Abdominal pain in pregnancy protocol (MRI)
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Updates to Article Attributes
The abdominal pain in pregnancy MRI protocol encompasses a set of MRI sequences for assessment of causes of non-traumatic abdominal pain in pregnancy.
Note: This article aims to frame a general concept of an MRI protocol for the assessment of the abdomen in pregnancy. Protocol specifics will vary depending on MRI scanner type, specific hardware and software, radiologist and perhaps referrer preference, patient factors e.g. implants, specific indications and time constraints.
Indications
Acute non-traumatic abdominal pain in a pregnant woman, either as a primary imaging modality or following indeterminate or abnormal ultrasound findings.
1.5 vs 3 Tesla
Due to considerations around fetal heating, 1.5 teslaT is recommended for this type of study.
Patient preparation
No specific preparation is required.
Patient positioning
The study can be conducted with the patient in the supine position, but with increasing gestational age, patients may be more comfortable lying in the left lateral position to reduce pressure on the IVC byinferior vena cava (IVC) by the gravid uterus.
Technical parameters
Coil
- phased-array surface body coil
Planning
Due to pain often not being localised to one region, and due to the anatomic changes encountered during pregnancy, images are acquired from the diaphragm to the pubic symphysis, provide complete anatomic coverage.
Sequences
The set of sequences used must allow for adequate interrogation of the altered anatomy of the pregnant abdomen, yet also minimise the specific absorption rate (SAR) and minimise the time spent in the scanner.
Standard sequences
-
T2-weighted
- purpose: to identify bowel including appendix, solid upper abdominal organs and uterus
- technique: single-shot fast spin-echo (SSFSE)
- planes: axial, coronal and sagittal
-
T2-weighted with fat saturation
- purpose: to identify oedema and free fluid
- technique: single-shot fast spin-echo (SSFSE) with fat saturation
- planes: axial, coronal and sagittal
-
Gradientgradient echo (+/- fat saturation)- purpose: to identify blooming artifact in the appendix confirming luminal gas and therefore patency; to identify retroperitoneal structures such as dilated ureter and ovarian vein
- technique: gradient-echo +/- fat saturation
- planes: axial (optional: coronal and sagittal)
-
T1-weighted
- purpose: to identify blood products, such as in degenerating fibroids
- technique: dual-echo or T1W spin-echo (SE)
- planes: axial (optional: coronal and sagittal)
-
Diffusiondiffusion-weighted imaging- purpose: to identify oedema and inflammatory changes
- technique: diffusion-weighted imaging, b0-50, b400, b800
- planes: axial or coronal
Practical points
- the use of MRI in all trimesters of pregnancy is considered to be safe by the American College of Radiology's Manual of MRI Safety, but patients should be consented about the as-yet-unknown long term effects of MRI on the fetus
- the use of gadolinium contrast is relatively contraindicated in pregnancy due to gadolinium crossing the placental barrier and the unknown effects on the fetus
- the appendix may be difficult to identify on MRI, particularly in the latter stages of pregnancy, due to movement outside of the usual position in the right iliac fossa and compression of bowel loops
- the presence of restricted diffusion in the region of the caecal pole helps to diagnose acute appendicitis
- physiologic hydronephrosis is commonly seen in pregnancy, more frequently on the right side, with gradual tapering of the ureter as it is compressed between the uterus and psoas muscle
- a dilated ovarian vein is another tubular retroperitoneal structure that may be mistaken for an appendix but can be followed caudally from the ovary to its cranial drainage to the IVC on the right and left renal vein on the left
- if fetal assessment
isn'tis not carried out, a statement explicitly stating this should be added to the report
-<p>The<strong> abdominal pain in pregnancy MRI protocol</strong> encompasses a set of MRI sequences for assessment of causes of <a href="/articles/acute-non-traumatic-abdominal-pain-in-pregnancy">non-traumatic abdominal pain in pregnancy</a>.</p><p><em>Note: This article aims to frame a general concept of an MRI protocol for the assessment of the abdomen in pregnancy. Protocol specifics will vary depending on MRI scanner type, specific hardware and software, radiologist and perhaps referrer preference, patient factors e.g. implants, specific indications and time constraints.</em></p><h4>Indications</h4><p>Acute non-traumatic abdominal pain in a pregnant woman, either as a primary imaging modality or following indeterminate or abnormal ultrasound findings.</p><h4>1.5 vs 3 Tesla</h4><p>Due to considerations around fetal heating, 1.5 tesla is recommended for this type of study.