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* 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.
* 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.
* Chemical shift imaging (CSI) MRI is a form of lipid sensitive imaging based upon the principle that the hydrogen protons in water and lipid molecules resonate at different frequencies, referred to as "chemical shift".<ref name="pmid15208141">{{cite journal| author=Israel GM, Korobkin M, Wang C, Hecht EN, Krinsky GA| title=Comparison of unenhanced CT and chemical shift MRI in evaluating lipid-rich adrenal adenomas. | journal=AJR Am J Roentgenol | year= 2004 | volume= 183 | issue= 1 | pages= 215-9 | pmid=15208141 | doi=10.2214/ajr.183.1.1830215 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15208141  }}</ref>
* Chemical shift imaging relies on the fact that, within magnetic fields, protons in water vibrate at a slightly different frequency than protons in lipid.<ref name="pmid15208141">{{cite journal| author=Israel GM, Korobkin M, Wang C, Hecht EN, Krinsky GA| title=Comparison of unenhanced CT and chemical shift MRI in evaluating lipid-rich adrenal adenomas. | journal=AJR Am J Roentgenol | year= 2004 | volume= 183 | issue= 1 | pages= 215-9 | pmid=15208141 | doi=10.2214/ajr.183.1.1830215 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15208141  }}</ref>
* 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.<ref name="pmid21997291">{{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>
* Benign adrenal cortical adenomas lose signal on out-of-phase images, but appear relatively bright on in-phase images.<ref name="pmid21997291">{{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>
* (60, 61, 62, 63, 64, 65)
* 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 (58, 65, 66).


==References==
==References==

Revision as of 16:25, 28 August 2017

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:

Overview

There are no MRI findings associated with [disease name].

OR

[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].

OR

There are no MRI findings associated with [disease name]. However, a MRI may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].

MRI

  • [Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include:

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.[1]

  • T1 and T2-weighted imaging can distinguish benign adenomas from malignancy and pheochromocytoma.
  • 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.
  • Chemical shift imaging relies on the fact that, within magnetic fields, protons in water vibrate at a slightly different frequency than protons in lipid.[2]
  • 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.[3]
  • (60, 61, 62, 63, 64, 65)
  • 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 (58, 65, 66).

References

  1. Peppercorn PD, Grossman AB, Reznek RH (1998). "Imaging of incidentally discovered adrenal masses". Clin Endocrinol (Oxf). 48 (4): 379–88. PMID 9640401.
  2. 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.
  3. 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.

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