Coronal CT Research Articles

Key Factors for Predicting Appendicitis from Contrast-Enhanced Computed Tomography Images Obtained Through Multiplanar Reconstruction

Background: The diameter of the appendix is a key parameter in diagnosing appendicitis. The diagnostic threshold for this parameter is 6 mm, originally established through graded compression sonography of the right lower quadrant (RLQ) of the abdomen. However, without corroborative findings from computed tomography (CT), this threshold may not be a reliable indicator of appendicitis. To ensure accurate diagnosis, clinicians should perform a comprehensive, multiparameter imaging assessment of the appendix, rather than relying solely on appendix diameter. Objectives: This study aimed to identify key factors for predicting appendicitis using contrast-enhanced coronal and sagittal CT images obtained through multiplanar reconstruction. Patients and Methods: This single-center, retrospective, cross-sectional study included patients who presented to our emergency department (ED) with RLQ abdominal pain and subsequently underwent contrast-enhanced CT between July 2019 and September 2020. The primary study outcome was pathologically confirmed appendicitis. Two experienced radiologists assessed parameters such as appendix diameter, wall thickness, abnormal appendix enhancement, abnormal appendix content, appendix erection, and periappendiceal fat stranding. Multivariate logistic regression was performed to identify significant predictive factors for appendicitis. Results: The study included 173 patients (median age: 37 years; women: 86). They were divided into appendicitis (n = 102) and alternative diagnosis (n = 71) groups. Significant differences were observed between the groups in terms of appendix diameter, wall thickness, wall enhancement, luminal content, appendix erection, and periappendiceal fat stranding (P < 0.001). The diagnostic sensitivity and specificity values for an appendix diameter threshold of 7.7 mm were 91% and 82%, respectively. An appendix diameter of > 7.7 mm (OR: 15.3; P < 0.001), abnormal appendix enhancement (OR: 12.5; P < 0.001), and appendix erection (OR: 6.1; P = 0.004) emerged as significant independent predictors of appendicitis. Conclusion: An appendix diameter of 7.7 mm appears to be the optimal threshold for diagnosing appendicitis. Additionally, the detection of abnormal appendix enhancement and appendix erection on contrast-enhanced CT images holds considerable diagnostic value.

The Frequency of Presence of the Infraorbital Canal in the Maxillary Sinus and its Clinical Importance.

The infraorbital canal (IOC) houses critical structures like the infraorbital artery, vein, and nerve, and its atypical location within the maxillary sinus could pose risks during surgical procedures, making it crucial to understand its prevalence and distribution. The study aims to investigate the localization and frequency of the IOC within the maxillary sinus. This retrospective study analyzed computed tomography (CT) images from 1000 randomly selected patients (500 males, 500 females) aged 18 to 65 years who underwent paranasal region imaging at Istanbul Medipol University Medipol Mega University Hospital between 2015 and 2020. Exclusion criteria included major pathologies, prior surgeries, and poor image quality. The study focused on evaluating the localization of the IOC and its presence within the maxillary sinus, using coronal CT sections. The IOC was found within the maxillary sinus in 8% of cases (44 males, 36 females). This variation was bilateral in 34 cases and unilateral in 46 cases, with no statistically significant relationship between sex and the occurrence or type of variation. The study's findings align with previous research, which reported similar prevalence rates for this anatomical variation. The study confirms that the IOC is located within the maxillary sinus in a significant percentage of cases, emphasizing the importance of preoperative CT evaluation to prevent potential complications during maxillary sinus surgeries. These findings highlight the clinical relevance of considering individual anatomical differences in the localization of the IOC.

