Biomedical subjects

M G P Cavalcanti

Publications and source records attributed to M G P Cavalcanti.

4 recordsLinked to original sources

PubMed2004

Craniofacial measurements based on 3D-CT volume rendering: implications for clinical applications.

OBJECTIVES: This study was designed to determine the precision and accuracy of anthropometric measurements using three-dimensional computed tomography (3D-CT) volume rendering by computer systems for craniofacial clinical applications, and to compare the craniometric landmarks using bone and soft tissue protocols. METHODS: The study population consisted of 13 cadaver heads that were examined with spiral CT. The archived CT data were transferred to a workstation, and 3D-CT volume rendered images were generated using computer graphics tools. Linear measurements (n = 10), based upon conventional craniometric anatomical landmarks (n = 08), were identified in 2D-CT and in 3D-CT images by two radiologists twice each independently, and then performed by 3D-CT imaging using a computer graphics systems using bone and soft tissue protocols. In total, 520 imaging measurements were made. The soft tissues were subsequently removed from the cadaver heads and the measurements were repeated using an electromagnetic 3 Space trade mark digitizer. RESULTS: The results demonstrated no statistically significant difference between interobserver and intraobserver measurements or between imaging and physical measurements in both 3D-CT protocols. The standard error was found to be between 0.45% and 1.44% for all the measurements in both protocols, indicating a high level of precision. Furthermore, there was no statistically significant difference between imaging and physical measurements (P > 0.01). The error between the mean actual and mean 3D-based linear measurements was 0.83% for bone and 1.78% for soft tissue measurements, demonstrating high accuracy of both 3D-CT protocols. CONCLUSIONS: 3D-CT volume rendering images using craniometric measurements can be used for anthropological studies involving craniofacial applications.

Aged↗

PubMed2003

Clinical-embryological and radiological correlations of oculo-auriculo-vertebral spectrum using 3D-CT.

OBJECTIVES: The purpose of this paper is to present a variety of imaging findings of oculo-auriculo-vertebral spectrum (Goldenhar syndrome) using three-dimensional reconstructed images from computed tomography (3D-CT), associating clinical and embryological patterns of the syndrome. METHODS: The study population consisted of 10 patients with oculo-auriculo-vertebral spectrum with clinically identified hemifacial microsomia. The patients were examined using spiral CT, and abnormal imaging features were grouped under facial, ear and temporal bone, vertebral, and skull base anomalies. The original CT data were transferred to a networked computer workstation with a computer graphics system to generate 3D-CT volume rendered images of the skull and vertebra. Two observers analysed the bone and muscular setting protocols to assess the relationship between bone and muscular structures. RESULTS: Asymmetric underdevelopment was a characteristic pattern of this syndrome resulting from hypoplasia of the mandibular ramus and condyle, the zygomatic, sphenoid and auricular conduct bones, and the temporal and masseter muscles. The syndrome was associated with local atrophy seen on 3D-CT images using specific bone and muscles protocols in all cases. CONCLUSIONS: Understanding the aetiology, embryology and wide imaging spectrum of this syndrome is essential to make a correct diagnosis, for treatment planning, and for evaluation when associated with a 3D-CT computer graphics system.

Adolescent↗

PubMed2002

3D volume rendering using multislice CT for dental implants.

OBJECTIVES: To determine the precision and accuracy of three-dimensional (3D) volume rendering spiral multislice computed tomography (CT)-based linear measurements of the mental foramen for dental implants, in vitro, and their precision, in vivo. METHODS: Five cadaver heads were imaged by multislice spiral CT (Toshiba Aquilion) with 0.5 mm thick axial slices (0.5 mm/0.5 s of table feed) at 0.5 mm interval reconstructions. The image data sets were transferred to a networked computer workstation. Using computer graphics the data were analysed with a 3D volume rendering technique using Vitrea software. Two oral and maxillofacial radiologists, independently, made electronic linear measurements from the superior border of the mental foramen to the crest of the alveolar process. The soft tissues were removed and physical measurements made using a 3 Space (Polhemus, Colchester, VT, USA) electromagnetic digitizer with a personal computer running Windows 98. The same linear measurements of 15 patients using the same imaging methodology were performed and the precision was analysed. RESULTS: The findings showed no statistically significant inter- or intra-observer differences in vitro and in vivo, or between imaging and physical measurements in vitro (P>0.05). CONCLUSIONS: 3D multislice spiral CT imaging allows highly accurate measurements for dental implant placement in proximity to the mental foramen. Computer graphics software, using volume rendering is suitable for implant planning.

Aged↗

PubMedDate not supplied

Volumetric and linear assessment of maxillary sinuses using computed tomography.

The purpose of this work was to compare linear and volumetric measurements of maxillary sinus (with and without lesion), using 3D (gold standard) and multiplanar reconstructions (MRP) by computed tomography in order to establish the precision and accuracy of these methods, determining which one would allow more effective assessments for this site. Linear measurements were performed in the maxillary sinus of 50 patients and compared with MPR and 3D images. We also analyzed the area and volume of this anatomic structure. Inter- and intra-observer average percentage errors for linear measurements were lower than 4%, the samples with lesion presenting higher values. The average error of accuracy was 4.94% for sinuses with lesion, and 7.41% for those without. We could verify that the antero-posterior and right-left measurements in axial view showed smaller figures of error when compared to sagittal and coronal reconstructions, respectively. The largest diameters observed for the sinuses had, in average, 39.6 mm in the antero-posterior direction, 28.35 mm in the right-left direction, and 36.3 mm in the supero-inferior. For the volume and area assessment, the values of error ranged lower than 9%, the highest values corresponding to the samples with lesion. The precision of measurements was inferior for maxillary sinus with lesion when compared with those without lesion. Measurements performed in the axial view were more precise than those performed in MPR images, and the coronal view measurements were considered to be more precise than the sagittal measurements.

Cephalometry↗