mrimaster

MRI of Adnexal Mass in Pregnancy

Introduction

An adnexal mass in pregnancy refers to an abnormal growth or lump found in the adnexa area, encompassing the ovaries, fallopian tubes, and surrounding tissues, during pregnancy. Although most adnexal masses detected during pregnancy are typically benign, the potential for malignancy must be considered and evaluated. Symptoms associated with adnexal masses may include pelvic pain, discomfort, or the presence of a palpable mass. Ultrasound imaging is the usual method for diagnosis, as it is the primary imaging modality employed. However, MRI scans offer additional valuable information for accurate diagnosis and management. MRI scans aid in distinguishing between benign and malignant masses, identifying complex or atypical features, and assessing the extent of tumor involvement. Detailed anatomical images provided by MRI facilitate improved characterization of the adnexal mass. Performing an MRI scan for an adnexal mass in pregnancy can be challenging due to the potential location of the lesion anywhere within the abdomen or pelvis. Radiographers must initially conduct a large field of view (FOV) abdominal and pelvic scan to locate the mass. Once the mass is identified, subsequent small FOV scans should be performed to characterize the lesion accurately.

Indications for the scan

Contraindications

Patient preparation

Positioning

MRI GYNAECOLOGY PELVIS positioning image

Recommended MRI Adnexal Mass in Pregnancy Protocols and Planning

localiser

To localize and plan the sequences, it is essential to acquire a three-plane T2 HASTE localizer initially. These fast single-shot localizers have an acquisition time of under 25 seconds and are highly effective in accurately localizing abdominal structures.

Adnexal Masses in Pregnancy MRI localiser

T2 STIR\HASTE FAT SAT 6 mm Multiple breath-hold coronal

Plan the coronal slices based on the axial image, positioning the block horizontally across the abdomen as shown below. Confirm the positioning in the other two planes. Establish an appropriate angle in the sagittal plane, aligning it vertically across the abdomen. Ensure that an adequate number of slices are acquired to cover the abdomen and pelvis, extending from the anterior abdominal wall to the spinal canal. The field of view (FOV) should be sufficiently large to encompass the abdomen and pelvis, from the xiphisternum to the pubic symphysis. To prevent wrap-around artifacts, employ phase oversampling. Instruct the patient to hold their breath during image acquisition.

Adnexal Masses in Pregnancy MRI coronal big fov planning and protocol

Parameters

TR

2000-2500

TE

90-110

FLIP

130

NEX

1

SLICE

6MM

MATRIX

256×256

FOV

350

PHASE

R>L

OVERSAMPLE

50%

TRIGGER

NO

T1 tse\ vibe 6 mm multiple breath-hold axial

Plan the axial slices on the coronal image by positioning the block across the abdomen as shown below. Verify the positioning in the other two planes. Establish an appropriate angle in the sagittal plane, aligning it horizontally across the abdomen.  The slices must be sufficient to cover the entire lower abdomen and pelvis, ranging from the middle of the kidneys down to the symphysis pubis. Phase oversampling can be employed to prevent wrap-around artifacts. Instruct the patient to hold their breath during image acquisition.

Adnexal Masses in Pregnancy MRI axial big fov planning and protocol

TR

2500-3000

TE

90-110

FLIP

130

NEX

1

SLICE

5MM

MATRIX

256×256

FOV

350

PHASE

R>L

OVERSAMPLE

50%

TRIGGER

NO

The patient has a lesion situated in the left iliac fossa. To assess and characterize the lesion, it is recommended to conduct a series of imaging scans in the left iliac fossa using small field of view (FOV) T2, T1 fat-saturated, and diffusion-weighted imaging (DWI). It is important to monitor the Specific Absorption Rate (SAR) carefully to prevent excessive heating of the fetus during the procedure.

