2. Index tests ‐ description and common abbreviations.

Test name as presented in the review	Description	Alternative names presented in the included studies
MRI tests
MRI (magnetic resonance imaging)	Equipment: 1.5 Tesla magnet device with a parallel or phased array body or pelvic coil for signal excitation and reception Participants’ preparation: Fasting for 3‐6 hours before the test and/or bowel preparation with oral laxatives was described by some investigators; an intravenous injection of anti‐peristaltic agent at the outset of the examination to decrease bowel peristalsis; supine position. Some groups performed MRI with full bladder to correct the angle of the ante‐flexed uterus; some groups described introducing of ultrasonographic gel (˜ 50 to 60 mL) into the vaginal canal to distend the vaginal fornices Protocol: Imaging is performed in the axial plane with or without sagittal or coronal planes. Different types of sequences allow to image the same tissue in various ways, and combinations of sequences reveal important diagnostic information about the tissue in question. The imaging parameters (section thickness, field of view (FOV), matrix size) vary between protocols. Images are documented on radiographic film and in digital files and analysed at workstation
MRI T1/T2‐w (conventional T1‐/T2‐weighted)	The protocol includes axial spin‐echo or gradient echo T1‐weighted (T1‐w) images followed by fast spin‐echo (FSE)/turbo spin‐echo (TSE) images or fast relaxation fast‐spin echo (FR‐FSE) T2‐w images	MRI; CSE (conventlonal spin echo)
MRI fat‐suppressed (T1‐weighted)	Protocol includes T1‐w imaging using chemical fat suppression, which aids in the differentiation of lipid and haemorrhagic pathologies. Fat suppression is a generic term that includes various techniques to suppress the signal from normal adipose tissue to reduce chemical shift artefact and can be achieved by various methods. This is commonly a part of the MRI protocol and is rarely used in isolation	Fat‐saturated MRI
MRI T1/T2‐w + fat‐suppressed/ Gd (T1‐/T2‐weighted with fat‐suppression contrast enhanced)	Protocol includes gradient echo T1 images with and without fat suppression followed by FSE or FR‐FSE T2‐w images before and after intravenous injection of the paramagnetic contrast agent gadolinium	MRI; CSE/TIFS (conventlonal spin echo in combination with T1‐w fat‐suppressed) CSE/TIFS/Gd‐TIFS (conventlonal spin echo in combination with T1‐w fat‐suppressed and gadolinium‐enhanced TlFS)
MRI 'jelly method'	Protocol involves pretreatment of participants for MRI by simultaneous injection of ultrasonographic gel into the vagina (˜ 50 mL) and into the rectum (150 mL gel 50% diluted with water). Another technique evolves introduction of 300‐400 mL of diluted ultrasonographic gel (1:8 dilution) for rectosigmoid distension without use of intravaginal gel	MRI‐e (magnetic resonance enema)
3D‐MRI (3‐dimensional MRI)	Protocol includes 3D coronal single‐slab (containing all the slices) MRI, entitled 'CUBE' with FSE T2‐w images. The technique involves using variable flip angle refocusing, auto‐calibrating, 2D accelerated parallel imaging and nonlinear view ordering to produce high‐resolution volumetric image data sets and to reduce imaging time by using multi‐planar reformations
3.0T MRI	Equipment: 3.0Tesla Magnetom system with a multi‐channel phased‐array surface body‐coil Participants’ preparation: Fasting for 3 hours before the test was reported by some but not all studies; intravenous injection of anti‐peristaltic agent at the outset of the examination to decrease bowel peristalsis; administration of a negative super‐paramagnetic oral contrast agent to reduce signal intensity of the bowels. Examination with the full bladder in a ‘feet first’ supine position Protocol: combination of all or some of the following sequences: T‐w FSE, 2D‐T2‐w FR‐FSE/FSE, 3D‐T2‐w FR‐FSE CUBE, 3D‐T1‐w fat‐suppressed and/or LAVA‐flex (liver imaging with volume acceleration‐flexible) sequences. MRI images are acquired according to multiple scan planes, in particular axial, coronal and sagittal planes of the pelvis and sacral para‐coronal plane. Contrast agent (gadolinium) is administered in selected cases. Total acquisition time ˜ 20 min without or 30‐40 min with contrast injection
Ultrasound tests
