Computed Tomography Studies Research Articles

Inner Ear Breaches from Vestibular Schwannoma Surgery: Revisiting the Incidence of Otologic Injury from Retrosigmoid and Middle Cranial Fossa Approaches.

To assess the rate of iatrogenic injury to the inner ear in vestibular schwannoma resections. Retrospective case review. Multiple academic tertiary care hospitals. Patients who underwent retrosigmoid or middle cranial fossa approaches for vestibular schwannoma resection between 1993 and 2015. Diagnostic with therapeutic implications. Drilling breach of the inner ear as confirmed by operative note or postoperative computed tomography (CT). 21.5% of patients undergoing either retrosigmoid or middle fossa approaches to the internal auditory canal were identified with a breach of the vestibulocochlear system. Because of the lack of postoperative CT imaging in this cohort, this is likely an underestimation of the true incidence of inner ear breaches. Of all postoperative CT scans reviewed, 51.8% had an inner ear breach. As there may be bias in patients undergoing postoperative CT, a middle figure based on sensitivity analyses estimates the incidence of inner ear breaches from lateral skull base surgery to be 34.7%. A high percentage of vestibular schwannoma surgeries via retrosigmoid and middle cranial fossa approaches result in drilling breaches of the inner ear. This study reinforces the value of preoperative image analysis for determining risk of inner ear breaches during vestibular schwannoma surgery and the importance of acquiring CT studies postoperatively to evaluate the integrity of the inner ear.

Anatomical Evaluation of the Greater Palatine Foramen: A Cone-Beam Computed Tomography Study in Tunisian Patients

This study used CBCT to examine the greater palatine foramen in Tunisian patients, aiming to provide crucial anatomical information for administering greater palatine nerve block anesthesia and identifying appropriate locations for harvesting palatal donor tissue. A total of 63 CBCT scans were conducted on Tunisian patients. All patients had fully erupted first, second, and third molars, leading to the examination of 100 greater palatine foramina (GPF). The evaluation of the GPFs encompassed their positioning, Antero-posterior (AP) and latero-medial (LM) diameters, as well as their distances from both the midline maxillary suture (MMS) and the alveolar ridge top (ART). The measurements were conducted using the distance measuring tool of Romexis® viewer software. The IBM® SPSS® version 20.0 statistical package was used to carry out all statistical analyses. The study included 100 CBCTs, with participants consisting of 37 males (58.73%) and 26 females (41.27%), having an average age of 34±12 years. Among the 100 GPFs analyzed, 68% were near the third molar, 23% were situated behind it, and 9% were positioned opposite to the second molar. The average AP and LM diameters were 4.64mm (±1.15) and 2.53mm (±0.68), respectively. The mean distances to the MMS and ART were 13.9mm (±1.51) and 11.45mm (±2.09), respectively. Among Tunisian patients, the GPF position is quite variable, seldom found opposite to the second molar, and tends to be in closer proximity to the third molar.

Assessment of Hounsfield Units and Factors Associated with Fragmentation of Renal Stones by Extracorporeal Shock Wave Lithotripsy: A Computerized Tomography Study.

This retrospective single-center study was conducted in the King Fahad Hospital. Sixty-seven adult patients with renal and ureteric stones were selected randomly and enrolled in the study. Their ages ranged from 20 to 69 years. The patients were examined with non-contrast enhancement (NCCT) to assess the HU of their stones and were consequently treated with ESWL. Of the 67 patients, 37.3% had stones that were completely fragmented, while 62.7% had stones that were partially fragmented. The HU, location of the stone, multiplicity of the stone, and patient age were found to be significant factors contributing to stone fragility (p-values < 0.05). The HU data were found to have a positive significant linear correlation with serum calcium (r = 0.28, p-value = 0.036), while serum acid had a negative correlation (r = -0.55, p-value < 0.001). Thus, the probability of calcium-containing stone formation increases with increased HU. In contrast, uric acid stone formation likely develops with decreasing HU with serum uric acid. Renal stones in patients with diabetes mellitus and hypertension were not completely fragmented compared to those without clinical history. Mean HU, location of the stone, laterality, stone status, and the number of ESWL sessions are the most significant factors affecting stone fragility. CT attenuation values can predict the composition of stones from serum calcium and uric acid examinations. Hypertension and diabetes mellitus are risk factors for renal stone fragmentation.