Sagittal computed tomography evaluation of osteochondritis dissecans of the capitellum correlates with clinical outcomes of arthroscopic debridement in adolescent baseball players

ObjectivesTo investigate the relationship between the size and location of osteochondral defects in capitellar osteochondritis dissecans (OCD) measured on coronal and sagittal reconstructed computed tomography (CT) images and the clinical outcomes of arthroscopic debridement in adolescent baseball players. MethodsThis retrospective study investigated the clinical outcomes of arthroscopic debridement for capitellar OCD in adolescent baseball players with ≥24 months of follow-up after surgery between 2008 and 2020. On preoperative coronal CT images, medial and lateral distance (%) were used to evaluate the location of the defect. Defect size (%) was also evaluated. On preoperative sagittal CT images, superior and inferior angles (deg) were used to evaluate the location of the defect. The size of the defect was evaluated using the defect angle (deg). Outcome measures were determined using the Timmerman–Andrews score at the latest follow-up. Spearman’s rank correlation coefficient was used to examine relationships between these parameters and the Timmerman–Andrews score. Statistical significance was set at p ​< ​0.05. ResultsThirty players [mean age, 14 (range, 11–16) years] underwent arthroscopic debridement: 5 were pitchers, 7 were catchers, 13 were infielders, and 5 were outfielders. Mean follow-up duration was 26 (range, 24–66) months. The median Timmerman–Andrews score at the latest follow-up was 193 [interquartile range (IQR), 181–200] points. Inferior angle showed statistically significant positive correlations with Timmerman–Andrews score (rs ​= ​0.520, p ​< ​0.01), pain (rs ​= ​0.478, p ​< ​0.01), and sagittal arc of motion (rs ​= ​0.409, p ​= ​0.025). Defect angle showed statistically significant negative correlations with Timmerman–Andrews score (rs ​= ​−0.462, p ​= ​0.010) and flexion contracture (rs ​= ​-0.424, p ​= ​0.020). Medial distance, lateral distance, defect size, and superior angle were not correlated with the Timmerman–Andrews score or any of its subscores. ConclusionPosterior or large osteochondral defects of the humeral capitellum on preoperative sagittal CT images affected the outcomes of arthroscopic debridement for capitellar OCD in adolescent baseball players. Level of evidenceLevel V, case series.

Physeal Location on the Distal Femoral Cortical Surface Is Consistently Proximal to Apparent Location on the Perfect Lateral Radiograph: A 3-Dimensional Digitally Reconstructed Radiograph Study.

The perfect knee lateral radiograph visualizes anatomic landmarks on the distal femur for clinical and scientific purposes. However, radiographic imaging is a two-dimensional (2D) representation of a three-dimensional (3D) physis. The aim of this study was to characterize the perceived radiographic projection of the femoral physis using perfect lateral digitally reconstructed radiographs (DRRs) and to evaluate discrepancies from this projection to the physis at the lateral and medial cortices. Pediatric patients from a cohort of CT scans were analyzed. Inclusion criteria were an open physis; exclusion criteria were any implant or pathology affecting the physis. CT scans were imported into 3D imaging software and transformed into lateral DRRs and 3D renderings of the femur. The physis was divided into four equal segments, with fiducial markers placed at the "anterior," "midpoint," and "posterior" points. Lines extended from these points in the lateral and medial direction. The vertical distance from these lines, representing the radiographic projection of the physis, was measured relative to the physis at the lateral and medial cortex of the femur on coronal CT slices. Thirty-one patients were included. On the perfect lateral radiograph DRR, the physis on the medial cortex was located proximal to the visualized physis by 6.64 ± 1.74 mm, 11.95 ± 1.67 mm, and 14.30 ± 1.75 mm at the anterior (25%), midpoint (50%), and posterior (75%) locations, respectively. On the lateral side, the physis on the lateral cortex was proximal to the visualized physis by 2.19 ± 1.13 mm, 3.71 ± 1.19 mm, and 6.74 ± 1.25 mm at the anterior, midpoint, and posterior locations, respectively. In this cohort of pediatric patients, the location of the cortical physis was, in all areas measured, proximal to the projection of the visualized physis as seen on the perfect knee lateral DRR. The distance from radiographic physis to cortical physis was greater at the medial cortex compared with the lateral cortex. Descriptive laboratory study. III, observational radiographic anatomic study.

