Computed Tomography Scan Measurements Research Articles

Evaluating Growth Patterns of Abdominal Aortic Aneurysm Diameter With Serial Computed Tomography Surveillance

Small abdominal aortic aneurysms (AAAs) are common in the elderly population. Their growth rates and patterns, which drive clinical surveillance, are widely disputed. To assess the growth patterns and rates of AAAs as documented on serial computed tomography (CT) scans. Cohort study and secondary analysis of the Non-Invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA3CT), a randomized, double-blind placebo-controlled clinical trial conducted from 2013 to 2018, with CT imaging every 6 months for 2 years. The trial was a multicenter, observational secondary analysis, not related to treatment hypotheses of data collected in the N-TA3CT. Participants included 254 patients with baseline AAA diameter between 3.5 and 5.0 cm. Patients received serial CT scan measurements, analyzed for maximum transverse diameter, at 6-month intervals. The primary study outcome was AAA annual growth rate. Secondary analyses included characterizing AAA growth patterns, assessing likelihood of AAA diameter to exceed sex-specific intervention thresholds over 2 years. A total of 254 patients, 35 women with baseline AAA diameter 3.5 to 4.5 cm and 219 men with baseline diameter 3.5 to 5.0 cm, were included. Yearly growth rates of AAA diameters were a median of 0.17 cm/y (interquartile range [IQR], 0.16) and a mean (SD), 0.19 (0.14) cm/y. Ten percent of AAAs displayed minimal to no growth (<0.05 cm/y), 62% displayed low growth (0.05-0.25 cm/y), and 28% displayed high growth (>0.25 cm/y). Baseline AAA diameter accounted for 5.4% of variance of growth rate (P < .001; R2, 0.054). Most AAAs displayed linear growth (70%); large variations in interval growth rates occurred infrequently (3% staccato growth and 4% exponential growth); and some patients' growth patterns were not clearly classifiable (23% indeterminate). No patients with a maximum transverse diameter less than 4.25 cm exceeded sex-specific repair thresholds at 2 years (men, 0 of 92; 95% CI, 0.00-0.055; women, 0 of 25 ; 95% CI, 0.00-0.247). Twenty-six percent of patients with a maximum transverse diameter of at least 4.25 cm exceeded sex-specific repair thresholds at 2 years (n = 12 of 83 men with diameter ranging from 4.25 to <4.75 cm; 95% CI, 0.091-0.264; n = 21 of 44 men with diameter ranging from 4.75-5.0 cm; 95% CI, 0.362-0.669; n = 3 of 10 women with diameter ≥4.25 cm; 95% CI, 0.093-0.726). Most small AAAs showed linear growth; large intrapatient variations in interval growth rates were infrequently observed over 2 years. Linear growth modeling of AAAs in individual patients suggests smaller AAAs (<4.25 cm) can be followed up with a CT scan in at least 2 years with little chance of exceeding interventional thresholds. ClinicalTrials.gov Identifier: NCT01756833.

Identification of Tibial Malrotation After Nailing Using Unique CT Scan Reference Line, and Influence of Position of Leg for Distal Locking on Rotation.

Tibial torsion can be measured by various clinical and radiological methods. Computed tomography (CT) scan measurement is currently the investigation of choice. The purpose of our study was to compare the clinical and CT scan methods to reveal malrotation after nailing of tibia and also to find out if leg position for distal locking has any influence on incidence of malrotation. We have included 106 patients (21-68years) of tibia nailing, and categorised them as category A (figure of four position n = 54) and category B (knee straight position n = 52) based on limb position for distal locking. The plumb line measurement, Thigh Foot Axis (TFA) and CT scan measurement (using new reference line) were documented and compared with the uninjured limb. We observed plumb line measurement to be the most inaccurate method followed by TFA method. CT scan measurement was the most accurate method showing external rotations (> 10º) in 32 cases (30.1%) and internal rotation (> -10º) in five cases (4.71%). The TFA method had a sensitivity of 44% and specificity of 86% in identifying malrotations. The interobserver reliability for CT scan measurement was 0.96. Even though statistically not significant (P value), figure of four position for distal locking leads to larger number of malrotations (both external and internal rotation). CT scan is the most accurate method of measuring malrotation. The new reference line used in our study provides accurate measurement of malrotation. The two different positions of leg for distal locking do not have a statistically significant influence on incidence of malrotation.

