Anatomical Deviations Research Articles

A conceptual study on real-time adaptive radiation therapy optimization through ultra-fast beamlet control

A central problem in the field of radiation therapy (RT) is how to optimally deliver dose to a patient in a way that fully accounts for anatomical position changes over time. As current RT is a static process, where beam intensities are calculated before the start of treatment, anatomical deviations can result in poor dose conformity. To overcome these limitations, we present a simulation study on a fully dynamic real-time adaptive radiation therapy (RT-ART) optimization approach that uses ultra-fast beamlet control to dynamically adapt to patient motion in real-time. A virtual RT-ART machine was simulated with a rapidly rotating linear accelerator (LINAC) source (60 RPM) and a binary 1D multi-leaf collimator (MLC) operating at 100 Hz. If the real-time tracked target motion exceeded a predefined threshold, a time dependent objective function was solved using fast optimization methods to calculate new beamlet intensities that were then delivered to the patient. To evaluate the approach, system response was analyzed for patient derived continuous drift, step-like, and periodic intra-fractional motion. For each motion type investigated, the RT-ART method was compared against the ideal case with no patient motion (static case) as well as to the case without the use RT-ART. In all cases, isodose lines and dose-volume-histograms (DVH) showed that RT-ART plan quality was approximately the same as the static case, and considerably better than the no RT-ART case. Based on tests using several different motion types, RT-ART was able to recover dose conformity to the level that it was similar to an ideal RT delivery with no anatomical changes. With continued advances in real-time patient motion tracking and fast computational processes, there is significant potential for the RT-ART optimization process to be realized on next generation RT machines.

GP.05 Intraoperative acquisition of diffusion tensor imaging in cranial neurosurgery: readout-segmented DTI versus standard single-shot DTI

Background: Diffusion-tensor imaging (DTI) tractography is commonly used in neurosurgical practice, but is largely limited to the preoperative setting. This is due primarily to image degradation caused by susceptibility artifact when conventional single-shot (SS) echo-planar imaging DTI is acquired for open cranial, surgical position intraoperative DTI (iDTI). A novel, artifact-resistant, readout-segmented (RS) DTI has not yet been evaluated in the intraoperative MRI (iMRI) environment. Our objective was to evaluate the performance of RS-DTI versus SS-DTI for intraoperative white matter imaging. Methods: Pre- and intraoperative 3T, T1-weighted and DTI (RS-iDTI and SS-iDTI) in 22 adults undergoing intraaxial iMRI resections (low-grade glioma: 14, 64%; high-grade glioma: 7, 32%; cortical dysplasia: 1). Regional susceptibility artifact, anatomical deviation relative to T1WI, and tractographic output were compared between iDTI sequences. Results: RS-iDTI resulted in less regional susceptibility artifact and mean anatomic deviation (RS-iDTI: 2.7±0.2 mm versus SS-iDTI 7.5±0.4 mm; p<0.0001). Tractographic failure occurred in 8/22 (36%) patients for SS-iDTI whereas RS-iDTI permitted successful reconstruction in 4 of these 8. Maximal tractographic differences between DTI sequences were substantial (mean 9.7±5.7 mm). Conclusions: Readout-segmented EPI enables higher quality and more accurate DTI for surgically relevant tractography of major white matter tracts in intraoperative, open cranium, neurosurgical applications at 3T.

One-year Test-retest Properties Of Binocular Vision Tests

PURPOSE: Binocular vision tests (BVTs) are increasingly recommended for use in concussion management, but their reliability remains unknown. Our objective was to determine the one-year test-retest reliability of 10 BVTs proposed for use in concussion management, where concussions may occur months after a baseline measure. METHODS: We used routinely collected data on young athletes who had two sessions of pre-season baseline testing of 10 BVTs at least 11 months apart with no intervening concussion or training that might influence BVT scores. The tests assessed: 3D vision (gross stereoscopic acuity, GSA), saccades, anatomic deviation (AD) at 30cm and 3m, ability of eyes to move/fixate in-sync (positive fusional vergence [PFV] and negative fusional vergence [NFV] at 30cm and 3m, near point of convergence [NPC], and near point of convergence - break [i.e. double vision, (NPCb)]). RESULTS: There were 8 males and 9 females with a mean age of 22.4 (SD = 4.6) years. The intraclass correlations (ICC) suggest good reliability for PFV (0.94) and NPV (0.72) at 30cm. There was moderate reliability for NPCb (0.58), saccade (0.57), and PFV at 3m (0.58). There was poor reliability for AD 30cm (0.34) and NPC (0.45). Reliability was essentially 0 for NPV at 3m, and GSA (0.0). Limits of agreement (LoA) were best for saccade (±25%) and worst for AD 30 cm (±172%), and ranged from ±40% to ±114% for 7 of the 8 other tests. For AD 3m, the distribution was highly skewed leading LoA to be uninformative. CONCLUSIONS: The results indicate one-year test-retest reliability of the BVTs ranged from poor to good, with the majority being moderate. The effect of concussion must have a moderate to large effect on the scores of most BVTs to be clinically useful.

