCMRL is an effective tool in diagnosis confirmation, in providing information about the structural changes of the affected limbs, in grading this disorder, and provides a guide for LE management and treatment planning. This article aims to provide an overview of the literature regarding this examination, analyzing the acquisition technique, the interpretation of the imaging findings and their usefulness, the advantages and limits of this technique, to help the radiologist approach this relatively new investigation in cases of cancer-related LE.

Noncontrast Magnetic Resonance Lymphography in Secondary Lymphedema Due to Prostate Cancer.

Background: As survival from malignancies continues to improve, a greater emphasis is being placed on the quality of life after cancer treatments. Lymphedema (LE) represents a common and devastating sequela of neoplastic therapies, even if its incidence in patients submitted to lymphadenectomy for prostatic cancer is still poorly documented. The purpose of the current study was to analyze the imaging findings provided by noncontrast magnetic resonance (MR) lymphography in secondary lower limb LE related to prostate cancer therapies. Methods and Results: Patients with diagnosed secondary LE related to prostatic cancer treatment who underwent noncontrast MR lymphography (NCMRL) between November 2019 and February 2020 were assessed. Image datasets were retrospectively reviewed for the severity of lymphedema and characteristics of the subcutaneous tissue, muscular compartment appearance, number of iliac and inguinal lymphatics, and number of locoregional lymph nodes. Ten patients with 17 affected lower extremities, nine right extremities, and eight left extremities were included in our analysis. Magnetic resonance imaging grading was classified as one in four extremities, two in five extremities, and three in eight lower extremities. Honeycomb pattern was observed in 15 extremities, without significant correlation with MR grading (p = 0.684); dermal thickening showed correlation with MR grading (p < 0.001), as well as reduction of muscular trophism (p = 0.021). We observed a significant correlation between the number of inguinal lymph nodes and recognizable inguinal lymphatics (p = 0.039). Conclusion: NCMRL is able to provide useful information for the management of secondary lower limb LE caused by prostate cancer treatments. Clinical Trials.gov ID: n.2019/ST/187.

Magnetic resonance lymphography as three-dimensional navigation for lymphaticovenular anastomosis in patients with leg lymphedema.

BACKGROUND: Precise mapping of functional lymphatic vessels is essential for successful lymphaticovenular anastomosis (LVA). This study aimed to clarify the precision of magnetic resonance lymphography (MRL) in detecting lymphatic vessels prior to LVA. METHODS: Eighteen patients with leg lymphedema were recruited for this prospective study. All patients underwent MRL before LVA to obtain three-dimensional coordinates of lymphatic vessels from MRL images. The precision of MRL for detecting lymphatic vessels was evaluated and compared with those of other contrast techniques. RESULTS: Twenty legs from 18 patients were analyzed. A total of 40 skin incisions were made, 32 of which were determined by MRL. The precision of MRL to detect lymphatic vessels was 94%. With the addition of MRL, the number of lymphatic vessels identified preoperatively was increased as compared with indocyanine green lymphography (ICG-L) alone. Assuming a detection sensitivity of MRL for lymphatic vessels of 1, those of other contrast techniques were 0.90 for ICG-L under microscopy, 0.73 for patent blue staining, and 0.43 for ICG-L before incision. Whereas ICG-L before incision could not detect lymphatic vessels at depths greater than 17.0 mm, all deeper anastomosed lymphatic vessels were identified by MRL. CONCLUSION: Lymphatic vessels enhanced on MRL can be reliably identified intraoperatively. MRL is a promising preoperative examination in LVA that can selectively depict suitable lymphatic vessels even in deep tissue layers.

Magnetic Resonance Lymphangiography of the Central Lymphatic System: Technique and Clinical Applications.

Magnetic resonance lymphangiography (MRL) is a noninvasive imaging technique that can be used in the management of lymphatic disorders to delineate the central lymphatic system for treatment planning. This article reviews the MRL technique, its advantages, limitations, indications, and impact on patient management. Level of Evidence 5 Technical Efficacy Stage 3 J. MAGN. RESON. IMAGING 2021;53:374-380.

MR lymphography with superparamagnetic iron oxide for sentinel lymph node mapping of N0 early oral cancer: A pilot study.

OBJECTIVES: The purpose of this pilot study was to evaluate the usefulness of magnetic resonance lymphography (MRL) with superparamagnetic iron oxide (SPIO) in sentinel lymph node (SLN) mapping of clinically N0 early oral cancer, and to conduct a comparative study of this MRL with CT lymphography (CTL). METHODS: CTL and MRL were performed for SLN mapping before surgery for 20 patients with clinically N0 early oral cancer. The detection rate, number, and location of SLNs in CTL and MRL were evaluated. Furthermore, optimal scanning/imaging timing in MRL was examined. RESULTS: SLNs were detected by CTL in 18 (90%) patients, and the total and mean number of SLN were 35 and 1.8, respectively. All SLNs could be detected 2 min and 3.5-5 min after contrast medium injection. In all patients, SLNs were detected by MRL at 10 min after SPIO injection, and the total and mean number of SLN was 53 and 2.7, respectively. MRL at 30 min after the injection showed additional 18 secondary lymph nodes. CONCLUSION: MRL with SPIO is safe and useful imaging for the detection of SLNs in clinically N0 early oral cancer, and the optimal imaging timing is 10 min after SPIO injection.

Non-contrast MR Lymphography of lipedema of the lower extremities.