Improving Access to Intracranial Volume Measurements for Clinical Use: Open-Source Method using Computed Tomography

Introduction: Three-dimensional measurements of intracranial volume (ICV) can guide clinical management of brain and skull disorders. However, widespread clinical access is limited by the scarcity of software methods for analyzing CT scans, which are more available than MRI images, and the inaccessibility of proprietary and expensive commercial software. The presented method can calculate ICV from CT scans, using an open-source software, 3D Slicer. Methods: The open-source workflow was optimized with a data-driven approach to find the optimal parameters for ICV accuracy. The accuracy of the open-source method was determined by comparing it to commercial and proprietary software with CT scans of pediatric hydrocephalic macrocephaly patients with craniosynostosis undergoing total vault reconstruction (N = 5 patients,15 scans). Results: An open-source pipeline that combines an initial semi-automatic segmentation of a coronal CT reconstruction with a fully automatic segmentation minimizes the ICV error. The open-source method shows excellent agreement with both the commercial and proprietary software methods (R2 = 0.998 and 95% confidence interval of best-fit line slope: [0.986; 1.047], [0.985;1.066] respectively). The mean percent difference of ICV measurements of the open-source software from the commercial software was −0.56% [95% CI: −1.08%, −0.028%] and from the proprietary software was −0.07% [95% CI: −1.26%, 1.1%]. The mean percent difference of ICV measurements of the commercial software from the proprietary software was 0.36% [95% Confidence Interval: −0.61%, 1.32%]. Conclusions: This is the first study comparing an open-source method for measuring ICV with commercial and proprietary options. A high degree of fidelity was found, confirming this open-source method as a viable option for clinicians who are looking to incorporate ICV measurements into their practice.

Lateral Globe Exposure Associated With Graves Upper Eyelid Retraction: The Influence of the Superior Complex Enlargement and Proptosis.

To investigate the association of the lateral exposure of the globe with proptosis and the enlargement of the superior complex (SC) (levator palpebrae superioris muscle + superior rectus muscle) in patients with Graves upper eyelid retraction. Twenty-eight patients with upper lid retraction secondary to Graves orbitopathy and 28 controls matched by age and gender participated in the study. The variables exophthalmometry, margin-reflex distance 1, and upper lid fissure temporal and nasal areas were assessed. Coronal CT scans were evaluated for the measurement of the SC area. A 5% level of significance was assumed for analysis. Abnormal temporal nasal area differences (T-N), defined as values above the superior limit of the control distribution (15.58mm2) were detected in 18 patients. Multiple regression analysis showed a significant correlation of abnormal temporo-nasal asymmetries with the SC area and the proptosis (T-N = -6.7 + 0.62* proptosis + 12.3 SC area, R2 = 0.37; p = 0.003). The etiology of the enhanced lateral globe exposure is not unifactorial. SC enlargement and, to a lesser extent, proptosis are important factors correlated to lateral globe exposure.

Increased combined anteversion is associated with larger posterior acetabular rim ossification in patients with femoroacetabular impingement syndrome.

(1) To determine the prevalence, magnitude and distribution pattern of acetabular rim ossification in patients with femoroacetabular impingement syndrome (FAIS) and (2) to determine the association between acetabular rim ossification and rotational abnormalities of the hip. Patients underwent hip arthroscopic surgery for FAIS at our institute between January 2021 and May 2022 were retrospectively reviewed. Patients were included if preoperative computed tomography (CT) images of the operated hip and ipsilateral distal femur were available for the measurement of femoral and acetabular anteversion. The presence and size of acetabular rim ossification were evaluated on coronal CT sections for the superior half of the acetabulum on each clockface location. The associations between acetabular rim ossification and radiographic parameters of hip rotational morphology were examined. A total of 214 hips were included. Acetabular rim ossification was found in 167 hips (78%) and the most common locations were 10 and 11 o'clock. Patients presenting with acetabular rim ossification had a mean size of 4.6 ± 1.6 mm. It was the largest at 9 o'clock position (4.9 ± 2.2 mm), with a decreasing trend in size from posterior to anterior. Logistics regression analysis found age was associated with the occurrence of posterior ossification (p = 0.002). Linear regression analysis found age (p = 0.049) and male sex (p < 0.001) were significantly correlated with the size of ossification. Patients with increased cranial combined anteversion had larger posterior ossification than patients with normal and decreased cranial combined anteversion (4.2 ± 2.9 vs. 3.1 ± 2.5 mm, p = 0.016; 4.2 ± 2.9 vs. 2.5 ± 2.4 mm, p = 0.005). Increased combined anteversion is associated with greater posterior acetabular rim ossification. The presence and size of acetabular rim ossification are positively associated with older age and male sex. Level III.