Exploiting Epistemic Uncertainty of Anatomy Segmentation for Anomaly Detection in Retinal OCT.

Diagnosis and treatment guidance are aided by detecting relevant biomarkers in medical images. Although supervised deep learning can perform accurate segmentation of pathological areas, it is limited by requiring a priori definitions of these regions, large-scale annotations, and a representative patient cohort in the training set. In contrast, anomaly detection is not limited to specific definitions of pathologies and allows for training on healthy samples without annotation. Anomalous regions can then serve as candidates for biomarker discovery. Knowledge about normal anatomical structure brings implicit information for detecting anomalies. We propose to take advantage of this property using Bayesian deep learning, based on the assumption that epistemic uncertainties will correlate with anatomical deviations from a normal training set. A Bayesian U-Net is trained on a well-defined healthy environment using weak labels of healthy anatomy produced by existing methods. At test time, we capture epistemic uncertainty estimates of our model using Monte Carlo dropout. A novel post-processing technique is then applied to exploit these estimates and transfer their layered appearance to smooth blob-shaped segmentations of the anomalies. We experimentally validated this approach in retinal optical coherence tomography (OCT) images, using weak labels of retinal layers. Our method achieved a Dice index of 0.789 in an independent anomaly test set of age-related macular degeneration (AMD) cases. The resulting segmentations allowed very high accuracy for separating healthy and diseased cases with late wet AMD, dry geographic atrophy (GA), diabetic macular edema (DME) and retinal vein occlusion (RVO). Finally, we qualitatively observed that our approach can also detect other deviations in normal scans such as cut edge artifacts.

Assessment of efficacy of CT scan and diagnostic nasal endoscopy in chronic atrophic rhinitis cases

<p class="abstract"><strong>Background:</strong> Chronic rhinosinusitis (CRS) is a heterogeneous disorder leads to inflammation of nose and paranasal air sinuses. CRS affects quality of life of affected people, its diagnosis and management of is still a major challenge for the ENT specialists. CT scan and diagnostic nasal endoscopy of nose and paranasal sinuses plays an important role in the management of CRS.</p><p class="abstract"><strong>Methods:</strong> A total 42 cases with clinically diagnosed chronic rhinosinusitis between age group 2<sup>nd</sup> -6<sup>th</sup> decade were considered. All the participants underwent a systemic diagnostic nasal endoscopy and CT scan of nose and paranasal air sinuses before surgery. </p><p class="abstract"><strong>Results:</strong> Nasal blockage/obstruction (95.2%), headache/facial pain (90.4%), nasal discharge (85.7%), sneezing (76.1%) are commonest symptoms. Diagnostic nasal endoscopy noted to be a sensitive investigation tool for the sphenoethmoid recess, hiatus semilunaris and frontal recess. The sensitivity of above parameters is 100%, 94.8% and 95.1% respectively whereas, specificity is 83.2%, 79.5% and 94.8%.</p><p class="abstract"><strong>Conclusions:</strong> Diagnostic nasal endoscopy findings and CT scan findings correlated very well with the operative findings. In few cases DNE could not visualize all the parameters due to anatomical deviations. But CT scan is a specific diagnostic tool which depicted all the parameters except maxillary sinus and its bony shell in very few cases.</p>

EPID-based invivo dosimetry using Dosimetry Check™: Overview and clinical experience in a 5-yr study including breast, lung, prostate, and head and neck cancer patients.