AIM: To assess imaging findings and characteristics of the lymphatic system in patients affected by lipedema and lipolymphedema of the lower extremities on Non-Contrast MR Lymphography (NCMRL). MATERIALS AND METHODS: 44 lower extremities in 11 consecutive female patients affected by lipedema, and 11 patients with lipolymphedema were examined by NCMRL. MR imaging was performed on 1.5-T system MR equipment. The examination consisted of one 3D short-tau inversion recovery (STIR) and one heavily T2-weighted 3D-Turbo Spin Echo (TSE) sequence. RESULTS: All patients showed symmetrical enlargement of the lower extremities with increased subcutaneous fat tissue. The fat tissue was homogeneous, without any signs of edema in pure lipedema patients. In all the extremities with lipolymphedema, high signal intensity areas in the epifascial region could be detected on the 3D-TSE sequence (p < .001) with evidence of mild epifascial fluid collections (p < .001). No sign of honeycomb pattern fat appearance was observed. The appearance of the iliac lymphatic trunks was normal in both lipedema and lipolymphedema patients. Dilated peripheral lymphatics were observed in 2 patients affected by lipedema, indicating a subclinical status of lymphedema, and in 10 patients with lipolymphedema (p = .001). Signs of vascular stasis were observed in both groups, without statistically significant difference (p = .665). CONCLUSION: NCMRL is a non-invasive imaging technique that is suitable for the evaluation of patients affected by lipedema and lipolymphedema, helping in the differential diagnosis.

Lymph node detection in MR Lymphography: false positive reduction using multi-view convolutional neural networks.

PURPOSE: To investigate whether multi-view convolutional neural networks can improve a fully automated lymph node detection system for pelvic MR Lymphography (MRL) images of patients with prostate cancer. METHODS: A fully automated computer-aided detection (CAD) system had been previously developed to detect lymph nodes in MRL studies. The CAD system was extended with three types of 2D multi-view convolutional neural networks (CNN) aiming to reduce false positives (FP). A 2D multi-view CNN is an efficient approximation of a 3D CNN, and three types were evaluated: a 1-view, 3-view, and 9-view 2D CNN. The three deep learning CNN architectures were trained and configured on retrospective data of 240 prostate cancer patients that received MRL images as the standard of care between January 2008 and April 2010. The MRL used ferumoxtran-10 as a contrast agent and comprised at least two imaging sequences: a 3D T1-weighted and a 3D T2*-weighted sequence. A total of 5089 lymph nodes were annotated by two expert readers, reading in consensus. A first experiment compared the performance with and without CNNs and a second experiment compared the individual contribution of the 1-view, 3-view, or 9-view architecture to the performance. The performances were visually compared using free-receiver operating characteristic (FROC) analysis and statistically compared using partial area under the FROC curve analysis. Training and analysis were performed using bootstrapped FROC and 5-fold cross-validation. RESULTS: Adding multi-view CNNs significantly (p < 0.01) reduced false positive detections. The 3-view and 9-view CNN outperformed (p < 0.01) the 1-view CNN, reducing FP from 20.6 to 7.8/image at 80% sensitivity. CONCLUSION: Multi-view convolutional neural networks significantly reduce false positives in a lymph node detection system for MRL images, and three orthogonal views are sufficient. At the achieved level of performance, CAD for MRL may help speed up finding lymph nodes and assessing them for potential metastatic involvement.

Non-enhanced MR lymphography of the thoracic duct: improved visualization following ingestion of a high fat meal-initial experience.

PURPOSE: The objective of this study was to compare the clarity of magnetic resonance lymphography (MRL) images of the thoracic duct (TD) obtained from subjects following an overnight fast with those obtained from the same subjects after ingestion of a high fat meal. METHODS: Nineteen healthy volunteers were included in this study. TD images were acquired on a 3·0T MRI system with the imaging sequence of magnetic resonance cholangiopancreatography. TD MRL images were obtained from subjects following an overnight fast and from the same subjects 3-4 h after ingestion of a high fat meal. Images were displayed in maximum intensity projection format and degree of visualization was evaluated using a scoring system. RESULTS: The mean TD score obtained following an overnight fast was significantly lower than the mean TD score obtained 3-4 h after ingestion of a high fat meal (P<0·05). CONCLUSION: The clarity of TD MRL images is improved if subjects have ingested a high fat meal 3-4 h prior to examination.

[Chyluria with "nephrotic syndrome-like" presentation: Diagnostic and therapeutic approach]. / Chylurie révélée par un « pseudo-syndrome néphrotique ¼ : démarche diagnostique et thérapeutique.

Chyluria implies an abnormal communication between the lymphatic system and the urinary tract. It is more frequent in endemic areas of lymphatic filariasis, which constitutes the main cause. Chyluria may mimic a nephrotic syndrome. Diagnosis of chyluria is based on urinary cytological and biocheminal analysis. Localization of the fistula needs medical imaging: cystoscopy, retrograde pyelography, lymphoscintigraphy and more recently magnetic resonance lymphography. Due to frequent spontaneous remissions, traitement can require only dietary measures. In case of malnutrition or clinical complications, sclerotherapy should be rapidly undertaken, before considering surgery of renal lymphatic disconnection.

Influence of contrast injection methods in interstitial magnetic resonance lymphography of breast cancer / 局解手术学杂志

Objective To study the influence of different contrast injection skills in interstitial magnetic resonance lymphography( IMRL) of breast cancer, and standardize the IMRL contrast injection process. Methods A total of 36 patients with invasive breast cancer were ran-domly divided into four groups. The imaging time of different contrast agent dose and local massage time on sentinel lymph node ( SLN) were analyzed. According to the results, the best contrast injection methods technology program was choosed. Results For the same massage time, different contrast agent doses showed no significant difference in the SLN imaging time (P>0. 05);For same contrast agent dose, dif-ferent massage time showed significant statistically different SLN imaging time(P<0. 05). Conclusion In clinical work, IMRL with a con-trast agent injection dose of 0. 5 mL/person, local massage 1 min after injection can successfully achieve the lymphatic system image of breast cancer.