Result type: MRI Orbits w/ + w/o Cont
Result date: Jul 01, 2016, 11:14 a.m.
Result status: authenticated
Performed by: Kimberly Higdon
Modified by: Kristen Baugnon
Accession number: 00001MR20160163270
MRI Orbits w/ + w/o Cont
Patient: JAMES AVERY DOB: Jan 14, 1962
REPORT
MRI OF THE ORBITS WITHOUT AND WITH IV CONTRAST:
CLINICAL INDICATION: Sudden right-sided vision loss. Presumed nonarteritic anterior ischemic optic neuropathy of the right eye in the setting of crystal meth abuse.
TECHNIQUE: 3.0-Tesla system. Pre-contrast sagittal T1-w and axial diffusion-w images of the brain with ADC map, and axial T1- and T2-w and coronal T1-w and T2-w fat-saturated images of the orbits. Post-contrast axial and coronal T1-w fat-saturated images of the orbits. Intravenous contrast material was administered for the examination.
COMPARISON: None.
FINDINGS:
1.4 x 1.0 (axial, series 10 image 6) x 0.9 cm (craniocaudal, series 9 image 22) hypoenhancing mass in left aspect of sella turcica. Mass is minimally T1 hypointense and T2 hyperintense. No involvement of left cavernous sinus. No mass effect on optic chiasm or optic nerves.
Questionable mild T2 hyperintensity in intraorbital segment of right optic nerve. Optic nerves otherwise appear symmetric.
The globes are of normal contour and signal intensity. There is no orbital mass or abnormal enhancement along the course of the optic nerves, chiasm and optic tracts. The intraconal and extraconal fat is within normal limits. The extraocular muscles are normal in size and signal intensity. The lacrimal glands appear normal. The orbital apices and cavernous sinuses demonstrate no abnormality.
IMPRESSION:
1. Questionable mild T2 hyperintensity in intraorbital segment of right optic nerve, which could be consistent with history of right optic neuropathy.
2. 1.4 x 1.0 x 0.9 cm hypoenhancing mass in left sella turcica, likely pituitary macroadenoma. No mass effect on optic nerves or chiasm. Correlate with endocrine function.
This study has been reviewed and interpreted by Kristen L. Baugnon, M.D., attending neuroradiologist.
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Pituitary adenomas
https://en.wikipedia.org/wiki/Pituitary_adenoma: Pituitary adenomas are tumors that occur in the pituitary gland. Pituitary adenomas are generally divided into three categories dependent upon their biological functioning: benign adenoma, invasive adenoma, and carcinomas, with carcinomas accounting for 0.1% to 0.2%, approximately 35% being invasive adenomas and most being benign adenomas. Pituitary adenomas represent from 10% to 25% of all intracranial neoplasms [1]and the estimated prevalence rate in the general population is approximately 17%.
Non-invasive and non-secreting pituitary adenomas are considered to be benign in the literal as well as the clinical sense; however a recent meta-analysis (Fernández-Balsells, et al. 2011) of available research has shown there are to date scant studies - of poor quality - to either support or refute this assumption.
Adenomas which exceed 10 millimetres (0.39 in) in size are defined as macroadenomas, with those smaller than 10 mm referred to as microadenomas. Most pituitary adenomas are microadenomas, and have an estimated prevalence of 16.7% (14.4% in autopsy studies and 22.5% in radiologic studies). A majority of pituitary microadenomas often remain undiagnosed and those that are diagnosed are often found as an incidental finding, and are referred to as incidentalomas.
Pituitary macroadenomas are the most common cause of hypopituitarism, and in the majority of cases they are non-secreting adenomas.
The Pituitary gland is in close proximity to the brain, invasive adenomas may invade the dura mater, cranial bone, or sphenoid bone. While Pituitary adenomas are extremely common, affecting approximately one in 6 of the general population, clinically active pituitary adenomas requiring surgical treatment are more rare, affecting approximately one in 1000 of the general population.
The pituitary gland or hypophysis is often referred to as the "master gland" of the human body. Part of the hypothalamic-pituitary axis, it controls most of the body's endocrine functions via the secretion of various hormones into the circulatory system. The pituitary gland is located below the brain in a depression (fossa) of the sphenoid bone known as the sella turcica. Although anatomically and functionally connected to the brain, the pituitary gland sits outside the blood–brain barrier. It is separated from the subarachnoid space by the diaphragma sella, therefore the arachnoid mater and thus cerebral spinal fluid cannot enter the sella turcica.
The pituitary gland is divided into two lobes, the anterior lobe (which accounts for two thirds of the volume of the gland), and the posterior lobe (one third of the volume) separated by the pars intermedia.
The posterior lobe (the neural lobe or neurohypophysis) of the pituitary gland is not, despite its name, a true gland. The posterior lobe contains axons of neurons that extend from the hypothalamus to which it is connected via the pituitary stalk. The hormones vasopressin and oxytocin, produced by the neurons of the supraoptic and paraventricular nuclei of the hypothalamus, are stored in the posterior lobe and released from axon endings (dendrites) within the lobe.
The pituitary gland's anterior lobe (adenohypophysis) is a true gland which produces and secretes six different hormones: thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone(FSH), luteinizing hormone (LH), growth hormone (GH), and prolactin (PRL).
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