Midline Sagittal Plane Research Articles

Research into the anatomy of the subaxial cervical pedicle for ensuring screw insertion safety.

The study aimed to determine the optimal entry points and trajectories for posterior subaxial cervical pedicle screw (CPS) fixation. Computed tomography (CT) and Mimics software were used to evaluate the subaxial cervical pedicle in 42 cervical spine CT scans. The width of the cervical pedicle was measured and compared at medial angulations of 30°, 35°, 40°, 45°, 50°, 55°, and 60° relative to the midline sagittal plane. Based on an observational examination of the positions of all cervical 3-dimensional models and screws, the proposed entry point for C3-7 CPS was analyzed. Although the variations in C3-6 pedicle width (PW) among 45°, 50°, and 55° were not statistically significant, they were significantly larger than the differences among 30°, 35°, 40°, and 60° angles (P < .05). The differences in C7 PW between the 30°, 35°, 40°, and 45° angles were not statistically different even though the 30°, 35°, 40°, and 45° angles were significantly bigger. (P < .05). The proposed entry point for C3-7 CPS was below the junction of the lateral and lower borders of the superior articular process joint surface. The entry point for C3-7 levels was below the junction of the lateral and lower borders of the superior articular process joint surface. The optimal medial angulation for the posterior C3-6 CPS was 45°-55° and that for the posterior C7 CPS was 30°-45°. The sagittal angle of the posterior C3-7 CPS was parallel to the corresponding upper endplate.

Modification of surgical and positioning splint for orthognathic surgical treatment of facial asymmetry

Present short communication demonstrates innovative approach for surgical and positioning splint modification, which could improve accuracy of orthognathic surgery during facial asymmetry treatment. Usage of traditionally designed splint leads to the orientation of the midline based just on visual control, which inevitably associated with some level of maxilla deviation. It was proposed to design splint with mutually perpendicular planes in its’ frontal part at the specialized software. Such approach helps to align vertical plane of the splint with the midline vertical facial plane, while horizontal component could be aligned with the horizontal one accordingly. Proposed approach was approbated in five different clinical cases of facial asymmetry treated by orthognathic surgery. In all analyzed cases dental midline aligned perfectly with the planned one, in two cases the midline sagittal plane deviations (from ANS to PNS) resulted to be less than 2°. The horizontal occlusal plane deviations were considered clinically non-significant. Modification of the surgical splint for jaws positioning in orthognathic surgery treatment enables possibilities to check and control position of maxilla regarding reference facial planes intraoperatively, which in turn increases the accuracy of bone fragments placement and assure high precision of orthognathic surgery for asymmetric cases.

Validating a Simple Urethra Surrogate Model to Facilitate Dosimetric Analysis to Predict Genitourinary Toxicity.

The urethra may be a critical structure in prostate radiotherapy planning as some studies have shown that higher urethral dose correlates with worse genitourinary (GU) toxicity. Identifying the urethra requires an MRI planning scan or foley catheter insertion at CT planning. Most surrogates have been developed and validated against the urethra identified by a foley catheter. However, the urethral position can shift with catheter placement. We, therefore, aim to validate a simple urethra surrogate model against MRI-defined urethra. The surrogate model can be used to correlate urethra dose-volume parameters (DVP) with late GU toxicity and to apply urethral constraints in those with a CT-only based workflow. Thirty-nine MRI-defined urethras from patients in the PACE-C trial were assessed to determine the average position of the urethra in the midline sagittal prostate plane along the ¼ gland, midgland, ¾ gland, apex and 3mm below apex. Using these average positions, a Python script was developed, which places a 10mm diameter circle in the 1/4 gland, midgland, ¾ gland, apex and 3mm below the apex. The observer manually contours a 10mm circle at the prostate base (prostate-bladder neck interface) to infer the urethra position and interpolates the contours. The urethra surrogate model was compared against 20 MRI-defined urethras (within the treatment PTV) in patients treated with 36.25Gy in 5 fractions as part of the PACE-B trial. To assess the surrogate's geometric performance, the Dice similarity coefficient (DSC), Hausdorff distance (HD), mean surface distance to agreement (MDTA) and the percentage of MRI-defined urethra outside the surrogate (UOS) were calculated. The surrogate model's dosimetric performance was assessed by comparing the mean D99, D98, average dose, D50, D2 and D1 using a paired t-test. The D(n) is the dose (Gy) to (n)% of the urethra. The median results were: DSC 0.36 (IQR 0.28-0.42), HD 0.88cm (IQR, 0.70-1.04), MDTA 0.24cm (IQR, 0.21-0.28), UOS 29% (IQR, 17-52%). When comparing DVP between the MRI-defined urethra and surrogate urethra, the mean D99, D98 and D95 as 38.8Gy vs 39.1Gy (p = 0.17), 39.3Gy vs 39.5Gy (p = 0.23), 40.1Gy vs 40.4Gy (p = 0.21), respectively. The mean D50, average dose, D2 and D1 was 41.8Gy vs 41.9Gy (p = 0.03), 41.7 vs 41.8Gy (p = 0.04), 42.9Gy vs 43.0Gy (p = 0.05) and 43.0Gy vs 43.1Gy (p = 0.03), respectively. While there were geometric differences between the surrogate urethra and MRI-defined urethra, there was no statistically significant difference between most urethral dose-volume parameters (D99, D98, D95, and D1). Similarly, the actual differences in urethra DVP were not clinically significant. This surrogate model could be validated in a larger cohort and then used to estimate the urethra position on CT planning scans for dosimetric analysis in those without an MRI planning scan or urinary catheter.

