Midsagittal Magnetic Resonance Imaging Research Articles

Single Sequence Whole-Spine Screening Magnetic Resonance Imaging: Diagnostic and Therapeutic Role in Multiple-Level Spinal Tuberculosis.

Spinal tuberculosis (TB) is the most common form of skeletal tuberculosis. Paradiscal continuous vertebral involvement at a single level is the most prevalent pattern among all forms of spinal TB. There is a wide range of reported incidences of multiple-level non-contiguous spinal TB in the literature. We would like to discuss on the utility of single whole spine screening T2-weighted (T2W) mid-sagittal magnetic resonance imaging (MRI) film in diagnosing multiple-level spinal TB and therapeutic benefits it can provide. We have done a retrospective review of the collected data of patients in Vardhman Mahavir Medical College and Safdarjung Hospital from August 2017 to October 2021 to find the incidence of multiple-level spinal TB and possible factors attributed to this specific disease pattern. All the patients who had been diagnosed of spinal TB either microbiologically or histopathologically or by a good clinical response to anti-tubercular treatment (ATT) and had a whole spine screening MRI film, were included. Patients of spinal TB who did not have a whole spine screening MRI were excluded from the study. Multiple-level spinal TB was diagnosed when lesions were identified in vertebral levels other than a typical paradiscal lesion, and additional lesions were separated from the primary disease by at least one normal spinal segment. Among the patients, 242 met the inclusion criteria, and 76 showed multiple-level non-contiguous spinal TB on MRI, incidence being 31.4%. The rest of the 166 patients showed typical single-segment contiguous lesions. By doing multivariate analysis to determine the independent risk factors for multiple-level spinal TB, extremes of age (<20 years and >50 years) have been found to be a significant factor with p value of 0.0001. Though drug resistance was not found to be a significant risk factor (p value 0.051), the proportion of patients having multiple-level TB was far more in the drug-resistant group (13/76). Single sequence whole spine screening MRI film is an effective, economical, and time-saving tool to detect multiple-level spinal TB. Along with its diagnostic accuracy, it also provides therapeutic benefits like access to a more approachable site for biopsy.

Comparative analysis of discoid lateral meniscus size: a distinction between symptomatic and asymptomatic cases.

This study evaluated the differences in meniscal sizes and occupancy between symptomatic and asymptomatic patients diagnosed with discoid lateral meniscus (DLM) using magnetic resonance imaging (MRI) to understand how these variations relate to the presence of symptoms and the patients' age. A retrospective review of 98 patients with DLM was conducted, excluding those with meniscal displacement. Both the width and extrusion of DLM and the percentage of the meniscus to the tibia were measured using mid-coronal and mid-sagittal MRI and compared between symptomatic and asymptomatic DLM groups. The relationships among each parameter, meniscal size, and patient age were evaluated. Symptomatic cases were divided into those with and without horizontal tears on MRI to compare the differences in meniscal morphology. A total of 92 knees from 74 patients were included. Sixty-one knees required surgical intervention for symptomatic DLM, while 31 were asymptomatic and included the contralateral side of symptomatic knees. The symptomatic group exhibited larger morphological variations than the asymptomatic group. Moreover, the sagittal meniscal ratio reduced with age in the asymptomatic group (r = - 0.54, p = 0.002) but remained constant in the symptomatic group. The symptomatic cases with horizontal tears demonstrated larger meniscal dimensions and smaller posterior capsule distances than those without tears. Symptomatic patients with DLM had larger knee morphological changes than asymptomatic ones. Age affected the meniscal occupancy in the sagittal plane only in asymptomatic patients. III.

Prevalence of pineal cysts in healthy individuals: Emphasis on size, morphology and pineal recess crowding