Retromolar intubation for the general anesthesia of maxillofacial fracture patients

BackgroundEvaluate the possibility of retromolar intubation for general anesthesia in patients with maxillofacial fractures.MethodsThe medical records of 54 patients with maxillofacial fractures who visited the Oral and Maxillofacial Surgery Department of Nantong First People’s Hospital from January 2020 to August 2022 were collected. The retromolar areas of each patient were measured from the coronal CT images, and correlated with the patient’s age, sex, type of fracture (i.e., maxillary fracture, mandibular fracture, or complex fracture of multiple maxillofacial bones), and the presence of the third molar (verified from 3D CT). The dimensions of the retromolar areas were finally compared with the outer diameter (OD) of standard endotracheal tubes (ETTs), most importantly the size 7.5 ETT (OD 10.3 mm) for male and the size 7.0 ETT (OD 9.8 mm) for female.ResultsThe survey included 38 male and 16 female patients, with an average age of 44.1 and 54.3 years, respectively. The dimensions of the retromolar area (height × width) were as follows: male, (9.39 ± 1.77) mm × (12.08 ± 0.98) mm on the left and (9.81 ± 2.23) mm × (11.77 ± 1.08) mm on the right; female, (8.82 ± 1.53) mm × (10.51 ± 1.00) mm on the left and (9.73 ± 1.60) mm × (10.63 ± 1.58) mm on the right. The width was always larger than the OD of the routinely used ETT, but the height could be smaller by less than 1 mm. However, the oral mucosa can be compressed to allow the ETT to fit in the retromolar area.ConclusionsThe retromolar area provided appropriate space to place a reinforced ETT for patients with maxillofacial fractures needing general anesthesia that must not interfere with intermaxillary ligation. Retromolar intubation can help maxillofacial fracture surgeries that focus on occlusal restoration.

30° anteriorly tilted CT for visualizing the drainage pathway of the frontal sinus.

The optimal tilt for anteriorly tilted coronal CT was examined. A 30° anteriorly tilted coronal CT best visualized the frontal sinus drainage pathway.

The Outcome of Inferior Oblique Myectomy for Apparent Inferior Oblique Overaction Associated with Craniosynostosis.

Strabismus in patients with craniosynostosis is common, but surgical correction of strabismus in these patients remains challenging. We report our findings in six patients (four of whom were Korean) with craniosynostosis who underwent strabismus surgery to specifically address V-pattern horizontal strabismus with moderate-to-severe inferior oblique (IO) overaction, using IO myectomy at a single tertiary hospital between 2005 and 2016. We recorded preoperative characteristics including sex, age, type of strabismus, versions grading, refractive error, and visual acuity. The grading of cyclorotation of horizontal rectus muscles by V-pattern categorized using coronal computed tomography imaging. Of the six patients, exodeviation was found in four patients and vertical deviation in two patients in primary position. One patient had both horizontal and vertical strabismus. Available computed tomography imaging showed that V-patterns were category 1 (mild) in two patients, category 2 (moderate) in one patient, and category 3 (severe) in two patients. Complete success was defined as absence of IO overaction any more. Overall complete success rate of IO myectomy was 83.3%. IO myectomy appeared to have some benefits in V-pattern horizontal strabismus with moderate-to-severe IO overaction in patients with craniosynostosis.

Transforaminal lumbar interbody fusion subsidence: computed tomography analysis of incidence, associated risk factors, and impact on outcomes.

