PubMed Health⌕ Search

Biomedical subjects

A Genc

Publications and source records attributed to A Genc.

9 recordsLinked to original sources
PubMed2001

Voxel-based morphometry using the RAVENS maps: methods and validation using simulated longitudinal atrophy.

Statistical analysis of anatomical maps in a stereotaxic space has been shown to be a useful tool in population-based studies for quantifying local anatomical differences or changes, without a priori assumptions about the location and extent of the regions of interest. This paper presents an extension and validation of a previously published methodology, referred to as RAVENS, for characterizing regional atrophy in the brain. A new method for elastic, volume-preserving spatial normalization, which allows for accurate quantification of very localized atrophy, is used. The RAVENS methodology was tested on images with simulated atrophy within two gyri: precentral and superior temporal. It was found to accurately determine the regions of atrophy, despite their localized nature and the interindividual variability of cortical structures. Moreover, it was found to perform substantially better than the voxel-based morphology method of SPM'99. Improved sensitivity was achieved at the expense of human effort involved in defining a number of sulcal curves that serve as constraints on the 3D elastic warping.

Atrophy↗
PubMed2001

Benign paroxysmal positional vertigo after stapedectomy.

OBJECTIVE: To determine the incidence of benign paroxysmal positional vertigo (BPPV) following stapedectomy in a patient group and the efficacy of the Epley maneuver in this group. STUDY DESIGN: Prospective study in a university-based tertiary referral system. METHODS: The patient group comprised 63 patients who had undergone stapedectomy; a control group consisted of normal healthy individuals with no otolaryngological complaints. All individuals underwent the Dix-Hallpike maneuver for the diagnosis of BPPV. Patients who exhibited vertigo, torsional nystagmus (which reverses its direction on return to sitting position) preceded by a latent period, and the fatigability of these findings were considered to have BPPV. If the test result was positive, they underwent the Epley therapeutic maneuver. RESULTS: Four of the patients who had undergone a stapedectomy showed characteristic findings of BPPV. No individual in the control group had BPPV. All patients responded well to the Epley maneuver. CONCLUSIONS: Stapedectomy may be regarded as an etiological factor in BPPV. Because the fenestra is located in the posterior part of the stapes footplate, the pathophysiology appears to be related to utricular rather than saccular trauma. Correct measurement of the distance between the incus and stapes footplate is essential in stapedectomy. An Internet survey of the relevant literature in English shows a scarcity of publications on the incidence of BPPV following stapedectomy. In the present study, 63 patients who had undergone a stapedectomy were investigated for the presence of BPPV; all had Dix-Hallpike maneuvers performed for the diagnosis. Sixty-three individuals with no otolaryngological complaints made up the control group. Four of the patients who had undergone stapedectomy showed characteristic findings of BPPV, and no individual in the control group had BPPV; the difference between the two groups was statistically significant. All four of the patients diagnosed with BPPV responded well to the Epley maneuver. The pathophysiology appears to be related to utricular trauma. Correct measurement of the distance between the incus and stapes footplate is essential in stapedectomy.

Adult↗
PubMed1999

Taurodontism in association with supernumerary teeth.

The dental, radiological, genetic and dermatoglyphic findings of an additional patient with taurodontism in association with supernumerary teeth were presented and the findings of the patient were compared with those in the literature.

Adult↗
PubMed1998

Leukemic children: clinical and histopathological gingival lesions.

The relation between leukemia and gingiva was investigated in the present study. An extensive tumor infiltration in the gingiva was established in 1 of 2 patients with acute leukemia (AML). An inflammatory cell infiltration in various degrees was noticed in total 28 patients with leukemia (L). Various degrees of epithelium hyperplasia in all patients existing in 14 patients with medium intensity and occurring in 14 patients with light intensity of hyperplasia were observed. An increase in the keratinization of epithelium, in 3 patients with medium intensity and 1 patient with light intensity was found. It was also seen that there were fungal infections in 3 patients with medium intensity, in 6 patients with light intensity and existing in a total 26 patients with acute lymphoblastic leukemia (ALL).

Adolescent↗
PubMed1997

Congenital hypodontia of maxillary lateral incisors in association with coloboma of the iris and hypomaturation type of amelogenesis imperfecta in a large kindred.

The dental, clinical, genetic, radiological and dermatoglyphic findings in patients from a large kindred with congenital hypodontia of maxillary lateral incisors (CHMLI) in association with coloboma of the iris (Cl) and hypomaturation type of amelogenesis imperfecta (HTAI) are presented. The pedigree of the kindred showing multiple consanguinaeous marriages and the findings of the family members with CHMLI and a family member with CHMLI, Cl and HTAI and two members with both CHMLI and HTAI suggested that the isolated CHMLI was due to an autosomal recessive gene, but, the Cl was determined by an autosomal dominant gene linked to CHMLI gene. HTAI was an autosomal recessive character linked to both CHMLI and Cl.

Abnormalities, Multiple↗
PubMed1996

Local, hypoplastic type of amelogenesis imperfecta: a clinical, genetic, radiological and dermatoglyphic study.

A patient and her family members showing X-linked dominant form local, hypoplastic type of amelogenesis imperfecta (AI) were investigated from view-point of their teeth, clinical, genetic, radiological and particularly dermatoglyphic findings. It was suggested that it might be a close relationship between the intra-uterine development of both AI and unusual dermatoglyphs originated from the same layer, ectoderm and an X-linked dominant gene could determine both abnormal teeth and unusual dermatoglyphic characteristics in questions.

Adolescent↗
PubMedDate not supplied

Evaluation of 3D image registration as applied to MR-guided thermal treatment of liver cancer.

There are many potential applications of three-dimensional (3D) image registration in MR-guided radiofrequency (RF) thermal ablation of tumors. For example, after registration of image volumes obtained before and after thermal ablation, a variety of quantitative and visual assessments of therapy were performed. For liver tumors, the accuracy of rigid body, manual registration on 19 pairs of image volumes was evaluated, almost all of which were obtained during thermal treatment sessions. Registration error was estimated as a distance between anatomical landmarks, including both internal vascular structures as well as the surface of the liver. Over all image pairs and throughout a large portion of the liver, the registration error was 3.1 mm (mean + 1 SD). From the bottom to the top of the liver, error increased on the order of 13%, probably because of liver motion and deformation resulting from respiration. Although probably insufficient for blind guidance of therapy, registration accuracy was undoubtedly sufficient for interesting applications in the planning, assessment, and optimization of interventional MR-guided thermal treatment of liver tumors.

Catheter Ablation↗