BackgroundIndependent verification of the dose delivered by complex radiotherapy can be performed by electronic portal imaging device (EPID) dosimetry. This paper presents 5‐yr EPID in vivo dosimetry (IVD) data obtained using the Dosimetry Check (DC) software on a large cohort including breast, lung, prostate, and head and neck (H&N) cancer patients.Material and MethodsThe difference between in vivo dose measurements obtained by DC and point doses calculated by the Eclipse treatment planning system was obtained on 3795 radiotherapy patients treated with volumetric modulated arc therapy (VMAT) (n = 842) and three‐dimensional conformal radiotherapy (3DCRT) (n = 2953) at 6, 10, and 15 MV. In cases where the dose difference exceeded ±10% further inspection and additional phantom measurements were performed.ResultsThe mean and standard deviation (μ±σ) of the percentage difference in dose obtained by DC and calculated by Eclipse in VMAT was: 0.19±3.89% in brain, 1.54±4.87% in H&N, and 1.23±4.61% in prostate cancer. In 3DCRT, this was 1.79±3.51% in brain, −2.95±5.67% in breast, −1.43±4.38% in bladder, 1.66±4.77% in H&N, 2.60 ± 5.35% in lung and −3.62±4.00% in prostate cancer. A total of 153 plans exceeded the ±10% alert criteria, which included: 88 breast plans accounting for 7.9% of all breast treatments; 28 H&N plans accounting for 4.4% of all H&N treatments; and 12 prostate plans accounting for 3.5% of all prostate treatments. All deviations were found to be as a result of patient‐related anatomical deviations and not from procedural errors.ConclusionsThis preliminary data shows that EPID‐based IVD with DC may not only be useful in detecting errors but has the potential to be used to establish site‐specific dose action levels. The approach is straightforward and has been implemented as a radiographer‐led service with no disruption to the patient and no impact on treatment time.

An anatomical study of the spinous process of the seventh cervical vertebrae based on the three-dimensional computed tomography reconstruction.

Palpation of the seventh cervical vertebra (C7) is important for the diagnosis and treatment of neck and chest conditions. However, the spinous process of C7 (C7-SP) displays an anatomical deviation among individuals. The present study aimed to clarify anatomic characteristics of C7-SP by using a three-dimensional (3D) computed tomographic (CT) reconstruction technique. A total of 245 subjects meeting the selection criteria were examined. After CT scanning, the images were reconstructed in 3D. All subjects were grouped according to their deviation of C7-SP: Deviating to the right (DR group), deviating to the left (DL group) and no deviation (ND group). Three distances and three angles were recorded on C7-SP. The vertical distances between the borders of the left and right transverse processes and the tip of the SP, were termed DLTS and DRTS, respectively. The length of the SP was also determined. The angle of the SP deviation was referred to as ∠α, the angle between the SP axis and the line crossing the tips of the transverse processes was referred to as ∠β and the angle between the vertebral body axis and the SP axis was referred to as ∠γ. Among the three groups, differences in ∠α and ∠β were statistically significant (P<0.05). Furthermore, the DLTS was significantly different between the DL and ND groups (P<0.05). In addition, a significant difference in the DRTS was identified between the DR and ND groups (P<0.05). 3D CT reconstruction was reliable for studying anatomic characteristics of C7-SP. Based on this, patients may be preliminarily grouped according to the deviation of their C7-SP and the measurement of the C7-SP may guide clinical diagnoses and treatments.

Determining Consistency And Agreement Of Scores Across Two Measurements Of The Visual System

