Endometriosis: clinical features, MR imaging findings and pathologic correlation

Insights into Imaging

Table 2 MRI protocol. Synoptic table summarizes the imaging parameters of MR sequences. Axial T2-weighted SSFSE sequence is used as second localiser to identify the longitudinal axis of the uterus. Sagittal T2-weighted FRFSE sequence is oriented parallel to the longitudinal axis of the uterus identified on the previous axial T2-weighted SSFSE sequence. Oblique coronal and oblique axial T2-weighted FRFSE sequences are oriented respectively parallel or perpendicular to the longitudinal axis of the uterus

MRI protocol	Axial T2 W SSFSE	Sagittal T2 W FRFSE	Oblique coronal/axial T2 W FRFSE	Axial T2*	Axial DWI SE EPI	Sagittal, oblique coronal/axial T1 W 3D GRE LAVA
Repetition time/Echo time (ms)	765/59	4675/100	4675/100	650/11.8	3000/74.1	4.4/2.1
Flip angle	90°	90°	90°	20°	90°	12°
Section thickness (mm)	6	4	4	5	5	3.4
Interslice gap (mm)	0.6	0.4	0.4	0	1	−1.7
Bandwidht (kHz)	31.25	41.67	41.67	8.33	250	62.5
Field of view (cm)	38	32	32	25	46	40
Matrix	320 × 288	320 × 224	320 × 224	256 × 256	160 × 160	320 × 192
N. of averages	0.54	4	4	1	16	0.75
N. of images	30	26	26	30	28	104
Frequency direction	Right to left	Anterior to posterior	Right to left	Anterior to posterior	Anterior to posterior	Superior to inferior
Acquisition time	24 s	3 min 49 s	3 min 49 s	1 min 28 s	3 min 18 s	22 s
b-value (s/mm²)	–	–	–	–	0–800	–

Sagittal, oblique coronal and oblique axial T1-weighted 3D gradient-echo liver acquisition with volume acceleration (LAVA) sequences with fat suppression are acquired before and after intravenous administration of paramagnetic contrast agent (0.1 mmol/kg at a flow rate of 2 mL/s, followed by 20 mL of saline solution at the same flow rate); in particular, the sagittal sequence is acquired at 60 and 120 s after contrast administration. About 10 min after contrast administration, T1-weighted 3D gradient-echo LAVA sequences are acquired in the sagittal, coronal and axial planes, to obtain an urographic phase
T2-weighted FRFSE, T2* and DW sequences are acquired with patient breathing freely, T1-weighted 3D gradient-echo LAVA sequences are acquired in breath hold. T2* and DW sequences are not routinely performed and represents optional sequences
T2 W T2-weighted, T1 W T1-weighted, SSFSE single-shot fast spin-echo, FRFSE fast relaxation fast spin-echo, DWI diffusion-weighted imaging, SE spin-echo, EPI echoplanar imaging, GRE gradient-echo, LAVA liver acquisition with volume acceleration