Association between increased Subcutaneous Adipose Tissue Radiodensity and cancer mortality: Automated computation, comparison of cancer types, gender, and scanner bias

PurposeBody composition analysis using computed tomography (CT) is proposed as a predictor of cancer mortality. An association between subcutaneous adipose tissue radiodensity (SATr) and cancer-specific mortality was established, while gender effects and equipment bias were estimated. Methods7,475 CT studies were selected from 17 cohorts containing CT images of untreated cancer patients who underwent follow-up for a period of 2.1–118.8 months. SATr measures were collected from published data (n = 6,718) or calculated according to CT images using a deep-learning network (n = 757). The association between SATr and mortality was ascertained for each cohort and gender using the p-value from either logistic regression or ROC analysis. The Kruskal-Wallis test was used to analyze differences between gender distributions, and automatic segmentation was evaluated using the Dice score and five-point Likert quality scale. Gender effect, scanner bias and changes in the Hounsfield unit (HU) to detect hazards were also estimated. ResultsHigher SATr was associated with mortality in eight cancer types (p < 0.05). Automatic segmentation produced a score of 0.949 while the quality scale measurement was good to excellent. The extent of gender effect was 5.2 HU while the scanner bias was 10.3 HU. The minimum proposed HU change to detect a patient at risk of death was between 5.6 and 8.3 HU. ConclusionsCT imaging provides valuable assessments of body composition as part of the staging process for several cancer types, saving both time and cost. Gender specific scales and scanner bias adjustments should be carried out to successfully implement SATr measures in clinical practice.

The predictive role of computed tomography with oral contrast in the successful management of adhesive small bowel obstruction

Background Adhesive small bowel obstruction (SBO) stands out as one of the most frequent and clinically significant complications following abdominal surgery. The present study aimed to investigate the role of computed tomography (CT) with oral contrast media in guiding treatment and predicting the success of conservative treatment in patients presenting with adhesive SBO. Patients and methods This is a prospective study that was conducted on adult patients who were clinically and radiologically proven to have SBO and had a history of at least one previous abdominal surgical intervention. The included patients underwent CT examination of the abdomen and pelvis with oral contrast. Patients who had the oral contrast seen reaching the right colon were admitted and completed conservative management. Surgical intervention was indicated in patients who showed failure of treatment with oral contrast. Results This study included 70 patients, of whom 29 (41.4%) had contrast in the right colon during CT examination after the first oral contrast administration. The remaining patients (n=41, 58.6%) indicated a second oral contrast CT study after 24 h. Sixteen (22.9%) patients had nonresolving obstructions and underwent surgical intervention. Overall, 52 (74.3%) patients were successfully treated with oral contrast studies, with no subsequent morbidity. Significant predictors for surgical intervention were a history of more than one previous surgical intervention (OR=6.08, CI: 1.75–21.14, P=0.005) and nonpassage of contrast to the right colon in the CT study (OR=0.099, CI: 0.029–0.341, P&lt;0.001). Conclusion This study highlights the clinical relevance of CT with oral contrast studies in guiding management. A history of multiple previous surgeries and nonpassage of the oral contrast to the right colon emerged as a significant predictor for surgical intervention.

CT correlation of spinal canal diameter with pedicle size for safer posterior cervical pedicle screw fixation.