The aims of this study were to 1) define the incidence of transforaminal lumbar interbody fusion (TLIF) interbody subsidence; 2) determine the relative importance of preoperative and intraoperative patient- and instrumentation-specific risk factors predictive of postoperative subsidence using CT-based assessment; and 3) determine the impact of TLIF subsidence on postoperative complications and fusion rates. All adult patients who underwent one- or two-level TLIF for lumbar degenerative conditions at a multi-institutional academic center between 2017 and 2019 were retrospectively identified. Patients with traumatic injury, infection, malignancy, previous fusion at the index level, combined anterior-posterior procedures, surgery with greater than two TLIF levels, or incomplete follow-up were excluded. Interbody subsidence at the superior and inferior endplates of each TLIF level was directly measured on the endplate-facing surface of both coronal and sagittal CT scans obtained greater than 6 months postoperatively. Patients were grouped based on the maximum subsidence at each operative level classified as mild, moderate, or severe based on previously documented < 2-mm, 2- to 4-mm, and ≥ 4-mm thresholds, respectively. Univariate and regression analyses compared patient demographics, medical comorbidities, preoperative bone quality, surgical factors including interbody cage parameters, and fusion and complication rates across subsidence groups. A total of 67 patients with 85 unique fusion levels met the inclusion and exclusion criteria. Overall, 28% of levels exhibited moderate subsidence and 35% showed severe subsidence after TLIF with no significant difference in the superior and inferior endplate subsidence. Moderate (≥ 2-mm) and severe (≥ 4-mm) subsidence were significantly associated with decreases in cage surface area and Taillard index as well as interbody cages with polyetheretherketone (PEEK) material and sawtooth surface geometry. Severe subsidence was also significantly associated with taller preoperative disc spaces, decreased vertebral Hounsfield units (HU), the absence of bone morphogenetic protein (BMP) use, and smooth cage surfaces. Regression analysis revealed decreases in Taillard index, cage surface area, and HU, and the absence of BMP use predicted subsidence. Severe subsidence was found to be a predictor of pseudarthrosis but was not significantly associated with revision surgery. Patient-level risk factors for TLIF subsidence included decreased HU and increased preoperative disc height. Intraoperative risk factors for TLIF subsidence were decreased cage surface area, PEEK cage material, bullet cages, posterior cage positioning, smooth cage surfaces, and sawtooth surface designs. Severe subsidence predicted TLIF pseudarthrosis; however, the causality of this relationship remains unclear.

Clinical Significance of the Inferomedial Orbital Strut in Orbital Blowout Fractures: Incidence of Symptomatic Diplopia in a Fractured vs. Intact Strut.

Background/Objectives: This study aims to compare the clinical findings, particularly symptomatic diplopia, associated with an inferomedial orbital strut fracture versus intact strut and to determine the clinical significance of the inferomedial orbital strut in patients with orbital floor and medial orbital wall fractures. Methods: A 10-year retrospective observational study involving orbital blowout fracture cases was conducted in our institution. Patients with fractures of the orbital floor medial to the infraorbital groove and medial orbital wall, as seen on computed tomography (CT) scans, were included in this study. Patients with concomitant orbital rim fracture and those with old orbital fractures were excluded. Fracture of the inferomedial orbital strut was diagnosed via coronal CT images and patients were classified into those with an inferomedial orbital strut fracture and those without. Results: A total of 231 orbits from 230 patients was included in the study (fractured strut on 78 sides and intact strut on 153 sides). Approximately 2/3 of patients in both groups had the field of binocular single vision in primary position upon first examination (p = 0.717). Patients with strut fractures demonstrated only comminuted or open fractures, while those without strut fractures showed diverse fracture patterns (p < 0.001). Conclusions: Inferomedial orbital strut fracture does not automatically result in diplopia in patients with orbital blowout fractures. The integrity of the orbital periosteum plays a more essential role in hampering extraocular muscle displacement, thereby preventing symptomatic diplopia in these patients.

Assessment of Arterial Involvement in Pancreatic Cancer: Utility of Reconstructed CT Images Perpendicular to Artery.