The present study aimed to determine prevalence of non-hydrocephalic pineal cysts of different size and morphology in healthy individuals. In a cohort of healthy individuals who as part of research volunteered to undergo magnetic resonance imaging (MRI) of the brain, we performed a systematic search for occurrence of pineal cysts of different sizes, morphology and evidence of crowding of the pineal recess. Degree of crowding in the pineal recess was estimated by the imaging biomarkers anterior-posterior diameter and cyst-tectum-splenium (CTS) ratio at midsagittal MRI. The study included a cohort of 994 healthy individuals, aged 47.0 ± 21.1 years in whom a pineal cyst was demonstrated in 337/994 (37.5%) individuals. A small cyst within a mainly solid gland was observed in 252/994 (25.4%) subjects and a mainly cystic gland in121/994 (12.2%). The pineal cysts were more frequent in women than men, and were associated with age, though not with reduced prevalence in aged individuals, as previously reported. Cysts with maximum anterior-posterior diameter ≥ 10 mm were seen in 51/994 (5.1%) individuals, and with CTS ratio ≥ 0.9 in 16/994 (1.6%) individuals. The occurrence of pineal cysts is frequent and is seen more frequently in women. It usually presents as a small cyst in a predominantly solid gland; however, pineal cysts causing crowding of the pineal recess with a CTS ratio ≥ 0.9 was seen in merely 1.6% of participants.

Statistical shape analysis of Corpus Callosum in vaginismus

Aim of the studyVaginismus is the presence spasm of the muscles in the vagina in the absence of any disease. Neurological diseases can cause degenerative changes in brain structures such as the corpus callosum (CC). The aim of this study is to evaluate the corpus callosum of patients with vaginismus with statistical shape analysis (SSA) using magnetic resonance imaging (MRI) images and compare it with healthy controls.Subject or material and methodsTen female patients with vaginismus and healthy individuals who met the study criteria, were equal in number and age were selected as the control. Mid-sagittal T1-weighted MRI images of each individual were obtained, and the corpus callosum was marked with software on each image using anatomical landmarks, and data were collected. The mean of 'Procrustes' landmarks was calculated and shape deformations were evaluated using thin plate spline (TPS) analysis.ResultsA significant slightly difference was found in terms of corpus callosum areas in the mid-sagittal images of patients with vaginismus and controls. Maximum CC deformation was observed in almost all regions markings in those with vaginismus. In the evaluation of allometry, multivariate regression test was used for the relationship between size and shape and a statistically significant model was obtained for CC.DiscussionCC analysis with SSA using MRI images revealed significant differences between patients and healthy subjects.ConclusionsThe study findings highlighted the abnormal distribution of white matter in the corpus callosum and the variable subregional nature of CC in vaginismus patients. This study may help future studies in terms of vaginismus etiology, diagnosis and treatment options.

The presence or absence of midsagittal tissue bridges and walking: a retrospective cohort study in spinal cord injury.

Cohort study. Retrospective analysis of T2-weighted magnetic resonance images (MRIs) and clinical documentation. To evaluate the relationship between the presence/absence and widths of midsagittal tissue bridges and walking ability among veterans with cervical, predominantly chronic SCI. University research and hospital setting. T2-weighted midsagittal MRIs of 22 United States veterans with cervical spinal cord injuries were examined. The presence/absence of midsagittal tissue bridges were determined, and the widths of present ventral and dorsal tissue bridges were measured. Midsagittal tissue bridge characteristics were related to each participant's ability to walk based off examination of clinical documentation. Fourteen of the analyzed participant images revealed the presence of midsagittal tissue bridges. Ten of those individuals (71%) possessed overground walking ability. The 8 individuals with no apparent tissue bridges were all unable to walk. There was a significant correlation between walking and widths of ventral midsagittal tissue bridges (r = 0.69, 95%CI: 0.52, 0.92, p < 0.001), as well as dorsal midsagittal tissue bridges (r = 0.44, 95%CI: 0.15, 0.73, p = 0.039). The evaluation of midsagittal tissue bridges may be useful in various rehabilitation settings to help inform patients' plan of care, allocation of neuromodulatory resources, and appropriate stratification into research cohorts.

MRI-based vertebral bone quality score compared to quantitative computed tomography bone mineral density in patients undergoing cervical spinal surgery.

The vertebral bone quality (VBQ) score based on magnetic resonance imaging (MRI) was introduced as a bone quality marker in the lumbar spine. Prior studies showed that it could be utilized as a predictor of osteoporotic fracture or complications after instrumented spine surgery. The objective of this study was to evaluate the correlation between VBQ scores and bone mineral density (BMD) measured by quantitative computer tomography (QCT) in the cervical spine. Preoperative cervical CT and sagittal T1-weighted MRIs from patients undergoing ACDF were retrospectively reviewed and included. The VBQ score in each cervical level was calculated by dividing the signal intensity of the vertebral body by the signal intensity of the cerebrospinal fluid on midsagittal T1-weighted MRI images and correlated with QCT measurements of the C2-T1 vertebral bodies. A total of 102 patients (37.3% female) were included. VBQ values of C2-T1 vertebrae strongly correlated with each other. C2 showed the highest VBQ value [Median (range) 2.33 (1.33, 4.23)] and T1 showed the lowest VBQ value [Median (range) 1.64 (0.81, 3.88)]. There was significant weak to moderate negative correlations between and VBQ Scores for all levels [C2: p < 0.001; C3: p < 0.001; C4: p < 0.001; C5: p < 0.004; C6: p < 0.001; C7: p < 0.025; T1: p < 0.001]. Our results indicate that cervical VBQ scores may be insufficient in the estimation of BMDs, which might limit their clinical application. Additional studies are recommended to determine the utility of VBQ and QCT BMD to evaluate their potential use as bone status markers.

