Magnetic resonance imaging features influencing high-intensity focused ultrasound ablation of adenomyosis with a nonperfused volume ratio of ≥90% as a measure of clinical treatment success: retrospective multivariate analysis

Figures & data

Table 1. Comparison of the baseline characteristics in patient groups with NPVr ≥90% and NPVr <90%.

Characteristics	All patients (n = 66)	NPVr <90% (n = 40)	NPVr ≥90% (n = 26)	p value
Subcutaneous fat thickness (mm)	12.1 ± 4.1 (3.0.0–20)	12.4 ± 4.8 (3.0–20.0)	11.5 ± 2.9 (5.0–17.0)	.377
Distance^a (mm)	94.2 ± 13.6 (40.0–118.0)	92.6 ± 16.0 (40.0–118.0)	96.7 ± 8.5 (80.0–117.0)	.239
Adenomyosis volume (ml)	116.27 ± 60.98 (17.0–246.0)	97.97 ± 54.04 (17.0–240.0)	144.42 ± 61.26 (42.0–246.0)	.002*
Adenomyosis Location				.802
Anterior	10	7	3
Posterior	32	19	13
Anterior-Posterior	24	14	10
Adenomyosis Types				.799
Focal	42	26	16
Diffuse	24	14	10
Uterus position				.202
Anteverted	38	26	12
Retroverted	28	14	14

^aDistance from the posterior surface of the adenomyosis lesion to the skin. NPVr Nonperfused volume ratio.

*Statistically significant (one-way analysis of variance [ANOVA]).

Table 2. Independent factors associated with an NPVr ≥90%: Multivariate analysis.

Variable	Estimate	95% CI	p value	Tolerance	VIF
MRI features
Baseline characteristics features
Uterus position	1.028	–0.275 to 2.331	.122	0.820	1.220
Adenomyosis location	–0.088	–1.674 to 1.498	.914	0.194	5.168
Adenomyosis types	0.235	0.077 to 20.695	.869	0.181	5.510
Adenomyosis volume	–0.018	–0.028 to –0.008	.001*	0.871	1.149
Subcutaneous fat thickness	0.181	0.042 to 0.320	.011*	0.821	1.218
Distance^a	–0.033	–0.080 to 0.015	.177	0.723	1.383
T2 features
Foci^b	–0.029	–0.123 to 0.065	.546	0.968	1.033
SI of adenomyosis	–0.006	–0.018 to 0.007	.383	0.971	1.030
SI ratio of adenomyosis to myometrium	2.451	1.241 to 3.662	.001*	0.995	1.005
Quantitative T1-perfusion features
K^trans of adenomyosis	0.003	–0.016 to 0.022	.756	0.281	3.561
Kep of adenomyosis	0.023	–0.151 to 0.197	.798	0.115	8.701
Ve of adenomyosis	–0.164	–0.407 to 0.078	.184	0.845	1.184
Vp of adenomyosis	–0.078	–0.736 to 0.580	.817	0.356	2.810
K^trans ratio of adenomyosis to myometrium	3.398	1.426 to 5.369	.001*	0.738	1.355
Kep ratio of adenomyosis to myometrium	2.328	–4.666 to 9.323	.514	0.173	5.785
Ve ratio of adenomyosis to myometrium	NA	NA	NA	0.061	16.327
Vp ratio of adenomyosis to myometrium	–0.985	–4.405 to 2.434	.572	0.428	2.337

^aDistance from the posterior surface of the adenomyosis lesion to the skin.

^bNumber of foci inside the adenomyosis.

NPVr: nonperfused volume ratio; SI: signal intensity; CI: confidence interval; Ktrans: volume transfer constant; Kep: reverse reflux rate constant; Ve: volume fraction of extravascular extracellular space; Vp: volume fraction of plasma; VIF: variance inflation factor.

*Statistically significant (multivariate logistic regression).

Figure 1. A 39-year-old woman with a 138 ml adenomyosis was treated with magnetic resonance imaging (MRI)-guided high-intensity focussed ultrasound (HIFU) ablation. (A) A sagittal T2-weighted (T2W) MR image of the adenomyosis prior to HIFU treatment. (B) A quantitative perfusion MR image was analyzed by drawing a region of interest (ROI) within the area of the adenomyosis lesion and the myometrium on one of the perfusion MR images. (C) The generated K^trans map. (D) A contrast-enhanced T1-weighted (CE-T1W) MR image obtained immediately after MRI-guided HIFU treatment.

Figure 2. A 38-year-old woman with a 116 ml adenomyosis was treated with magnetic resonance imaging (MRI)-guided high-intensity focussed ultrasound (HIFU) ablation. (A) A sagittal T2-weighted (T2W) MR image of the adenomyosis prior to HIFU treatment. (B) A quantitative perfusion MR image was analyzed by drawing a region of interest (ROI) within the area of the adenomyosis lesion and the myometrium on one of the perfusion MR images. (C) The generated K^trans map (lower left, left section). (D) A contrast-enhanced T1-weighted (CE-T1W) MR image obtained immediately after MRI-guided HIFU treatment.

