Translation Correction Research Articles

A Nash game based variational model for joint image intensity correction and registration to deal with varying illumination

Registration aligns features of two related images so that information can be compared and/or fused in order to highlight differences and complement information. In real life images where bias field is present, this undesirable artefact causes inhomogeneity of image intensities and hence leads to failure or loss of accuracy of registration models based on minimization of the differences of the two image intensities. Here, we propose a non-linear variational model for joint image intensity correction (illumination and translation) and registration and reformulate it in a game framework. While a non-potential game offers flexible reformulation and can lead to better fitting errors, proving the solution existence for a non-convex model is non-trivial. Here we establish an existence result using the Schauder’s fixed point theorem. To solve the model numerically, we use an alternating minimization algorithm in the discrete setting. Finally numerical results can show that the new model outperforms existing models.

Predictors of Rectal Toxicity in Patients Receiving Prostate SBRT: The Effect of Intrafraction Rotation

Stereotactic Body Radiation Therapy (SBRT) is an emerging treatment option for men with localized prostate cancer. While the extent of prostate intrafraction translation and rotation has been previously investigated, the clinical impact of rotation independent of translation has not. Several series have characterized low rates of rectal toxicity when SBRT is used with different dose regimens. This study attempts to quantify the impact of intrafraction rotation on grade 2+ rectal toxicity for men diagnosed with prostate cancer treated with SBRT. Between April 11, 2006 and August 13, 2018, 1712 patients with prostate cancer were treated with robotic-based SBRT at an academic institution. 91.2% were treated with 3500cGy in 5 fractions while 8.8% received 3625cGy. 328 (19.7%) patients received ADT as a component of their treatment. By NCCN grouping, patients were treated for low risk (26.9%), intermediate risk (60.1%), and high risk (13.0%) disease. Each fraction employed real-time intrafraction translation correction. Due to prostate fiducial configuration or body habitus, 75 (4.4%) patients did not receive intrafraction rotation correction during treatment. Intrarectal amifostine was administered to patients prior to each SBRT fraction. Long-term rectal toxicity was scored by RTOG late toxicity scale. Freedom from grade 2+ proctitis was assessed using the Kaplan-Meier method and analyzed using Cox regression methods. 13 patients developed grade 2 proctitis while 7 developed the grade 3 endpoint. 0.41% of all patients required hyperbaric oxygen or procedural intervention to manage toxicity. With a mean follow-up of 29 months (6-148), the 5-year freedom from grade 2+ proctitis was 97.8%. Rectal bleeding was more likely for patients older than age 75 (7.4% vs. 2.0%, p=.003). In rare cases where intrafraction rotation was not corrected, a higher rate of patients experienced rectal bleeding (10.5% vs. 2.9%, p=.03). Dosimetrically, a rectal V3600cGy <3cc predicted for decreased risk of bleeding (2.6% vs. 7.8%, p=.006), as did Rectal V3400cGy<6cc’s (1.9% vs. 4.3%, p=.021). NCCN risk grouping, ADT, Race, and prescription dose (3500cGy vs. 3625cGy) were not significant. On multivariate analysis, the lone predictor of grade 2+ proctitis was intrafraction rotation non-correction (OR 4.033, CI 1.042-15.610, p=.043). SBRT for prostate cancer is well tolerated with a low actuarial risk of grade 2+ proctitis. Prostate rotation independent of translation has the potential to modestly affect rectal toxicity. In patients treated on robotic platforms with pre-treatment administration of amifostine, intrafraction translation and rotation correction minimizes long-term rates of rectal bleeding.

Robustness of elective lymph node target coverage with shrinking Planning Target Volume margins in external beam radiotherapy of locally advanced cervical cancer.