Utilizing computed tomography (CT) studies, we correlated cervical spinal canal diameters (SCDs) with pedicle size between the C3 and C7 levels to more safely perform posterior cervical surgery. We retrospectively analyzed CT studies for 71 patients with cranial or spinal disorders and correlated the cervical SCD with the pedicle outer width (POW) between the C3 and C7 levels. Patients were divided into normal (SCD ≥12 mm at any level, n = 30) and stenosis groups (SCD <12 mm at any level, n = 41). C7 exhibited the largest SCD and POW values, while C3 and C4 exhibited the smallest SCD and POW values. Moderate correlations (r = 0.3, P = 0.002) were observed at the C3 and C4 levels but no significant correlations were observed from the C5 to C7 levels. For SCD values, the normal group demonstrated significantly greater values between the C3 and C7 levels versus the stenosis group. For POW values, only the C4 level differed significantly between the two groups (P = 0.014, Mann-Whitney U-test). Preoperative pedicle size evaluation remains an essential manoeuvre before performing cervical C3-C7 pedicle screw placement. In 71 cervical CT studies, we found no consistent correlation between POW and SCD values, indicating that it is difficult to estimate POW values based on spinal canal size.

The efficacy of XP endo retreatment system in removing bioceramic sealer from dentinal walls: An in vitro micro computed tomography study

Objectives: This study compared the efficacy of the XP endo retreatment (XPER) system in removing Total Fill Hi Flow BC (Bio ceramic) and Total Fill BC sealers from dentinal walls to that of the Pro Taper Universal retreatment (PTUR) system using micro-computed tomography (micro CT) analysis.

Evaluation of the relationship between the presence of an accessory maxillary ostium and the presence and types of nasal septum deviation: A computed tomography study.

The maxillary accessory ostium (AMO) has been associated with chronic rhinosinusitis and nasal septal deviation (NSD), but AMO may also be present in healthy individuals. AMO's purpose, origin, and effects are uncertain. This study aimed to investigate the types and frequency of AMO and NSD, as well as their relationship. In our retrospective, single-center study, paranasal sinus tomographs performed in our clinic between 2022 and 2023 were scanned, and 200 patients who met the inclusion criteria were evaluated in terms of AMO direction (right/left), accessory ostium location (superior/middle/inferior 1/3), presence of NSD, and deviation type according to the Mladina index. 60.5% of the patients were female and 39.5% were male. AMO distribution was similar between the groups (p>0.05). There was no significant correlation between the presence and localization of AMO and the presence of NSD (p>0.05). NSD was detected in 93 patients (89.4%) with AMO and 78 patients (81.3%) without AMO (p=0.16). The distribution of NSD presence and types was similar in right or left localization, AMO (+) and AMO (-) patients (p>0.05). The evidence that AMOs cause chronic sinusitis and FESS failure is insufficient and cannot explain the presence of AMOs in healthy individuals or children. There are very few studies in the literature examining the NSD-AMO relationship. In our study, high rates of NSD and AMO were found in individuals without paranasal disease, but no statistically significant relationship was found between the presence, location, and type of NSD and AMO. Early-onset, long-term prospective studies on the relationship between NSD and AMO may help to explain the etiopathogenesis of paranasal diseases that reduce quality of life.

Differences in pulmonary nodular consolidation and pulmonary cavity among drug-sensitive, rifampicin-resistant and multi-drug resistant tuberculosis patients: the Guangzhou computerized tomography study.

Pulmonary nodular consolidation (PN) and pulmonary cavity (PC) may represent the two most promising imaging signs in differentiating multidrug-resistant (MDR)-pulmonary tuberculosis (PTB) from drug-sensitive (DS)-PTB. However, there have been concerns that literature described radiological feature differences between DS-PTB and MDR-PTB were confounded by that MDR-PTB cases tend to have a longer history. This study seeks to further clarify this point. All cases were from the Guangzhou Chest Hospital, Guangzhou, China. We retrieved data of consecutive new MDR cases [n=46, inclusive of rifampicin-resistant (RR) cases] treated during the period of July 2020 and December 2021, and according to the electronic case archiving system records, the main PTB-related symptoms/signs history was ≤3 months till the first computed tomography (CT) scan in Guangzhou Chest Hospital was taken. To pair the MDR-PTB cases with assumed equal disease history length, we additionally retrieved data of 46 cases of DS-PTB patients. Twenty-two of the DS patients and 30 of the MDR patients were from rural communities. The first CT in Guangzhou Chest Hospital was analysed in this study. When the CT was taken, most cases had anti-TB drug treatment for less than 2 weeks, and none had been treated for more than 3 weeks. Apparent CT signs associated with chronicity were noted in 10 cases in the DS group (10/46) and 9 cases in the MDR group (10/46). Thus, the overall disease history would have been longer than the assumed <3 months. Still, the history length difference between DS patients and MDR patients in the current study might not be substantial. The lung volume involvement was 11.3%±8.3% for DS cases and 8.4%±6.6% for MDR cases (P=0.022). There was no statistical difference between DS cases and MDR cases both in PN prevalence and in PC prevalence. For positive cases, MDR cases had more PN number (mean of positive cases: 2.63 vs. 2.28, P=0.38) and PC number (mean of positive cases: 2.14 vs. 1.38, P=0.001) than DS cases. Receiver operating characteristic curve analysis shows, PN ≥4 and PC ≥3 had a specificity of 86% (sensitivity 25%) and 93% (sensitivity 36%), respectively, in suggesting the patient being a MDR cases. A combination of PN and PC features allows statistical separation of DS and MDR cases.