Craniotopographic Characteristics of Sinuous-Liquor Relationships in Mature People

The purpose of the study was to determine the craniotopographic (craniometric) indicators of sinuous-liquor relationships in the horizontal plane in people of the first and second periods of mature age, based on the maximum permissible depth of its introduction. Materials and methods. The object of the study was the dura mater of the brain with its sinuses, the ventricles of the brain and the vault of the skull of mature people. The study was performed on 100 corpses of people of different ages and gender with the manufacturing of native preparations of the brain with membranes and liquor structures. Of the indicated number of morphological objects, 70 preparations of veins and sinuses of the dura mater of the brain and 30 preparations of the cerebrospinal fluid system of the brain of mature people were made. The study used such research methods as: macro- and micropreparation of anatomical objects of the brain; cranio- and morphometry of veins, sinuses of the dura mater of the brain and liquor structures of the brain; manufacturing of corrosive (acrylic) casts – preparations of veins, sinuses of the dura mater of the brain and liquor formations of the brain; injection technique; variational-statistical analysis of morphometric data; computer-graphic analysis. Results and discussion. As a result of the study, it was found that the puncture of the central part of the lateral ventricle is better to be performed at the level of the bregma point, or between this point and the vertex (v). The puncture needle penetrates to a depth of 6.0–7.0 cm through the milling hole, which is displaced by 3.0–4.0 cm from the arrow line at an angle of 70–75°. The obtained data make it possible to determine the most optimal craniometric puncture points of the cerebrospinal fluid system of the brain. To penetrate into the cavity of the anterior horn of the lateral ventricle, the metopion point is proposed, which is located at the intersection of the median plane of the head with the line connecting the most convex areas of the frontal humps. The upper puncture of the lateral ventricle is better to be performed by puncturing at the bregma point (the point of connection of the sagittal and coronal sutures) 2.0 cm from the midline (sagittal plane); the needle is directed down and backwards and at a depth of 5–6 cm (taking into account that it is enlarged and stretched) it enters the ventricular cavity. The suboccipital puncture or a puncture of the cerebellar-cerebral cistern must be performed between the opisthocranion and lambda points. The puncture needle is inserted to a depth of 6.0–7.5 cm, and the end of the needle is gradually lowered to the base of the skull. Conclusion. The most optimal puncture points of the constituent parts of the cerebrospinal fluid system of the brain – the cavity of the anterior horn and the central part of the lateral ventricle, the cavity of the cerebellar-cerebral cistern – were determined using craniometric analysis

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

Magnetic resonance imaging findings of the posterior fossa in 47 patients with mucopolysaccharidoses: A cross-sectional analysis.

