RPS 1007 - Imaging of benign female pelvic disorders

Author Block: S. Viganò, S. Annibali, C. Cazzella, P. A. Bonaffini, P. Marra, S. Sironi; Bergamo/IT
Purpose: To assess the added diagnostic value of T2-weighted fat-saturated (T2-FS) MRI sequences for the detection of nerve involvement in lateral deep infiltrating endometriosis (DIE), in comparison to the standard MRI protocol.
Methods or Background: Patients who underwent a pelvic MRI for clinical and/ or ultrasound lateral DIE suspicion were retrospectively enrolled (February 2021- April 2023). Two radiologists, with 10 and 2 years of experience respectively, independently assessed the presence of lateral DIE and of nerve involvement, first evaluating the standard MRI protocol and then with the addition of T2-FS sequences. The findings of the senior reader were considered the reference standard. Interobserver agreement was assessed with Cohen’s kappa.
Results or Findings: Fifty-one patients (mean age 34 years) were included. The senior radiologist detected nerve involvement in 13/51 patients (25,5%) with the standard protocol, increasing to 17/51 patients (33,3%) at re-evaluation with the addition of T2-FS sequences. Nerve structures most frequently involved were the sacral plexus, particularly the pudendal nerve. Interobserver agreement increased from poor with the standard protocol to moderate with T2-FS sequences. The additional T2-FS sequences particularly enhanced the junior radiologist’s ability to identify indirect sign of nerve involvement, improving diagnostic confidence.
Conclusion: T2-FS MRI sequences may provide added value in the evaluation of nerve involvement in lateral DIE. Although radiological experience remains crucial, their inclusion in pelvic MRI protocols may support less experienced radiologists and should be considered when nerve involvement is suspected.
Limitations: The limited sample size. Lack of surgical correlation.
Funding for this study: None.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: Y. Qi, Y. Zhang, X. Gao, P. Zhang, Y. He, S. Wang, H. Xue, L. Zhu; Beijing/CN
Purpose: HWWS is a rare triad of didelphys uterus, oblique vaginal septum and ipsilateral renal agenesis. Accurate preoperative diagnosis and classification are crucial for surgical planning, This study aims to investigate the diagnostic value of high-resolution three-dimensional T2-weighted MRI in the preoperative evaluation and classification of HWWS.
Methods or Background: The study prospectively enrolled 70 patients clinically diagnosed with HWWS between 2020 and 2024. All patients underwent pelvic MRI examinations, including high-resolution 3D T2WI (1 mm slice thickness) and conventional T2 TSE sequences, supplemented by large-FOV T2 coronal imaging for urinary system evaluation and full-spine X-ray examinations for skeletal assessment. Two radiologists blinded to clinical data recorded uterine morphology, obstruction level and communications, and related complications. Consistency analysis was performed between imaging findings and surgical results in 52 surgical patients.
Results or Findings: The results showed the following uterine morphological classifications: didelphys uterus (54 cases, 77.1%), complete septate uterus (14 cases, 20%), and bicornuate uterus (2 cases, 2.9%). Among surgical patients, 31 cases had vaginal-level obstruction (18 Type I, 11 Type II, and 2 Type III), while 21 cases had cervical-level obstruction (19 Type IV and 2 special Type III+IV). 3D-T2 detected 7/11 vaginal-septum fistulas that TSE missed; both sequences showed 2 cervical communications. Associated anomalies including ipsilateral renal agenesis 69 (99%), ovarian endometriosis 16 (type IV predominance), hematosalpinx 16, scoliosis 26 (37%), mild scoliosis 29 (41%).
Conclusion: Sub-millimeter 3D-T2 MRI significantly outperforms TSE in identifying vaginal communications and precisely localizing HWWS obstruction, enabling confident surgical planning. Routine adoption of high-resolution 3D protocols plus renal/spinal imaging is recommended.
Limitations: Despite 3D MRI’s clear benefit for detecting cervix–septum fistulas, collapsed vaginal walls occasionally obscured the tract; with consent, we will trial gel distension to sharpen vaginal anatomy.
Funding for this study: National High Level Hospital Clinical Research Funding（2022-PUMCH-B-069）
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the PUMC Ethics Committee (No. K24C2950).