Poster 259: Compartmental Static Anterior Tibial Translation After ACL Reconstruction: A Quantitative MRI Study

Objectives:Post-traumatic osteoarthritis (PTOA) develops in 50% of individuals who sustain an anterior cruciate ligament (ACL) injury. The mechanisms responsible for accelerated cartilage deterioration in ACL-injured knees are not well established. Abnormal tibiofemoral spatial relationship, resulting from ACL deficiency, has been purported as a potential contributor to altered cartilage loading and, consequently, accelerated PTOA. On magnetic resonance imaging (MRI), ACL-injured knees have been found to exhibit excess static anterior tibial translation (ATT) relative to control knees of separate, uninjured patients (Figure 1). However, the quantitative extent of ATT restoration following ACL reconstruction (ACLR) is largely unknown. We aimed to determine if ACLR restores static ATT in the lateral and medial compartments in comparison to the contralateral knee. We hypothesized that ACLR would not restore static ATT of the lateral and medial compartments back to the normal position.Methods:A prospective cohort study consisting of 30 patients with an acute ACL injury, with or without reparable meniscus tears, was designed. All patients underwent ACLR, performed by fellowship-trained orthopaedic surgeons using an anatomic, single bundle technique with accessory anteromedial portal drilling using autografts. MRI scans of both the injured and uninjured knees were performed 1) preoperatively within one month of ACL injury and 2) postoperatively six months after reconstruction. ATT of the lateral tibial plateau (LTP) and medial tibial plateau (MTP) were measured using a previously validated measurement method (Figure 2). This method entails identifying the mid-sagittal T1 MRI slice of the LTP and of the MTP. On each slice, the posterior aspect of the femoral condyle is located by plotting a best-fit ellipse to the condyle. The posterior aspect of the tibial plateau is then also identified. ATT for each compartment is then calculated as the anterior-to-posterior distance between tangential lines coincident with the posterior aspect of the femoral condyle and tibial plateau (Figure 2). Two-way analysis of variance (ANOVA) testing was performed to compare ATT between knees before and six months after ACLR. The two requisite factors for two-way ANOVA testing were limb, i.e. injured vs. uninjured, and time, i.e. preop vs. six months postop.Results:ACL-injured knees exhibited higher LTP ATT than uninjured control knees, regardless of timepoint (Pre-op: Injured = 5.73 ± 2.67mm; Uninjured = 3.35 ± 2.06mm. 6 months post-op: Injured = 4.81 ± 2.38mm; Uninjured = 3.36 ± 1.96mm, p < 0.001). LTP ATT trended towards decreasing in the injured limb after ACLR but this difference did not reach statistical significance (p for limb x time interaction = 0.053, Figure 3). ACL-injured knees also exhibited higher MTP ATT than uninjured control knees, regardless of timepoint (Pre-op: Injured = 1.52 ± 2.58mm; Uninjured = -0.12 ± 2.44mm. 6 months post-op: Injured = 1.46 ± 2.46mm; Uninjured = 0.07 ± 2.46mm, p < 0.001). MTP ATT did not change after ACLR as there was no significant interaction of limb x time (p = 0.486, Figure 4).Conclusions:ACLR did not restore pathologic ATT of the LTP and MTP back to levels present in uninjured knees. Persistent pathologic tibiofemoral relationships may contribute to abnormal cartilage loading over time and possible accelerated PTOA. Further study of early chondral changes after ACLR is necessary to elucidate if compartment-specific ATT is associated with local cartilage degeneration. Such understanding of the mechanistic factors responsible for PTOA after ACL injury may inform future potential preventative interventions.Figure 1.Pathologic anterior tibial translation (ATT) seen after ACL ruptureFigure 2.MRI ATT measurement method in lateral compartment of injured knee. Line 1 intersects the posterior tibia. Line 2 intersects the posterior femoral condyle. ATT is the AP distance between Line 1 and Line 2.Figure 3.Lateral Tibial Plateau ATTFigure 4.Medial Tibial Plateau ATT

Evaluation of the Association between Lumbar Spinal Stenosis and Lumbar Subcutaneous Fat Tissue Thickness by MRI: A Novel Perspective.