Background and purposeImage-Guidance decreases set-up uncertainties, which may allow for Planning Target Volume (PTV) margins reduction. This study evaluates the robustness of the elective lymph node target coverage to translational and rotational set-up errors in combination with shrinking PTV margins and determines the gain for the Organs At Risk (OARs).Material and methodsTen cervix cancer patients who underwent external beam radiotherapy with 45 Gy/25Fx were analysed. Daily Image-Guidance was based on bony registration of Cone Beam CT (CBCT) to planning CT (pCT) and daily couch correction (translation and yaw). On each pCT, four Volumetric Modulated Arc Therapy dose-plans were generated with PTV margins of 0, 3, 5 and 8 mm. The elective clinical target volume (CTV-E) was propagated from daily CBCTs to the pCT to evaluate daily CTV-E dose. Additional systematic translational isocenter shifts of 2 mm were simulated. D98% (dose received by 98% of the volume of interest) and D99.9% were extracted from each CTV-E for all dose-plans and scenarios. Total dose was accumulated by Dose-Volume Histogram addition. The dosimetric impact of PTV margin reduction on the OARs was evaluated through V30Gy (volume included within the 30 Gy isodose), V40Gy and body V43Gy.ResultsWhen decreasing the PTV margin from 5 to 0 mm, bowel V30Gy was decreased by 13% (from 247 cm3 to 214 cm3), body V43Gy by 19% (from 1462 cm3 to 1188 cm3) and PTV by 39% (from 1416 to 870 cm3). The dosimetric impact of combined systematic shifts and residual rotations on the elective target with a 0 mm PTV margin was a decrease of D98% (mean ± SD) from 44.1 Gy ± 0.4 Gy to 43.7 Gy ± 0.8 Gy and a minimum of 42.4 Gy.ConclusionPTV margin reduction from 5 to 0 mm induced significant OARs dosimetric gains while elective target coverage remained robust to positioning uncertainties.

Korean EFL Learners’ Processing of English Caused-Motion Construction

This study explores how Korean English learners process English caused-motion constructions (CMC) through online and offline experiments. The focus was on how Korean learners’ processing of English CMC is affected by the typological difference between English and Korean. Of the 77 volunteer participants recruited, 17 were native English speakers and 60 were Korean EFL learners. The experiments included a sentence completion task (SCT) as an online experiment, and an acceptability jugment task (AJT) and a translation (correction) task as offline experiments. The results showed that in the SCT, the Korean learners showed difficulty in combining process and result events with intransitive manner verbs. In the AJT, they rarely accepted the CMCs with intransitive manner verbs, but easily accepted the ‘causative verb + byphrase’ structures with the same type of verbs. When the sentences were employed in the AJT were asked to be translated into Korean, the low-intermediate Korean learners were likely to drop the result meaning and interpret the preposition phrase as a locative rather than a goal. In sum, Korean learners showed similar patterns to native English speakers in processing path verbs and transitive manner verbs, but different pattern in processing intransitive manner verbs. These findings demonstrate that Korean learners' processing of English CMC is heavily influenced by their L1 when the construction accompanied intransitive manner verbs.

Spinopelvic Dissociation: A Retrospective Case Study and Review of Treatment Controversies.

Spinopelvic dissociation is a rare injury resulting in discontinuity between the spine and pelvis. We review the English- language literature and discuss critical treatment controversies. We present a series of spinopelvic dissociation cases from a level I trauma center. In this retrospective review of 18 consecutive cases treated surgically over a period of 4 years, we collected patient, injury, and surgical demographics and clinical and radiographic outcome measures. Twelve patients had associated injuries, five were intubated on arrival, and six had neurologic deficits at presentation. No patient had spinal decompression, and all patients underwent closed reduction and percutaneous fixation. There were no cases of iatrogenic nerve injury, despite the use of partially threaded sacroiliac screws and closed reduction techniques. Five patients showed progressive neurologic improvement postoperatively. After reduction, eight patients (44%) had radiographic loss of the sacrococcygeal angle at the latest follow-up, but correction of fracture translation was preserved in all. Spinopelvic dissociation represents a heterogeneous group of injuries often in the context of polytraumatized patients with other injuries. Our closed reduction and fixation technique resulted in satisfactory outcomes. We present a treatment algorithm for these rare injuries.