A Comparative Study of Clinical vs. Digital Exophthalmometry Measurement Methods.

Background A number of orbital diseases may be evaluated based on the degree of exophthalmos, but there is still no gold standard method for the measurement of this parameter. In this study we compare two exophthalmometry measurement methods (digital photography and clinical) with regard to reproducibility and the level of correlation and agreement with measurements obtained with Computerized Tomography (CT) measurements. Methods Seventeen patients with bilateral proptosis and 15 patients with normal orbits diseases were enrolled. Patients underwent orbital CT, Hertel exophthalmometry (HE) and standardized frontal and side facial photographs by a single trained photographer. Exophthalmometry measurements with HE, the digital photographs and axial CT scans were obtained twice by the same examiner and once by another examiner. Pearson correlation coefficient (PCC) was used to assess correlations between methods. Validity between methods was assessed by mean differences, interintraclass correlation coefficients (ICC's), and Bland–Altman plots. Results Mean values were significantly higher in the proptosis group (34 orbits) than in the normal group (30 orbits), regardless of the method. Within each group, mean digital exophthalmometry measurements (24.32 ± 5.17 mm and 18.62 ± 3.87 mm) were significantly greater than HE measurements (20.87 ± 2.53 mm and 17.52 ± 2.67 mm) with broader range of standard deviation. Inter-/intraclass correlation coefficients were 0.95/0.93 for clinical, 0.92/0.74 for digital, and 0.91/0.95 for CT measurements. Correlation coefficients between HE and CT scan measurements in both groups of subjects (r = 0.84 and r = 0.91, p < 0.05) were greater than those between digital and CT scan measurements (r = 0.61 and r = 0.75, p < 0.05). On the Bland–Altman plots, HE showed better agreement to CT measurements compared to the digital photograph method in both groups studied. Conclusions Although photographic digital exophthalmometry showed strong correlation and agreement with CT scan measurements, it still performs worse than and is not as accurate as clinical Hertel exophthalmometry. This trail is registered with NCT01999790.

Suitability of 3D-Printed Root Models for the Development of Transcatheter Aortic Root Repair Technologies.

Transcatheter aortic root repair (TARR) is still not available because of the complex anatomy. In order to develop future TARR technologies, a human-derived bench test model is required before performing animal tests. For this purpose, we aimed to validate computed tomography (CT)-derived 3D-printed root models for TARR technologies. Four human CT-derived roots were printed using different resins: Visijet M3 Crystal, Photopolymer gel SUP705, Formlabs flexible resin, and Materialise HeartPrint Flex. A stress test was performed using a 26-mm balloon-expandable Sapien valve deployed in aortic position. The too rigid Visijet M3 Crystal was not tested. Among the others, all but one (HeartPrint Flex, Materialise, Leuven, Belgium) ruptured during the test showing low wall resistances. Further tests were then performed in two roots made of HeartPrint Flex resin. The anatomic validation was performed comparing human CT scan-derived 3D reconstructions and CT scan measurements: a mean difference of 0.57 ± 0.4 mm for aortic annulus diameter and for the distance between the aortic annulus and the coronary ostia was measured. Concerning the coronary arteries, they are of paramount importance for new TARR technologies, and therefore, we tested the coronary flows of the HeartPrint Flex root at different pressure levels. At 60 mm Hg, right and left mean adjusted coronary flows were 471 and 663 ml/min; at 80 mm Hg, right and left mean coronary flows were 551 and 777 ml/min; and at 100 mm Hg, right and left mean coronary flows were 625 and 858 ml/min. In our study, 3D-printed root models correlate well with human anatomy and guarantee physiologic coronary flows for TARR technologies.

Effect of a Controlled Ankle Motion Walking Boot on Syndesmotic Instability During Weightbearing: A Cadaveric Study.

