Mri Findings in Patients With Hypogonadotrophic Hypogonadism That Are Characteristics of Kallmann Syndrome

Abstract

One of the congenital disorders that is characterized by reduced or even absent sense of smell, hyposmia or anosmia, is Kallmann syndrome. Actually, the principal problem is hypogonadism since this congenital disorder is characterized in addition to smell abnormality by hypogonadotrophic hypogonadism.In addition to hormonal assays, imaging techniques and mainly MRI plays an important role in establishing the diagnosis. In this Iraqi study, 20 patients with hypogonadotrophic hypogonadism have been examined by MRI in order to identify features that are caharcetristic of Kallmann syndrome contrasted to idiopathic hypogonadotrophic hypogonadism. The current study was carried out in the radiology unit at AL-Hilla Teaching Hospital, Babylon province, Iraq. The study was carried out in cooperation with urology unit. The study included a series of 20 patients who were referred by urology department for the assessment of cause of hypogonadotrophic hypogonadism following initial suggestion based on hormonal levels, FSH, LH and testosterone. The age range of those patients was form 20 to 27 years. The MRI imaging included coronal, sagital and axial T1 and T2 weighted images. The thickness of images was 3 mm and the interslice gap was 0.3 mm. Performance of MRI imaging was carried out using 1.5 T GE system. According to MRI examination, there were 5 patients with absent olfactory bulb accounting for 25 % and 3 with absent olfactory sulcus accounting for 15 %, as shown in figure 1. Twelve patients had no detectable MRI abnormality and therefore were considered to have idiopathic hypogonadotrphic hypogonadism; where those 8 patients with abnormal MRI findings were considered to have Kallman syndrome. Absent olfactory bulb was significantly asscoaited with anosmia. The principal findings in MRI that differentiate Kallman syndrome from idiopathic hypogonadotrophic hypogonadism are olfactory bulb and sulcus abnormalities that are best visualized using coronal MRI scanning.