Some authors have suggested concussion symptoms may be due to subtle visual problems because they are similar to those that occur with difficulty focusing the eyes. Although binocular vision tests (BVTs) are frequently used to evaluate visual symptoms, their reliability has not been evaluated. The 10 BVTs under investigation measure: 3D vision (gross stereoscopic acuity (GSA)), saccades, anatomic deviation (AD) at 30cm and 3m, and the eye’s ability to move/focus in-sync [convergence motor punctum proximum (CMPP), binocular fusion with convergence (BFC) and divergence (BFD) at 30cm and 3m, convergence fusional proximum (CFP)]. PURPOSE: To determine the one-week test-retest reliability of 10 BVTs in healthy participants. METHODS: One clinician examined each participant at their earliest convenience (T1), and one week after their first visit (T2). We assessed test-retest reliability using intraclass correlation coefficient (ICC) and limits of agreement (LoA). We judged an ICC of ≤0.5 as poor, 0.51-0.74 as moderate, 0.75-0.89 as good, and ≥0.90 as excellent reliability. We present 95% LoA for the % difference i.e. the difference in scores (T1-T2) divided by the average of the scores (T1+T2)/2 times 100. RESULTS: We tested 20 participants (1 lost at T2, excluded from analysis). There were 10 males and 10 females with a mean age of 25.5 (SD = 4.0) years. Our ICC results suggest good reliability for AD 3m (0.88), and moderate reliability for GSA (0.62), AD 30cm (0.69), CMPP (0.54), BFC (0.54) and BFD (0.66) at 30cm, and CFP (0.64). There was poor reliability for saccade (0.34), and BFC (0.49) and BFD (0.43) at 3m. LoA was best for saccade (±34%) and worst for AD 30 cm (±121%), and ranged from ±58% to ±70% for 7/8 other tests. For AD 3m, LoA (±200%) did not provide an accurate summary as it assumes a Normal distribution of values. In fact, 18/20 pairs of measurements were identical, one paired scored 0 and 1, the other scored 0 and 2. CONCLUSIONS: Our results demonstrate moderate to good test-retest reliability for 7 out of 10 BVTs, and poor reliability for saccades, and BFC and BFD at 3m. LoA results suggest the effect of concussion must have a moderate to large effect on the scores of most of the tests if they are to be clinically helpful.

Concurrent radiofrequency ablation and Nissen fundoplication

Endoscopic radiofrequency ablation (RFA) today represents a well-established, safe and effective procedure for the treatment of Barrett’s esophagus (BE). Choice of additional treatment to RFA emerges as an important clinical issue, due to the fact that recurrence of BE after complete eradication (CE) of intestinal metaplasia (IM) or dysplasia may occur. Concerning the data available so far, recurrence may occur due to insufficient reflux control with standard PPI’s regimen, while those with large hiatal hernia and long segment BE represent the subgroup of patients at highest risk for recurrence. Due to the anatomical deviation in distal esophageal segment proper ablation may be difficult in such patients. These patients can be treated by employing concurrent ARS and RFA. Concurrent ARS and RFA was proven to be safe, not time consuming, and it can be performed in conjunction with the basic rules of RFA procedure. Early results, in term of enhanced healing of treated epithelium, and possible reduction in number of ablation sessions needed to achieve CE of IM or dysplasia, are promising. To conclude, antireflux surgery may have important role in some patients undergoing RFA, especially those with significant hiatal hernia and anatomical impairment in distal esophageal segment.

Minor physical anomalies in neurodevelopmental disorders: a twin study

BackgroundMinor physical anomalies (MPAs) are subtle anatomical deviations in one’s appearance and may suggest altered embryogenesis. MPAs have been shown to be more common in neurodevelopmental disorders (NDDs) compared with typical development. Still, further studies are needed on MPAs in NDDs, especially using twins to adjust for confounding familial factors.MethodsClinical assessments were conducted on 116 twins (61 NDD, 55 controls) from 51 monozygotic and 7 dizygotic pairs to examine MPAs and their association with DSM-5 defined NDDs. Additionally, the relationship between the number of MPAs within twins by zygosity was investigated.ResultsWithin the cohort sample, a specific association was found between MPAs and autism spectrum disorder (ASD) diagnosis (crude odds ratio = 1.29, p = .047; adjusted odds ratios = 1.26–1.33, adjusted p values = .032–.073) and autistic traits (crude β = 3.02, p = .002; adjusted β = 2.28, p = .019), but not NDDs in general or ADHD, nor within-pairs. Identified MPAs in ASD included overweight, hypermobility, pes planus, straight eyebrows, vision impairment, arachnodactyly/long toes, long eyelashes, and microtia. The number of MPAs within all monozygotic pairs was highly correlated (r = .88, p < .001).ConclusionMPAs are more frequent in participants with ASD and may be influenced by genetics. The value of MPAs for (early) detection should be further explored, as they might index individuals at increased risk for ASD in particular.