Pedicle morphometry of the C7 and T1 vertebrae in an argentine population.

We evaluated how and whether the pedicular morphometry of the C7 and T1 vertebrae might impact C7/T1 spinal fusions for patients from Argentina. Using computed tomography (CT) scans, we evaluated the pedicular morphology at the C7 and T1 levels. Among 102 male and female CT studies, we observed significant differences in the height, width, length, and morphometry of the C7 and T1 pedicles. This study of C7/T1 CT scans revealed significant sex-based morphometric differences, particularly in pedicle height, width, and length at C7 and T1. Given the notable variability in vertebral characteristics observed in our study sample, we recommend preoperative planning with CT scans for C7/T1 fusion.

Healing of Humeral Intracondylar Fissure Following Distal Ulnar Ostectomy to Treat Concurrent Elbow Joint Incongruity in a Dog

AbstractA 22-week-old female Labrador retriever presented with intermittent bilateral forelimb lameness. Computed tomography (CT) study interpretation revealed bilateral humeral intracondylar fissures (HIF) surrounded by sclerotic epiphyseal bone. Other changes included bilateral distal ulna retained cartilage core, secondary negative radioulnar incongruity (RUI), and medial coronoid process disease. The patient underwent bilateral dynamic distal ulnar ostectomies (DUO) in an attempt to address the elbow incongruity. Follow-up CT studies were performed at 2, 4, and 10 months postoperatively, which showed a bilateral improvement of elbow congruence and complete healing of HIF on the left side. The degree of congruence correction in the right elbow was possibly suboptimal, and following an initial improvement, a transcondylar screw was placed due to HIF progression.

Evaluation of the infrazygomatic crest and mandibular buccal shelf in different sagittal skeletal patterns: a cone-beam computed tomography study

Abstract Objectives To compare bone thickness, bone height, and density in the infrazygomatic crest (IZC) and the mandibular buccal shelf (MBS) associated with different sagittal skeletal patterns. Material and Methods This retrospective study included three groups of which a Class I group consisted of 28 patients (24 female, 4 male, mean age: 26.46 ± 6.1), a Class II group comprised 31 patients (28 female, 3 male, mean age: 30.08 ± 5.9), and a Class III group included 26 patients (22 female, 4 male, mean age: 26.21 ± 5.3). Evaluations of bone characteristics were performed for both the IZC and MBS using cone-beam computed tomography (CBCT). Maxillary length and mandibular body length were also measured on lateral cephalograms. One-way ANOVA, chi-squared, and Spearman’s correlation tests were applied for statistical analysis. Results The Class II group showed significantly greater bone thickness at the distal root level of the maxillary second molar in IZC (p &lt; 0.05). While bone thickness showed no statistically significant difference in the MBS between the groups (p &gt; 0.05), the Class II group showed significantly higher bone height values at the distal root level of the mandibular second molar in the MBS (p &lt; 0.05). A statistically significant increase from the mesial aspect to the distal aspect was observed in total bone thickness in the Class I group and total bone thickness and height in the Class II and III groups in the MBS. The mandibular body length and SNB values were positively correlated with the total bone thickness and bone height of the MBS. Conclusions Bone thickness in the IZC and bone density in both the IZC and MBS were similar in the different sagittal skeletal patterns. Total bone thickness in the Class I and III groups and the total bone height in the Class II group showed a gradual increase from the mesial to the distal in the MBS. The length of the mandibular body may be a clinical clue to assist in the selection of the appropriate implantation area.

