Image resampling is of particular interest in digital radiology. When resampling an image to a new set of coordinate, there appears blocking artifacts and image changes. To enhance image quality, interpolation algorithms have been used. Resampling is used to increase the number of points in an image to improve its appearance for display. The process of interpolation is fitting a continuous function to the discrete points in the digital image. The purpose of this study was to determine the effects of the seven interpolation functions when image resampling in digital periapical images. The images were obtained by Digora, CDR and scanning of Ektaspeed plus periapical radiograms on the dry skull and human subject. The subjects were exposed to intraoral X-ray machine at 60kVp and 70 kVp with exposure time varying between 0.01 and 0.50 second. To determine which interpolation method would provide the better image, seven functions were compared ; (1) nearest neighbor (2) linear (3) non-linear (4) facet model (5) cubic convolution (6) cubic spline (7) gray segment expansion. And resampled images were compared in terms of SNR(Signal to Noise Ratio) and MTF(Modulation Transfer Function) coefficient value. The obtained results were as follows ; 1. The highest SNR value(75.96dB) was obtained with cubic convolution method and the lowest SNR value(72.44dB) was obtained with facet model method among seven interpolation methods. 2. There were significant differences of SNR values among CDR, Digora and film scan(p<0.05). 3. There were significant differences of SNR values between 60kVp and 70kVp in seven interpolation methods. There were significant differences of SNR values between facet model method and those of the other methods at 60kVp(p<0.05), but there were not significant differences of snr values among seven interpolation methods at>0.05). 4. There were significant differences of MTF coefficient values between linear interpolation method and the other six interpolation methods(p<0.05). 5. The speed of computation time was the fastest with nearest neighbor method and the slowest with non-linear method. 6. The better image was obtained with cubic convolution, cubic spline and gray segment method in ROC analysis. 7. The better sharpness of edge was obtained with gray segment expansion method among seven interpolation methods.
Artifacts ; Humans ; Noise ; Radiography, Dental, Digital ; ROC Curve ; Skull

The purpose of this study was to aid in the use of the digital images by edge-detect interpolation for direct digital periapical images using edge-deted interpolation. This study was performed by image processing of 20 digital periapical images; pixel replication, linear non-interpolation, linear interpolation, and edge-sensitive interpolation. The obtained results were as follows ; 1. Pixel replication showed blocking artifact and serious image distortion. 2. Linear interpolation showed smoothing effect on the edge. 3. Edge-sensitive interpolation overcame the smoothing effect on the edge and showed better image.
Artifacts

The purpose of this study was to compare E-speed film, CDR, and modified CDR images by means of observing some artificial defects of alveolar bone wall in the sound human dried mandibles. High diagnostic accuracy was shown in 1 wall and 4 wall defects by all 5 observers (2 Radiologists, 2 Periodontists, 1 General practitioner), but the diagnosis in 2 wall and 3 wall defects was inaccurate. Modified CDR images had the more diagnostic accuracy than E-speed film and CDR images, but there was no statistical difference among them. Finally, radiologist used modified CDR images more than others and used equalization effect more than the change in contrast and/or brightness.
Diagnosis ; Humans ; Mandible ; Radiographic Image Enhancement*

PURPOSE: To evaluate whether radial rigidity measured using RigiScan(R) represents the intracorporeal pressure effectively. MATERIALS AND METHODS: From January 1998 to May 1999, total of 23 patients with erectile dysfunction were evaluated by RigiScan(R) and duplex ultrasonography after the intracorporeal injection of prostaglandin E1. Peak systolic velocity and end diastolic velocity were measured by duplex ultrasonography and then the resistance index was calculated as (peak systolic velocity-end diastolic velocity)/(peak systolic velocity). Radial rigidity of penile tip and base was measured by RigiScanR . The results were analyzed statistically by PC-SPSS version 7.5. RESULTS: There were statistically significant correlations between radial rigidity of penile tip and base and the resistance index by Spearman's correlation analysis, respectively (r=0.680, p<0.001)(r=0.703, p<0.001). When radial rigidity of penile tip and base exceeded 60% of maximum, radial rigidity of penile tip and base again correlated well with the resistance index, respectively (r=0.659, p=0.020)(r=0.759, p=0.011). Based on clinically determined degree of erection, radial rigidity of penile tip and base represented the intracorporeal pressure effectively. CONCLUSIONS: Radial rigidity measured by RigiScan(R) represents the intracorporeal pressure effectively.
Alprostadil* ; Erectile Dysfunction ; Humans ; Male ; Ultrasonography