The purpose of this study was to investigate the utility of reconstructed CT images perpendicular to the artery for assessing arterial involvement from pancreatic cancer and compare the interobserver variability between it and the current diagnostic imaging method. This retrospective study included patients with pancreatic cancer in the pancreatic body or tail who underwent preoperative pancreatic protocol CT and distal pancreatectomy. Five radiologists used axial and coronal CT images (current method) and perpendicular reconstructed CT images (proposed method) to determine if the degree of solid soft-tissue contact with the splenic artery was ≤180° or >180°. The generalized estimating equations were used to compare the diagnostic performance of solid soft-tissue contact >180° between the current and proposed methods. Fleiss' ĸ statistics were used to assess interobserver variability. The sensitivity and negative predictive value for diagnosing solid soft-tissue contact >180° were higher (p < 0.001 for each) and the specificity (p = 0.003) and positive predictive value (p = 0.003) were lower in the proposed method than the current method. Interobserver variability was improved in the proposed method compared with the current method (ĸ = 0.87 vs. 0.67). Reconstructed CT images perpendicular to the artery showed higher sensitivity and negative predictive value for diagnosing solid soft-tissue contact >180° than the current method and demonstrated improved interobserver variability.

FIRST METATARSAL ROTATION AFTER SCARF OSTEOTOMY FOR HALLUX VALGUS

IntroductionRecurrence after surgical correction of hallux valgus may be related to coronal rotation of the first metatarsal. The scarf osteotomy is a commonly used procedure for correcting hallux valgus but has limited ability to correct rotation. Using weightbearing computed tomography (WBCT), we aimed to measure the coronal rotation of the first metatarsal before and after a scarf osteotomy, and correlate these to clinical outcome scores.MethodsWe retrospectively analyzed 16 feet (15 patients) who had a WBCT before and after scarf osteotomy for hallux valgus correction. On both scans, hallux valgus angle (HVA), intermetatarsal angle, and anteroposterior/lateral talus-first metatarsal angle were measured using digitally reconstructed radiographs. Metatarsal pronation (MPA), alpha angle, sesamoid rotation angle and sesamoid position was measured on standardized coronal CT slices. Preoperative and postoperative(12 months) clinical outcome scores(MOxFQ and VAS) were captured.ResultsMean HVA was 28.6±10.1 degrees preoperatively and 12.1±7.7 degrees postoperatively. Mean IMA was 13.7±3.8 degrees preoperatively and 7.5±3.0 degrees postoperatively. Before and after surgery, there were no significant differences in MPA (11.4±7.7 and 11.4±9.9 degrees, respectively; p = 0.75) or alpha angle (10.9±8.0 and 10.7±13.1 degrees, respectively; p = 0.83). There were significant improvements in SRA (26.4±10.2 and 15.7±10.2 degrees, respectively; p = 0.03) and sesamoid position (1.4±1.0 and 0.6±0.6, respectively; p = 0.04) after a scarf osteotomy. There were significant improvements in all outcome scores after surgery. Poorer outcome scores correlated with greater postoperative MPA and alpha angles (r= 0.76 (p = 0.02) and 0.67 (p = 0.03), respectively).ConclusionA scarf osteotomy does not correct first metatarsal coronal rotation, and worse outcomes are linked to greater metatarsal rotation. Rotation of the metatarsal needs to be measured and considered when planning hallux valgus surgery. Further work is needed to compare postoperative outcomes with rotational osteotomies and modified Lapidus procedures when addressing rotation.

Based on CT imaging, surgical approach selection for frontal and ethmoid sinus osteoma

Objective:To investigate the criteria for selecting surgical approaches for frontal and ethmoid sinus osteomas of different locations and sizes on CT imaging. Methods:Using sagittal and coronal CT images, the following lines were delineated: the F-line（a horizontal line passing nasofrontal beak）, the M-line（a vertical line passing paries medialis orbitae）, and the P-line（a vertical line passing the center of the pupil）. Classification of frontal and ethmoid sinus osteomas was based on their relationship with these lines. Appropriate surgical approaches were selected, including pure endoscopic approaches, endoscopic combined with eyebrow incision approach, and endoscopic combined with coronal incision approach. This method was applied to a single center at the Third Affiliated Hospital of Sun Yat-sen University for endoscopic resection of frontal and ethmoid sinus osteoma. Case Data: Sixteen cases of ethmoid sinus osteomas were treated from January 2020 to September 2023. Among these cases, there were 9 males and 7 females, with ages ranging from 18 to 69 years, and a median age of 48 years. Results:Thirteen cases underwent pure endoscopic resection of the osteoma, while in three cases, a combined approach was utilized. Among the combined approach cases, two exceeded both the M-line and the F-line but did not cross the P-line; therefore, they underwent endoscopic combined with eyebrow incision approach. One case exceeded all three lines and thus underwent endoscopic combined with coronal incision. In all cases, complete resection of the osteoma was achieved as per preoperative planning, and none of the patients experienced significant postoperative complications. Conclusion:For frontal and ethmoid sinus osteomas, it is advisable to perform a thorough preoperative radiological assessment. Based on the size of the osteoma and its relationship to the three lines, an appropriate surgical approach should be chosen to optimize the diagnostic and treatment plan.