Cone beam computed tomography study for evaluation of morphology of pterygoid hamulus – A retrospective study

Cone beam computed tomography study for evaluation of morphology of pterygoid hamulus – A retrospective study

The relative location of mandibular foramen to occlusal plane: A cone-beam computed tomography study

The relative location of mandibular foramen to occlusal plane: A cone-beam computed tomography study

Multidimensional tooth movement boundaries in the extended aesthetic zone: a cone-beam computed tomography study

Abstract Purpose To establish tooth movement boundaries in four directions by a novel morphometric analysis of alveolar bone using conebeam computed tomography (CBCT) images. The aim was to assist clinicians in minimising the occurrence of bone fenestration and dehiscence, thereby facilitating safe and efficient orthodontic treatment. Methods CBCT images of 123 male volunteers comprising 55 individuals with hypodivergent vertical skeletal patterns and 68 individuals with normodivergent vertical skeletal patterns and normal occlusions but without a history of previous orthodontic treatment, were analysed. The mesiodistal and labiolingual alveolar bone height (ABH) as well as the labiolingual cancellous bone thickness (CBT) were measured in relation to the maxillary and mandibular anterior teeth and premolars. These parameters were subsequently compared between the different vertical skeletal patterns. Results Teeth within the extended aesthetic zone exhibited a limited range of safe movement on the labial aspect across all three root aspects, with 97.6% of the upper lateral incisors and 98.4% of the lower lateral incisors positioned against the labial cortical plate (&lt;0.5 mm). The lingual aspects had significantly more space for tooth movement compared with the labial aspects (P &lt; 0.05). The ABH was significantly greater in the hypodivergent group than the normodivergent group involving particular teeth and sites in the maxilla (P &lt; 0.05), while no significant difference was noted in the mandible. The hypodivergent group also exhibited thicker cancellous bone on most labial and some lingual aspects. Conclusions The findings provided the average tooth movement range in the horizontal and vertical directions within the extended aesthetic zone in male individuals presenting with a normal occlusion. It was concluded that a hypodivergent growth pattern may have a relatively large range of safe tooth movement in the sagittal and vertical directions.

Validation of novel measurement protocols proposed for the standardized assessment of crestal bone levels: A cone-beam computed tomography study

Validation of novel measurement protocols proposed for the standardized assessment of crestal bone levels: A cone-beam computed tomography study

Morphometric Study of the Mastoid Process and its Role in Sex Differentiation: A Nigerian Computed Tomography Study

Abstract Background: The mastoid process can be utilized in forensic identification due to its resistance to alterations and population variations in its morphology. The study investigated the role of mastoid parameters in the determination of sex in a Nigerian population. Aims and Objectives: The aim of this study was to determine the gender differences in measurements of the mastoid process. Furthermore, the study aimed at assessing the percentage accuracy of using the mastoid variables in sex discrimination. Materials and Methods: This cross-sectional study used computed tomographic images of the brain, stored in the radiology unit of a referral hospital in Delta State, Nigeria. Permission was granted by the hospital’s Ethics Board. The measurements of the mastoid process were taken on images of 310 patients (170 males and 140 females) aged 20–80 years. Data were summarized using means and standard deviations. Gender, side, and age group comparisons were assessed using the independent t-test, paired t-test, and analysis of variance, respectively. The association between variables was probed using Pearson’s correlation test. The discriminant function analysis was used to determine the accuracy of correct sex allocation. The probability value was set at &lt;0.05. Results: All the measurements were larger in males than in females (P &lt; 0.05). All except the conventional height, oblique sagittal diameter, and mediolateral inclination angle showed significant differences between age groups (P &lt; 0.05). The true height and oblique coronal diameter showed a significant positive correlation with age (0 &lt;r&lt; 0.05) (P &lt; 0.05). The lateral intermastoid distance was the best sex-discriminating variable (89.4%). Using all nine variables, the accuracy of sex prediction was 89.7%. Conclusion: The sexually dimorphic mastoid dimensions can collectively be used for sex determination with acceptable accuracies, in cases where only the fragmented parts of the temporal bone are available in Delta State, Nigeria.

