3D power Doppler in uterine fibroids; influence of gain, cardiac cycle and off-line measurement techniques

Figures & data

Table 1. Baseline patient and fibroid characteristics.

Patient and fibroid characteristics	N = 40
Age
Mean (SD)	41.53 (7.06)
Range	30–52 year
Parity
0	28.6%
≥1	71.4%
Ethnicity
North European	39.4%
Other	60.6%
Symptoms
Heavy menstrual bleeding	32.2%
Pain/Bulk symptoms	35.7%
Combination of symptoms	10.7%
Non-fibroid related symptoms	21.4%
Number of fibroids
1	64.3%
>1	35.7%
Fibroid size (diameter in cm)
Mean (SD)	4.33 cm (1.93)
Range	1.5–8.8 cm
Fibroid location
Submucosal (FIGO^a 0–2)	3.6%
Intramural (FIGO 3–5)	60.7%
Subserosal (FIGO 6–7)	35.7%

^a Fibroid classification according to the FIGO (PALM-COIN) classification.

Table 2. Effect of the cardiac cycle and different gain settings on Vascular Index (VI) measured with 3D power Doppler ultrasound in patients with fibroids (N = 40).

	Mean VI	Mean difference	95% CI	p value*
Sweep 1 vs sweep 2^a	0.97/0.93	0.04	−0.32 to 0.40	.82
Gain 50 dB vs chosen gain^b	0.88/1.19	−0.31	−0.73 to 0.12	.15
Gain 50 dB vs gain 65 dB	0.98/1.82	0.84	0.29 to 0.94	<.01

* p value of <.05 was considered statistically significant, fibroid volumes were not normally distributed therefore values were log transformed.

^a Two consecutive 3D PD sweeps were performed and considered representative to investigate the influence of the cardiac cycle. Patients had at least four cardiac cycles during 3D PD sweep recording.

^b The chosen gain was an individualised gain obtained by increasing the gain until noise artefacts were visible followed by reducing the gain until artefacts just disappeared.

Figure 1. Vascular Index (VI)* in fibroids calculated from two consecutive 3D power Doppler sweeps in the same patient #. *VI was measured using VOCAL software (manual contour mode, histogram function). #Little difference can be observed between two consecutive measurements. Only in a few individuals, all with a high VI, large differences can be observed.

Figure 2. 3D power Doppler image: well vascularised fibroid, moderate peripheral penetration.

Figure 3. 3D power Doppler image in VOCAL: oval fibroid with vascular capsule, good peripheral penetration.

Table 3. Observer preference^a for type of volume measurement in fibroids using 3D power Doppler ultrasound and VOCAL software.

	Manual^b	Automatic^c	No preference
Fibroids 0–3cm	5	0	6
Fibroids 3–6cm	15	0	8
Fibroids >6cm	6	0	0
Total fibroids N = 40	26	0	14

^a Observer preference was noted based on several items expecting volume contour to exactly match fibroid’s contour.

^b For the manual contour mode, the poles were placed at the boundaries of the fibroid and the circumference of the fibroid had to be drawn manually in six planes (rotation steps of 30 degrees).

^c For the automatic contour mode, the poles were placed at the boundaries of the fibroid and a sphere contour was chosen which automatically generated a volume.

Table 4. Shell size preference^a in measuring vascular indices using 3D power Doppler ultrasound and VOCAL software for the capsule of the fibroid^b.

	Shell 0.5cm	Shell 1cm	No preference
Fibroids 0–3cm	11	0	0
Fibroids 3–6cm	19	1	3
Fibroids >6cm	3	1	2
Total fibroids N = 40	33	2	5

^a Observer preference was noted based on several items expecting the optimal shell contour to contain the vascular capsule only (and should not contain vessels outside the capsule or miss part of the vascular capsule).

^b After fibroid volume measurement, a symmetrical shell contour was chosen of 0.5 or 1 cm.