Surgical treatment for severe and rigid scoliosis: a case-matched study between idiopathic scoliosis and syringomyelia-associated scoliosis

Background ContextTreatment guidelines for severe and rigid syringomyelia-associated scoliosis (SRSMS) are limited. Typically, surgeons apply practice guidelines for severe and rigid idiopathic scoliosis (SRIS) to treat SRSMS. No study has directly compared the results of surgical treatment between patients with SRSMS and those with SRIS. PurposeThe present study was performed to compare the outcomes of surgical correction of SRSMS and SRIS from clinical and radiographic perspectives. Study DesignThis is a retrospective, case-matched, single-center, institutional review board-approved study. Patient SampleA total of 26 patients with SRSMS or SRIS treated by an anterior and posterior vertebral column resection approach or an internal distraction approach were enrolled. Outcome MeasuresThe SRSMS and SRIS groups were compared on the following variables: fusion length, screw number, operation time, estimated blood loss, follow-up duration, different radiological parameters (including main thoracic curve, cranial compensatory curve, caudal compensatory curve, thoracic kyphosis, lumbar lordosis, thoracic apical vertebral translation, coronal balance, and sagittal vertical axis), Scoliosis Research Society (SRS)-22 scores, and complication rate. MethodsThirteen patients with SRSMS were matched with patients with SRIS on curve magnitude, the flexibility of the main curve, surgical procedure, age, and gender. All patients had a minimum of 2 years of follow-up. The radiographic parameters and demographic data from patients were evaluated before surgery, immediately after surgery, and at the latest follow-up. ResultsThe case matches were relatively ideal except one pair with the main curve in the opposite direction. There was no significant difference in fusion length, screw number, operation time, estimated blood loss, or follow-up duration between the two groups. No significant differences were found between the two groups in the main curve or caudal compensatory curve before surgery, immediately after the operation, or at the final follow-up. The correction of thoracic apical vertebral translation in the SRIS group was better than that in the SRSMS group. The SRSMS group had a larger preoperative, postoperative, and final follow-up cranial compensatory curve and a lower correction rate than did the SRIS group. There was no significant difference in preoperative coronal balance between the two groups. After surgery, the coronal balance in the SRSMS and SRIS groups averaged 24.4±13.2 mm and 12.1±7.9 mm, respectively, which was significantly different (p=.04). At the most recent follow-up, the coronal balance in the SRSMS group improved to 14.8±12.6 mm, and it was 11.8±8.6 mm in the SRIS group. No significant difference was found between the two groups (p=.56). There was no significant difference in thoracic kyphosis, lumbar lordosis, or sagittal vertical axis before surgery, immediately after the operation, or at the final follow-up. Before surgery and at the final follow-up, the two groups had similar scores on function, pain, self-image, mental health, and satisfaction. There was no significant difference in complication rates between the two groups. ConclusionsTypically, surgical correction outcomes are similar in patients with SRSMS and SRIS. Patients with SRIS tended to have a smaller cranial compensatory curve and better correction of the cranial compensatory curve and thoracic apical vertebral translation. Patients with SRSMS tended to have a higher proportion and greater amount of postoperative coronal imbalance, which may be improved during follow-up.

Dinamika Terjemah Al-Qur'an (Studi Perbandingan Terjemah Al-Qur'an Kemenerian Agama RI dan Muhammad Thalib)

This paper compares two translations of the Qur’an: Al-Quran dan Terjemahnya by the team of the Ministry of Religious Affairs/MORA and Al-Quran Tarjamah Tafsiriyah by Muhammad Thalib. Scholars argue differently as to whether the Qur’an is translatable or not. Several classical and contemporary scholars argue that translating the Qur’an is forbidden (haram), while others allow it. Muhammad Thalib claims that Al-Quran dan Terjemahnya includes literal (harfiyah) translation, which is forbidden by scholars, and contains 3400 errors. On that basis, he composed Al-Quran Tarjamah Tafsiriyah as a correction of the former translation. I compare Al-Quran dan Terjemahnya’s translations of several verses on theological doctrine, syari’ah and mu’amalah, of which Thalib considers as containing errors, and those of Thalib’s translation himself to look for similarities and differences. The research shows that there is no significant difference between the two translations. The difference was limited to their respective method and purpose. MORA’s translation was oriented to translate the Qur’an faithfully, while Muhammad Thalib’s translation was oriented to provide an interpretive translation. For some verses, Thalib’s translation provides clearer meaning than that MORA’s. I argue that while translation errors are found in Thalib’s translation, none is found in MORA’s translation.Key words: Al-Quran Terjemahnya, Tarjamah Tafsiriyah, comparison, strength, weakness.

