Diffusion-weighted imaging of solid or predominantly solid gynaecological adnexial masses: is it useful in the differential diagnosis?

Abstract

Objectives: This study investigated whether diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values provide specific information that allows the diagnosis of solid or predominantly solid gynaecological adnexial lesions, especially whether they can discriminate benign and malignant lesions.

Methods: DWI was performed in 37 patients with histologically proven solid or predominantly solid adnexial lesions (22 malignant and 15 benign neoplasms). The lesions in our data set were divided into two groups, all adnexial lesions or lesions of ovarian origin, for evaluation. The areas of the highest signal intensity on DWI (b = 800 s mm(-2)) and the lowest ADC values within the lesions were evaluated.

Results: On DWI, high signal intensity was observed more often in malignant than in benign lesions (p<0.0001). There was no significant difference between the ADC values of the malignant and benign lesions in either the adnexial (0.88±0.16 vs 0.84±0.42; p = 0.96) or the ovarian (0.85±0.14 vs 1.05±0.2; p = 0.133) lesions. When signal intensities on DWI were compared, however, malignant lesions had higher values than the benign lesions in both the adnexial (0.69±0.21 vs 0.29±0.13; p<0.0001) and the ovarian lesions (0.75±0.14 vs 0.37±0.24; p = 0.003).

Conclusion: On DWI, high signal intensity was observed more frequently with the malignant lesions.

Figure 1

Dysgerminoma in a 17-year-old girl. (a) On T₂ weighted axial MRI, a homogeneous mild hyperintense solid lesion is seen in the right adnex (arrows). (b) A sagittal T₂ weighted image shows the tumour (arrows). (c) T₁ weighted fat-saturated post-contrast axial MRI shows homogeneous enhancement of the lesion. (d) A diffusion-weighted (b = 800 s mm⁻²) axial MRI demonstrates that the lesion has high signal intensity. (e) On the apparent diffusion coefficient (ADC) map, the ADC value within the mass is 0.71 × 10⁻³ mm² s⁻¹.

Figure 2

Bilateral serous adenocarcinoma in a 65-year-old woman. (a) On T₂ weighted axial MRI, two solid masses with heterogeneous signal intensity are seen in bilateral lower abdominal quadrants (arrows). (b) A T₁ weighted fat-saturated post-contrast axial MRI shows homogeneous enhancement of the lesions. (c) A diffusion-weighted (b = 800 s mm⁻²) axial MRI demonstrates the high signal intensity of the lesions. (d) On the apparent diffusion coefficient (ADC) map, the ADC value within the large mass is 0.70 × 10⁻³ mm² s⁻¹.

Figure 3

Granulosa cell tumour in a 20-year-old woman. (a) A T₂ weighted axial MRI shows a mass with a predominantly solid appearance in the right adnex (thick arrows), which extends behind the uterus (thin arrows). The tumour has a cystic component (arrowhead). There is also a cystic lesion in the left adnex (open arrow). (b) A T₁ weighted fat-saturated post-contrast axial MRI shows prominent enhancement of the solid components of the lesion. (c) A diffusion-weighted (b = 800 s mm⁻²) axial MRI demonstrates the high signal intensity of the lesion. (d) On the apparent diffusion coefficient (ADC) map, the ADC value within the mass is 0.88 × 10⁻³ mm² s⁻¹.

Figure 4

Serous adenocarcinoma of the fallopian tube in a 58-year-old woman. (a) The T₂ weighted axial MRI shows a hypointense solid mass in the right adnex (thick arrows), which extends behind the uterus (thin arrows). (b) A sagittal T₂ weighted image shows the tumour (thick arrows). Thin arrows show the uterus. (c) A diffusion-weighted (b = 800 s mm⁻²) axial MRI demonstrates the predominantly high signal intensity of the lesion (thick arrows). Thin arrows show the uterus. (d) On the apparent diffusion coefficient (ADC) map, the ADC value within the mass (thick arrows) is 1.20 × 10⁻³ mm² s⁻¹. Thin arrows show the uterus.

Figure 5

Leiomyosarcoma in a 47-year-old woman. (a) T₂ weighted axial MRI shows a hypointense solid mass in the middle of the lower abdomen (arrows). (b) A T₁ weighted fat-saturated post-contrast axial MRI shows prominent enhancement of the lesion. (c) A diffusion-weighted (b = 800 s mm⁻²) axial MRI demonstrates the high signal intensity of the lesion. (d) On the apparent diffusion coefficient (ADC) map, the ADC value within the mass is 0.82 × 10⁻³ mm² s⁻¹.

Figure 6

Fibrothecoma in a 56-year-old woman. (a) On T₂ weighted axial MRI, a heterogeneous hypointense solid lesion is seen in the right adnex (thick arrows). Thin arrows show the uterus. (b) A T₁ weighted fat-saturated post-contrast axial MRI shows no enhancement of the lesion (arrows). (c) On a diffusion-weighted (b = 800 s mm⁻²) axial MRI, the lesion is hypointense (thick arrows). Thin arrows show the uterus. (d) On the apparent diffusion coefficient (ADC) map, the ADC value within the mass (thick arrows) is 0.75 × 10⁻³ mm² s⁻¹. Thin arrows show the uterus.

Figure 7

Ordinary leiomyoma in a 37-year-old woman. (a) On T₂ weighted axial MRI, a homogeneous hypointense solid lesion (thick arrows) is seen in the left adnex near the uterus (thin arrows). There is also a small leiomyoma in the fundus of the uterus (arrowhead). (b) On the diffusion weighted (b = 800 s mm⁻²) axial MRI, the lesion is hypointense (thick arrows). Thin arrows show the uterus. (c) On the apparent diffusion coefficient (ADC) map, the ADC value within the mass is 0.42 × 10⁻³ mm² s⁻¹.

Figure 8

Degenerated leiomyoma in a 42-year-old woman. (a) On T₂ weighted axial MRI, a heterogeneous hypointense solid lesion (thick arrows) is seen in the left adnex near the uterus (thin arrows). (b) On the diffusion-weighted (b = 800 s mm⁻²) axial MRI, the lesion is hypointense. (c) On the apparent diffusion coefficient (ADC) map, the ADC value within the mass is 1.30 × 10⁻³ mm² s⁻¹.