Background:Syndesmotic injuries can lead to long-term complications; hence, they require careful management. Conservative treatment is adequate when 1 syndesmotic ligament is injured, but surgery is often necessary to achieve articular congruity when 3 syndesmotic ligaments are ruptured. However, there is some controversy over the best treatment for 2-ligament injuries.Purpose:To evaluate the effect of a controlled ankle motion (CAM) walking boot on syndesmotic instability following iatrogenic isolated anterior inferior tibiofibular ligament (AiTFL) injury and combined AiTFL/interosseous ligament (IOL) injuries in a cadaveric simulated weightbearing model.Study Design:Controlled laboratory study.Methods:Ten cadaveric specimens were dissected to expose the tibial plateau and syndesmosis. The specimens were fitted to a custom-made device, and a reproducible axial load of 750 N was applied. Iatrogenic rupture of the syndesmotic ligaments (AiTFL + IOL) was done sequentially. Uninjured syndesmoses, isolated AiTFL rupture, and combined AiTFL/IOL rupture were compared with and without axial loading (AL) and CAM boot. The distal tibiofibular relationship was evaluated using a previously validated computed tomography scan measurement system. Wilcoxon tests for paired samples and nonparametric data were used.Results:The only difference noted in the distal tibiofibular relationship during AL was an increase in the external rotation of the fibula when using the CAM boot. This was observed with AiTFL rupture (8.40° vs 11.17°; P = .009) and combined AiTFL/IOL rupture (8.81° vs 11.97°; P = .005).Conclusion:AL did not cause a significant displacement between the tibia and fibula, even when 2 ligaments were ruptured. However, the CAM boot produced a significant external rotation with 1 or 2 injured ligaments.Clinical Relevance:Further studies are needed to assess the capacity of the CAM walking boot to prevent malreduction when external rotation forces are applied to the ankle. Moreover, special care should be taken during the fitting of the CAM boot to avoid overinflation of the cushions.

CT evaluation of normal bone thickness overlying the superior semicircular canal

Superior semicircular canal dehiscence (SSCD) is a rare inner ear disorder with variable amounts of auditory and vestibular dysfunction. In addition to the absence of bone overlying the superior semicircular canal, thinning of bone in this area can also initiate the vestibulocochlear symptoms of SSCD. We evaluated normal bone thickness overlying the course of the semicircular canal using computed tomography (CT) scans and assessed correlations between bone thickness and age, gender, and location of the thinnest bone. A single-institution retrospective chart review was conducted on 133 high-resolution CT scans from 76 healthy, asymptomatic patients between ages 9 and 96 years. These CT scans of the temporal bone were obtained between January 2012 and August 2017. The superior semicircular canal dome thickness at the apex was reported with a mean of 1.25 mm for all 76 patients; the 10th percentile was 0.60 mm, and the 90th percentile was 2.08 mm. The thinnest area of bone at any location yielded a mean of 0.86 mm. The normal bone thickness overlying the superior semicircular canal does not depend on gender or age. The thinnest location was evenly distributed across the superior semicircular canal. A bone thickness of 0.40 mm or greater was present in 90% of normal patients based on CT scan measurements at the thinnest location.

Clinical and Radiological Predictors of Functional Outcome After Isolated Medial Patellofemoral Ligament Reconstruction at Midterm Follow-up

Background: Isolated medial patellofemoral ligament reconstruction (iMPFLR) is increasingly used for the surgical treatment of recurrent patellofemoral instability. Purpose: The purpose of this study was to identify the clinical and radiological predictors that can significantly influence the functional outcomes after an iMPFLR. Study Design: Case series; Level of evidence, 4. Methods: A total of 107 patients (112 ligament reconstructions) who underwent iMPFLR were evaluated with a mean ± SD follow-up of 59 ± 33 months (range, 12-123 months). Functional International Knee Documentation Committee (IKDC) and Kujala scores were assessed preoperatively and every 12 months. Radiological assessment of patellar height and tilt (Laurin angle, Merchant angle, Maldague classification) and computed tomography (CT) scan measurement of patellar tilt (contracted and relaxed quadriceps) and tibial tubercle–trochlear groove distance were performed preoperatively and at 6 months. Femoral tunnel position was assessed following the criteria formulated by Schöttle. The amount of femoral tunnel widening was measured by means of 3-dimensional CT scan at 6 months. Predictors were determined from univariate and multivariate regression analyses integrating clinical and radiological criteria pre- and postoperatively. The dependent variable was defined as the difference between pre- and postoperative scores. Results: Between pre- and postoperative measurement at last follow-up, a significant improvement for IKDC and Kujala functional scores was observed (Kujala: 57 ± 11.3 to 87 ± 12.9, P < .001; IKDC: 47.8 ± 13.1 to 79 ± 15.8, P < .001). Demographics (age, body mass index, sex), dislocation characteristics (number of dislocations, time between first dislocation and surgery, age at first dislocation, mechanism of first dislocation, knee side), clinical data (frontal limb alignment, hyperlaxity, recurvatum, pre- and postoperative range of motion), and complications (quadriceps atrophy, complex regional pain syndrome) did not influence functional scores. The predictors of lower improvement in functional scores included small correction of the patellar tilt reported on the CT scan measurement, malpositioning of the femoral tunnel, and a widening of this tunnel near the medial cortex. Malpositioning of the femoral tunnel was correlated with tunnel widening, and patients with anterior and proximal malpositioning experienced stiffness in flexion. Conclusion: Overall, iMPFLR demonstrated good outcomes. Predictors influencing the functional results were identified. Less improvement in clinical outcome was reported for patients with a high preoperative patellar tilt and only a small correction in tilt and for those who had femoral tunnel malpositioning, which was correlated with tunnel widening.