Author Block: P. Dhakar, A. Bose, V. Mishra, P. Sukhani, J. Chowdhary; Jaipur/IN
Purpose: Evaluate the efficacy of the ENZIAN score by comparing magnetic resonance imaging (MRI) results with intraoperative findings in cases of deep infiltrating endometriosis
Methods or Background: This retrospective study examined 50 patients with endometriomas and suspected deep infiltrating endometriosis of age ranging from 25 to 52 years (mean age 38.5 years), who underwent surgery between October 1, 2025 and September 31, 2024, at our institution (n = 50). The study compared preoperative MRI findings with intraoperative results using the #ENZIAN score and assessed the sensitivity , specificity , positive predictive value and negative predictive value of this approach.
Results or Findings: The diagnostic accuracy of MRI in detecting various endometriotic lesions by application of #ENZIAN Score was evaluated, with results confirmed through surgical findings. Sensitivity and negative predictive values of MRI confirmed by surgery were 98% and 92.6% (endometriomas), 95.2% and 91.7% (lesions in the vaginal/rectovaginal space), 78.4% and 56% (uterosacral ligaments), 91.4% and 89.7% (rectum/sigmoid colon), 57.1% and 94.1% (myometrium), 85.7% and 98.3% (bladder), and 73.3% and 92.2% (intestine), respectively
Conclusion: The #ENZIAN score serves as a detailed anatomical map that closely aligns with surgical findings, thereby facilitating more effective surgical planning. It demonstrates a strong correlation between MRI and intraoperative results, enhancing diagnostic efficacy, and serves as a valuable communication tool between radiologists and gynecologists.
Limitations: Despite its high sensitivity and NPV, MRI has limitations in detecting certain forms of DIE, particularly those involving the uterosacral ligaments and myometrium. Additionally, MRI’s ability to accurately assess the severity of lesions in each compartment may be influenced by the operator’s experience, the quality of the imaging, and the resolution of the MRI sequences used.
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: H. M. M. Smid, O. d. f. Henneman; Den Haag/NL
Purpose: Analysing clinical usefulness of preoperative #Enzian score as predictor for operative time planning in endometriosis surgery.
Methods or Background: Retrospective study in which 369 patients with deep infiltrating endometriosis had a procedural time planning in a multidisciplinary meeting. #Enzian score was used to assess endometriosis in abdominal compartments with preoperative transvaginal ultrasound (TVUS) and MRI. Procedural time was estimated (EPT) after discussing patient history, symptoms, physical examination and #Enzian-scored imaging.
Difference between EPT and actual operating time (AOT) was calculated. Accurate EPT was defined as AOT within 30 minutes of EPT. Sensitivity and specificity of dichotomised imaging #Enzian scores were calculated for individual compartments. Correlating and non-correlating MRI and surgical #Enzian scores were analysed per compartment, in relation to three outcomes: AOT >30 minutes shorter than EPT, accurate AOT (+/- <30 minutes of EPT) and AOT >30 minutes longer than EPT.
Results or Findings: Sensitivity and specificity of pre-operative imaging differs between compartments and is lower in most compartments compared to literature.
In total, 39.3% of operations were shorter than accurate EPT, 48.2% were within accurate EPT and 12.5% were longer than accurate EPT. There was no significant difference in AOT distribution in individual compartments comparing correlating and non-correlating #Enzian scores.
Conclusion: There is no correlation between mismatch in pre-/peroperative #Enzian scores in individual compartments and non-accurate EPT. As the EPT is set in a multidisciplinary meeting, personal experience of surgeon, patient history and physical examination play a large role in assessing EPT, next to the imaging results. The complexity of accurate EPT cannot only be defined in one (preoperative) classification.
Limitations: Retrospective study
Funding for this study: No funding for this study
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Local ethics committee