Development of an adjustable patient-specific rigid guide to improve the accuracy of external ventricular catheter placement.

The most common method for external ventricular drain (EVD) placement is the freehand approach, which has reported inaccuracy rates of 12.3%-44.9%, especially in the case of altered ventricular anatomy. Current assistive devices require added time or equipment or do not account for shifted ventricles. To improve the accuracy of emergent EVD placement in the setting of altered ventricular anatomy, the authors designed a patient-specific EVD (PS-EVD) guide. The PS-EVD guide has a tripod base and a series of differently angled inserts that lock in place at multiple rotational positions, allowing for numerous insertion angles. For testing, the authors designed a 3D-printed phantom skull with a gelatin brain analog containing ventricles simulating normal and altered ventricular anatomy. Low-resolution CT scans of the phantom were used to calculate the insertion angle in relation to the standard perpendicular entry. The corresponding insert at the correct rotational position within the base unit was positioned over the entry point on the phantom, and the catheter was inserted. Accuracy was evaluated with repeat CT scans. With normal ventricular anatomy, as well as abnormally shifted ventricles, proper use of the PS-EVD guide led to accurate catheter insertion into the ventricle in trials, as confirmed on coronal and sagittal CT images, including cases in which a perpendicular trajectory, such as with the Ghajar guide, was insufficient. The PS-EVD guide allows consistent and accurate EVD placement in phantom skulls with both normal and altered ventricular anatomy. Further trials comparing this device to the freehand approach are required.

Computed tomography-based morphometric analysis of normal distal tibiofibular syndesmosis in the Indian population

BackgroundIn suspected Ankle Instability, the parameters that can be defined in the X-ray have their limitation owing to their variability in positioning and rotation of the tibiofibular joint. This inaccuracy further increases due to variability in morphometric parameters of distal tibiofibular syndesmosis among different populations based on race and sex. This research aims to study morphometry of normal distal tibiofibular syndesmosis based on computed tomography imaging in the Indian population. MethodsAn Prospective observational study was performed from December 2020 to October 2022 on normal ankle CT scans of 100 Indian population using axial, sagittal, and coronal CT images. Anterior and posterior tibiofibular distance, Morphology of the incisura fibularis based on depth, Tibiofibular clear space (TFCS) and tibiofibular overlap (TFO), Transverse and longitudinal length of the fibula, and Relationship between the center of the talus and the center of a line joining the outer aspect of malleoli in the coronal plane were measured and analyzed by two different observers. ResultsOut of the 100 participants, 77 (77 %) were male, and 23 (23 %) were female. The overall mean age of participants was 34.69 ± 9.7 years. The incisura fibularis was concave in 54 %, and shallow in 46 %. Anterior tibiofibular distance, Posterior tibiofibular distance, and Tibiofibular overlap were significantly different in comparison to the male with female populations (p-value < 0.05). ConclusionThis study gives the indices that describe normal variations in the anatomical relationship between the fibula and fibular incisure in the Indian population, which will be helpful for improving the diagnostic accuracy of distal tibiofibular syndesmoses and providing optimal treatment in order to improve functional outcomes and reduce the risk of complications. Level of EvidenceIII.

Multidetector Computed Tomography Used in Evaluation of Olfactory Fossa Depth in a Tertiary Hospital in Eastern Region of Nepal: A Descriptive Cross-sectional Study.