No abstract available.
Diskectomy*

We report a case of cutis verticis gyrata-mental deficiency syndrome associated with generalized epidermal nevus. The clinical features of the patient included severe mental retardation, drug resistant epilepsy, short stature, scaphocephaly and dysmorphic face with scanty scalp hair, hypertelorism, long palpebral fissure, low nasal bridge, hyperplasia of ala nasi, low-set ears with convoluted fold, and partial obstruction of the nasolacrimal ducts. Multiple convoluted folds and furrows on the scalp were extended to eyebrows and nose. Both lateral ventricle with periventricular leukomalacia were dilated markedly and the corpus callosum was hypoplastic on brain MRI. The nature of the yellowish brown colored elevated skin nevi on the whole body was consistent with systemic epidermal nevus by pathological study.
Brain ; Corpus Callosum ; Craniosynostoses ; Ear ; Epilepsy ; Eyebrows ; Hair ; Humans ; Hyperplasia ; Hypertelorism ; Infant, Newborn ; Intellectual Disability ; Lateral Ventricles ; Leukomalacia, Periventricular ; Magnetic Resonance Imaging ; Nasolacrimal Duct ; Nevus* ; Nose ; Scalp ; Skin

No abstract available.
Stroke*

The location of the mandibular canal and the cortical thickness of the mandible is important in the practice of de ntistry. This study was preformed on twenty chosen dry mandibles, which were of adults and included fully erupted premol ars and molars. The purpose of this study was to evaluate the location of the mandibular canal and the cortical thikness of the mandi ble on computed tomograms and to aid in the surgical treatment plans. The obtained results were as follows : 1. The horizontal distance between the mandibular canal and the buccal external border was 6.6+/-0.9mm on S0( mesial root of the first molar), and it was increased posteriorly. The horizontal distance between the mandibular canal and the lingual external border was 4.1+/-1.1mm on S0, and it was decreased posteriorly. 2. The vertical distance between the alveolar crest and the mandibular canal was 16.9+/-1.6mm on S0, and it w as decreased posteriorly. The vertical distance between the inferior border of mandible and mandibular canal was 8.8+/-1. 3mm on S0. and it was increased anteriorly and posteriorly. 3. The thickness of the buccal cortical plate was 2.2+/-0.4mm on S0. and it was increased posteriorly. But, t hat of the lingual cortical palte was 2.0+/-0.6mm on S0. and it was decreased posteriorly. 4. The area of the buccal cortical plate was 66.5+/-1.0mm2 on S0. and it was increased posteriorly . But, that of the lingual cortical plate was 65.8+/-0.9mm2 on S0 and it was decreased posteriorly.
Adult ; Humans ; Mandible* ; Molar

The location of the mandibular canal and the cortical thickness of the mandible is important in the practice of de ntistry. This study was preformed on twenty chosen dry mandibles, which were of adults and included fully erupted premol ars and molars. The purpose of this study was to evaluate the location of the mandibular canal and the cortical thikness of the mandi ble on computed tomograms and to aid in the surgical treatment plans. The obtained results were as follows : 1. The horizontal distance between the mandibular canal and the buccal external border was 6.6+/-0.9mm on S0( mesial root of the first molar), and it was increased posteriorly. The horizontal distance between the mandibular canal and the lingual external border was 4.1+/-1.1mm on S0, and it was decreased posteriorly. 2. The vertical distance between the alveolar crest and the mandibular canal was 16.9+/-1.6mm on S0, and it w as decreased posteriorly. The vertical distance between the inferior border of mandible and mandibular canal was 8.8+/-1. 3mm on S0. and it was increased anteriorly and posteriorly. 3. The thickness of the buccal cortical plate was 2.2+/-0.4mm on S0. and it was increased posteriorly. But, t hat of the lingual cortical palte was 2.0+/-0.6mm on S0. and it was decreased posteriorly. 4. The area of the buccal cortical plate was 66.5+/-1.0mm2 on S0. and it was increased posteriorly . But, that of the lingual cortical plate was 65.8+/-0.9mm2 on S0 and it was decreased posteriorly.
Adult ; Humans ; Mandible* ; Molar

The purpose of this study was to identify the branching patterns and the distribution of the cortical branches of the middle cerebral artery (MCA) in 100 cerebral hemispheres of Korean adults. The intracranial arteries were perfused with red latex compounds. The territory of the MCA was divided into 12 areas: orbitofrontal, prefrontal, precentral, central, anterior parietal, posterior parietal, angular, temporo -occipital, posterior temporal, middle temporal, anterior temporal and temporopolar. Branching pattern of the main trunk of the MCA was divided into five types: Type I: a single -trunk type of MCA in 34% of cases; Type II: bifurcation (57%); Type III: trifurcation (5%); Type IV: quadrifurcation (1%); Type V: two MCAs originated from the internal carotid artery (3%). The MCA of the bifurcation type was classified into equal bifurcation (20%), superior trunk dominant (11%) and inferior trunk dominant (26%) according to the cortical area. The superior trunk of the equal bifurcation supplied from the orbitofrontal to posterior parietal area. The outer diameter of the main trunk of the MCA was 3.15 +/-0.52 mm on average. The anatomical types of the MCA were discussed with the related symptoms in disease of the MCA.
Adult ; Arteries ; Carotid Artery, Internal ; Cerebrum ; Humans ; Latex ; Middle Cerebral Artery* ; Rabeprazole