Author Block: A. Asokan¹, D. George², R. M. Kuruvilla², V. K. Jagan¹, A. Anbarasu¹, M. Farooque³, A. N. Parimalai⁴, A. Chellathurai⁴; ¹Coimbatore/IN, ²Abu dhabi/AE, ³Kochi/IN, ⁴Chennai/IN
Purpose: Cesarean scar pregnancies (CSPs) are a type of ectopic pregnancy that occur when an embryo implants within the fibrous scar tissue of a previous cesarean surgery. If not promptly detected and treated, CSPs can result in serious maternal complications, such as uterine rupture and hemorrhage.

TVUS (transvaginal ultrasonography) represents the imaging of choice for the diagnosis of CSPs; however, recent studies proposed a complementary role of MRI due to its capability in soft tissue characterization that may impact the therapeutical decision-making process.
Methods or Background: Structural assessment of the uterus employing ultrasound involves:
• Scan the entire uterus from left to right
• Scan the entire uterus from cervix to fundus
• 3D may help to recognize abnormal localisation
• If no intra-uterine pregnancy: use power doppler!
Further, we have included MRI in our study to see if it offers any additional role to 3D Ultrasound Imaging & advanced ultrasound imaging.
Results or Findings: CSP types:
Localisation according to two imaginary lines
1) uterine cavity line
2) serosal line

Type 1: Largest part towards the uterine cavity
Type 2: Largest part embedded in myometrium
& is not crossing serosal line
Type 3: Partly protruding outside the serosal line

Does CSP classification change treatment?

• CSP type 1: D&C or expectant & risk on PAS
• CSP that does not cross the serosal line lower risk on complications:
D&C under US guidence (±intrauterine folley/temporary cerclage):
low risk on complications
• CSP that crosses serosal line:
laparoscopic niche resection
Conclusion: Early diagnosis of CSP is extremely important since treatment options depend on the classifications of CSP and available expertise.
Limitations: Nil
Funding for this study: Nil
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: R. Praveenkumar, F. Abubacker Sulaiman, J. Lydia, D. Velan; Chennai/IN
Purpose: To compare the accuracy of transvaginal ultrasound (USG) and magnetic resonance imaging (MRI) in measuring lower uterine segment (LUS) scar thickness and detecting defective or thinned cesarean scars, and to assess their predictive value for uterine rupture or dehiscence in subsequent pregnancies.
Methods or Background: In this prospective study, 60 women with a history of one previous cesarean section and planned repeat delivery were enrolled. LUS scar thickness was measured using transvaginal USG and 1.5T MRI (T2-weighted sequences). Presence of scar defects such as niches or thinning was documented. Imaging findings were correlated with intraoperative observations at the time of repeat cesarean delivery. Statistical analysis included paired t-tests for scar thickness comparison and sensitivity/specificity calculation for defect detection.d
Results or Findings: Mean scar thickness measured by USG was 3.8 ± 1.1 mm, while MRI measured 4.1 ± 1.2 mm (p = 0.04). MRI detected scar defects in 22/60 patients, whereas USG detected defects in 14/60. MRI demonstrated higher sensitivity (88%) and specificity (92%) for detecting scar defects compared to USG (sensitivity 64%, specificity 85%). All cases of intraoperative dehiscence (n = 4) were correctly identified preoperatively by MRI, whereas USG identified 2/4.
Conclusion: MRI provides superior detection of defective or thinned cesarean scars and offers more reliable prediction of uterine dehiscence than USG. Transvaginal USG remains useful for routine scar thickness assessment, but MRI may be recommended for high-risk patients to guide clinical management.
Limitations: Single-center study with a small sample size; operator dependency of USG; MRI limited to 1.5T; findings may not generalize to women planning VBAC
Funding for this study: Not applicable
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Institutional Ethics Committee approval obtained; informed consent taken from all participants