To evaluate whether lumbar subcutaneous fat tissue thickness (LSFTT) on midsagittal magnetic resonance imaging (MRI) is associated with lumbar spinal stenosis (LSS). Observational cross-sectional study. Department of Radiology and Neurosurgery, Istanbul Medeniyet University School of Medicine, Istanbul, Turkey between January 2018 and December 2020. The study group included 79 patients, who had undergone surgery for lumbar spinal stenosis. The control group included MRI scans of 80 individuals without lumbar spinal stenosis. Association between LSFTT and LSS was analysed through a comparison of both the groups. The agreement between the two observers was found to be very good agreement with a two-way mixed intra-class correlation coefficient of 0.986 or higher (p <0.001). There was statistically significant differences between the LSS and non-LSS groups for both L5-S1 and L4-5 level measurements, p=0.001, and p=0.004, respectively. L5-S1 level measurements in the LSS group showed 29% increase in average with respect to the non-LSS group; and in L4-L5 level measurements, the increase was 40% in median. Females exhibited significantly higher values in both levels, (p <0.001 and p <0.001, respectively). Lumbar subcutaneous fat tissue thickness is significantly associated with lumbar spinal stenosis. Measuring LSFTT on mid-sagittal MRI is an easily applicable, reproducible alternative method for predicting LSS. Key Word: Lumbar, Spinal canal, Stenosis, Subcutaneous fat tissue, Magnetic resonance imaging.

Corpus Callosal Morphometry in Mid-sagittal Plane MRI in Patients of Different Age Groups: A Retrospective Study

Introduction: Corpus callosum is the largest and most important of the forebrain commissural tracts connecting the two cerebral hemispheres. This white matter tract plays essential role in sensory, motor, and cognitive signal transmission across the right and left cerebral hemispheres. Hence, corpus callosal thickness and morphology reflects the hemispheric volume and functional ability of the brain. Thinning of corpus callosum which can be due to abnormal or absent myelination, demyelinating conditions, hypoxic-ischemic encephalopathy and metabolic diseases affecting the white matter can lead to developmental impairment and behavioural disorders which need to be properly evaluated. Aim: To identify possible age-associated variability in the anteroposterior diameter and the thickness of different parts of the corpus callosum. Materials and Methods: A retrospective cross-sectional study of 420 patients over a period of two years from January 2019 to December 2020 done at Dr. PSIMS and RF, Gannavaram, Andhra Pradesh. Magnetic Resonance (MR) examinations were performed with 1.5T Philips Healthcare Magnetic Resonance Imaging (MRI) scanner. The subjects who underwent MRI for various suspected or known central nervous system diseases were included in the study. The thickness of various parts along with the anteroposterior diameter of the corpus callosum were measured with mid-sagittal T1 weighted MR sequence and the mean and standard deviation was calculated. Results: The anteroposterior diameter of the corpus callosum was more in older adults (61-70 age group) than in children and younger adults. The mean thickness of genu, body and isthmus was found to be significantly more in younger adults (21-30 age group), whereas thickness of splenium was more significant in the age group of 31-40 years. Conclusion: The anteroposterior diameter was more in the elderly age group, whereas the thickness of corpus callosal regions was more in the young adult age group. Therefore, variations in corpus callosal thickness would help in the diagnosis of disease presence and progression.

Evaluation of the corpus callosum shape in patients with obstructive sleep apnea.

BackgroundThe aim of this study was to examine whether or not there was a difference in corpus callosum shape between patients with mild to moderate and severe obstructive sleep apnea (OSA) compared with patients who have simple snoring.MethodsThe landmark coordinate data was obtained from the mid-sagittal magnetic resonance imaging (MRI) images of 70 patients who underwent polysomnography. For comparisons, mild and moderate OSA groups were combined and analyses were performed on three groups; simple snoring/control group, mild or moderate OSA group, and severe OSA group.ResultsThe corpus callosum shape of controls was significantly different from that of the severe OSA group. The most prominent deformities were observed in the genu and rostral body of the corpus callosum for the patients with severe OSA. No significant difference was found between mild/moderate OSA group and simple snoring group in terms of global corpus callosum shape.ConclusionThe data demonstrated that severe OSA patients have structural changes in the corpus callosum and deformities may vary as the severity of disease changes.