Deviation in the Position of Foveal Bulge from Foveal Center in Normal Subjects Measured Using Spectral-Domain OCT

To report a deviation in the position of the foveal bulge (FB) from the foveal center and to analyze its relationship with the foveal shape in normal subjects using spectral-domain (SD) OCT. Cross-sectional study. A total of 146 clinically normal subjects. Macular Cube 512× 128 was used to obtain the cross-sectional images of the macula in Cirrus HD-OCT (Carl Zeiss Meditec, Inc, Dublin, CA). The foveal center was identified manually as the deepest point within the foveal dip, which was termed the "manually identified foveal center" (MFC). The position of the FB with respect to the MFC was noted, and the radial distance between them was measured. The foveal center detected by the inbuilt auto-fovea finder algorithm was considered as the automatically detected foveal center (AFC), and the distance between the AFC and the FB was measured. The radial distances of the FB from the MFC and the AFC were compared, and its direction of deviation from the foveal center was noted. All OCT measurements were adjusted for the ocular magnification factor. The amount of deviation was correlated with the foveal shape parameters, such as foveal radius. Radial distance between FB and foveal center and its direction of deviation. Mean age of the subjects was 43.9±14.4 years. The position of the FB was deviated from the foveal center in 125 subjects (85.6%). Median radial distance between the FB and the MFC was 58.6 μm (35.16-75.04 μm) with the maximum separation of 222.68 μm. From the AFC, the FB was separated by a median of 58.6 μm (46.88-84.51 μm), maximum separation being 181.94 μm. The direction of deviation of the FB from foveal center was nasal in a majority of subjects (n= 75, 51% in MFC). The separation between the FB and the foveal center was not associated with age (P=0.149), gender (P= 0.762), or axial length (P= 0.25). The position of the FB did not coincide with the foveal center and was deviated in the direction of the optic disc in a majority of normal subjects. Further studies are required to correlate this anatomic deviation with the fixation locus of the individuals.

Postpartum Abdominal Pain, With a Twist

Introduction: Intestinal malrotation classically presents in the neonatal period as acute obstruction due to intestinal, or midgut, volvulus. Midgut volvulus due to intestinal malrotation is rare in adults, with an estimated incidence of 0.2-0.6%. We present a case of a young, post-partum woman who presented with two months of abdominal pain and was found to have a midgut volvulus from intestinal malrotation. To our knowledge, this is one of the first cases of intestinal malrotation presenting as midgut volvulus after uterine involution. Case Report: A 22-year-old female with no history presented with progressively worsening post-prandial epigastric pain that started after she gave birth 2 months prior. She had an uncomplicated pregnancy and normal vaginal delivery. Over the past week, the pain had became more severe and persistent, and was accompanied by nausea and bilious vomiting. She denied weight loss and had no other constitutional symptoms. She did note constipation over the past few days but was still passing flatus. Exam revealed tenderness to palpation over the epigastrium without evidence of an acute abdomen. Labs were significant for a blood urea nitrogen of 33, hemoglobin of 16.3, and hematocrit of 50. Hepatic function panel revealed an elevated total bilirubin level of 3.5. A RUQ ultrasound done to rule out biliary obstruction showed a twisting of the proximal superior mesenteric artery (SMA) and vein (SMV) with patent flow. A CT angiography of the abdomen and pelvis showed the classic “whirlpool sign,: confirming a midgut volvulus with intestinal malrotation, with resultant duodenal obstruction. There was no evidence of bowel ischemia or perforation. An emergent surgical consultation was placed and the patient was taken down for an exploratory laparotomy with detorsion of volvulus, lysis of Ladd's bands, broadening of the mesentery, and an appendectomy.Figure: Sonographic evidence of SMV and SMA twisting.Figure: Classic “whirlpool” sign seen on CT angiography of abdomen/pelvis.Figure: Anatomic deviation of congenital malrotation; appendix seen in left upper quadrant.Discussion: Total small intestinal volvulus with malrotation classically (64-80% of the time) presents in neonates, typically within the first month of life. Symptomatic intestinal malrotation is rare in adults. This is often an incidental finding, although symptoms can range from those associated with obstruction or reflux to those found in acute intestinal infarction. CT findings can be pathognomonic if the whirlpool sign is seen. CT also allows for rapid diagnosis and surgical treatment, which is important as delayed diagnosis or treatment can result in bowel necrosis and death.