Author Block: Y. LUO, M. Zhang, Z. Huang, X. Zhang; Guangzhou/CN
Purpose: To prospectively assess the efficacy, safety, and impact on ovarian reserve of ultrasound-guided lauromacrogol sclerotherapy (UGLS) for ovarian endometriomas (OE).
Methods or Background: This prospective study enrolled patients undergoing UGLS between April 2024 and April 2025. Preoperative assessment comprised cyst maximum diameter, cyst volume, serum cancer antigen 125 (CA-125), serum anti-Müllerian hormone (AMH), and visual analogue scale (VAS) pain scores. The UGLS procedure involved cyst aspiration, irrigation, and instillation of 1% lauromacrogol. Follow-up assessments at 1, 3, and 6 months evaluated cyst reduction rate, relevant biomarker levels, and pain scores.
Results or Findings: This study enrolled 78 patients (106 lesions) undergoing UGLS. The mean age of the participants was 30.17 ± 3.75 years. At baseline, the mean VAS scores were 4.66 ± 2.82 for dysmenorrhea and the mean volume was 105.06 ± 96.65 ml. After the operative, the technical success rate was 97.81%. Significant reductions in cyst volume was observed at 6 months (P<0.001), with volume reduction rates of 81.51 ± 15.65%(1 month), 90.63 ± 12.02%(3 months), and 93.21 ± 9.51% (6 months), and the mean cyst volume was 18.53 ± 74.24 ml at 6 months. CA-125 levels decreased postoperatively, while no significant change in AMH levels was observed (P＞0.05). The incidence of mild complications was 5.13%, which were relieved after observation.
Conclusion: UGLS is an effective, minimally invasive treatment for OE that successfully preserves ovarian reserve, and demonstrating promise for patients with diminished ovarian reserve.
Limitations: This article is a single arm, single center study
Funding for this study: supported by“the Third Affiliated Hospital of Sun Yat-sen University, Clinical Research Program (QHJH202303)
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: the Third Affiliated Hospital of Sun Yat-sen University (RG2024-021-01)

Author Block: Y. H. Song, A. Chua, S. Tan, D. Richmond, E. E. Alibrahim, J. Keene, C. Shadbolt, S-F. Oon; Melbourne/AU
Purpose: While placental MRI is well-established as a useful diagnostic tool for the evaluation of placenta accreta spectrum disorder (PASD), the optimal gestational age for assessment and diagnostic value of repeat MRI remains uncertain. The aim of this study was to retrospectively assess the utility of routine repeat placental MRIs performed at a tertiary Specialist Women's Imaging referral centre.  We evaluated inter-study concordance and diagnostic accuracy of MRI performed at 28- and 32-weeks gestation at diagnosing PASD, using placental pathology as the reference standard.
Methods or Background: We retrospectively reviewed all placental MRI studies performed from 2015-2025, identifying patients who underwent two placental MRIs for PASD assessment beyond 24-weeks gestation. Diagnostic accuracy was assessed by comparing dichotomised MRI findings with placental pathology at delivery. Sensitivity and specificity with 95% confidence intervals (CIs) were calculated for the initial and repeat studies. Inter-study concordance was assessed using Cohen’s kappa coefficient with 95% CIs for disease severity (normal, accreta/increta, or percreta) and diagnosis of PASD.
Results or Findings: Between 2015 and 2025, 61 women had two placental MRI studies beyond 24-weeks gestation for PASD assessment. For diagnosis of PASD, the initial scan (median gestation 29-weeks) demonstrated 97.4% sensitivity (95% CI 86.5–99.5) and 60.0% specificity (95% CI 31.3–83.2). The repeat scan (median gestation 31-weeks) demonstrated 100.0% sensitivity (95% CI 90.8–100.0) and 50.0% specificity (95% CI 23.7–76.7). Inter-study concordance was substantial for disease severity (κ = 0.72, 95% CI 0.58–0.87), PASD diagnosis (κ = 0.77, 95% CI 0.59–0.96), and placenta percreta diagnosis (κ = 0.77, 95% CI 0.63–0.95).
Conclusion: There is comparable accuracy and substantial concordance between initial and repeat placental MRI studies performed beyond 24-weeks gestation. This suggests limited diagnostic benefit in routinely repeating MRI for the diagnostic evaluation of PASD, but larger studies would be required to confirm this.
Limitations: The study results are limited by a small sample size but could contribute to future meta-analyses.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was approved by the Royal Women’s Hospital Ethics Committee (Reference QA/111988/RWHV-2024-455133).

