Mr lymphangiography: How i do it

Abstract

Lymphedema is a chronic progressive edematous disease that in the United States is most commonly related to malignancy and its treatment. Lymphaticovenular anastomosis is a recently introduced microsurgical treatment option for lymphedema that requires the identification and mapping of individual lymphatic channels. While nuclear medicine lymphoscintigraphy has been the primary imaging modality performed to evaluate suspected lymphedema, lymphoscintigraphy does not provide the spatial information necessary for presurgical planning. High-resolution dynamic 3D magnetic resonance imaging (MRI) can noninvasively image abnormal lymphatic channels to both diagnose lymphedema and depict the location and number of individual lymphatic channels for surgical planning. MR lymphangiography can be performed at 1.5T or 3.0T using multichannel phased array surface coils. The main components of the exam are a heavily T2 -weighted 3D sequence to define the severity and extent of edema, a high-resolution dynamic 3D gradient echo imaging after intracutaneous contrast injection to visualize lymphatic channels, and a delayed 3D gradient echo sequence after intravenous contrast to define veins. This article reviews the pathophysiology and microsurgical treatment of lymphedema, presents the imaging protocol used at our institution, and describes exam interpretation and the image postprocessing performed for surgical planning.

Primary lower limb lymphoedema: classification with non-contrast MR lymphography

“…In contrast with these techniques non contrast MR lymphography does not provide any functional information, however the precise anatomic information can be used to identify sites for lymph node transplantation or suitable sites for lympho-venous anastomosis and to optimize mapping of the manual lymphatic drainage. We believe that it could be very interesting to associate non-contrast MR lymphography with a functional imaging modality such as contrast-enhanced MR lymphangiography as already proposed by Mitsumori et al (14). In addition, contrast-enhanced MR lymphangiography appears to be optimal for evaluation of distal lymphatic vessels whereas non-contrast MR lymphography may be superior for evaluation of proximal lymphatic trunks including inguinal and iliac vessels.…”

“…To improve differentiation from venous structures, Mitsumori et al (14) added contrast enhanced MR venography. In addition enhanced lymphatic vessels may not be demonstrated in healthy limbs, probably because of a faster lymphatic flow (14). (36).…”

“…The spatial resolution is far higher than that of lymphoscintigraphy (14). Enhancement of lymphatic vessels is optimal near the contrast media site.…”

MR Lymphangiography: A Practical Guide to Perform It and a Brief Review of the Literature from a Technical Point of View

“…Furthermore, we would like to point out the importance of a precontrast sequence in performing 3D MRL, in order to subtract it from the later postcontrast images. In fact, although Mitsumori et al did not find this technique useful, as it was invalidated by patient movements [10], we found an advantage from this approach in the visualization of small lymphatic vessels; evidently the patient should be instructed to maintain complete collaboration. In our experience only in 3 out of 24 patients with secondary lymphedema, we observed a poor lymphatic drainage limited to the lower part of the limb, because of the extremely impaired lymphatic circulation (Figure 7); therefore in these cases LVA treatment was restricted to this anatomical region.…”

“…The imaging protocol generally consists of a heavily T2-weighted sequence in order to evaluate the extent and distribution of the lymphedema and of a 3D fast spoiled gradient-echo T1-weighted sequence with a fat-saturation technique for the lymphatic visualization [3, 9, 10]. In our experience we performed a 3D steady-state free precession (SSFP) balanced electrocardiography- (ECG-) triggered sequence (FIESTA, GE) with spectral fat saturation (SPECtral inversion at lipid, SPECIAL, GE) instead of a heavily T2-weighted sequence in order to obtain a good visualization of both the venous system and the distribution of the lymphedema within the same sequence and at the same time.…”