TVUS (transvaginal ultrasonography)	Equipment: any of the commercially available ultrasound machines equipped with a wide‐band high‐resolution vaginal transducer (brands of scanners and frequencies of transducers vary between studies) Participants' preparation: Examination is performed in a dorsal lithotomy position with empty or half‐full bladder; no bowel preparation is routinely required Protocol: An ultrasound gel is applied to the tip of the transducer probe to create a lubricating, acoustically correct interface with the tissue. Scans are obtained by inserting the transducer (protected by disposable thin cover) into the vagina, followed by sequential movement of the probe within the vaginal canal to allow systematic evaluation of pelvic structures (uterus and adnexal regions; attention paid to the ovaries, pouch of Douglas, vesicouterine pouch and uterosacral ligament). The technique involves longitudinal, transverse and angled movements of the probe with sliding up and down, back and forward to obtain both longitudinal and transversal scans of pelvic structures. Examination protocols vary between studies. Each examination is interpreted in real time and can be documented in printed photographs	TVS 'transvaginal ultrasound' 'transvaginal sonography'
TVUS‐BP (transvaginal ultrasonography with bowel preparation)	Examination consists of TVUS combined with bowel preparation including the following: low‐residue diet for 1‐3 days, oral laxative on the eve of the examination, rectal enema within an hour before the examination or a combination of the above
RWC‐TVS (rectal water contrast transvaginal ultrasonography)	Examination consists of TVUS combined with bowel preparation and instillation of water contrast in rectum during TVUS; procedure does not require general anaesthesia Protocol: After the transducer is introduced into the vagina, a flexible thin catheter (18‐28 Ch) with a rubber balloon is inserted into the rectal lumen up to 20 cm from the anus (gel infused with lidocaine is used to facilitate passage of the catheter). Rectal water contrast of 100 to 300 mL of warm saline solution is instilled inside the balloon under ultrasonographic guidance to provide high‐definition images of the rectal wall and its layers. Back flow of the solution is prevented by placement of a Klemmer forceps on the catheter. Images are obtained before, during and after saline injection	'transvaginal sonography with water‐contrast in the rectum' 'water‐contrast in the rectum during transvaginal ultrasonography'
SVG (sonovaginography)	Examination consists of TVUS combined with the introduction of saline solution or gel to the vagina to create an acoustical window between the transvaginal probe and surrounding structures and to distend the vaginal walls, permitting enhanced visualisation of pelvic structures Protocol: Procedure involves introduction of a Foley catheter into the vagina followed by insertion of the transvaginal probe with further injection of 200‐400 mL of saline through the catheter by the assistant. To prevent reflux of saline solution from the vagina, the vaginal canal is closed with the operator’s hand. Alternative method involves placement of 20 mL of ultrasound gel into the posterior vaginal fornix with a plastic syringe, followed by insertion of a transvaginal probe. Reported procedure time ranges from 30 to 45 minutes	'transvaginal sonography and acoustic window with intravaginal gel'
tg‐TVUS (tenderness‐guided TVUS)	Examination consists of TVUS combined with particular attention to the tender points evoked during examination Protocol: Larger amount of ultrasound gel (˜ 12 mL instead of the usual 4 mL) is introduced into the probe cover to create a stand‐off for visualisation of the near‐field area. The probe is inserted gently to avoid the risk of squeezing out the gel. After the initial sonographic evaluation, the participant is asked to inform the operator about the onset and site of any tenderness experienced during probe pressure within the posterior fornix. When tenderness is evoked, the sliding movement is stopped, and particular attention is paid to the painful site via gentle pressure with the probe’s tip to detect endometriosis lesions. Reported procedure time is 15 to 20 minutes in cases of suspected lesions, but less time when the examination is negative
3D‐TVUS (3‐dimensional transvaginal ultrasonography)	Equipment: An ultrasound scanner equipped with 3D/4D imaging modes and a wide‐band high resolution volume transvaginal transducer. The method enables the acquisition of ultrasonographic volumetric data that can be assessed off‐line; in most institutions used as an adjunct to 2D US Protocol: region‐of‐interest (ROI) is identified using a B‐mode scan and a transvaginal volume transducer. During the volumetric scan, the transducer carries out a series of parallel scans of varying speeds focusing on the ROI. The anatomical ROI is visualised on the monitor as a graphic containing the 3 orthogonal planes. During volumetric scans, the investigator adopts some expedients such as positioning the probe near the anatomical ROI and reducing or eliminating participant movements. The volume obtained is stored on a hard disk and displayed later using dedicated software