Author Block: E. A. Kirillova, I. Mashchenko, P. Kozlova, N. Osipova, V. Markina, I. Zazerskaya, G. Trufanov; St. Petersburg/RU
Purpose: Hypertensive disorders of pregnancy (HDPs) are major causes of maternal morbidity worldwide. A hallmark of these conditions is impaired placental perfusion. Intravoxel incoherent motion (IVIM) MRI enables non-invasive quantification of placental microcirculation and may serve as a useful biomarker of placental disorders in this cohort. The study aimed at comparing IVIM parameters in whole placenta and maternal/foetal compartments in patients with or without HPDs.
Methods or Background: 16 women aged 26-43 years underwent placental IVIM-MRI, including ten patients in the HDP group and six patients in the control group. Mean gestational age at the time of 3T-MRI was 31.6 weeks (95% CI: 29.4–33.8) in the HDP group and 30.5 weeks (95% CI: 27.6–33.3) in the control group. A multi-b-value DWI protocol (0–800 s/mm²) was applied. Group differences and subgroup trends were analysed descriptively. Subgroups included patients with severe preeclampsia (PE) ± chronic hypertension (CH), moderate PE ± CH, and isolated CH.
Results or Findings: Whole-placenta perfusion fraction (f) value reflecting villous vascularity was reduced in patients with HDPs (19.2%, 95% CI 15.2–23.1) vs controls (24.8%, 95% CI 16.0–33.7). Maternal f (18.6% vs 24.0%) and foetal f (19.2% vs 25.8%) values showed similar decreases. The diffusion coefficient (D and D*) parameters indicating water diffusion in the tissue and the microvascular flow, respectively, also tended to be lower in the HDP group. The subgroup analysis revealed the most pronounced reductions of all IVIM parameters in severe PE ± CH vs controls.
Conclusion: IVIM parameters of the placenta showed consistent reductions in patients with HDPs compared to the control group, reflecting impaired placental microperfusion in this cohort.
Limitations: The limitation of the study was a small sample size.
Funding for this study: No funding was received for this study
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: All participants were informed about scientific purposes of this study and gave their informed consents.

Author Block: R. V. Ninkova, F. Curti, S. Riccardi, C. Cutonilli, M. Gennarini, F. Frezza, C. Amoroso, C. Catalano, L. Manganaro; Rome/IT
Purpose: To evaluate the role of magnetic resonance imaging (MRI) in guiding treatment choice between medical and surgical management in patients with bowel endometriosis, based on detailed analysis of lesion morphology and anatomical involvement.
Methods or Background: A retrospective study was conducted on 215 patients with bowel endometriosis who underwent MRI between 2017 and March 2024, with at least one year of follow-up. Among them, 135 received surgical treatment (alone or combined with medical therapy), while 80 underwent exclusive medical treatment.
MRI evaluation focused on lesion location (low, mid, or upper rectum; rectosigmoid junction; extrapelvic sites), number of nodules, longitudinal extension, thickness, and circumferential involvement. Clinical symptoms were recorded using the NRS scale, comparing pre- and post-treatment scores. The occurrence of bowel obstruction and post-surgical complications were also documented.
Results or Findings: The upper rectum was the most frequently affected site (33%), followed by the rectosigmoid junction (22%) and mid-rectum (20%). Bowel obstruction occurred in 5.1% of cases, exclusively in lesions ≥10 cm from the anal verge with ≥4/8 circumferential involvement. Surgical treatment achieved a significantly greater reduction in symptom severity in patients with lesions >14 mm and ≥4/8 circumferential extension (mean NRS reduction = 4.3 ± 1.2 vs. 2.1 ± 1.0; p < 0.001). In smaller or less extensive lesions, outcomes were comparable between medical and surgical therapy.Postoperative complications occurred in 65.2% of surgical cases, most commonly bladder incontinence (26.7%).
Conclusion: MRI proved essential for precise lesion characterization and for guiding personalized therapeutic decision-making based on features associated with symptom severity.
Limitations: This study is limited by its retrospective, single-center design and the absence of randomization, which may introduce selection bias. The follow-up duration and subjective assessment of symptoms using the NRS scale could also affect result consistency.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was performed according to the principles of the Declaration of Helsinki