Measurements and Modeling of Volumetric and Phase Behavior of Carbon Dioxide + Higher Alkanes: CO2 + n-Pentadecane at Temperatures 313 to 410 K and Pressures up to 77 MPa

Experimental compressed liquid density and bubble pressure of {xCO2 + (1 – x)C15H32} are reported for x = 0.376, 0.562, and 0.757 at temperatures from 313, 363, and 410 K and pressures from bubble points up to about 77 MPa. Density was measured using a vibrating U-tube driven and scanned in frequency domain by a lock-in amplifier to accurately measure the resonance peak in complex form where density is determined with an expanded uncertainty of U(ρ) = 0.003ρ. The experimental measurements are compared with cubic equations of state of Redlich–Kwong–Soave (RKS), Peng–Robinson 1976 (PR76), and the improved version Peng–Robinson 1978 (PR78) with and without volume translation correction. PR78 EOS gives best predictions with an average deviation of 1.2%. The deviations are maximum near the bubble points and increase in a systematic manner with increasing CO2 mole fraction x. Bubble pressures were determined from the discontinuity of p–V plots completed during a series of isothermal constant composition expansi...

Single Cut Distal Femoral Varus Osteotomy (SCFO): A Preliminary Study.

Genu valgum usually originates from a deformity of distal femur that is often corrected by distal femoral varus osteotomy. The osteotomy includes both components of angulationcorrection and translation because the site of osteotomy is not commonly at the apex of deformity. Improvement of patellar tracking not only depends on valgus correction, but also it may be partially due to centralization of the trochlear groove under the femoral anatomical axis (FAA).We asked whether we could accurately correct the deformities based on our preoperative goals for the correction of the mechanical axis and centralization of the trochlear groove under the FAA by using a single bone cut.This study describes a new lateral single cut distal femoral osteotomy (SCFO) that enables concurrent correction of angulation and translation. This study was done on 12 young adult patients with femoral juxta-articular genu valgum deformity using SCFO. The average age at operation was 21 years (range: 16-25). SCFO is a type of closing-opening distal femoral osteotomy that corrects the valgus deformity of the distal femur while the translation of the distal fragment is done using one oblique cut. It centralizes the trochlear groove under the FAA. We compared the pre and postoperative radiographic and clinical variables including mechanical tibiofemoral angle, knee range of motion (ROM), International knee documentation committee (IKDC) score and the time to union. Mean follow-up of the patients was 24 months. The average mechanical tibiofemoral angle improved from 16 degrees (10-23) to 1 degrees (-2 to +2). IKDC subjective score slightly improved from preoperative (65) to 2-year follow-up (71). Centralization of the trochlea was achieved in all patients. SCFO can be a reasonable alternative for correction of the distal femur genu valgum deformity. It can centralize the patellar groove under the FAA with satisfactory clinical outcomes.

Motion-corrected k-space reconstruction for interleaved EPI diffusion imaging.

To develop a new approach to correct for physiological and macroscopic motion in multishot, interleaved echo-planar diffusion imaging. This work built on the previous SPIRiT (iterative self-consistent parallel imaging reconstruction) based reconstruction for physiological motion correction in multishot diffusion-weighted imaging to account for macroscopic motion. In-plane rotation, translation correction, data rejection, and weighted combination are integrated in SPIRiT-based reconstruction to correct for ghosting artifacts, blurring, altered b-matrix, and residual artifacts caused by motion. Numerical simulations (one data set was obtained from the Human Connectome Project) and in vivo experiments with deliberate bulk motion were performed to demonstrate the effectiveness of the proposed method. Diffusion images and quantitative tensor parameters were calculated to evaluate the correction performance. The proposed method provided images with reduced artifacts and diffusion tensors with improved accuracy in both simulations and in vivo experiments. For in vivo experiments with deliberate motion, the percentage error of fractional anisotropy in the genu of the corpus callosum was significantly reduced from 17.01 ± 12.64 to 5.73 ± 3.77 through motion correction. The proposed method can effectively correct for physiological and macroscopic motion artifacts in multishot interleaved echo-planar imaging, generate high resolution diffusion images, and improve the accuracy of tensor calculation. Magn Reson Med 79:1992-2002, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Study on the design of excessive typhoon and its induced storm surge