Surgical Outcomes of Adult Chiari Malformation Type 1: Experience at a Tertiary Institute.

BackgroundChiari type I malformation (CM1) is a herniation of the caudal cerebellum and/or medulla oblongata into the upper spinal canal, occurring in pediatric and adult populations. We aimed to analyze the surgical outcomes of adult patients with CM1 consecutively treated with a posterior fossa decompression and duraplasty (PFDD) in a tertiary institution.Patients and methodsWe retrospectively reviewed the medical charts of 45 adult patients with CM1 who underwent PFDD at the Neurosurgery Department of our institution between January 2012 and December 2017. Radiological evaluation was based on pre- and postoperative syrinx/cord ratio, syrinx length, and regression of the ectopic cerebellar tonsils on coronal and sagittal magnetic resonance imaging (MRI) images, and clinical assessment of the patients was performed with the Chicago Chiari Outcome Scale (CCOS).ResultsOf the 45 patients included in the study, 25 (four men, 21 women) were diagnosed with symptomatic CM1 with an age average of 36.6±11.4 (18-66) years. Headache was the most common symptom (72.0%), while pinprick losses were prevalent in 13 (52.0%) patients. The mean postoperative CCOS score was 14.7±2.0 (8-16). Symptoms improved in 20 patients (80.0%) at the last follow-up. The mean regression in ectopic tonsils on midsagittal and coronal images were 9.1±1.8 (range: 0-16.5) mm and 8.3±1.2 (0-12.0) mm, respectively (p<0.05). The syrinxes had regressed completely or significantly in 7 (87.5%) of eight patients with syrinx.ConclusionOur findings showed that PFDD is sufficient to relieve most of the major symptoms and resolve the syrinx cavity without additional surgical interventions. The CCOS keeps its measurability of assessment of the clinical outcomes. A reliable radiological evaluation should be performed on midsagittal and coronal MRI images.

Normal human brainstem development in vivo: aquantitative fetal MRI study.

ABSTRACTObjectivesTo characterize spatiotemporal growth differences of prenatal brainstem substructures and cerebellum, using linear biometry and planimetry on fetal magnetic resonance imaging (MRI).MethodsIn this retrospective study, we included fetuses with normal brain and a precise midsagittal T2‐weighted brain MRI sequence obtained between May 2003 and April 2019. The cross‐sectional area, rostrocaudal diameter and anteroposterior diameter of the midbrain, pons (basis pontis and pontine tegmentum), medulla oblongata and cerebellar vermis, as well as the transverse cerebellar diameter, were quantified by a single observer. The diameters were also assessed by a second observer to test inter‐rater variability.ResultsWe included 161 fetuses with normal brain and a precise midsagittal MRI sequence, examined at a mean ± SD gestational age of 25.7 ± 5.4 (range, 14 + 0 to 39 + 2) weeks. All substructures of the fetal brainstem and the cerebellum could be measured consistently (mean ± SD interobserver intraclass correlation coefficient, 0.933 ± 0.065). We provide reference data for diameters and areas of the brainstem and cerebellum in the second and third trimesters. There was a significant quadratic relationship between vermian area and gestational age, and all other measured parameters showed a significant linear growth pattern within the observed period (P < 0.001). A significant change in the relative proportions of the brainstem substructures occurred between the beginning of the second trimester and the end of the third trimester, with an increase in the area of the pons (P < 0.001) and a decrease in that of the midbrain (P < 0.001), relative to the total brainstem area.ConclusionsThe substructures of the fetal brainstem follow a distinct spatiotemporal growth pattern, characterized by a relative increase in the pons and decrease in the midbrain, between 15 and 40 weeks of gestation. Caution is needed when interpreting fetal brainstem appearance during the early second trimester, as the brainstem proportions differ significantly from the adult morphology. The reference data provided herein should help to increase diagnostic accuracy in detecting disorders of defective hindbrain segmentation. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

New Grading System for Cervical Paraspinal Soft Tissue Damage After Traumatic Cervical Spinal Cord Injury Without Major Fracture Based on the Short-T1 Inversion Recovery Mid-Sagittal MRI for Prediction of Neurological Improvements: The STIR-MRI Grade.