Measurement of changes in optic nerve sheath diameter using ultrasound and computed tomography scan before and after the ventriculoperitoneal shunt surgery in patients with hydrocephalus - A prospective observational trial

Background: The standard methods for measuring intracranial pressure (ICP) are invasive in nature. Non invasive methods such as ONSD may help circumvent these complications and may serve as a surrogate marker for increased ICP. The primary aim of this study was to assess the ONSD (optic nerve sheath diameter) changes using ultrasonography (USG) and computed tomography (CT) scan in hydrocephalus patients before and after the insertion of VP shunt. Materials and methods: A prospective observational study was conducted among 69 patients undergoing VP shunt surgery between the ages of 2 to 60 years. ONSD variation was measured by USG and CT scan both before and after the surgery. The difference in the pre-operative and post-operative ONSD measurement was analyzed using a paired t-test. Whereas, the measurements of ONSD were compared for agreement between two modalities (USG and CT) using Interclass correlation (ICC) and Bland Altman graph plot. Results: Among 69 patients 38 were males, 31 were females and 12 were under the age of 10 years. In the adult group, average preoperative and postoperative ONSD measurement by USG was 5.80 ± 0.63 mm and 4.52 ± 0.72 (p < 0.001) and by CT was 5.77 ± 0.83 mm and 4.49 ± 0.76 mm (p < 0.001) respectively. Similarly, in the pediatric population, average preoperative and postoperative ONSD measurement by USG was found to be 4.76 ± 1.14 mm and 3.90 ± 1.08 mm and by CT was found to be 4.75+/-1.11 mm and 3.85 ± 1.09 mm respectively (p <0.001). Conclusion: In patients with hydrocephalus undergoing VP shunt surgery, we found a significant reduction in ONSD after the shunt insertion in both pediatric and adult population. We also found a good correlation between the USG and CT scan measurements of ONSD.

Posterior Transpedicular Screw Fixation of Subaxial Vertebrae: Accuracy Rates and Safety of Mini-laminotomy Technique.

Background and Aim:Posterior cervical transpedicular screw fixation has the strongest resistance to pullout forces compared with other posterior fixation systems. Here, we present a case on the use of this technique combined with a mini-laminotomy technique, which serves as a guide for accurate insertion of posterior cervical transpedicular screws.Materials and Methods:We retrospectively analyzed data from 40 patients who underwent this procedure in our clinic between January 2014 and March 2017.Results:The study population comprised 27 males (67.5%) and 13 females (32.5%) aged 15–80 years (median, 51.5 years). Surgical indications included trauma (n = 18, 45%), degenerative disease (n = 19, 47.5%), spinal infection (n = 2, 5%), and basilar invagination due to systemic rheumatoid disease (n = 1, 2.5%). In the 18 trauma patients, 14 short-segment (1–2 levels) and 4 long-segment (≥3 levels) posterior cervical instrumentation and fusion procedures were performed. The mini-laminotomy technique was used in all patients to insert, direct, and achieve exact screw fixation in the pedicles. Pedicle perforations were classified as medial or lateral and were also graded. Among the 227 cervical pedicle fixations performed, 48 were at the C3 level, 49 at C4, 60 at C5, 50 at C6, and 20 at C7. Axial computed tomography scan measurements showed that 205 of 227 (90.3%, Grade 0 and 1) screws were accurately placed, whereas 22 (9.69%, Grade 2 and 3) were misplaced. However, no additional neurological injury due to misplacement was observed.Conclusion:As negligible complications were observed when performed by experienced surgeons, the mini-laminotomy technique can be safely used for posterior transpedicular screw fixation in the subaxial vertebrae for single-staged fusion.

