Hypoglycemia MRI: Difference between revisions
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==Overview== | ==Overview== | ||
[[Magnetic resonance imaging|MRI]] scan is helpful in the diagnosis of [[insulinoma]] in the case of failed [[Computed tomography|CT.]] It shows enhancement. | [[Magnetic resonance imaging|MRI]] scan is helpful in the diagnosis of [[insulinoma]] in the case of failed [[Computed tomography|CT.]] It shows enhancement. MRI has better sensitivity than CT scan. It is still considered as the second line of investigation due to cost and availability. Insulinoma shows low intensity on T1 weighted and high intensity on T2 weighted signals, having better visualization on T1 and T2 weighted images with fat suppression.They exhibit typically homogenous enhancement when small and ring enhancement when more than 2 cm. A similar pattern is seen in metastatic lesion as of primary tumor. | ||
== MRI == | == MRI == | ||
Revision as of 22:41, 19 September 2017
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Hypoglycemia Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Hypoglycemia MRI On the Web |
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American Roentgen Ray Society Images of Hypoglycemia MRI |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];{AE}} Mohammed Abdelwahed M.D[2]
Overview
MRI scan is helpful in the diagnosis of insulinoma in the case of failed CT. It shows enhancement. MRI has better sensitivity than CT scan. It is still considered as the second line of investigation due to cost and availability. Insulinoma shows low intensity on T1 weighted and high intensity on T2 weighted signals, having better visualization on T1 and T2 weighted images with fat suppression.They exhibit typically homogenous enhancement when small and ring enhancement when more than 2 cm. A similar pattern is seen in metastatic lesion as of primary tumor.
MRI
- MRI scan is helpful in the diagnosis of insulinoma in the case of failed CT.
- T1 C typically shows enhancement, although contrast enhancement may not improve tumor visualization.[1]
- MRI is superior in detecting insulinoma in that it has greater sensitivity currently ~85%. In a study of 21 insulinomas by Owen et al,the sensitivity was noted to be 94%.(19/21 cases).
- The 2 cases were of 5 and 7 mm size and in pancreatic tail.[1][2]
- T1 and T2 relaxation times for islet cell tumor like insulinoma has lower protein and proton concentration time.[3] Abdominal MRI may be helpful in the diagnosis of insulinoma. Findings on MRI suggestive of Insulinoma include[4][3]:
- Low in signal intensity on fat suppressed T1-weighted images High on intensity on fat suppressed T2-weighted images independent of lesion size
- Enhancement patterns are due to hypervascularity. Homogeneous enhancement is exhibited commonly in insulinoma, ring enhancement if they are larger than 2 cm.
- same pattern can be seen in metastatic lymph node as of the primary; homogeneous when small and ring enhancement if the tumor is more than 2 cm. Modern MRI has rapid tri-phasic, breath held T1 rapid gadolinium- enhanced sequences which help to reduce artifacts produced by motion.[1][3]
- MRI enables accurate location of the tumor in terms of resectability and involvement of vessels.[1][3]
References
- ↑ Pongprasobchai S, Lertwattanarak R, Pausawasdi N, Prachayakul V (2013). "Diagnosis and localization of insulinoma in Thai patients: performance of endoscopic ultrasonography compared to computed tomography and magnetic resonance imaging". J Med Assoc Thai. 96 Suppl 2: S187–93. PMID 23590041.