Retrospective cohort study. To develop a grading method for cervical paraspinal soft tissue damage after cervical spinal cord injury (CSCI) without major fracture based on the short T1 inversion recovery (STIR) mid-sagittal magnetic resonance image (MRI) for prediction of neurological improvements. This study included 34 patients with CSCI without major fracture, treated conservatively for at least 1 year and graded using the STIR-MRI Grade. This system consists of anterior grades; A0: no high-intensity area (HIA), A1: linear HIA, and A2: fusiform HIA, and posterior grades; P0: no HIA, P1: HIA not exceeding the nuchal ligament, and P2: HIA exceeding the nuchal ligament, within 24 hours postinjury. The American Spinal Injury Association impairment scale (AIS) and the Japanese Orthopedic Association (JOA) scores were examined. Anterior grades were not significantly correlated with the AIS and JOA score. At both injury and final follow-up, the AIS in P2 patients was significantly more severe (P = 0.007, P = 0.015, respectively) than that in P0 patients. At the injury, the AIS in P2 patients was significantly more severe (P = 0.008) than that in P1 patients. Among P2 patients only, the JOA score at the injury (1.4 points) did not improve by the final follow-up (3.9 points). The final follow-up JOA score (3.9 points) in P2 patients was significantly lower than that (13.6 points) in P0 patients (P = 0.016). Grade P2 led to poor neurological outcomes. The STIR-MRI Grade is a prognostic indicator for neurological improvements past-CSCI.

Midbrain atrophy related to parkinsonism in a non-coding repeat expansion disorder: five cases of spinocerebellar ataxia type 31 with nigrostriatal dopaminergic dysfunction

BackgroundSpinocerebellar ataxia type 31 (SCA31) is caused by non-coding pentanucleotide repeat expansions in the BEAN1 gene. Clinically, SCA31 is characterized by late adult-onset, pure cerebellar ataxia. To explore the association between parkinsonism and SCA31, five patients with SCA31 with concomitant nigrostriatal dopaminergic dysfunction (NSDD) development, including three cases of L-DOPA responsive parkinsonism, were analyzed.MethodsTo assess regional brain atrophy, cross-sectional and longitudinal imaging analyses were retrospectively performed using magnetic resonance imaging (MRI) planimetry. The midbrain-to-pons (M/P) area ratio and cerebellar area were measured on midsagittal T1-weighted MRI in five patients with SCA31 with concomitant NSDD (NSDD(+)), 14 patients with SCA31 without NSDD (NSDD(−)), 32 patients with Parkinson’s disease (PD), and 15 patients with progressive supranuclear palsy (PSP). Longitudinal changes in the M/P area ratio were assessed by serial MRI of NSDD(+) (n = 5) and NSDD(−) (n = 9).ResultsThe clinical characteristics assessed in the five patients with NSDD were as follows: the mean age at NSDD onset (72.0 ± 10.8 years), prominence of bradykinesia/akinesia (5/5), rigidity (4/5), tremor (2/5), dysautonomia (0/5), vertical gaze limitation (1/5), and abnormalities on 123I-ioflupane dopamine transporter scintigraphy (3/3) and 3-Tesla neuromelanin MRI (4/4). A clear reduction in the midbrain area and the M/P area ratio was observed in the NSDD(+) group (p < 0.05) while there was no significant difference in disease duration or in the pons area among the NSDD(+), NSDD(−), and PD groups. There was also a significant difference in the midbrain and pons area between NSDD(+) and PSP (p < 0.05). Thus, mild but significant midbrain atrophy was observed in NSDD(+). A faster rate of decline in the midbrain area and the M/P area ratio was evident in NSDD(+) (p < 0.05).ConclusionThe clinical characteristics of the five patients with SCA31 with concomitant NSDD, together with the topographical pattern of atrophy, were inconsistent with PD, PSP, and multiple system atrophy, suggesting that SCA31 may manifest NSDD in association with the pathomechanisms underlying SCA31.