T2 TSE axial multiple breath holds 4mm SFOV

Plan the axial slices based on the coronal image, positioning the block horizontally across the adnexal mass as shown below. Verify the positioning block in the other two planes. Ensure an appropriate angle is given in the sagittal plane, perpendicular to the rectus abdominis muscle. The slices should adequately cover the adnexal mass. Select a SFOV (typically ranging from 200mm to 250mm) that sufficiently encompasses the affected area. To avoid wrap-around artifacts, consider using phase oversampling. Additionally, placing saturation bands on the top and bottom of the axial block will help reduce arterial pulsation and breathing artifacts. Instruct the patient to hold their breath during image acquisition.

This sequence is a modified version of a T2 TSE breath-hold scan commonly used in abdominal and liver imaging. To obtain high-resolution breath-hold scans, users can customize the T2 sequence. The default sequence parameters are as follows: 350-400 FOV, matrix 256×256, NEX 1, slice thickness 6mm, and acquisition of 25-30 slices within a 30-second breath hold. To achieve the desired high-resolution scan, make the following modifications: 200-250 FOV, matrix 256×192, NEX 2, and a slice thickness of 4mm with parallel imaging (IPAT) enabled. Typically, the adapted sequence will take approximately 90 seconds, requiring it to be divided into 4 acquisitions (concatenations). This division ensures that each breath-hold acquisition lasts approximately 22 seconds.

Adnexal Masses in Pregnancy MRI axial SFOV planning and protocol

Parameters

TR

3000-4000

TE

100

FLIP

150

NEX

2

SLICE

4 MM

MATRIX

256X192

FOV

200-250

PHASE

A>P

OVERSAMPLE

30%

IPAT

On

T1 VIBE DIXON SFOV 4mm axial breath hold

Plan the axial slices based on the coronal image, positioning the block horizontally across the adnexal mass as shown below. Verify the positioning block in the other two planes. Ensure an appropriate angle is given in the sagittal plane, perpendicular to the rectus abdominis muscle. The slices should adequately cover the adnexal mass. Select a SFOV (typically ranging from 200mm to 250mm) that sufficiently encompasses the affected area. To avoid wrap-around artifacts, consider using phase oversampling. Additionally, placing saturation bands on the top and bottom of the axial block will help reduce arterial pulsation and breathing artifacts. Instruct the patient to hold their breath during image acquisition.

Adnexal Masses in Pregnancy MRI axial SFOV planning and protocol

Parameters

TR

7-8

TE

2.39   4.77

FLIP

10

NXA

1

SLICE

3 MM

MATRIX

224×224

FOV

200

PHASE

R>L

OVERSAMPLE

50%

BH

YES

T2 TSE fat sat/ STIR axial multiple breath holds 4mm SFOV

Plan the axial slices based on the coronal image, positioning the block horizontally across the adnexal mass as shown below. Verify the positioning block in the other two planes. Ensure an appropriate angle is given in the sagittal plane, perpendicular to the rectus abdominis muscle. The slices should adequately cover the adnexal mass. Select a SFOV (typically ranging from 200mm to 250mm) that sufficiently encompasses the affected area. To avoid wrap-around artifacts, consider using phase oversampling. Additionally, placing saturation bands on the top and bottom of the axial block will help reduce arterial pulsation and breathing artifacts. Instruct the patient to hold their breath during image acquisition.

Adnexal Masses in Pregnancy MRI axial SFOV planning and protocol

Parameters

TR

4000-5000

TE

500

FLIP

150

NEX

1

SLICE

4MM

MATRIX

256X208

FOV

200-250

PHASE

R>L

OVERSAMPLE

50%

IPAT

ON

DWI epi 3 scan trace axial 4mm free breathing

Plan the axial slices based on the coronal image, positioning the block horizontally across the adnexal mass as shown below. Verify the positioning block in the other two planes. Ensure an appropriate angle is given in the sagittal plane, perpendicular to the rectus abdominis muscle. The slices should adequately cover the adnexal mass. Select a SFOV (typically ranging from 200mm to 250mm) that sufficiently encompasses the affected area. To avoid wrap-around artifacts, consider using phase oversampling. Additionally, placing saturation bands on the top and bottom of the axial block will help reduce arterial pulsation and breathing artifacts. Instruct the patient to breathe normally during image acquisition.

