Lymphoscintigraphic Evaluation of Systemic Tracer Uptake in Patients With Primary Lymphedema

Evaluation of Primary Lymphedema with Intranodal Lymphangiography

PURPOSE

There are limited existing data on the lymphatic anatomy of patients with primary lymphedema (LED), which is caused by aberrant development of lymphatic channels. In addition, there is a paucity of contemporary studies that use groin intranodal lymphangiography (IL) to evaluate LED anatomy. The purpose of this retrospective observational study was to better delineate the disease process and anatomy of primary LED using groin IL.

MATERIALS AND METHODS

We identified common groin IL findings in a cohort of 17 primary LED patients performed between 1/1/2017 and 1/31/2022 at a single institution. These patients were clinically determined to have primary lymphedema and demonstrated associated findings on lower extremity MR and lymphoscintigraphy.

RESULTS

Ten patients (59%) demonstrated irregular lymph node morphology or a paucity of lymph nodes on the more symptomatic laterality. Eight patients (47%) demonstrated lymphovenous shunting from pre-existing anastomoses between the lymphatic and venous systems. Eight patients (47%) demonstrated passage of contrast past midline to the contralateral lymphatics. Finally, 12 patients (71%) failed to opacify the cisterna chyli and thoracic duct on their initial lymphangiograms. Delayed computed tomography of 3 patients showed eventual central lymphatic opacification up to the renal veins, but none of these patients showed central lymphatic opacification to the thorax.

CONCLUSION

This descriptive, exploratory study demonstrates common central groin IL findings in primary LED to highlight patterns interventional radiologists should identify and report when addressing primary LED.

Magnetic resonance lymphangiography: with or without contrast?

Lymphedema is an important medical issue around the world, caused by an anomalous collection of fluid in soft tissue due to congenital malformations or stenosis or obstruction of lymphatic vessels. Magnetic resonance lymphangiography (MRL) is an emerging technique focused on noninvasive or minimally invasive imaging of lymphatics with the goal to diagnose and treat lymphedema. This review will briefly discuss lymphatic imaging starting with lymphography and radionuclide lymphoscintigraphy up to the newest methods, focusing on MRL, a rising technique, and highlighting the technical aspects fundamental for achieving high-resolution MRL.

Volumetric analysis of Non-contrast Magnetic Resonance Lymphangiography in patients affected by lower extremities primary lymphedema

AIM

Since the response to conservative and surgical treatments in lymphedema is based only on clinical evaluation, we want to propose a new technique for the volume calculation of lower extremities affected by lymphedema.

MATERIALS AND METHODS

Ten female patients affected by primary LE of the lower limbs (mean age 33 ± 5 years; age range 16-42) underwent NCMRL in September 2019. Acquisition protocol included a STIR sequence (FOV 460 × 504 mm; matrix 315 × 384 pixel; voxel size 1.1 × 1.1 × 1.0 mm; TR 3000 ms; TE 254 ms; TI 160 ms). Two readers independently performed a manual segmentation with ITK-SNAP open-source software to assess the volume of the lower limbs. The agreement for volumetric segmentation between the two operators was assessed through intraclass correlation coefficient (ICC).

RESULTS

Mean segmentation time was 5 ± 0.3 min. ICC demonstrated excellent intra-examiner agreements for both readers 1 (ICC = 0.9991, p < 0.0001) and 2 (ICC = 0.9989, p < 0.0001). Inter-reader agreement was excellent (ICC = 0.9991, p < 0.0001).

CONCLUSIONS

Manual segmentation with ITK-SNAP of NCMRL examinations in patients affected by primary lower limb LE represents a reproducible procedure for an objective evaluation of volumes, useful for follow-up.