A deep cascaded segmentation of obstructive sleep apnea-relevant organs from sagittal spine MRI

PurposeThe main purpose of this work was to develop an efficient approach for segmentation of structures that are relevant for diagnosis and treatment of obstructive sleep apnea syndrome (OSAS), namely pharynx, tongue, and soft palate, from mid-sagittal magnetic resonance imaging (MR) data. This framework will be applied to big data acquired within an on-going epidemiological study from a general population.MethodsA deep cascaded framework for subsequent segmentation of pharynx, tongue, and soft palate is presented. The pharyngeal structure was segmented first, since the airway was clearly visible in the T1-weighted sequence. Thereafter, it was used as an anatomical landmark for tongue location. Finally, the soft palate region was extracted using segmented tongue and pharynx structures and used as input for a deep network. In each segmentation step, a UNet-like architecture was applied.ResultsThe result assessment was performed qualitatively by comparing the region boundaries obtained from the expert to the framework results and quantitatively using the standard Dice coefficient metric. Additionally, cross-validation was applied to ensure that the framework performance did not depend on the specific selection of the validation set. The average Dice coefficients on the test set were 0.89pm 0.03, 0.87pm 0.02, and 0.79pm 0.08 for tongue, pharynx, and soft palate tissues, respectively. The results were similar to other approaches and consistent with expert readings.ConclusionDue to high speed and efficiency, the framework will be applied for big epidemiological data with thousands of participants acquired within the Study of Health in Pomerania as well as other epidemiological studies to provide information on the anatomical structures and aspects that constitute important risk factors to the OSAS development.

Acoustic and articulatory analysis and synthesis of shouted vowels

Acoustic and articulatory differences between spoken and shouted vowels were analyzed for two male and two female subjects by means of acoustic recordings and midsagittal magnetic resonance images of the vocal tract. In accordance with previous acoustic findings, the fundamental frequencies, intensities, and formant frequencies were all generally higher for shouted than for spoken vowels. The harmonics-to-noise ratios and H1-H2 measures were generally lower for shouted vowels than for spoken vowels. With regard to articulation, all subjects used an increased lip opening, an increased jaw opening, and a lower tongue position for shouted vowels. However, the changes of vertical larynx position, uvula elevation, and jaw protrusion between spoken and shouted vowels were inconsistent among subjects. Based on the analysis results, a perception experiment was conducted to examine how changes of fundamental frequency, subglottal pressure, vocal tract shape, and phonation type contribute to the perception of stimuli created by articulatory synthesis as being shouted. Here, fundamental frequency had the greatest effect, followed by vocal tract shape and lung pressure, with no measurable effect of phonation type.

Radiological approach to basilar invagination type B: Reliability and accuracy

ObjectivesThis study aims to determine the reliability of the radiological tests used in the diagnosis of basilar invagination (BI). MethodsPatients diagnosed with type B basilar invagination, who had both magnetic resonance (MR) and computed tomography (CT) imaging between January 2014 and November 2019 were included in this retrospective reliability study. In this study, distance from odontoid apex to Chamberlain’s line (OA-CL) was accepted as a reference method for the diagnosis. Forty-two BI cases and 79 controls were included. Three radiologists with different levels of experience individually evaluated OA-CL, Boogard’s angle (BoA), clivo-axial angle (CXA), clivo-dens angle (CDA), and clivo-palate angle (CPA) on midsagittal CT and MR images. Statistical analysis was made with the intraclass correlation coefficient (ICC), t-test, and receiver operating characteristic (ROC) curve. ResultsThe ICC for CT and MR were; 0.977−0.973 (OA-CL), 0.912−0.882 (BoA), 0.845−0.846 (CXA), 0.862−0.864 (CDA), and 0.762−0.747 (CPA) respectively (P < 0.001). The areas under the ROC curve were 0.977 (BoA), 0.832 (CXA), 0.852 (CDA), and 0.719 (CPA) (P < 0.001). The cut-off measures were ≥137.84° (BoA), ≤149.25° (CXA), ≤129.58° (CDA), and ≤61.83° (CPA). The diagnostic accuracies were 0.954 (BoA), 0.664 (CXA), 0.704 (CDA), 0.438 (CPA) (P < 0.001). ConclusionsOA-CL and BoA express excellent inter-rater agreement than CXA, CDA, and CPA, which are limited due to morphological variations and head spatial position. BoA is the second most reliable diagnostic test. CXA, CDA, should only be used for complementary information. CPA was found inadequate for the diagnosis of BI.

Postoperative Syrinx Shrinkage in Spinal Ependymoma of WHO Grade II.