Comparison of Photon and Proton Liver SBRT Plan Quality Affected by Daily Positioning and Anatomic Deviations

Comparison of Photon and Proton Liver SBRT Plan Quality Affected by Daily Positioning and Anatomic Deviations

Comparison of Photon and Proton Lung SBRT Treatment Impacted by Daily Positioning and Anatomic Deviations

Comparison of Photon and Proton Lung SBRT Treatment Impacted by Daily Positioning and Anatomic Deviations

Use of Nasal Obstruction Symptom Evaluation Scale in Objective Evaluation of Symptomological Improvement in Post Septoplasty Patients

Introduction&#x0D; The complaint of nasal obstruction or difficulty in nasal breathing is highly subjective. Benefits of Septoplasty, as perceived by the patient, also varies widely with subjective satisfaction ranging from complete alleviation of symptoms to a total failure.&#x0D; Materials and Methods&#x0D; Fifty three patients above 18 years of age, with anatomical deviation of the nasal septum as the sole cause of obstruction and symptoms persisting for more than 3 months, underwent septoplasty. Nasal endoscopy was done for Mladina typing of the nasal septal deviation. Pre and post operative NOSE (Nasal Obstruction &amp; Symptom Evaluation) score were analysed.&#x0D; Results&#x0D; Mean preoperative NOSE score was 11.98 ±1.23. On the 6th and 12th postoperative week follow up NOSE score was 3.13±1.30 &amp; 1.05±0.87 respectively with p value &lt;0.05. &#x0D; Conclusion&#x0D; Mladina typing along with NOSE score will help in letting the patient know about his or her expected outcome following septoplasty.

Template-Based Orbital Wall Fracture Treatment Using Statistical Shape Analysis

Aim of this study was to investigate whether a mold generated from a statistical shape model of the orbit could be generated to provide a cost-efficient means for the treatment of orbital fractures. A statistical shape model was created from 131 computed tomographic (CT) scans of unaffected adult middle European human orbits. To generate the model, CT scans were segmented in Brainlab software, preregistered using anatomic landmarks, trimmed to an identical size, and definitely registered. Then, the model was created using the global master algorithm. Based on this model, a mold consisting of a male part and a female part was constructed and printed using a rapid prototyping technique. A statistical shape model of the human orbit was generated from 125 CT scans. Six scans (4.5%) presented major anatomic deviations and were discarded. A solid mold based on this model was printed. Using this mold, flat titanium mesh could be successfully deformed to serve as an orbital implant. A mold based on the statistical orbital shape could serve as a cost-effective means for the treatment of orbital fractures. It allows the anatomic preformation of titanium or resorbable implant material for orbital reconstruction. Because these materials could be cut from larger sheets, the use of a mold would be a cost-effective treatment alternative.

The human placenta: Function and morphological assessments using ultrasound and magnetic resonance elastography

s / Placenta 45 (2016) 63e133 74 P1.6 THE HUMAN PLACENTA: FUNCTION AND MORPHOLOGICAL ASSESSMENTS USING ULTRASOUND AND MAGNETIC RESONANCE ELASTOGRAPHY Richard K. Miller , Stephan McAleavey , Juvenal Ormachea , Eva Pressman, Loralei Thornburg , David Dombroski , Jianhui Zhong, Marvin Doyley , Ronald W. Wood, Jonathan Carrol-Nellenback , Ollivier Hyrien , Philip Katzman , Christopher Stodgell , Kam Szlachetka, Henry Wang, Kevin Parker . University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; University of Rochester Haijm School of Engineering, Rochester, New York, USA Objective: In utero evaluations of placental anatomy and function offer the promise of associating placental pathophysiology with neonatal outcomes, and thus potential for enhanced management of perinatal complications and improved long-term health of the mother and child. Ultrasound Elastography (USE) and Magnetic Resonance Elastography (MRE) provide means to evaluate tissue stiffness in utero. In conjunction with measures of vascular anatomy and perfusion, we can test mechanistic hypotheses about the relationship with anatomical function and deviations associated with disease states. For example, The Parker Hypothesis (Parker, Phys. Med. Biol. 59: 4443,14) proposes that viscoelastic measures of soft tissue stiffness are related to the fractal branching properties of the vascular anatomy. Methods: Term human placentae were obtained immediately upon delivery and evaluated directly either in a 3T GE MRI with Elastography or using a Siemens Antares US scanner and VF10-5 Probe with custom single track location shear wave elasticity imaging pulse sequences and accelerated processing. Other placentae were perfused through the umbilical cord and imaging, Doppler measures and elastography were conducted. At the end of the experiments, a barium gel was infused to enhance subsequent CT imaging of the fetal vasculature. Results: The utility of elastography in functional evaluation of the placenta are readily demonstrated in the following examples: 1) Placental tissue anomalies (e.g., infarcted areas) are stiff, and provided dramatic examples of the sensitivity USE and MRE methodologies for the detection of placental pathology; 2) Ex vivo placental perfusions have been used to relate placental stiffness to fetal vasculature when measured by USE, as seen when fetal vascular dynamics were pharmacologically manipulated. Clinical and high-resolution microCT systems can and have been used on placentae to provide additional post-delivery anatomical characterization and quantification of the vascular beds. These CT observations provide confirmation of in vivo Doppler US and the potential use of MR angiography for vascular characterization. We demonstrated that these datasets are amenable to automated identification and characterization of branching morphology, including centerline tree and Sholl analyses. Conclusion: These USE and MRE technologies enable promising new approaches for the prediction of risks during and after pregnancy. (Support: Goode Foundation) MRI localization of a placental infarct with associated elastographic ortho slice A: gross examination of placental lesion. B, MR segmented volume. C. Superimposed MRE. Yellow arrow directs attention to lesion.

