Figure 1. Quantification of the Lymphatic Flow Index from the cardiac grafts to the mediastinal lymph nodes.

SPECT/CT images were taken after injection of nanocoll into the apex of transplanted hearts. Representative images are shown (n = 4-5 per group) in four planes the anterior-posterior view, sagittal, coronal and transverse taken at the same point of the “crosshairs” (white). One (a-b), five (c-d) or ten (e-f) weeks after either gender-matched (a, c & e) or HY-mismatched (b, d & f) abdominal heart transplantation, the animal was scanned 30 min and four hours after nanocoll injection. Images are shown at four-hours post-injection. Representative examples of direct visualisation of lymph drainage from donor heart grafts after transplantation using Evan's Blue injection (n=3 in each group). Recipient of HY-mismatched donor graft showing mdLN, above the native heart (white arrows), staining blue with Evan's Blue dye (g & h, yellow arrows). Recipient of gender-matched donor graft showing mediastinal not staining blue (i). A sphere is drawn around each “region of interest” (j; blue & red sphere) and the radioactivity quantified in the mdLN (j; Yellow arrow; Rad_LN) and the transplanted donor cardiac graft (j; Red arrow; Rad_graft). Decay corrected values are used to quantify the lymphatic flow index with T1 being the time of the first scan and T2 being the time of the second scan (k). Shown here is the mean ± SEM, of four to five animals at each time point, of the lymphatic flow index (l) or the percentage loss of injected radiation from the graft (m); with gender-matched and HY-mismatched grafts at weeks, one, five and ten (W1**p = 0.0080, W5*p = 0.0286 & W10*p = 0.0156).