Advances in Imaging of Lymph Flow Disorders

Abstract

Conventional oil-contrast lymphography has long been the mainstay for lymphatic imaging. However, the emergence of computed tomography (CT) and magnetic resonance (MR) imaging has severely curtailed its use. Because of recent improvements and refinements, lymphangioscintigraphy now permits high-resolution imaging of peripheral lymphatic vessels and provides insight into lymph flow dynamics. It is indispensable for patients with known or suspected lymphatic circulatory disorders in confirming the diagnosis and delineating the pathogenesis and evolution of lymphedema. In addition, lymphangioscintigraphy helps evaluate lymphatic truncal anatomy and radiotracer transport. It can also be used to evaluate the efficacy of various treatment options designed to facilitate lymph flow or reduce lymph formation. The procedure is essentially noninvasive, can easily be repeated, and does not adversely affect the lymphatic vascular endothelium. MR imaging complements lymphangioscintigraphy in the monitoring and treatment of more complex lymphatic circulatory disorders, whereas CT facilitates catheter-guided percutaneous sclerosis or obliteration of specific lymphangiectasia or lymphangioma syndromes. Ultrasonography has proved useful in the setting of filariasis. Patients with a provisional diagnosis of peripheral lymphatic dysfunction or idiopathic edema should undergo diagnostic lymphangioscintigraphy and, in some cases, MR imaging to verify diagnostic accuracy, pinpoint the specific abnormality, and help guide subsequent therapy.

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

“…Because of its invasiveness compared with new techniques, conventional oilcontrast X-ray lymphangiography is no longer performed in patients with lower limb lymphedema (10,28). The current primary imaging modality is lymphoscintigraphy.…”

“…However, the ideal imaging technique for the evaluation of patients with primary lymphedema has been elusive. The invasiveness and the morbidity of conventional oil-contrast lymphangiography have resulted in a dramatic decrease of examinations (10). The current primary imaging modality for the investigation of peripheral lymphedema is lymphoscintigraphy performed with 99mTc-labeled nanocolloids.…”

“…Though MR imaging with heavily T2-weighted MR images has already been used for the morphological diagnosis of lymphedema, analysis of lymphatic vessels has not yet been performed (10,(17)(18)(19).…”

Advances in small animal mesentery models for in vivo flow cytometry, dynamic microscopy, and drug screening

“…Obtaining data from human subjects involves many difficulties (e.g., unpredictability of the time of clinical onset of PML, limitations of diagnostic methods, etc.) [170,173] . In experimental studies in rat, dog, and rabbit extremities, the multi-layers of lymph vascular networks, the rapid development of a good collateral network, and sufficient angiogenesis permit quick restoration of lymph pathways and drainage function, leading to prompt resolution of even acute edema without the appearance of long-term or chronic edema [174][175][176][177] .…”

The treatment of chyluria secondary to advanced carcinoma of the prostate

“…A high-resolution scintiscan camera produces an anatomical image of lymphatic transport, identifying abnormal nodes and delayed transport suggestive of lymphatic obstruction. 19 Lymphoscintigraphy has been used to demonstrate lymphaticourinary fistulae in previously reported cases of chyluria. Such fistulae are indicated by accumulation of the tracer in the renal collecting system.…”