Hypoglycemia CT
|
Hypoglycemia Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Hypoglycemia CT On the Web |
|
American Roentgen Ray Society Images of Hypoglycemia CT |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Mohammed Abdelwahed M.D[2]
Overview
CT scan is currently accepted as the first line of investigation for diagnosing insulinoma. Currently, with the advances in technology, the sensitivity has risen to 80% and 94.4% for helical CT scan with dual-phase multidetector CT scan. Insulinoma is hypervascular and thus CT shows greater enhancement (hyper-attenuation) than rest of the pancreatic parenchyma. Cystic and nodular masses with calcification indicates malignant insulinoma. Metastasis can be detected by CT scan.
CT
- Hypoglycemia caused by endogenous insulin the differential diagnosis includes insulinoma and islet-cell hypertrophy.
- Ultrasound, Computed tomography and MRI can differentiate between both.[1]
- A negative imaging study does not exclude insulinoma and patient need more tests.
- CT shows hyperattenuating on arterial phase so arterial or pancreatic phase imaging may aid in better detection. Some may show calcification.[2]
- Sensitivity of CT scan for diagnosing insulinoma was 33-64%. With the recent advances in technology and knowledge of rapid contrast-enhanced CT scan in early phase has increased the sentivity to 80%. [1]Most insulinomas are smaller,<1.3 cm (50%) and many of these are non-contour forming. therefore CT scan is less effective in diagnosing them than MRI.[2][3]
- Abdominal Contrast enhanced CT(CECT) scan may be helpful in the diagnosis of insulinoma. Findings on CT scan suggestive of insulinoma include[1]:
- Greater degree of enhancement(hyper-attenuation) than parenchyma of the rest of pancreas(as its hypervascular)during the vascular phases of the contrast
- Atypically can appear hypovascular and hypodense lesions after the administration of contrast, as compared to hyperdense lesions before the administration; cystic masses, and calcified masses(in malignant lesions when they are nodular and discrete)[2][3]
- CT quality have been improved with techology advances with using dual-phase thin-section multdetector CT having senstivity of 94.4% as compared to 57% for dual-phase multidetector without thin sections and 28.6% with sequential CT.[2][4]
- It is helpful for detetcting metastasis.
References
- ↑ Noone TC, Hosey J, Firat Z, Semelka RC (2005). "Imaging and localization of islet-cell tumours of the pancreas on CT and MRI". Best Pract Res Clin Endocrinol Metab. 19 (2): 195–211. doi:10.1016/j.beem.2004.11.013. PMID 15763695.
- ↑ King AD, Ko GT, Yeung VT, Chow CC, Griffith J, Cockram CS (1998). "Dual phase spiral CT in the detection of small insulinomas of the pancreas". Br J Radiol. 71 (841): 20–3. doi:10.1259/bjr.71.841.9534694. PMID 9534694.