BackgroundMucopolysaccharidoses (MPS) is a group of hereditary multisystemic lysosomal disorders. Most neuroimaging studies in MPS have focused on the supratentorial compartment and craniocervical junction abnormalities, and data regarding posterior fossa findings are scarce in the literature. Thus, our purpose is to describe posterior fossa findings on magnetic resonance imaging (MRI) of MPS patients.MethodsWe reviewed routine MRI scans of MPS patients being followed up at our institution (types I, II, III, IV, and VI), focusing on posterior fossa structures.ResultsForty‐seven MPS patients were included. MRI‐visible perivascular spaces were commonly found in the midbrain and adjacent to the dentate nuclei (85% and 55% of patients, respectively). White‐matter lesion was not identified in most cases. Its most frequent localizations were in the pons and cerebellum (34% and 30% of patients, respectively). Enlargement of cerebrospinal fluid (CSF) spaces in the posterior fossa was present in 55% of individuals and was more frequent in neuronopathic patients (73% vs 40%; P = .02). Cerebellar volume was classified as normal, apparent macrocerebellum, atrophic, and hypoplastic in 38%, 38%, 21%, and 3% of patients, respectively. A depression of the posterior fossa floor in the midline sagittal plane was found in 22 patients (47%), which was statistical significantly associated with enlargement of CSF spaces (P = .02) and with apparent macrocerebellum (P = .03).ConclusionThe present study compiled the main posterior fossa findings in MPS patients. Classically described in the supratentorial compartment, MRI‐visible perivascular spaces, white matter lesions, and enlarged perivascular spaces were also found in the posterior fossa. However, atrophy, which commonly affects cerebral hemispheres, was not the most frequent cerebellar morphology found in our study. Moreover, potential findings for future research were described.

Dynamic orthognathic surgical procedure (DOSP) in asymmetric maxillomandibular dysmorphism secondary to unilateral micrognathia: Outcomes of 12 consecutive cases

This study aimed to evaluate the outcomes following a dynamic orthognathic surgical procedure performed at the end of growth to treat asymmetric maxillomandibular deformities linked to unilateral micrognathia when conventional orthognathic surgery was not feasible.The dynamic orthognathic surgical procedure (DOSP) combined concomitant mandibular distraction osteogenesis with contralateral poorly stabilized sagittal split osteotomy and Le Fort I osteotomy. Cephalometric studies were retrospectively conducted on pre- and postoperative lateral and frontal cephalographs, and maxillomandibular movements were calculated. Outcome scores were computed by both experts and laypersons based on photographic analyses.There was a significant postoperative increase in height of the micrognathic ramus in all patients (n = 12; p = 0.002). The angle between the occlusal cant and horizontal reference plane decreased significantly in all of the patients, as did the angle between the midline sagittal plane and mandibular tilt (p < 0.001). Postoperative outcome scores showed significant improvements in all cases, according to both expert and layperson groups.This procedure allows correction of maxillomandibular asymmetries linked to micrognathia. However, it cannot resolve all the factors participating in facial asymmetry, such as those originating in the oculo-auriculo-ventricular spectrum or complex tumor sequelae, and second-step procedures may be required.

Prediction of the mid-tracheal level using surface anatomical landmarks in adults: Clinical implication of endotracheal tube insertion depth.

Endotracheal tube (ETT) should be placed at the optimal level to avoid single lung ventilation or accidental extubation. This study was performed to estimate the mid-tracheal level by using surface anatomical landmarks in adult patients.Neck computed tomography images of 329 adult patients between the ages of 16 and 79 years were reviewed. In the midline sagittal plane, the levels corresponding to the vocal cords, cricoid cartilage, suprasternal notch, manubriosternal junction, and carina were identified. The surface distances from the cricoid cartilage to the suprasternal notch (extCC-SSN) and that from the suprasternal notch to the manubriosternal junction (extSSN-MSJ) were measured. The relationship between mid-tracheal level and the surface distances was analyzed using Bland–Altman plot.The difference between the extCC-SSN and the mid-tracheal level was −6.6 (12.5) mm, and the difference between the extSSN-MSJ and the mid-tracheal level was −19.2 (6.1) mm. The difference between the extCC-SSN and the mid-tracheal level was smaller in females compared with males [−1.7 (11.7) mm vs −12.8 (10.7) mm; P < 0.001].The mid-tracheal level, which is helpful in planning the insertion depth of an ETT, can be predicted by the surface distance between the cricoid cartilage and suprasternal notch in adults, especially in females.

AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine

AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine

AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

Crossed Pontine Hemiatrophy Associated with Unilateral Cerebellar Hemorrhage in Premature Infants.

Background Cerebellar hemorrhage is a complication of extreme prematurity with a significant impact on the neurodevelopmental outcome. It has been shown that cerebellar hemorrhage is associated with a reduction in the anteroposterior diameter of the pons on the midline sagittal plane at term-equivalent age, suggesting that cerebellar injury may impair overall pons development in premature infants. Objective This study stemmed from an incidental observation of crossed pontine hemiatrophy in a preterm infant with a history of unilateral massive cerebellar bleeding. We aimed to verify the presence of this association in a population of preterm infants. Methods Among all, very preterm infants (GA < 32 weeks) born at our institution over a 6-year period, those with a diagnosis of unilateral massive cerebellar hemorrhage were selected. Magnetic resonance imaging scans of the selected subjects were reviewed. Results Six patients with unilateral massive cerebellar hemorrhage were identified. MRI showed crossed hemiatrophy of the pons in all cases. Conclusion Crossed hemiatrophy of the pons was associated with massive unilateral cerebellar hemorrhage. This finding may reflect retrograde degeneration of pontocerebellar fibers and loss of neurons in contralateral hemipons.

An anatomic study to determine the optimal entry point, medial angles, and effective length for safe fixation using posterior C1 lateral mass screws.

Anatomic study of the C1 lateral mass using fine-cut computed tomographic scans and Mimics software. To investigate the optimal entry point, medial angles, and effective length for safe fixation using posterior C1 lateral mass screws. Placing posterior C1 lateral mass screws is technically demanding, and a misplaced screw can result in injury to the vertebral artery, spinal cord, or internal carotid artery. Although various insertion angles have been proposed for posterior C1 lateral mass screw, no clear consensus has been reached on the ideal medial angle of the C1 lateral mass. The C1 lateral masses were evaluated using computed tomographic scans and Mimics software in 70 patients. The effective width and effective screw length of posterior C1 lateral mass screws were measured at different medial angulations relative to the midline sagittal plane. The height (H) for screw entry point on the posterior surface of C1 lateral mass and the distance (D) between screw entry point and the intersection of the midline sagittal plane and the posterior arch of the atlas were also measured. The mean height (H) for screw entry on the posterior surface of the lateral mass was 4.25 mm, the mean distance (D) between screw entry point and the intersection of the midsagittal plane and the posterior arch of the atlas was 27.62 mm. The optimal medial angle was 20.86° with a corresponding effective width of 10.56 mm and effective screw length of 21.87 mm. This study helps to define the specific anatomy related to C1 posterior lateral mass screw placement in an effort to facilitate instrumentation. However, variation is seen in lateral mass anatomy, and this study must be combined with customized surgical planning that includes advanced imaging for safe and effective instrumentation. 1.

P16.08: Reproducibility of cervical length measurement: the effect of probe position and bladder visualisation in cervical shortening

Transvaginal sonography of the cervix is an important tool to identify patients with increased risk for preterm delivery. Due to cervical tissue softening, which is often associated with cervical shortening, clinically relevant inter- and intraobserver variations of measurement results can occur despite of a uniform measurement procedure (Iams et al. 2013). Our objective was to evaluate the effect of slight repositioning of the transducer to visualize the lower margin of the bladder on length measurements. In 50 patients (age: 15 - 46y., mean 30y., gestational age: 17 - 37 wks, mean 29 wks) measurement of the cervical length was performed with filled slightly urinary bladder. A midline sagittal plane was adjusted, initially by routine position of the transducer into the anterior vaginal fornix. Subsequently the transducer was slightly redrawn in order to visualize the lower unfolded margin of the bladder adjacent to the cervix. The results were compared using Wilcoxon signed-rank test. Measurement of the cervical length was easier to objectify after repositioning of the transducer with of the lower bladder margin visible and the results were significantly shorter (median: 7 mm). Cervical length measurements were significantly shorter after repositioning the transducer until unfolding of the lower bladder margin and the mean difference of 7mm may be clinically relevant. In patients with cervical shortening, the visualization of the bladder adjacent to the cervix may improve standardisation and reproducibility of cervical length measurement.