Figure 3. The receiver operating characteristic (ROC) curves of the prediction model in predicting the treatment outcome of high-intensity focussed ultrasound (HIFU) ablation with an immediate nonperfused volume ratio (NPVr) ≥ 90%. Sensitivity, specificity and area under the curve were 0.885, 0.8 and 0.889, respectively.

Table 3. Complications and adverse events (AEs) after HIFU ablation in patient groups with NPVr ≥90% and NPVr <90%.

SIR class	Description	Complications and AEs	Total	NPVr <90%	NPVr ≥90%	p value
A	No therapy, no consequences	Skin burn grade 1	6	4 (10%)	2 (7.6%)	1
		Buttock pain	4	3 (7.5%)	1 (3.8%)	1
		Back pain	3	2 (5%)	1 (3.8%)	1
		Nausea	4	2 (5%)	2 (7.6%)	.644
		Vaginal discharge	14	7 (17.5%)	7 (26.9%)	.375
		Pelvic pain	6	4 (10%)	2 (7.6%)	1
		Leg pain	3	2 (5%)	1 (3.8%)	1
		Numbness	1	1 (2.5%)	0 (0%)	1
B	Nominal therapy, observation, no consequences	Cystitis	1	1 (2.5%)	0 (0%)	1
C	Required therapy, minor hospitalization (<48 h)		0	0	0	NA
D	Major therapy, unplanned increase in level of care, prolonged hospitalization (≥48 h)		0	0	0	NA
E	Permanent adverse sequelae		0	0	0	NA
F	Death		0	0	0	NA

NA: not available. HIFU: high-intensity focussed ultrasound; NPVr: nonperfused volume ratio; SIR: Society of Interventional Radiology.

Figure 4. The box plot presents the serum anti-Mullerian hormone (AMH) concentrations before and 6 months after magnetic resonance imaging (MRI)-guided high-intensity focused ultrasound (HIFU) treatment in patients with a nonperfused volume ratio (NPVr) of ≥90% and <90%. Data are presented as box-and-whisker plots.

Figure 5. The box plot presents the serum anti-Mullerian hormone (AMH) concentrations before and 6 months after magnetic resonance imaging (MRI)-guided high-intensity focused ultrasound (HIFU) treatment in patients with a nonperfused volume ratio (NPVr) of <50%, ≥50% and <70%, ≥70% and <90% and ≥90%. Data are presented as box-and-whisker plots.

Figure 6. The box plot demonstrates the 6-month fibroid volume reduction ratios and transformed symptom severe score (tSSS) improvement ratios among different groups as a function of a nonperfused volume ratio (NPVr) of ≥90% and <90%. p < .001 is regarded as highly statistically significant.

Figure 7. The scatter plot demonstrates tSSS improvement ratios and adenomyosis volume reduction ratios at 6 months for each patient among different groups and subgroups as a nonperfused volume ratio (NPVr) of <50%, ≥50% and <70%, ≥70% and <90% and ≥90%.

Table 4. Adenomyosis volume and symptom changes in patient groups with NPVr ≥90% and NPVr <90%.

Treatment outcome	All patients (n = 66)	NPVr <90% (n = 40)	NPVr ≥90% (n = 26)	p value
Adenomyosis volume
Baseline				.002*
Mean ± SD	116.27 ± 60.98	97.97 ± 54.04	144.42 ± 61.26
Range	17.0–246.0	17.0–240.0	42.0–246.0
6 months				.224
Mean ± SD	86.79 ± 45.41	81.29 ± 47.77	95.26 ± 40.95
Range	16.0–222.0	16.0–222.0	24.0–168.0
Reduction ratio				.0001*
Mean ± SD	0.23 ± 0.12	0.17 ± 0.09	0.34 ± 0.07
Range	0.0–0.53	0.0–0.35	0.17–0.53
Transformed symptom severity score
Baseline				.976
Mean ± SD	68.23 ± 17.27	68.28 ± 18.29	68.14 ± 15.93
Range	28.1–100.0	28.1–100.0	43.7–90.6
6 months				.0001*
Mean ± SD	29.73 ± 22.99	41.88 ± 21.60	11.06 ± 6.92
Range	0.0–75.0	6.3–75.0	0.0–25.0
Improvement ratio				.0001*
Mean ± SD	0.56 ± 0.33	0.38 ± 0.30	0.84 ± 0.10
Range	0.0–1.0	0.0–0.83	0.59–1.0

SD: standard deviation; NPVr: nonperfused volume ratio.

*Statistically significant (one-way analysis of variance [ANOVA]).

Availability of data and materials

The datasets used and/or analyzed during the current study are not publicly available due the terms of consent to which the participants agreed but are available from the corresponding author on reasonable request.