Management of computed tomography scan detected hemothorax in blunt chest trauma: What computed tomography scan measurements say?

AIMTo investigate the hemothorax size for which tube thoracostomy is necessary.METHODSOver a 5-year period, we included all patients who were admitted with blunt chest trauma to our level 1 trauma center. Focus was placed on identifying the hemothorax size requiring tube thoracostomy.RESULTSA total number of 274 hemothoraces were studied. All patients with hemothoraces measuring above 3 cm received a chest tube. The 50% predicted probability of tube thoracostomy was 2 cm. Pneumothorax was associated with odds of receiving tube thoracostomy for hemothoraces below 2 cm (Odds Ratio: 4.967, 95%CI: 2.225-11.097, P < 0.0001).CONCLUSIONAll patients with a hemothorax size greater than 3% underwent tube thoracostomy. Prospective studies are warranted to elucidate the clinical outcome of patients with smaller hemothoraces.

New Algorithm for the Management of Orbital Blowout Fracture Based on Prospective Study.

Despite extensive debate and publications in the management of blowout fracture (BOF), there are still considerable differences in the surgeons' management of BOF due to a lack of reliable evidence-based studies. This article aimed to evaluate which BOF patients require surgical treatment due to functional and/or cosmetic deformities; evaluate which computed tomography (CT) scan findings predict these problems; and provide an algorithm in the management of BOF. Seventy-nine patients with BOF were treated conservatively and followed up prospectively regarding functional and cosmetic deformities for at least 1 year. The patients' CT scans were analyzed and several measurements were performed. Patients' symptoms and the clinical findings were correlated to the CT scan measurements. We found visible deformity in 37% of the patients, but only 10% chose to proceed to surgery due to cosmetic deformities. In patients with inferior BOF and a herniation < 1.0 mL, a visible deformity was found when the ratio between fracture and the fractured orbital wall areas was ≥42%, or the total area of the fracture was ≥ 2.3 cm 2 . In patients with inferior BOF and a herniation ≥ 1.0 mL, a visible deformity was found when the distance from the inferior orbital rim to the posterior edge of the fracture was ≥ 3.0 cm. In patients with inferomedial fracture, a visible deformity was found when the herniation was ≥ 0.9 mL. Diplopia improved significantly and remained in only 3% of the patients in nonoperated group. Hypoesthesia of the infraorbital nerve improved significantly, but 23% of the nonoperated and 50% of the operated patients still experienced loss of sensation at final control. In this prospective study, we found that not only herniated orbital volume but also other CT scan findings in BOF were crucial to predict late visible deformities. Based on these findings, we propose an algorithm for the prediction of late visible deformity with 83% accuracy. There are indications that diplopia without ocular motility disorder is due to edema and we recommend observation as long as the diplopia improves gradually.

Prospective Randomized Controlled Pilot Study on Orbital Blowout Fracture.

To clarify the conflicting recommendations for care of blowout fracture (BOF), a prospective randomized study is required. Here, we present a prospective randomized pilot study on BOF. This article aimed to evaluate which computed tomography (CT) findings predict late functional and/or cosmetic symptoms in BOF patients with ≥ 1.0 mL herniation of orbital content into maxillary and/or ethmoidal sinuses. It also aimed to evaluate which patients with BOF would benefit from surgical treatment or observational follow-up. Twenty-six patients with BOF ≥ 1.0 mL herniation were randomized to observational ( n = 10) or surgical treatments ( n = 16) and were followed up for functional and cosmetic symptoms for at least 1 year. The results from CT scan measurements were correlated to the patients' symptoms and clinical findings which we report in this pilot study. Of the 10 patients randomized to observation, five had an inferomedial BOF with a herniation of ≥ 1.3 mL and all patients developed cosmetic deformities and required surgery. The remaining five patients in the observational group had inferior BOF and one of them had a distance of 3.3 cm from the inferior orbital rim to the posterior edge of the fracture and developed a cosmetic deformity but was unwilling to proceed to surgical treatment, and four patients had a median distance of 2.9 cm from the inferior orbital rim to the posterior edge of the fracture and did not develop cosmetic deformities. The median time from injury to surgery was 13 (3-17) days for the surgical group and 37 (17-170) days for the patients who underwent surgery in the observational group. The surgical results were similar for all the operated patients at the final control. Diplopia decreased and remained partly in one patient in the surgical group and in two patients in the observational group. Hypoesthesia of the infraorbital nerve decreased in nonsurgically treated patients, but surgery seemed to induce hypoesthesia. In this prospective randomized controlled pilot study on BOF, all patients in the observational group with inferomedial fractures developed visible deformity. Diplopia in BOF, without ocular motility limitation, is believed to be due to edema. Diplopia is not an indication for surgery as long as it reduces over time.