Multileaf Collimator Modeling and Commissioning for Complex Radiation Treatment Plans Using 2-Dimensional (2D) Diode Array MapCHECK2.

Purpose: This study aims to develop a data-collecting package ExpressMLC and investigate the applicability of MapCHECK2 for multileaf collimator (MLC) modeling and commissioning for complex radiation treatment plans. Materials and methods: The MLC model incorporates realistic parameters to account for sophisticated MLC features. A set of 8 single-beam plans, denoted by ExpressMLC, is created for the determination of parameters. For the commissioning of the MLC model, 4 intensity modulated radiation therapy (IMRT) plans specified by the AAPM TG 119 report were transferred to a computed tomography study of MapCHECK2, recalculated, and compared to measurements on a Varian accelerator. Both per-beam and composite-beam dose verification were conducted. Results: Through sufficient characterization of the MLC model, under 3%/2 mm and 2%/2 mm criteria, MapCHECK2 can be used to accurately verify per beam dose with gamma passing rate better than 90.9% and 89.3%, respectively, while the Gafchromic EBT3 films can achieve gamma passing rate better than 89.3% and 85.7%, respectively. Under the same criteria, MapCHECK2 can achieve composite beam dose verification with a gamma passing rate better than 95.9% and 90.3%, while the Gafchromic EBT3 films can achieve a gamma passing rate better than 96.1% and 91.8%; the p-value from the Mann Whitney test between gamma passing rates of the per beam dose verification using full MapCHECK2 package calibrated MLC model and film calibrated MLC model is .44 and .47, respectively; the p-value between those of the true composite beam dose verification is .62 and .36, respectively. Conclusion: It is confirmed that the 2-dimensional (2D) diode array MapCHECK2 can be used for data collection for MLC modeling with the combination of the ExpressMLC package of plans, whose doses are sufficient for the determination of MLC parameters. It could be a fitting alternative to films to boost the efficiency of MLC modeling and commissioning without sacrificing accuracy.

Immediate implant placement in the premolar maxillary area: a cone-beam computed tomography study.

This research aimed to investigate potential factors associated with the risk of perforation of the labial bone plate, nasal floor, or maxillary sinus floor during immediate implant placement (IIP) in the maxillary premolar area, utilizing a cone-beam computed tomography (CBCT) virtual study. CBCT exams from 179 eligible participants, encompassing 716 teeth, were included. Implants were virtually positioned in 2 orientations: along the long axis of the tooth (the prosthetically-driven position) and in an optimal position relative to adjacent anatomical structures (the bone-driven position). Binary logistic regression analysis was employed to assess potential associations between perforation or invasion and various covariates, including sex, age, tooth region, the distance from the tooth apex to the nasal floor or maxillary sinus floor, the angle between the prosthetically- and bone-driven positions (implant-line A angle [ILAA]), and the labial concavity angle (LCA). The mean ILAA was 18.3°±8.0°, and the angle was significantly larger for the second premolar compared to the first premolar. The mean minimum implant length was 13.0±2.1 mm, with a bone anchorage of 4 mm. The incidence of perforation was 84.1% for the prosthetically-driven position and 40.5% for the bone-driven position. Factors associated with a higher risk of cortical bone wall perforation or invasion of the 2-mm safety margin from surrounding anatomical structures (in the bone-driven position) included female sex, older age, shorter distance from the tooth apex to the nasal cavity/maxillary sinus, and smaller LCA. A high prevalence of cortical bone wall perforation or invasion of the 2-mm safety margin is anticipated when performing IIP in the maxillary premolar region.

Anatomical variations of mandibular lingual foramen and its bony canals in Turkish Cypriot population: a cone-beam computed tomography study

Anatomical variations of mandibular lingual foramen and its bony canals in Turkish Cypriot population: a cone-beam computed tomography study