Excessive typhoon design is an interesting topic in coastal engineering. To design an excessive typhoon, the most popular method is typhoon path translation, but it may cause unreasonable results sometimes. In this paper, a correction method is introduced by using statistical air pressure map and wind speed map. Longquangang area along the north bank of Hangzhou Bay is taken as the research area here. The designed typhoon path is translated from Typhoon Khanun (2005). After typhoon strength correction and time translation, the result of wind speed and typhoon-induced storm surge seems more reasonable and can be used in coastal engineering, such as dike design and dike risk assessment.

Interference data correction methods for lunar observation with a large-aperture static imaging spectrometer.

The lunar spectrum has been used in radiometric calibration and sensor stability monitoring for spaceborne optical sensors. A ground-based large-aperture static image spectrometer (LASIS) can be used to acquire the lunar spectral image for lunar radiance model improvement when the moon orbits over its viewing field. The lunar orbiting behavior is not consistent with the desired scanning speed and direction of LASIS. To correctly extract interferograms from the obtained data, a translation correction method based on image correlation is proposed. This method registers the frames to a reference frame to reduce accumulative errors. Furthermore, we propose a circle-matching-based approach to achieve even higher accuracy during observation of the full moon. To demonstrate the effectiveness of our approaches, experiments are run on true lunar observation data. The results show that the proposed approaches outperform the state-of-the-art methods.

The effect of normalizing the sagittal cervical configuration on dizziness, neck pain, and cervicocephalic kinesthetic sensibility: a 1-year randomized controlled study.

Cervicogenic dizziness is a disabling condition commonly associated with cervical dysfunction. Although the growing interest with the importance of normal sagittal configuration of cervical spine, the missing component in the management of cervicogenic dizziness might be altered structural alignment of the cervical spinal region itself. To investigate the immediate and long-term effects of a 1-year multimodal program, with the addition of cervical lordosis restoration and anterior head translation (AHT) correction, on the severity of dizziness, disability, cervicocephalic kinesthetic sensibility, and cervical pain in patients with cervicogenic dizziness. A randomized controlled study with a 1 year and 10 weeks' follow-up. University research laboratory. Seventy-two patients (25 female) between 40 and 55 years with cervicogenic dizziness, a definite hypolordotic cervical spine and AHT posture were randomly assigned to the control or an experimental group. Both groups received the multimodal program; additionally, the experimental group received the Denneroll™ cervical traction. Outcome measures included AHT distance, cervical lordosis, dizziness handicap inventory (DHI), severity of dizziness, dizziness frequency, head repositioning accuracy (HRA) and cervical pain. Measures were assessed at three time intervals: baseline, 10 weeks, and follow-up at 1 year and 10 weeks. Significant group × time effects at both the 10 week post treatment and the 1-year follow-up were identified favoring the experimental group for measures of cervical lordosis (P<0.0005) and anterior head translation (P<0.0005). At 10 weeks, the between group analysis showed equal improvements in dizziness outcome measures, pain intensity, and HRA; DHI scale (P=0.5), severity of dizziness (P=0.2), dizziness frequency (P=0.09), HRA (P=0.1) and neck pain (P=0.3). At 1-year follow-up, the between-group analysis identified statistically significant differences for all of the measured variables including anterior head translation (2.4 cm [-2.3;-1.8], P<0.0005), cervical lordosis (-14.4° [-11.6;-8.3], P<0.0005), dizziness handicap inventory (29.9 [-34.4;-29.9], P<0.0005), severity of dizziness (5.4 [-5.9;-4.9], P<0.0005), dizziness frequency (2.6 [-3.1;-2.5], P<0.0005), HRA for right rotation (2.8 [-3.9;-3.3], P<0.005), HRA for left rotation (3.1 [-3.5;-3.4, P<0.0005], neck pain (4.97 [-5.3;-4.3], P<0.0005); indicating greater improvements in the experimental group. The addition of Denneroll™ cervical extension traction to a multimodal program positively affected pain, cervicocephalic kinesthetic sensibility, dizziness management outcomes at long-term follow-up. Appropriate physical therapy rehabilitation for cervicogenic dizziness should include structural rehabilitation of the cervical spine (lordosis and head posture correction), as it might to lead greater and longer lasting improved function.