MP51-07 ANATOMICAL CHANGE RELATED TO PERSISTENT INCONTINENCE FOLLOWING RADICAL PROSTATECTOMY: EVALUATION USING PREOPERATIVE AND POSTOPERATIVE MAGNETIC RESONANCE IMAGE

You have accessJournal of UrologyProstate Cancer: Localized V1 Apr 2014MP51-07 ANATOMICAL CHANGE RELATED TO PERSISTENT INCONTINENCE FOLLOWING RADICAL PROSTATECTOMY: EVALUATION USING PREOPERATIVE AND POSTOPERATIVE MAGNETIC RESONANCE IMAGE Woo Suk Choi, Hwanik Kim, Jun-Gyo Suh, Ja Hyeon Ku, Sang Youn Kim, Jeong Yeon Cho, Soo Woong Kim, Hyeon Hoe Kim, Jae-Seung Paick, Seung Hyup Kim, and Cheol Kwak Woo Suk ChoiWoo Suk Choi More articles by this author , Hwanik KimHwanik Kim More articles by this author , Jun-Gyo SuhJun-Gyo Suh More articles by this author , Ja Hyeon KuJa Hyeon Ku More articles by this author , Sang Youn KimSang Youn Kim More articles by this author , Jeong Yeon ChoJeong Yeon Cho More articles by this author , Soo Woong KimSoo Woong Kim More articles by this author , Hyeon Hoe KimHyeon Hoe Kim More articles by this author , Jae-Seung PaickJae-Seung Paick More articles by this author , Seung Hyup KimSeung Hyup Kim More articles by this author , and Cheol KwakCheol Kwak More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1663AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives We evaluated anatomical change that is related to incontinence after radical prostatectomy (RP) in the patients with prostate cancer, using magnetic resonance image (MRI). Methods We performed MRI at preoperative and postoperative 12 months to the patients who underwent RP between November, 2011 and March 2013. Preoperative membranous urethral length (pre-MUL), postoperative MUL (post-MUL), and postoperative thickness of anterior peri-urethral structure (post-APUS) were measured in the midline sagittal plane on T2-weighted MR images, respectively (Figure 1). Persistent incontinence was defined by using ≥ 1 pad (Pad 1), and persistent severe incontinence was defined by using ≥ 2 pads (Pad 2) at postoperative 12 months. Results The mean age of 245 patients were 66.4 ± 7.0 years. Open and robotic RP were performed on 128 (52.2%) and 117 (47.8%) patients. Patients in group Pad 1 and 2 were 50 (20.4%) and 11 (4.5%), respectively. On the ROC curve analysis, optimal cut-off values of pre-MUL, post-MUL, and post-APUS that could predict incontinence were <14.5mm, <10.5mm, and <3.0mm. On univariate analysis, factors related to Pad 1 were post-MUL (<10.5mm), an amount of decrease in MUL (>4.0mm), prostate volume (>45cc), clinical stage (≥cT2), and ASA score (≥2), and factors related to Pad 2 were post-MUL, an amount of decrease in MUL, post-APUS (<3.0mm), prostate volume, hypertension, and pathologic stage (pT3). On multivariate analysis, factors that influence on Pad 1 were post-MUL (OR=12.1, 95%CI=4.7-31.5) and clinical stage (OR=3.8, 95%CI=1.1-13.8), and variables that were related to Pad 2 were post-MUL (OR=16.4, 95%CI=3.8-71.8), post-APUS (OR=5.8, 95%CI=1.4-23.7), and pathologic stage (OR=6.2 95%CI=1.4-27.4). Although the patients have pre-MUL <14.5mm, Pad 1 and Pad 2 occurred only in 13.3% and 2.4%, respectively when post-MUL was preserved (≥10.5mm). In contrast, the occurrence of Pad 1 and Pad2 was 60.0% and 20.0%, respectively without preserved post-MUL. Conclusions Preserving MUL is important for preventing persistent incontinence, regardless of pre-MUL. In addition, saving APUS can help prevent the occurrence of severe persistent incontinence. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e599-e600 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Woo Suk Choi More articles by this author Hwanik Kim More articles by this author Jun-Gyo Suh More articles by this author Ja Hyeon Ku More articles by this author Sang Youn Kim More articles by this author Jeong Yeon Cho More articles by this author Soo Woong Kim More articles by this author Hyeon Hoe Kim More articles by this author Jae-Seung Paick More articles by this author Seung Hyup Kim More articles by this author Cheol Kwak More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Ideal starting point and trajectory for C2 pedicle screw placement: a 3D computed tomography analysis using perioperative measurements