Retinal Sequelae in Adults Treated With Cryotherapy for Retinopathy of Prematurity.

Cryotherapy, introduced in the mid-1980s, was the first treatment of severe retinopathy of prematurity (ROP) and resulted in ablation of larger retinal areas than did its later substitute, laser treatment. We defined the characteristics of the retinal structure and assessed visual function, in adult ex-preterms treated with cryotherapy. A total of 28 ex-preterms, included in a prospective study of infants born in Stockholm between September 1988 and March 1993, were treated with cryotherapy because of severe ROP. Of these individuals, 14 took part in this follow-up study and underwent ophthalmologic assessment including visual acuity, fundus photography, perimetry, and retinal imaging using optical coherence tomography (OCT) in their third decade of life. Their gestational ages were 24 to 28 (median 25) weeks at birth. The ex-preterms had reduced foveal depth (P < 0.0001) and increased thickness of the temporal retinal nerve fiber layer (RNFL; P > 0.001). A thicker temporal RNFL was not correlated with a thicker ganglion cell layer (P = 0.41, r = 0.29) as in controls (P = 0.0015, r = 0.78). Extreme thickening was seen in patients with pronounced retinal dragging. In their third decade of life, ex-preterm adults treated with cryotherapy for ROP have major microstructural retinal abnormalities in terms of reduced foveal depth and an altered distribution of the peripapillary RNFL. The main contributors seem to be gestational age and ROP rather than the cryotherapy. The possibility to evaluate the retinal structure in these individuals, with today's conventional OCT, is limited by those anatomic deviations.

A Cadaveric Study of Anatomical Deviations in the Position of Vermiform Appendix

A Cadaveric Study of Anatomical Deviations in the Position of Vermiform Appendix

Changes in the radiological depth correlate with dosimetric deterioration in particle therapy for stage I NSCLC patients under high frequency jet ventilation

ABSTRACTBackground. Particle dose distributions are highly sensitive to anatomy changes in the beam path, which may lead to substantial dosimetric deviations. Robust planning and dedicated image guidance together with strategies for online decision making to counteract dosimetric deterioration are thus mandatory. We aimed to develop methods to quantify anatomical discrepancies as depicted by repeated computed tomography (CT) imaging and to test whether they can predict deviations in target coverage.Material and methods. Dedicated software tools allowed for voxel-based calculations of changes in the water equivalent path length (WEPL) in beam directions. We prepared proton and carbon ion plans with different coplanar beam angle settings on a series of lung cancer patients, for which planning and localization CT scans under high frequency jet ventilation (HFJV) for tumor fixation were performed. We investigated the reproducibility of target coverage between the optimized and recalculated treatment plans. We then studied how different raster scan and planning settings influence the robustness. Finally, we carried out a systematic analysis of the variations in the WEPL along different coplanar beam angles to find beam directions, which could minimize such variations.Results. The Spearman's correlations for the GTV ΔV95 and ΔV98 with the ΔWEPL for the proton plans with a 0° and −45° two-field configuration were 0.701 (p = 0.02) and 0.719 (p = 0.08), respectively. For beam configurations 0° and −90°, or 0° and + 45°, with lower ΔWEPL, the correlations were no significant. The same trends were observed for the carbon ion plans. Increased beam spot overlap reduced dosimetric deterioration in case of large ΔWEPL.Conclusion. Software tools for fast online analysis of WEPL changes might help supporting clinical decision making of image guidance. Raster scan and treatment planning settings can help to compensate for anatomical deviations.