A retrospective study of preoperative and postoperative magnetic resonance imaging (MRI) findings in spinal ependymoma. The goal of the study was to examine MRI features, including the syrinx component volume, after surgical resection of spinal ependymoma, and to relate these features to extent of resection and improvement of postoperative neurological status. Spinal ependymomas have a variety of MRI findings preoperatively, including a hemorrhage cap sign, gadolinium enhancement, and a spinal tumor cyst. However, little is known about these features on postoperative MRI after tumor resection. The subjects were 38 patients treated for spinal cord ependymoma of World Health Organization grade II at our hospital. All had a spinal tumor cyst on preoperative MRI. All cases were followed with MRI for >1 year after surgery, including imaging at postoperative months (POM) 1 and 12. The maximum diameter of the syrinx was measured on mid-sagittal MRI. The extent of tumor resection was categorized as gross total resection (GTR) and subtotal resection (STR). The mean age of the 38 patients (22 male and 16 female individuals) was 50.9 years (range, 21-71 y) at the time of surgery. The mean preoperative duration from disease onset was 14.9 months (range, 2-47 mo). GTR was achieved in 28 patients (74%) and STR in 10 (26%). The mean syrinx sizes preoperatively and at POM 1 and POM 12 were 7.5±2.3, 4.1±1.9, and 2.5±1.8 mm, respectively, with significant differences among the time points (P<0.01). The syrinx size shrunk over time after GTR and STR. The shrinkage rate was significantly higher in GTR cases (P<0.05) and in cases with the improvement of McCormick grade for neurological status after both GTR and STR (P<0.05). These findings suggest that MRI can be used to evaluate the improvement of neurological status after surgery for spinal ependymoma.

Automatic vocal tract landmark localization from midsagittal MRI data

The various speech sounds of a language are obtained by varying the shape and position of the articulators surrounding the vocal tract. Analyzing their variations is crucial for understanding speech production, diagnosing speech disorders and planning therapy. Identifying key anatomical landmarks of these structures on medical images is a pre-requisite for any quantitative analysis and the rising amount of data generated in the field calls for an automatic solution. The challenge lies in the high inter- and intra-speaker variability, the mutual interaction between the articulators and the moderate quality of the images. This study addresses this issue for the first time and tackles it by means of Deep Learning. It proposes a dedicated network architecture named Flat-net and its performance are evaluated and compared with eleven state-of-the-art methods from the literature. The dataset contains midsagittal anatomical Magnetic Resonance Images for 9 speakers sustaining 62 articulations with 21 annotated anatomical landmarks per image. Results show that the Flat-net approach outperforms the former methods, leading to an overall Root Mean Square Error of 3.6 pixels/0.36 cm obtained in a leave-one-out procedure over the speakers. The implementation codes are also shared publicly on GitHub.

A new brain CT reference line: the lower eyelid to the inner occipital base line closely parallels the Talairach-Tournoux line.

BackgroundThere is no standardized brain computed tomography (CT) reference line that can be determined on both scout and reformatted sagittal CT images. Here, a tangential line from the anterior edge of the lower eyelid to the inner table of the occipital base (LEL/O line) appears nearly parallel to the Talairach–Tournoux (T/T) line, which shows a consistent intracranial anatomical relationship among subjects, and acts as a standard reference line for magnetic resonance (MR) imaging.PurposeTo quantitatively validate the LEL/O line as a new standard brain CT reference line.Material and MethodsWe measured: angle 1 = the LEL/O line on scout images from the LEL/O line on parasagittal CT images (n=93); and angle 2 = the LEL/O line on scout images from the T/T line on high resolution midsagittal MR images (n=97). Angles in a clockwise direction were defined as positive and were expressed as mean±SD with the 95% confidence interval (CI) of the SD. Angle 2 was measured independently by two observers and intraclass correlation coefficients (ICCs) were calculated.ResultsAngle 1 was –0.4°±1.2° (95% CI of SD 1.1°–1.5°); angle 2 was –0.4°±2.0° (95% CI of SD, 1.8°–2.4°). The ICC in the angle 2 measurement was 0.780 (P<0.001), which indicated high inter-observer reliability.ConclusionThe LEL/O lines on scout and parasagittal CT images show practically the same gradient, and these LEL/O lines are almost parallel to the T/T line. Use of the LEL/O line either for direct scanning or reformation can minimize intra- and inter-subject variations on CT images and mismatch between CT and MR images.