Investigation into diagnostic accuracy of common strategies for automated perfusion motion correction.

Respiratory motion is a significant obstacle to the use of quantitative perfusion in clinical practice. Increasingly complex motion correction algorithms are being developed to correct for respiratory motion. However, the impact of these improvements on the final diagnosis of ischemic heart disease has not been evaluated. The aim of this study was to compare the performance of four automated correction methods in terms of their impact on diagnostic accuracy. Three strategies for motion correction were used: (1)independent translation correction for all slices, (2)translation correction for the basal slice with transform propagation to the remaining two slices assuming identical motion in the remaining slices, and (3)rigid correction (translation and rotation) for the basal slice. There were no significant differences in diagnostic accuracy between the manual and automatic motion-corrected datasets ([Formula: see text]). The area under the curve values for manual motion correction and automatic motion correction were 0.93 and 0.92, respectively. All of the automated motion correction methods achieved a comparable diagnostic accuracy to manual correction. This suggests that the simplest automated motion correction method (method 2 with translation transform for basal location and transform propagation to the remaining slices) is a sufficiently complex motion correction method for use in quantitative myocardial perfusion.

Direct Vertebral Rotation versus Derotation Technique in Lenke Type 1 Idiopathic Scoliosis

Introduction To date, most of scoliosis corrections are made by derotation and translation of the road from the concave side. The coplanar alignment (VCA) technique recovers the normal anatomy of the spine in its three dimensions, correcting rotation, translation, and restoring the surgical outcomes of VCA against derotation maneuver in selective fusions of patients with Lenke 1 idiopathic scoliosis. Patients and Methods Prospective trial of 21 patients with Lenke 1 idiopathic scoliosis. Fusion levels were determined according to Lenke criteria. In group A (10 patients), the VCA was used; and in group B (11 patients), we perform derotation maneuvers. Multiple radiographic variables were analyzed and SRS-22 was also measured. Results Both the groups were similar in terms of preoperative demographic and radiological variables. Coronal Cobb correction rate was 66.5% in group A and 70.06% in group B. There were no differences in postoperative thoracic kyphosis (group A: 29degrees/group B: 30 degrees, p = 0.9438), but we found a significant difference in the correction of apical translation (group A: 14.5 mm vs. group B: 17 mm, p = 0.0069). None of the groups presented vascular or neurological complications. The SRS-22 score improved significantly after 1-year follow-up without differences between the groups. Conclusion In treating Lenke 1 idiopathic scoliosis with selective fusion, both techniques provide good clinical and radiological results. The only advantage of VCA lies in allowing a better correction of apical translation.

Surgical Outcomes of the Nondystrophic Scoliosis Secondary to Neurofibromatosis Type I versus Curve-Matched Adolescent Idiopathic Scoliosis