Medial patellofemoral ligament reconstruction with or without tibial tubercle transfer is an effective treatment for patellofemoral instability.

The hypotheses were that medial patellofemoral ligament reconstruction (MPFLr) would improve the long-term symptoms of patellofemoral Instability (PFI) and control patellar tilt, based on computed tomography (CT), and that the addition of a TT transfer, when it is necessary, would not deteriorate the outcome. The purpose of this study was to evaluate the long-term clinical and radiographic outcomes of a large series of MPFLr, either isolated or associated with a TT transfer. From 133 MPFLr with a minimum of 4years postoperatively, three groups were defined: isolated MPFLr, MPFLr with tibial tubercle (TT) medialisation or MPFLr with TT medialisation and distalisation. IKDC and Kujala scores were evaluated. Patellar tilt was evaluated on the patient's preoperative and the last available radiograph, and on CT scan measurements performed preoperatively and at 6-month postoperatively. The mean follow-up was 6.3 ± 1.7years [4.1-10.3] and four patients reported recurrent patellar dislocation. Between pre and postoperative at last follow-up a significant improvement in IKDC and Kujala functional scores was observed (P < 0.01), with no difference between the three groups. Regarding patellar tilt, there were significant decreases in Laurin and Merchant angles and an improvement of the Maldague stage (P < 0.01). The CT analysis of patellar tilt also demonstrates a significant improvement of the patella tilt (P < 0.01). The control of the patella tilt was correlated with a good functional result (P < 0.01). The MPFLr, whether isolated or associated with a TT transfer, provides good long-term clinical and radiological outcomes with a low rate of recurrence. The addition of a TT transfer, when necessary, results in the same good outcomes. This article provides a guide for surgeons evaluating PFI to choose the most appropriate procedure. IV.

A Novel Method for the Prediction of Pancreatic Fistula Following Pancreaticoduodenectomy by the Assessment of Fatty Infiltration

Pancreaticoduodenectomy is the gold standard treatment of neoplastic lesions of periampullary region. It is a well-known fact that postoperative pancreatic fistula is considered as the most common cause of morbidity. We aimed to present a novel technique using preoperative computed tomography (CT) evaluating the ratio of fatty volume to total pancreatic volume. A total of 40 patients who had been operated for periampullary neoplasm in a single tertiary center were included in the study. Study group was composed of 20 patients who had developed clinically relevant pancreatic fistula. Preoperative CT scans were evaluated retrospectively. Analysis of the image data was based on axial images and two-dimensional (2D) and three-dimensional (3D) post-processing images. Lipid component was estimated as the ratio of lipid volume to the total volume of the pancreas. Adenocarcinoma was the most frequent histopathological diagnosis in both groups (n = 33, 82.5%). Due to preoperative CT scan measurements, both pancreatic fat volume and the ratio of fatty volume to the whole pancreatic volume were found to be statistically higher in the study group (p < 0.01). Hospital stay was longer, and mortality rates were higher in study group. A ratio of 15% fat may be counted as a risk factor for PF development with a 95% sensitivity and 70% specificity, according to the ROC curve analysis. Preoperatively obtained triphasic CT can help in the prediction of postoperative pancreatic fistula. The assessment of the ratio of pancreatic lipid component may be a predictive factor (15%) for anastomotic failure, with the help of an experienced radiologist.

Benefit of Preoperative Temporal Bone CT for Atraumatic Cochlear Implantation.