Adnexal Masses in Pregnancy MRI axial SFOV planning and protocol

Parameters

TR

6000-7000

TE

90

IPAT

ON

NEX

 3     5     8

SLICE

4 MM

MATRIX

192X192

FOV

200-250

PHASE

R>L

GAP

10%

B VALUE

0
500
1000

T2 TSE coronal multiple breath holds 4mm SFOV

Plan the coronal slices on the axial image and position the block horizontally across the adnexal mass as shown below. Verify the positioning block in the other two planes. Ensure an appropriate angle is given in the sagittal plane, parallel to the rectus abdominis muscle. The number of slices should be sufficient to cover the adnexal mass. Choose a SFOV (field of view) that adequately covers the affected area (typically 200mm-250mm). To prevent wrap-around artifacts, consider using phase oversampling. Additionally, placing saturation bands on the top and bottom of the axial block will help reduce arterial pulsation and breathing artifacts. Instruct the patient to hold their breath during image acquisition.

Adnexal Masses in Pregnancy MRI coronal SFOV planning and protocol

Parameters

TR

3000-4000

TE

100

FLIP

150

NEX

2

SLICE

4 MM

MATRIX

256X192

FOV

200-250

PHASE

R>L

OVERSAMPLE

70%

IPAT

On

T2 TSE sagittal multiple breath holds 4mm SFOV

Plan the sagittal slices on the axial image and angle the positioning block approximately perpendicular to the rectus abdominis muscle. Verify the positioning block in the other two planes. Ensure an appropriate angle is set in the coronal plane, parallel to the rectus abdominis muscle. The number of slices should be adequate to encompass the adnexal mass. Select a small field of view (FOV) that adequately covers the affected area, typically ranging from 200mm to 250mm. Consider utilizing phase oversampling to prevent wrap-around artifacts. Instruct the patient to hold their breath during image acquisition.

Adnexal Masses in Pregnancy MRI sagittal SFOV planning and protocol

Parameters

TR

3000-4000

TE

100

FLIP

150

NEX

2

SLICE

4 MM

MATRIX

256X192

FOV

200-250

PHASE

A>P

OVERSAMPLE

30%

IPAT

On

Optional Scans

T2 HASTE axial 4 mm SFOV gated using table respiratory sensor

Respiratory gating in modern scanners can now be accomplished using built-in table respiratory sensors. This feature proves particularly beneficial when patients have irregular breathing patterns or are at risk of falling asleep during the scan. The advantage of table sensors is that they do not necessitate any specific planning. The only requirement is to ensure that the patient’s chest is accurately positioned over the table sensors to enable accurate monitoring of breathing. Additionally, it is important to select the appropriate gating option, such as the table sensor gating, in the protocol settings.

Plan the axial slices on the coronal image, positioning the block horizontally across the adnexal mass as shown below. Verify the positioning block in the other two planes. Ensure an appropriate angle is given in the sagittal plane, perpendicular to the rectus abdominis muscle. The slices should adequately cover the adnexal mass. Select a SFOV (typically ranging from 200mm to 250mm) that sufficiently encompasses the affected area. To avoid wrap-around artifacts, consider using phase oversampling. Additionally, placing saturation bands on the top and bottom of the axial block will help reduce arterial pulsation and breathing artifacts. Instruct the patient to breathe normally during image acquisition.

Adnexal Masses in Pregnancy MRI axial SFOV planning and protocol

Parameters

TR

4000-5000

TE

500

FLIP

150

NEX

1

SLICE

4MM

MATRIX

256X224

FOV

200-259

PHASE

R>L

OVERSAMPLE

50%

IPAT

ON

Table sensors

Advanced MRI scanners are equipped with built-in table sensors that detect the respiratory waveform and trigger data acquisition during the expiration phase of the respiratory cycle. Proper patient positioning over the sensor is critical for accurate respiratory gating. This method eliminates the need for external respiratory gating equipment, such as sensors and belts.

Advanced MRI scanners are equipped with built-in table sensors
If the patient is unable to hold their breath, perform small FOV HASTE scans in three planes. If the scanner does not have a table sensor, the scan can be conducted using navigator-based respiratory gating.