Answer for BIR CoW 27 Dec 2020
Idiopathic Central Diabetis Incipidus
Findings
In most healthy individuals, a normal posterior lobe appears hyperintense on T1-weighted MR images, due to phospholipid or secretory granules contained in pituicytes. In longstanding DI, this high signal intensity of the posterior lobe is absent as a result of failure to synthesize, transport or store neurosecretory granules.
Discussion
Discussion Current literature searches state that around 30% of cases are idiopathic, 25% related to malignant or benign tumors of the brain or pituitary, 16% secondary to head trauma, and 20% following cranial surgery . Common symptoms are polyuria, polydipsia, and nocturia (from 3-18 liters), hydronephrosis, bladder enlargement, and signs of dehydration . MRI of the pituitary gland and brain has an important role in the diagnosis of DI. It can confirm or exclude the presence of associated brain/pituitary disease, causing secondary DI; it can also correlate to previous trauma and/or results of previous surgical interventions on the brain and/or sellar region. T1-weighted images of the healthy posterior pituitary yield a hyperintense signal. In patients with central DI this signal is absent . This is a case of idiopathic diabetes insipidus, with the diagnosis confirmed by laboratory tests together with MRI.
Findings
In most healthy individuals, a normal posterior lobe appears hyperintense on T1-weighted MR images, due to phospholipid or secretory granules contained in pituicytes. In longstanding DI, this high signal intensity of the posterior lobe is absent as a result of failure to synthesize, transport or store neurosecretory granules.
Discussion
Discussion Current literature searches state that around 30% of cases are idiopathic, 25% related to malignant or benign tumors of the brain or pituitary, 16% secondary to head trauma, and 20% following cranial surgery . Common symptoms are polyuria, polydipsia, and nocturia (from 3-18 liters), hydronephrosis, bladder enlargement, and signs of dehydration . MRI of the pituitary gland and brain has an important role in the diagnosis of DI. It can confirm or exclude the presence of associated brain/pituitary disease, causing secondary DI; it can also correlate to previous trauma and/or results of previous surgical interventions on the brain and/or sellar region. T1-weighted images of the healthy posterior pituitary yield a hyperintense signal. In patients with central DI this signal is absent . This is a case of idiopathic diabetes insipidus, with the diagnosis confirmed by laboratory tests together with MRI.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
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Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!