The potentials of magnetic resonance tomography in the diagnosis of the “empty” sella turcica

Abstract

The term ~empty" sella turcica (EST) was first introduced by Bush in 1951, when in describing the data of 788 autopsies, the diaphragm of the sella was completely lacking in 5.5% of cases, and the hypophysis was spread out on the floor in the form of a thin lamina. This being the case, the sella appeared empty. As a disease, the EST was described in 1962 in patients subjected to surgical or radiation therapy because of endosellar adenoma of the hypophysis. It was later related to the syndrome of secondary EST. Primary EST is characterized by the presence of insufficiency of the diaphragm of the sella turcica with a decrease in the volume of the hypophysis and expansion of the intrasellar subarachnoid space. There are reports in the literature touching on the anatomical, roentgenological, and clinical manifestations of this pathological state [4,7,8]. However, the diagnosis of EST is complicated, since the clinical-roentgenological changes are insufficiently specific and may imitate an endosellar tumor of the hypophysis. The pneumocisternography and computerized tomography with preliminary contrasting that are used today [7,9] are invasive methods and are associated with a substantial radiation burden.One of the most promising methods in solving the problem of the recognition of EST is the new noninvasive method of endoscopic diagnosis, tomography based on the phenomenon of nuclear magnetic resonance, magnetic resonance tomography (MRT). The method makes it possible to carry out an investigation without the use of ionizing radiation or the introduction of iodide or any other contrast agents; the investigation can be carried out multiply, over the course of time, in the three mutually perpendicular planes; it has the Department of Endocrinology, I. M. Sechenov Moscow Medical Academy; Laboratory of Magnetic Resonance Tomography of the Cardiological Scientific Center, Russian Academy Medical Sciences, Moscow. capacity to differentiate soft tissue, and makes it possible to simultaneously obtain images of various organs and systems [1-3, 6, 11]. There are only individual reports relative to the use of MRT for the diagnosis of EST, which, in addition, are based on a small number of clinical observations, have highly contradictory data, relate mainly to secondary 9 EST following operative treatment of adenomas of the hypophysis, or include descriptions of patients with EST out of relationship with endocrinological symptomatology [5].The aim of this study was the determination of the capacities of MRT in the diagnosis of EST. 229 MATERIALS AND METHODSOne hundred and ten patients with the most prevalent diseases of the hypothalamohypophyseal system were examined. The distribution of the patients with the respect to nosologic forms is presented in Table 1.The diagnostic formulations were based on a comprehensive clinical-laboratory investigation, including x-ray craniography in two projections, investigation of the level of hormonal markers specific for the particular diseases (prolactin, TI'H, ACTH, STH, thyroid and adrena...

Brain Findings Associated with Iodine Deficiency Identified by Magnetic Resonance Methods: A Systematic Review

“…In total, 165 subjects were included from the 29 studies. Of these, 46 subjects were in studies on primary hypothyroidism [52][53][54][55][56][57][58][59][60][61][62][63][64][65][66] (i.e. in which hypothyroidism was related to ID), 97 subjects in studies on congenital hypothyroidism [67][68][69][70][71][72][73][74][75][76][77], 3 subjects in a study of endemic cretinism [78], 11 subjects in a study of subclinical hypothyroidism [79,80] and 8 subjects in a study of perinatal hypothyroidism [80] (Figure 2).…”

“…T2-weighted (T2W) sequence was utilised in 11/29 studies whilst 6/29 studies did not clarify the MRI sequence used. In 2 studies, only 60% of the hypothyroid patients showed brain changes on MRI [54,74] (Table 3).…”

“…None of the 29 included papers investigated the effect of using different MR magnetic field strengths on the appearance of brain changes caused by ID, with 11/29 of the studies not clarifying the strength used. Most studies used a 1.5 Tesla magnet strength (6/29 studies) with two sing a low 0.2 Tesla strength [54,70]. The animal study u…”