Introital 3D‐US (introital 3‐dimensional ultrasound)	Examination is performed with the transducer placed on the perineum against the symphysis pubis (firmly but without causing significant discomfort). To acquire a correct volume, the symphysis pubis, urethra, vagina, and rectum should be visualised in the same image. Gain is adjusted and focal area is set to the region of interest, with the sweep angle set at 90 or 120 degrees to produce a multi‐planar image in 3 planes: longitudinal, transverse and coronal
TRUS (transrectal ultrasonography)	Equipment: An ultrasound scanner with a 2‐dimensional axial and sagittal convex high‐frequency probe with or without a rigid linear probe or a flexible endoscope with lateral view and a convex high frequency echo probe Participants' preparation: A low‐residue diet for 3 days before the examination with or without laxatives and/or rectal enema is reported in some but not all studies; several groups described using general or local anaesthesia for the procedure, and some groups used no analgesia Protocol: A gel‐filled rubber sheath or water‐filled balloon is placed over the tip of the transducer to obtain better visibility. The transducer is inserted into the rectum and is advanced until the midline image of the cervix is visualised in the longitudinal view. Pelvic structures are evaluated by moving the transducer along its longitudinal axis and rotating it 130° to 140° along the main axis in both axial and longitudinal planes. Alternative technique includes insertion of the flexible probe into the sigmoid colon, over the aortic bifurcation and/or the upper part of the body of the uterus, with subsequent slow withdrawal, allowing optimum imaging of rectal and sigmoid colon walls/pelvic structures, with instillation of water into the intestinal lumen and alternating use of several frequencies (e.g. 5, 7.5, 12 MHz)	TRS (transrectal sonograph) Tr EUS (transrectal endoscopic ultrasonography) RES (rectal endoscopic sonography) REU (rectal endoscopic ultrasonography)
Other tests
MDCT‐e (multi‐detector computerised tomography enema)	Equipment: multi‐detector computed tomograph, which has a 2‐dimensional array of detector elements that permits CT scanners to acquire multiple slices or sections simultaneously and greatly increase the speed of CT image acquisition (unlike the linear array of detector elements used in typical conventional and helical CT scanners) Participants’ preparation: low‐residue diet for 3 days and bowel preparation with an oral laxative day before the examination; intravenous injection of anti‐peristaltic agent during the test Protocol: colonic distension performed by introducing about 2000 mL of water at 37ºC into the left lateral decubitus position. All participants receive an intravenous injection of iodine‐containing contrast. Participants are scanned in supine position from the dome of the diaphragm to the pubic symphysis in the portal phase (40 seconds after the arterial peak). Scan parameters (collimation, rotation time, tube voltage, effective mAs) differ between studies. Estimated radiation exposure is calculated by the scanner using CT dose index and is saved to the dose report. Both axial plane and multi‐planar reconstructions (sagittal and coronal) are evaluated. Images are reviewed at a workstation	MSCTe (multi‐slice computed tomography combined with colon distension by water enteroclysis) 'Water enema CT'
18FDG‐PET (fluorodeoxyglucose positron emission tomography)	Equipment: PET‐computed tomograph Participants’ preparation: Fasting for at least 6 hours before the test; 18FDG (a glucose analogue) injection 60 min before the test Protocol: Acquisition is performed with the participant in supine position, from mid‐thigh to the base of the skull. No iodine‐based contrast is administered. CT parameters reported in a single included study are 120 kV, 120 mA, pitch 1.5:1, speed 15 mm/rot. The PET element operates in 2D mode for 4 minutes per bed position. Attenuation correction is based on CT data
DCBE (double‐contrast barium enema)	Equipment: motorised tilting radiographic table and standard equipment for fluoroscopic and radiological examination Participants’ preparation: low‐residue diet for 1‐3 days before the examination with or without oral laxatives day before the procedure; an anti‐peristaltic agent is administered intravenously at the outset of the examination to decrease bowel peristalsis Protocol: The procedure is performed in 2 steps to obtain double contrast and involves change of participant positions to ensure detailed visualisation of all intestinal segments. Barium sulphate contrast (600 to 800 mL) is instilled into rectum with a gravity pressure in the left lateral decubitus position. Once the barium reached the hepatic flexure, the colon was drained by gravity to remove as much barium as possible from the rectal ampulla without clearing completely the rectosigmoid colon of barium. Room air is then gently insufflated into the colon. Sequential views of the bowel are obtained. Each colonic segment is viewed in detail on spot radiographs and in magnification images. The procedure lasts 15 to 20 minutes