Author Block: M. Bouhlali, P. Verpillat; Lille/FR
Purpose: To understand the clinico-biological principles of post-abortion follow-up.
To recognize simple trophoblastic retention on imaging.
To detail the main differential diagnoses of trophoblastic retention.
To differentiate trophoblastic retention from acquired arteriovenous fistula.
Methods or Background: Pelvic ultrasound and/or MRI evaluation was performed at Lille University Hospital, in patients after induced abortion, in cases of metrorrhagia or abnormal decline of β-hCG levels.
Results or Findings: Trophoblastic retention should be suspected in cases of metrorrhagia or plateauing β-hCG levels persisting more than 3 weeks after abortion.
An empty uterine cavity with a thin endometrium and negative β-hCG excludes trophoblastic retention.
Trophoblastic retention appears as heterogeneous echogenic intrauterine material, respecting the endometrium–myometrium interface, with vascularization on color Doppler, peak systolic velocities generally not exceeding 40 cm/s.

Major role of color Doppler ultrasound in differential diagnoses:
Intrauterine clot: strictly intracavitary echogenic mass, avascular on color Doppler, with negative β-hCG.
Arteriovenous fistula: endo-myometrial lesion with marked hypervascularization on color Doppler, peak velocities exceeding 1 m/s.
Ectopic pregnancy : empty uterine cavity, thickened gravid endometrium, β-hCG > 1500, with or without direct visualization of an extrauterine gestational sac