Evaluate the benefit of preoperative surgical planning using computed tomography (CT) for atraumatic cochlear implantation. The surgical technique has a direct impact on hearing and structure preservation. Much interest has been given to depth of electrode insertion. We focused on electrode diameter depending on exposure of round window membrane (RWM) as calculated on preoperative CT. Measurements were calculated radiologically and anatomically on 10 temporal bones. Results were compared with CT scans of a control population. Thereafter, preoperative CT scan measurements were applied to seven additional temporal bones that underwent cochlear implantation with the insertion of two electrodes of different diameters (14 implantations) to validate radiological analysis. RWM size was 1.5 ± 0.2 mm on CT and 1.2 ± 0.2 mm during dissection; posterosuperior bony overhang of round window niche was 1.1 ± 0.1 mm on CT and 1.3 ± 0.2 mm during dissection. There was no statistically significant difference between radiological and anatomical measurements and between radiological measurements of cadaveric temporal bones and control population (p > 0.05 for both). Also, preoperative surgical planning was reliable in the seven temporal bones implanted with two electrode types (accuracy 93%, sensitivity 85.7%, specificity 100%) yielding no damage to intracochlear structures. Difficulties to access RWM could be predicted on preoperative CT of temporal bones and control population, which correlated well with anatomical dissections and surgical findings during cochlear implantation. According to CT planning, electrode insertion through RWM was feasible in most patients, with or without drilling posterosuperior bony overhang of round window niche. Promontory cochleostomy could be recommended when electrode apical diameter exceeded maximal RWM exposure. There was no case of intracochlear trauma on microdissections.

Can Preoperative CT Scans Be Used to Predict Facial Nerve Stimulation Following CI?

1) To determine the ability of preoperative computed tomography (CT) to predict facial nerve stimulation (FNS) after cochlear implantation (CI). 2) To recognize the limitations of CT in predicting FNS. Patient control study. Tertiary care academic medical center. Adult patients with CI from 2003 to 2015. Patients with severe FNS (n = 4) were compared with randomly selected CI patients (n = 28). Three blinded reviewers evaluated preoperative temporal bone CT scans to measure the distance from the labyrinthine segment of the facial nerve to the basal turn of the cochlea and attempted to predict whether or not the subject had FNS after CI. In total, 32 CT scans were evaluated representing 49 ears that underwent CI.The distances (mm) measured from the labyrinthine segment of the facial nerve to the basal turn of the cochlea in both the axial (0.3 ± 0.3 versus 0.6 ± 0.3) and coronal (0.4 ± 0.2 versus 0.6 ± 0.2) orientation were significantly different between the two groups (p = 0.0001 and p = 0.0034) respectively. The intraclass correlation coefficient demonstrated good (K > 0.7) reviewer correlation in both the reviewers' measurements and predictions. The sensitivity, specificity, positive predictive value, and negative predictive value for preoperative CT scans to predict FNS were 38.5, 85.1, 19.2, and 93.8% respectively. The reviewers were 23% accurate in predicting FNS. Based on a blinded retrospective patient-control study, CT scan measurements show a significantly reduced distance between the labyrinthine facial nerve and the basal turn of the cochlea in patients with FNS. However, it is difficult to predict who will have FNS based on these measurements.

Robotic Ileal Interposition for Radiation-induced Ureteral Stricture Disease

To present a novel surgical concept using preoperative imaging to estimate length needed for ileal segment. This enables robotic ileal interposition to be completed with only 1 position change during surgery. The index patient is a 69-year-old woman with a history of stage IIIB cervical cancer treated with chemotherapy and radiation 5 years prior to presentation. The patient subsequently developed a long segment stricture of the left ureter, which had been managed with ureteral stents. The patient decided to proceed with robotic ileal ureter for management of her ureteral stricture disease. We used preoperative computed tomography scan measurements to estimate length needed for ileal segment. This eliminated the need for multiple position changes during surgery. The patient tolerated the procedure well. Estimated blood loss was 50 cc. Kidney ultrasound at 1 month post-op revealed no hydronephrosis. Renal scan at 12 months post-op revealed stable function at 32% and no evidence of obstruction. The patient reports she is doing well and is pain free at this time. Robotic ileal interposition is a technically feasible procedure with good functional outcomes. By using preoperative imaging to estimate length needed for ileal segment, only 1 position change is needed during surgery.

Computed tomography–based prediction of the straight antegrade humeral nail's entry point and exposure of “critical types”: truth or fiction?