Background contextC2 pedicle screws provide stable fixation for posterior cervical fusion. Placing C2 pedicle screws is fraught with risks, and a misplaced screw can result in cortical breach of the pedicle, resulting in injury to the vertebral artery or spinal cord. PurposeWe sought to identify a reproducible starting point and trajectory for C2 pedicle screw placement using three-dimensional (3D) computed tomography (CT) imaging. Our aims included identifying correct cephalad and mediolateral angles used for determining the most accurate trajectory through the C2 pedicle. Study designA radiographic analysis of the anatomy of the C2 pedicle using CT. Patient sampleA random sample of 34 cervical spine CT scans in patients without medical or surgical pathology of the cervical spine. Outcome measuresNormal anatomic measurements made in the axial and sagittal planes of the CT scans. Angles and measures in millimeters were recorded. MethodsThe C2 pedicles were evaluated using CT scanning with a 3D imaging application. The ideal trajectory through each pedicle was plotted. The mediolateral and cephalad angles were measured using the midline sagittal plane and the inferior vertebral body border as references. Other measurements made were the distances through the pedicle and vertebral bodies, and the surface distances along the laminae between the isthmus and the starting point of the chosen trajectories. Other measurements involving the height of the laminae were also made. The mean values, standard deviations, and intraobserver variations are presented. ResultsCT scans from 34 patients were reviewed. The sex of the patient did not predict angle measurements (p=.2038), so combined male and female patient measures are presented. The mean mediolateral angle measured was 29.2°, and the mean cephalad angle was 23.0°. The mean distance along the lamina surface between the isthmus and the starting point was 8.1 mm. The mean distance from the superior border of the lamina to the starting point was 5.7 mm. There were no statistically significant differences between the dataset collected in duplicate by the same observer (p=.74); as such, we present one data analysis on combined data from the two datasets collected. ConclusionIt is possible to determine an ideal trajectory through the C2 pedicle. These measurements may facilitate C2 pedicle screw fixation decreasing the risk of injury to the vertebral artery, spinal cord, or nerve roots. Delineating the individual anatomy in each case with imaging before surgery is recommended.

Paper 132: Gender Specific Thicknesses of the PCL from Femoral Origin to Tibial Insertion in the Midline Sagittal Plane

Paper 132: Gender Specific Thicknesses of the PCL from Femoral Origin to Tibial Insertion in the Midline Sagittal Plane

Morphological Evaluation of the Male External Urethral Sphincter Complex by Transrectal Ultrasound: Feasibility Study and Potential Clinical Applications

Introduction: Previous measurement of the male external urethral sphincter complex (EUSC) length by magnetic resonance imaging and urethral pressure profilometry did not consider the intraprostatic portion, although its role for urinary continence has been demonstrated. The aim of our study was to verify the feasibility of a morphological evaluation of the EUSC by transrectal ultrasound (TRUS). Materials and Methods: Data from 52 men that underwent TRUS were prospectively collected. The EUSC was identified in the midline sagittal plane. Total and intraprostatic EUSC length and prostate volume were measured. Results: EUSC appears as a hypoechoic area surrounding the urethra. The proximal end was identified between the verumontanum and the prostate apex by the net change in prostate echo patterns, while the distal end was identified by voluntary contraction of the external anal sphincter. Mean total and intraprostatic EUSC lengths were 20.17 and 3.78 mm, respectively. Total EUSC length presented a weak correlation with prostate volume (r = 0.41; p = 0.003), while the intraprostatic portion had a stronger correlation (r = 0.60; p = 0.001). Conclusions: The evaluation of the EUSC is feasible by TRUS, and length measurement should include the intraprostatic portion. Potential clinical application should be the preoperative assessment of the risk of urinary incontinence in men undergoing radical prostatectomy.