</p><h4>Patient preparation </h4><p>No specific preparation is required.</p><h4>Patient positioning</h4><p>The study can be conducted with the patient in the supine position, but with increasing gestational age, patients may be more comfortable lying in the left lateral position to reduce pressure on the IVC by the gravid uterus.</p><h4>Technical parameters</h4><h5>Coil</h5><ul><li>phased-array surface body coil</li></ul><h5>Planning</h5><p>Due to pain often not being localised to one region, and due to the anatomic changes encountered during pregnancy, images are acquired from the diaphragm to the pubic symphysis, provide complete anatomic coverage.</p><h4>Sequences</h4><p>The set of sequences used must allow for adequate interrogation of the altered anatomy of the pregnant abdomen, yet also minimise the specific absorption rate (SAR) and minimise the time spent in the scanner.</p><h5>Standard sequences</h5><ul>- +<p>The<strong> abdominal pain in pregnancy MRI protocol</strong> encompasses a set of MRI sequences for assessment of causes of <a href="/articles/acute-non-traumatic-abdominal-pain-in-pregnancy">non-traumatic abdominal pain in pregnancy</a>.</p><p><em>Note: This article aims to frame a general concept of an MRI protocol for the assessment of the abdomen in pregnancy. Protocol specifics will vary depending on MRI scanner type, specific hardware and software, radiologist and perhaps referrer preference, patient factors e.g. implants, specific indications and time constraints.</em></p><h4>Indications</h4><p>Acute non-traumatic abdominal pain in a pregnant woman, either as a primary imaging modality or following indeterminate or abnormal ultrasound findings.</p><h4>1.5 vs 3 Tesla</h4><p>Due to considerations around fetal heating, 1.5 T is recommended for this type of study.</p><h4>Patient preparation </h4><p>No specific preparation is required.</p><h4>Patient positioning</h4><p>The study can be conducted with the patient in the supine position, but with increasing gestational age, patients may be more comfortable lying in the left lateral position to reduce pressure on the <a title="Inferior vena cava" href="/articles/inferior-vena-cava-1">inferior vena cava (IVC)</a> by the gravid uterus.</p><h4>Technical parameters</h4><h5>Coil</h5><ul><li>phased-array surface body coil</li></ul><h5>Planning</h5><p>Due to pain often not being localised to one region, and due to the anatomic changes encountered during pregnancy, images are acquired from the <a title="Diaphragm" href="/articles/diaphragm">diaphragm</a> to the <a title="Pubic symphysis" href="/articles/pubic-symphysis">pubic symphysis</a>, provide complete anatomic coverage.</p><h4>Sequences</h4><p>The set of sequences used must allow for adequate interrogation of the altered anatomy of the pregnant abdomen, yet also minimise the <a title="Specific absorption rate (SAR)" href="/articles/specific-absorption-rate">specific absorption rate (SAR)</a> and minimise the time spent in the scanner.</p><h5>Standard sequences</h5><ul>
-<strong>Gradient echo (+/- fat saturation)</strong><ul>- +<strong>gradient echo (+/- fat saturation)</strong><ul>
-<strong>Diffusion-weighted imaging</strong><ul>- +<strong>diffusion-weighted imaging</strong><ul>
-<li>the use of MRI in all trimesters of pregnancy is considered to be safe by the American College of Radiology's Manual of MRI Safety, but patients should be consented about the as-yet-unknown long term effects of MRI on the fetus</li>-<li>the use of gadolinium contrast is relatively contraindicated in pregnancy due to gadolinium crossing the placental barrier and the unknown effects on the fetus</li>- +<li>the use of MRI in all trimesters of pregnancy is considered to be safe by the <a title="American College of Radiology" href="/articles/american-college-of-radiology">American College of Radiology's</a> Manual of MRI Safety, but patients should be consented about the as-yet-unknown long term effects of MRI on the fetus</li>
- +<li>the use of <a title="gadolinium contrast" href="/articles/gadolinium-contrast">gadolinium contrast</a> is relatively contraindicated in pregnancy due to gadolinium crossing the placental barrier and the unknown effects on the fetus</li>
-<li>physiologic hydronephrosis is commonly seen in pregnancy, more frequently on the right side, with gradual tapering of the ureter as it is compressed between the uterus and psoas muscle</li>- +<li>
- +<a title="Maternal hydronephrosis in pregnancy" href="/articles/maternal-hydronephrosis-in-pregnancy">physiologic hydronephrosis</a> is commonly seen in pregnancy, more frequently on the right side, with gradual tapering of the ureter as it is compressed between the uterus and psoas muscle</li>
-<li>if fetal assessment isn't carried out, a statement explicitly stating this should be added to the report</li>- +<li>if fetal assessment is not carried out, a statement explicitly stating this should be added to the report</li>