Straight antegrade intramedullary nailing of proximal humerus fractures has shown promising clinical results. However, up to 36% of all humeri seem to be "critical types" in terms of the potential violation of the supraspinatus (SSP) tendon footprint by the nail's insertion zone. The aims of this study were to evaluate if a computed tomography (CT) scan could reliably predict the nail's entry point on the humeral head and if it would be possible to preoperatively estimate the individual risk of iatrogenic violation of the SSP tendon footprint by evaluating the uninjured contralateral humerus. Twenty matched pairs of human cadaveric shoulders underwent CT scans, and the entry point for an antegrade nail as well as measurements regarding critical distances between the entry point and the rotator cuff were determined. Next, gross anatomic measurements of the same data were performed and compared. Furthermore, specimens were reviewed for critical types. Overall, 42.5% of all specimens were found to be critical types. The CT measurements exhibited excellent intra-rater and inter-rater reliability (intraclass correlation coefficients >0.90). Similarly, excellent agreement between the CT scan and gross anatomic measurements in contralateral shoulders (intraclass correlation coefficients >0.88) was found. Assessing the uninjured contralateral side, CT can reliably predict the entry point in antegrade humeral nailing and preoperatively identify critical types of humeral heads at risk of iatrogenic implantation damage to the SSP tendon footprint. This study may help surgeons in the decision-making processon which surgical technique should be used without putting the patient at risk for iatrogenic, implant-related damage to the rotator cuff.

Coronal displacement in proximal humeral fractures: correlation between shoulder radiographic and computed tomography scan measurements

The purpose of this study was to analyze if there is a correlation in displacement measurements in coronal projections between shoulder radiographs and computed tomography (CT) scans in patients with proximal humeral fractures (PHFs). A comparative, retrospective analysis of images from our database was performed. Ninety-seven cases with PHFs with radiographs and CT scans were included. Four evaluators measured PHF displacement using the following: metaphyseal extension (ME), medial calcar (MC) medialization, apex-tuberosity distance (ATD), and cervicodiaphyseal (CD) angle. Measurement reliability was evaluated with a pilot sample by performing intraclass coefficient correlation analysis. Surgery indication according to displacement (CD angle <105° or >155° and ATD <3 mm) and agreement analysis were assessed by κ tests. All evaluated parameters presented correlations among methods for intrarater and inter-rater reliability. All measurements showed significant differences (ME of 1.2 ± 6 mm, P = .034; MC of 1 ± 5 mm, P = .041; ATD of 2.6 ± 5 mm, P = .001; and CD angle of 9° ± 16°, P = .001). Regarding indications for treatment type relating to ATD and CD angle, there was agreement between CT scans and radiographs in 66 of 97 cases (κ = 0.351, P < .001). Twelve cases with surgical indications by CT scans had conservative indications by radiographs, whereas in 19 cases with conservative indications by CT scans, radiographic measurements suggested surgical treatment. This study documented regular concordance between radiographs and CT scans for coronal displacement measurements in PHFs. Statistical differences were documented for all measurements. Webelieve that ATD and CD angle differences are clinically relevant (mean, 3 mm and 9°, respectively) because these differences might change the type of treatment.

Evaluating Children With Metopic Craniosynostosis: The Cephalic Width-Intercoronal Distance Ratio.

To identify an additional objective measure to aid in the evaluation of children with isolated metopic craniosynostosis. This is a retrospective study comparing specific computed tomography scan measurements between surgical and nonsurgical cohorts of children with isolated metopic craniosynostosis. Children were included if they were diagnosed with isolated metopic craniosynostosis and ultimately underwent computed tomography scan imaging as part of their evaluation. The subjects were placed in the surgical or nonsurgical cohorts on the basis of the final treatment recommendation after they completed a full multidisciplinary, multimodality evaluation. Comparisons were made with a control group of unaffected patients from our institutional trauma registry. Tertiary academic institution. The subjects are patients who had been previously evaluated in our clinic for isolated metopic craniosynostosis and received a computed tomography scan as part of their workup. The average intercoronal distances were significantly different among all three groups (P < .002). The average cephalic width-intercoronal distance ratio for children who received a recommendation for surgery differed significantly from that of both the observation cohort and the control group (P < .001). However, the cephalic width-intercoronal distance ratio did not differ between the observation cohort and the control group (P = .927). The cephalic width-intercoronal distance ratio may be an additional objective measurement to aid in the clinical evaluation of children with metopic craniosynostosis.