MRI may reveal signs of an arteriovenous fistula on dynamic contrast-enhanced sequences, such as early venous return in the gonadal vein and helps differentiate it from a refluxing gonadal vein
Molar pregnancy or gestational trophoblastic tumor (GTT) should be suspected based on clinico-biological criteria (very high β-hCG levels) and imaging features.
Conclusion: Preserved endometrium–myometrium interface with PSV < 40 cm/s → trophoblastic retention.
Myometrial invasion with PSV > 1 m/s → acquired AVF/AVM, with early venous return on dynamic MRI.
Empty uterine cavity + β-hCG > 1500 → ectopic pregnancy until proven otherwise.
Very high β-hCG → molar pregnancy or GTT until proven otherwise.
Limitations: Comorbidity
Funding for this study: Lille university Hospital
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: A-K. Kaufmann-Bühler¹, M. Kopetzky¹, M. Puseljic¹, I. Vlasicek¹, B. Catalano², M. Fuchsjäger¹, M. Wölfler¹, W. Schöll¹, E. Talakic¹; ¹Graz/AT, ²Rome/IT
Purpose: To investigate whether the distribution of pelvic fat compartments, such as subcutaneous fat (SCF), intramuscular fat (IMF), and pelvic visceral fat (PVF), is associated with the severity of deep endometriosis (DE), based on pelvic MRI volumetry.
Methods or Background: In this retrospective single-center study, 71 women (mean age 33.4 ± 6.5 years) with surgically and/or histologically confirmed DE underwent standardized pelvic MRI between 2021-2023. Volumes of SCF, IMF, PVF, and gluteus maximus muscle (MV), were segmented semi-automatically using 3D Slicer software. Disease severity was classified according to the #Enzian system. Spearman’s correlation and non-parametric group comparisons were used to assess associations between body composition and disease severity. Multivariate linear regression models served to identify independent predictors of disease severity.
Results or Findings: PV correlated negatively with severity in compartment B (uterosacral ligaments/pelvic wall; r = −0.28, p = 0.008). IMF correlated positively with extragenital disease (compartment F; r = 0.26, p = 0.015) and with the overall #Enzian score (r = 0.21, p = 0.047. No significant associations were found for SCF or MV. Linear regression models identified IMF(β = 4.87, p = 0.023) and IMF/MV ratio (β = 31.6, p = 0.023) as independent predictors of #Enzian score, with a stronger normalized effect of IMF relative to MV.
Conclusion: Correlating with compartment-specific and overall disease severity, MRI-based pelvic fat and muscle volumes may serve as a novel non-invasive biomarker of disease burden in DE. These findings support the hypothesis that pelvic fat distribution reflects underlying pathophysiological mechanisms and could support non-invasive staging strategies. Prospective validation and integration with hormonal and clinical markers are warranted.
Limitations: Limitations of this study include its retrospective and cross-sectional design, precluding causal inference.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethics Committee of the Medical University of Graz (Reference number: EK 429 Ex: 22/23).

Author Block: L. Knorren¹, J. D. J. Slotman¹, I. M. Nijholt¹, J. Schutte¹, J. Huirne², C. M. Tax³, L. W. Bartels³, M. F. Boomsma¹; ¹Zwolle/NL, ²Amsterdam/NL, ³Utrecht/NL
Purpose: Reliable intraprocedural assessment of treatment efficacy during magnetic resonance–guided focused ultrasound (MRgFUS) for uterine fibroids may optimize outcomes and reduce procedure time. The non-perfused volume ratio (NPVr) is conventionally calculated post-treatment using contrast-enhanced T1-weighted imaging (CET1w). However, contrast administration precludes further ablation. In this explorative pilot study, the potential of intravoxel incoherent motion (IVIM)-derived perfusion fraction (f)- and apparent diffusion coefficient (D)-maps for real-time MRgFUS treatment monitoring was evaluated.
Methods or Background: Women undergoing MRgFUS treatment between September 2024 and July 2025 at our institution were consecutively enrolled. DWI was obtained at baseline, at 45-minute intervals during ablation and after final sonication. CET1w was subsequently performed and used to calculate NPVr from manual 3D segmentations of the total fibroid volume and non-perfused volume. IVIM-maps were generated post-procedurally using non-linear least-squares fitting. Explorative visual analysis was performed by two experienced researchers, with CET1w as reference for the final IVIM-maps.
Results or Findings: Fourteen women were included with a median of five DWI-scans per patient (range 3-6). Mean NPVr was 43,7±25,9% (range: 4,4-97,6%). In thirteen cases, progressive hypointense regions on f-maps and hyperintense regions on D-maps were observed intraprocedurally. In one patient, a global hypointense pattern on the f-map appeared 45 minutes after the start of treatment and persisted, corresponding to complete ablation (NPVr 97,6%). Absent or minimal changes on IVIM were associated with low NPVr (<10%, n=2). In eleven cases partial changes of the fibroid on IVIM-maps were observed, visually corresponding with intermediate ablation outcomes on CET1w (NPVr 12,3–66,7%).
Conclusion: Intraprocedural visual changes of fibroid tissue on f- and D-maps shows potential as a tool for visualizing intraprocedural progression of MRgFUS treatment. Clinical applicability will be evaluated in a future study.
Limitations: Small sample size
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: (MEC number: 200723, protocol ID: NL74716.075.20)