Incidentaloma MRI: Difference between revisions
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==MRI== | ==MRI== | ||
*[[Adrenal gland|Adrenal]] MRI may be helpful in the diagnosis of incidentaloma. Findings on [[Magnetic resonance imaging|MRI]] suggestive of/diagnostic of incidentaloma include: | *[[Adrenal gland|Adrenal]] MRI may be helpful in the diagnosis of incidentaloma. | ||
* [[Magnetic resonance imaging|MRI]] rather than [[Computed tomography|CT]] is suggested if dedicated adrenal imaging is required in children, adolescents, pregnant females, and adults younger than 40 years of age.<ref name="pmid28181818">{{cite journal| author=Sahdev A| title=Recommendations for the management of adrenal incidentalomas: what is pertinent for radiologists? | journal=Br J Radiol | year= 2017 | volume= 90 | issue= 1072 | pages= 20160627 | pmid=28181818 | doi=10.1259/bjr.20160627 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=28181818 }}</ref> | |||
*Findings on [[Magnetic resonance imaging|MRI]] suggestive of/diagnostic of incidentaloma include: | |||
* T1 and T2-weighted imaging can distinguish [[benign]] [[adenomas]] from [[malignancy]] and [[pheochromocytoma]].<ref name="pmid219972912">{{cite journal| author=Young WF| title=Conventional imaging in adrenocortical carcinoma: update and perspectives. | journal=Horm Cancer | year= 2011 | volume= 2 | issue= 6 | pages= 341-7 | pmid=21997291 | doi=10.1007/s12672-011-0089-z | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21997291 }}</ref> | * T1 and T2-weighted imaging can distinguish [[benign]] [[adenomas]] from [[malignancy]] and [[pheochromocytoma]].<ref name="pmid219972912">{{cite journal| author=Young WF| title=Conventional imaging in adrenocortical carcinoma: update and perspectives. | journal=Horm Cancer | year= 2011 | volume= 2 | issue= 6 | pages= 341-7 | pmid=21997291 | doi=10.1007/s12672-011-0089-z | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21997291 }}</ref> | ||
Revision as of 15:34, 6 September 2017
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American Roentgen Ray Society Images of Incidentaloma MRI |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohammed Abdelwahed M.D[2]
Overview
Adrenal MRI may be helpful in the diagnosis of incidentaloma. Findings on MRI suggestive of incidentaloma include mild enhancement and a rapid washout of contrast, while malignant lesions show rapid and marked enhancement and a slower washout pattern. MRI has advantages in certain clinical situations. The advantages of MRI over CT are its lack of radiation exposure, lack of iodine-based contrast media and its superior tissue contrast resolution.
MRI
- Adrenal MRI may be helpful in the diagnosis of incidentaloma.
- MRI rather than CT is suggested if dedicated adrenal imaging is required in children, adolescents, pregnant females, and adults younger than 40 years of age.[1]
- Findings on MRI suggestive of/diagnostic of incidentaloma include:
- T1 and T2-weighted imaging can distinguish benign adenomas from malignancy and pheochromocytoma.[2]
- MRI has advantages in certain clinical situations. The advantages of MRI over CT are its lack of radiation exposure, lack of iodine-based contrast media and its superior tissue contrast resolution.[3]
- On gadolinium-diethylene triamine pentaacetic acid (DTPA)-enhanced MRI, adenomas demonstrate mild enhancement and a rapid washout of contrast, while malignant lesions show rapid and marked enhancement and a slower washout pattern.[4]
- Chemical shift imaging relies on the fact that, within magnetic fields, protons in water vibrate at a slightly different frequency than protons in lipid.[5]
- As a result, water and fat protons oscillate in and out of phase with respect to one another.
- By selecting appropriate sequencing parameters, separate images can be generated with water and fat protons oscillating in phase or out of phase to each other.
- Benign adrenal cortical adenomas lose signal on out-of-phase images but appear relatively bright on in-phase images.[6]
- With a high content of intracellular lipid usually lose signal intensity on out-of-phase images compared with in-phase images, whereas malignant lesions and pheochromocytomas (but also lipid-poor adrenal adenomas) that all lack intracellular lipid remain unchanged.[7]
References
- ↑ Sahdev A (2017). "Recommendations for the management of adrenal incidentalomas: what is pertinent for radiologists?". Br J Radiol. 90 (1072): 20160627. doi:10.1259/bjr.20160627. PMID 28181818.
- ↑ Young WF (2011). "Conventional imaging in adrenocortical carcinoma: update and perspectives". Horm Cancer. 2 (6): 341–7. doi:10.1007/s12672-011-0089-z. PMID 21997291.
- ↑ Peppercorn PD, Grossman AB, Reznek RH (1998). "Imaging of incidentally discovered adrenal masses". Clin Endocrinol (Oxf). 48 (4): 379–88. PMID 9640401.
- ↑ Sahdev A, Reznek RH (2004). "Imaging evaluation of the non-functioning indeterminate adrenal mass". Trends Endocrinol Metab. 15 (6): 271–6. doi:10.1016/j.tem.2004.06.012. PMID 15358280.
- ↑ Israel GM, Korobkin M, Wang C, Hecht EN, Krinsky GA (2004). "Comparison of unenhanced CT and chemical shift MRI in evaluating lipid-rich adrenal adenomas". AJR Am J Roentgenol. 183 (1): 215–9. doi:10.2214/ajr.183.1.1830215. PMID 15208141.
- ↑ Young WF (2011). "Conventional imaging in adrenocortical carcinoma: update and perspectives". Horm Cancer. 2 (6): 341–7. doi:10.1007/s12672-011-0089-z. PMID 21997291.
- ↑ Haider MA, Ghai S, Jhaveri K, Lockwood G (2004). "Chemical shift MR imaging of hyperattenuating (>10 HU) adrenal masses: does it still have a role?". Radiology. 231 (3): 711–6. doi:10.1148/radiol.2313030676. PMID 15118113.