Introduction Patients with nondystrophic scoliosis caused by NF-1 mostly require surgery. Although the radiographic findings in patients with nondystrophic scoliosis secondary to NF-1 are similar to those in patients with idiopathic scoliosis, evidence-based surgical guidelines, and long-term results are not as established as those for patients with AIS. The objective of this study is to compare the surgical outcomes of nondystrophic scoliosis secondary to neurofibromatosis type I (NF-1) and curve-matched adolescent idiopathic scoliosis (AIS) to identify the feasibility of treating nondystrophic NF-1 using the same principals as AIS and seek for potential surgical improvement. Patients and Methods A total of 19 adolescent patients with nondystrophic scoliosis secondary to NF-1 and 19 curve-matched patients with AIS were recruited into the study. Preoperative immediately and 6-month postoperative, and follow-up radiological data were reviewed and analyzed. The mean age of patients with NF-1 was 14.4 ± 1.3 years compared with 15.7 ± 3.1 years of patients with AIS. The main curves were 70.1 ± 14.4 and 75.9 ± 11.3 degrees for the patients with NF-1 and AIS, respectively. The minor curves were 37.4 ± 14.2 and 39.5 ± 13.4 degrees for the patients with NF-1 and AIS, respectively. The mean follow-up durations were 33.8 months (range, 24–60 months) and 31.6 months (range, 24–41 months) for the NF-1 and AIS groups, respectively. Results After surgery, the nondystrophic NF-1 group had less main curve correction (62.3 ± 15.5 vs. 68.9 ± 13.2%, p &lt; 0.001), less apical vertebral translation (AVT) correction (−20.3 vs. −22.9 mm, p = 0.019), and less trunk shift (TS) correction (−7.8 vs. −16.0 mm, p &lt; 0.001). On the sagittal plane, significantly more correction of sagittal vertical axis (SVA) (−19.3 vs. −10.0 mm, p = 0.041) was noted in the nondystrophic NF-1 group. A significant trend to worse was observed in NF-1 group during the follow-up period. At the final follow-up, significantly more loss of correction (5.4 vs. −0.8 degrees, p = 0.013) of the main curve was observed in the nondystrophic NF-1 group. Conclusion Current results suggest that satisfactory short-term surgical outcomes can be achieved in both NF-1 patients with non-dystrophic scoliosis and patients with AIS while sharing the same management strategy. However, the long-term result of nondystrophic scoliosis in patients with NF-1 is not identical to that of patients with AIS. Despite all this, it is fair to suggest that applying the surgical strategy of AIS in treating nondystrophic scoliosis secondary to NF-1 should be acknowledged.

Dixon water-fat separation in PROPELLER MRI acquired with two interleaved echoes.

To propose a novel combination of robust Dixon fat suppression and motion insensitive PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) MRI. Two different echoes were acquired interleaved in each shot enabling water-fat separation on individual blades. Fat, which was blurred in standard PROPELLER because the water-fat shift (WFS) rotated with the blades, was shifted back in each blade. Additionally, field maps obtained from the water-fat separation were used to unwarp off-resonance-induced shifts in each blade. PROPELLER was then applied to the water, corrected fat, or recombined water-fat blades. This approach was compared quantitatively in volunteers with regard to motion estimation and signal-to-noise ratio (SNR) to a standard PROPELLER acquisition with minimal WFS and fat suppression. Shifting the fat back in each blade reduced errors in the translation correction. SNR in the proposed Dixon PROPELLER was 21% higher compared with standard PROPELLER with identical scan time. High image quality was achieved even when the volunteers were moving during data acquisition. Furthermore, sharp water-fat borders and image details were seen in areas where standard PROPELLER suffered from blurring when acquired with a low readout bandwidth. The proposed method enables motion-insensitive PROPELLER MRI with robust fat suppression and reduced blurring. Additionally, fat images are available if desired.

Migration of the penetrated rib head following deformity correction surgery without rib head excision in dystrophic scoliosis secondary to type 1 Neurofibromatosis.