Ultrasound and MRI Prenatal Diagnosis of Esophageal Atresia: Effect on Management

Ultrasound and MRI Prenatal Diagnosis of Esophageal Atresia: Effect on Management

Anatomic direction of entry for botulinum toxin injection to treat the adductor spasmodic dysphonia in Thais

Abstract Background: Botulinum toxin injections into the thyroarytenoid (TA) muscle of the larynx is the most popular treatment for adductor spasmodic dysphonia. Injection is usually done by percutaneous transcricothyroid membrane with either electromyography (EMG) or fiberoptic laryngoscopy (FOL) to verify placement of the needle within the TA muscle. This procedure requires a working knowledge of three-dimensional anatomy of the larynx to establish the direction for the accurate placement of the needle. Objective: Find out the appropriate angles and depth of the needle for placement of percutaneous transcricothyroid membrane method of botulinum toxin injection by means of studying the larynges of Thai cadavers. Methods: The descriptive study was performed in 45 Thai freshly thawed cadavers. The angle of the needle from midline sagittal plane, the angle in superior relation to tracheal plane, and the depth from midline cricothyroid (CT) membrane to midlength of TA muscle were measured from the two views of photographs, anteroposterior and lateral. Results: The mean angle of 24.2±6.76° (mean±SD) from the midline sagittal plane in male and 24.9±7.6° in female were worked out. A mean angle in superior relation to the tracheal plane was 47.7±7.8° and 51.4±9.6° in male and female, respectively. The mean depth was 1.7±0.2 and 1.4±0.1 cm in male and female, respectively. Conclusion: The mean angles and depth of the needle insertion from the midline of CT membrane to the center of TA muscle in Thai laryngeal specimens were evaluated. These values were different from the studies in Caucasians, but it could provide a direct relationship to the build of the races. This knowledge may help laryngologists do this procedure more accurately with better outcome, especially in hospitals that have no EMG or FOL guide.

The Effect of Backpacks on the Lumbar Spine in Children

This study is a repeated measures design to measure the lumbar spine response to typical school backpack loads in healthy children. The lumbar spine in this setting was measured for the first time by an upright magnetic resonance imaging (MRI) scanner. The purpose of this study is to measure the lumbar spine response to typical school backpack loads in healthy children. We hypothesize that backpack loads significantly increase disc compression and lumbar curvature. Children commonly carry school backpacks of 10% to 22% bodyweight. Despite growing concern among parents about safety, there are no imaging studies which describe the effect of backpack loads on the spine in children. Three boys and 5 girls, age 11 +/- 2 years (mean +/- SD) underwent T2 weighted sagittal and coronal MRI scans of the lumbar spine while standing. Scans were repeated with 4, 8, and 12 kg backpack loads, which represented approximately 10%, 20%, and 30% body weight for our sample. Main outcome measures were disc compression, defined as post- minus preloading disc height, and lumbar asymmetry, defined as the coronal Cobb angle between the superior endplates of S1 and L1. Increasing backpack loads significantly compressed lumbar disc heights measured in the midline sagittal plane (P < 0.05, repeated-measures analysis of variance [ANOVA]). Lumbar asymmetry was: 2.23 degrees +/- 1.07 degrees standing, 5.46 degrees +/- 2.50 degrees with 4 kg, 9.18 degrees +/- 2.25 degrees with 8 kg, and 5.68 degrees +/- 1.76 degrees with 12 kg (mean +/- SE). Backpack loads significantly increased lumbar asymmetry (P < 0.03, one-way ANOVA). Four of the 8 subjects had Cobb angles greater than 10 degrees during 8-kg backpack loads. Using a visual-analogue scale to rate their pain (0-no pain, 10-worst pain imaginable), subjects reported significant increases in back pain associated with backpack loads of 4, 8, and 12 kg (P < 0.001, 1-way ANOVA). Backpack loads are responsible for a significant amount of back pain in children, which in part, may be due to changes in lumbar disc height or curvature. This is the first upright MRI study to document reduced disc height and greater lumbar asymmetry for common backpack loads in children.