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Page 2 of 14 Calderwood et al. Plast Aesthet Res 2021;8:40 https://dx.doi.org/10.20517/2347-9264.2021.14

the retention of protein-rich fluid in the interstitial tissue due to a disruption of lymph flow through the
lymphatic system. It eventually results in limb deformity, skin changes, impaired immune function, and
skin infections [3,8,9,11] , which has physical and psychological impacts on patients. In the early stages of
lymphoedema, protein-rich fluid collects in the subcutaneous tissue, resulting in pitting oedema. It is later
replaced by the accumulation of adipose tissue and fibro-sclerotic tissue, which does not cause pitting but
causes a “woody” feel to the affected limb [7,12] .

The initial management of lymphoedema is conservative; however, advances within this field have led to a
range of surgical options. These include vascularized lymph node transfer, lymphovenous anastomosis
(LVA), and liposuction for advanced disease. Optimising imaging techniques allows clinicians to evaluate
the characteristics of a person’s condition, which in turn directs clinical decisions on appropriate
management. Conventional imaging of the lymphatic system has been radionuclide lymphoscintigraphy,
which was introduced in the 1950s . However, lymphoscintigraphy can only provide low-resolution
[13]
images without anatomical body landmarks. A relatively new imaging technique called magnetic resonance
lymphangiography (MRL) has been developed to map the lymphatic system, identify the structural change
[2,4]
of the lymphatics in lymphoedema and assist with pre-operative planning . A combination of T2-
weighted non-contrast MRL and contrast-enhanced T1-weighted MRL allows optimal visualisation of
individual lymphatic vessels, lymph nodes, and areas of dermal backflow and provides both anatomical and
functional assessments. This manuscript will discuss the current types of MRL sequences and the benefits
and limitations of their use in lymphoedema.

METHOD AND DATA COLLECTION
A selection of published journal articles about the clinical use of MRL in upper and lower limb
lymphoedema were collected from electronic databases, PubMed, Ovid, and CINAHL, to create a literature
review. Search topics included “magnetic resonance lymphography”, “magnetic resonance
lymphangiography”, “contrast MRL”, “non-contrast MRL”, and other related words. The research
outcomes, recommendations, and discussion points of these articles were compared and summarised to
create a review of the role of MRL in a clinical setting. A total of 35 articles were selected, dated from 2005
to 2020. These articles included a range of studies and literature review papers, with patient cohorts
consisting of both primary and secondary lymphoedema in the upper or lower limbs. Only papers written
in English were included.

TYPES AND TECHNIQUES OF MRL
MRL is a modification of 3D volumetric MR angiography . There are three types of MRL sequences used in
[2]
MRL.

Patient position
Patient position depends on the area being studied. With lower limb imaging, the patient is supine with
their feet first in the MRI machine, whilst with upper limb imaging, the patient is prone, head first with
their arms extended and palms down [1-3,6,7,14-16] . This positioning allows contrast administration during the
[2,6]
scan .

Image sequences
As outlined below, multiple MRI sequences can be used to produce an optimal assessment, and all three are
performed in the following sequence. First, a non-contrast heavily T2-weighted sequence is used to define
the severity of the lymphoedema (non-contrast MRL). Then an enhanced high-resolution fat-suppressed
T1-weighted sequence is performed at different time intervals following subcutaneous or intradermal