Dystrophic scoliosis secondary to Neurofibromatosis type 1 (NF1) may predispose to rib penetration into the spinal canal. No clear consensus was established regarding whether or not to resect the compressing rib head during correction maneuvers. The purpose of this study was to present imaging quantification of the migration of intraspinal-dislocated rib head in order to assess the extraction degree of dislocated rib heads and the associated influencing factors. Imaging data of NF1 scoliotic patients with intraspinal rib head dislocation from March 1998 to April 2014 were retrospectively reviewed. The location and migration of the rib head were evaluated in a spinal canal-based coordinate system to calculate their pre- and postoperative vector coordinates. Differences in multiple parameters representative of rib head position were compared by paired sample t test. We also explored whether correction of vertebral rotation and translation could contribute to the extraction of intra-canal rib head by linear regression analysis. The incidence of apical convex rib head penetration into the canal was 15.9 % (23/145). Only 14.8 % of the dislocated rib heads invaded into the concave half-circle of the spinal canal, which was reduced to 3.7 % postoperatively. The directions of rib head migration were mostly toward the anterior convex quadrant of the spinal canal (70.4 %). Paired sample t tests revealed significant reduction in intraspinal rib length (9.2 ± 3.6 vs. 5.2 ± 3.6 mm, p < 0.001) and improvement in distance between the rib head tip and the most concave spot of the spinal canal (DRCSSC) (14.2 ± 2.6 vs. 18.1 ± 3.3 mm, p < 0.001). Change of rib-vertebrae angle (RVA) was demonstrated to be positively correlated with reduction in intraspinal rib length (β = 0.534, p = 0.004), while Change of RVA (β = -0.460, p = 0.008) and vertebral translation (VT) (β = -0.381, p = 0.024) was negatively correlated with change of DRCSSC. Spontaneous migration of the dislocated rib head following posterior correction surgery resulted in shorter intraspinal rib length and larger uninvaded area. More correction of vertebral translation and rib-vertebrae angle could increase the degree of extraction from the spinal canal immediately after the surgery.

Stability Outcomes following Computer-Assisted ACL Reconstruction.

Purpose. The purpose of this study was to determine whether intraoperative prereconstruction stability measurements and/or patient characteristics were associated with final knee stability after computer-assisted ACL reconstruction. Methods. This was a retrospective review of all patients who underwent computer-assisted single-bundle ACL reconstruction by a single surgeon. Prereconstruction intraoperative stability measurements were correlated with patient characteristics and postreconstruction stability measurements. 143 patients were included (87 male and 56 female). Average age was 29.8 years (SD ± 11.8). Results. Females were found to have significantly more pre- and postreconstruction internal rotation than males (P < 0.001 and P = 0.001, resp.). Patients with additional intra-articular injuries demonstrated more prereconstruction anterior instability than patients with isolated ACL tears (P < 0.001). After reconstruction, these patients also had higher residual anterior translation (P = 0.01). Among all patients with ACL reconstructions, the percent of correction of anterior translation was found to be significantly higher than the percent of correction for internal or external rotation (P < 0.001). Conclusion. Anterior translation was corrected the most using a single-bundle ACL reconstruction. Females had higher pre- and postoperative internal rotation. Patients with additional injuries had greater original anterior translation and less operative correction of anterior translation compared to patients with isolated ACL tears.

Proximal first metatarsal opening wedge osteotomy: Geometric analysis on saw bone models

BackgroundFor hallux valgus correction, distal first metatarsal osteotomy is generally used for minor to moderate deformities, diaphyseal osteotomy for moderate deformities and basal osteotomy or arthrodesis for severe deformities. With the advent of locking plates, there has been renewed interest in opening wedge basal osteotomy. ObjectiveWe undertook this study in order to understand the power and limitations of this osteotomy. MethodProximal opening wedge osteotomies were performed on saw bone models in four orientations, with three different wedge sizes: (1) perpendicular to the ground (PG); (2) perpendicular to the shaft (PS); (3) perpendicular to shaft with 30° declination (DEC); (4) 30° oblique (OB). Pre- and post-osteotomy measurements were made of axial and plantar translation and inter-metatarsal angle. ResultsPlantar translation and intermetatarsal angle correction increased with increasing wedge size. The DEC osteotomy produced the greatest increase in length of metatarsal shaft, while the PS osteotomy gave the least. The most plantar translation was achieved with the DEC osteotomy. Overall, the PS osteotomy gave the largest correction of the intermetatarsal angle. ConclusionAlthough there are several published clinical case series of the proximal opening wedge osteotomy, this is the first study to fully evaluate its geometry.