Olfactory fossa (OF) is a depression in most infero-medial portion of anterior cranial fossa formed by cribriform plate, crista galli and lateral lamella of cribriform plate (LLCP). LLCP being thinnest and extremely variable parts, more prone for iatrogenic injury during sinus surgery in case of asymmetric and deep OF. Multidetector computed tomography (MDCT) is frequently used imaging modality in the evaluation of paranasal sinus. The objective of the study is to classify the OF depth according to the Keros classification. In this ethically approved prospective, cross-sectional descriptive study, CT scan was done in 530 consecutive patients from February 2022 to July 2023. Coronal CT images of paranasal sinuses and nose were used to measure the OF depth. The data collected was analyzed using SPSS. Out of 530 patients included in this study, 310 (58.49%) were male and 220 (41.51%) were female with mean age of 40.46±11.56 years. Total of 1060 olfactory fossa were analyzed with mean depth of 4.96±1.88 mm. In our study, 310 (29.24%) had type I, 730 (68.88%) had type II and 20 (1.88%) had type III according to Keros classification. Keros type II OF is more common. The dangerous type III OF having low prevalence, more commonly seen on right side and in males.

Feasibility, Clinical Potential, and Limitations of Trans-Burr Hole Ultrasound for Postoperative Evaluation of Chronic Subdural Hematoma: A Prospective Pilot Study.

Chronic subdural hematoma (CSDH) is commonly managed through burr hole surgery. Routine follow-up using computed tomography (CT) imaging is frequently used at many institutions, contributing to significant radiation exposure. This study evaluates the feasibility, safety, and reliability of trans-burr hole sonography as an alternative postoperative imaging modality, aiming to reduce radiation exposure by decreasing the frequency of CT scans. We conducted a prospective pilot study on 20 patients who underwent burr hole surgery for CSDH. Postoperative imaging included both CT and sonographic examinations through the burr hole. We assessed the ability to measure residual subdural fluid thickness under the burr hole sonographically compared with CT, the occurrence of complications, and the potential factors affecting sonographic image quality. The Pearson correlation coefficient was used to demonstrate relationships between CT and ultrasound and axial and coronal ultrasound. Sonography through the burr hole was feasible in 73.5% of cases, providing measurements of residual fluid that closely paralleled CT findings, with an average discrepancy of 1.2 mm for axial and 1.4 mm for coronal sonographic views. A strong positive correlation was found between axial and coronal ultrasound ( r = 0.955), CT and axial ultrasound ( r = 0.936), and CT and coronal ultrasound ( r = 0.920). The primary obstacle for sonographic imaging was the presence of air within the burr hole or the subdural space, which typically resolved over time after surgery. Trans-burr hole sonography emerges as a promising technique for postoperative monitoring of CSDH, with the potential to safely reduce reliance on CT scans and associated radiation exposure in selected patients. Our results support further investigation into the extended use of sonography during the follow-up phase. Prospective multicenter studies are recommended to establish the method's efficacy and to explore strategies for minimizing air presence postsurgery.

Discrepancies in Splenic Size Measurement: A Comparative Analysis of Ultrasound and Computed Tomography.

The accurate measurement of splenic size is essential for the diagnosis and management of various gastrointestinal and hematological conditions. While ultrasound (US) and computed tomography (CT) are widely used imaging modalities for assessing splenic size, discrepancies between their measurements have been observed in clinical practice. This study aimed to analyze the measurement differences between US and CT and identify factors influencing these differences. A retrospective analysis of 598 asymptomatic patients who underwent both abdominal US and CT was conducted. Measurements of splenic size obtained from US, axial CT, and coronal CT scans were compared, and various factors such as patient demographics, operator experience, and imaging parameters were evaluated to elucidate their impact on the measurement discrepancies. The results revealed that US consistently underestimated splenic size compared to CT. The magnitude of the discrepancy was influenced by factors such as patient age, body mass index (BMI), depth of the spleen from skin on US and that on CT, visibility of the splenic hilum on US, sonic window quality, and operator experience. This study underscores the importance of considering these factors when interpreting splenic measurements obtained from different imaging modalities in clinical practice.