Niladri Mahato - Academia.edu (original) (raw)
Papers by Niladri Mahato
Frontiers in aging, Mar 6, 2024
Asian spine journal, Jan 30, 2024
Testing between and within group differences and assessing reliability of measurements. Purpose: ... more Testing between and within group differences and assessing reliability of measurements. Purpose: To study and compare lumbar spine morphology in supine and weight-bearing (WB) magnetic resonance imaging (MRI). Overview of Literature: Upright lumbar MRI may uncover anatomical changes that may escape detection when using conventional supine imaging. This study quantified anatomical dimensions of the lumbar spine in the supine and WB MRI, compared specific morphometric differences between them, and tested the intra-rater reliability of the measurements. Repeated measures analysis was used to compare within-and between-session measurements performed on the supine and WB images. Reliability and agreement were assessed by calculating intraclass correlation (ICC) coefficient. Methods: Data from 12 adults without any history of back pain were used in this study. Sagittal T2-weighted images of the lumbar spine were acquired in the supine and WB positions twice (in two separate sessions scheduled within a week). Linear, angular dimensions, and cross-sectional areas (CSAs) were measured using proprietary software. Supine and WB data acquired from the two imaging sessions were tested for intra-rater reliability. Quantified data were normalized for each session to test the significance of differences. ICC was calculated to test the reliability of the measurements. Results: Linear, angular, and CSA measurements demonstrated strong within-position (supine and WB) correlations (r-values, 0.75-0.97). Between-position (supine vs. WB) differences were significant for all measured dimensions (p<0.05). Between-session measurements demonstrated a strong correlation (r-values, 0.64-0.83). Calculated ICC showed strong agreement among the measurements. Conclusions: Anatomical dimensions of the lumbar spine may demonstrate consistent and significant differences between supine and WB MRI for specific structural parameters.
International Journal of Anatomical Variations, 2014
The power of the mind: the cortex as a critical determinant of muscle strength/weakness [PDF] [Fu... more The power of the mind: the cortex as a critical determinant of muscle strength/weakness [PDF] [Full Text]
Indian Journal of Radiology and Imaging, May 6, 2023
Clinical Anatomy, Jan 24, 2023
Latrogenic vascular injuries at the posterior ilium during sacroiliac screw placements are not un... more Latrogenic vascular injuries at the posterior ilium during sacroiliac screw placements are not uncommon. Though intra‐operative imaging reduces the risk of such injuries, anatomical localization of the sacral segments using discrete topographical landmarks is not currently available. This descriptive study proposes the use of an anatomical grid system to localize the sacroiliac articulation on the posterolateral ilium. It also investigates the positional variability of the branches of the superior gluteal artery (SGA) within areas defined by the grid. 48 dried adult hip bones were examined to determine the position of the sacral articular surface on the posterolateral surface of the ilium. A novel grid‐system was defined and used to map the positions of the articulation of the first two sacral segments on the posterolateral ilium. Superficial and deep branches of the SGA were dissected in donor cadavers and their courses were virtually overlayed on the grid system. The grid system localized the sacral articular surfaces within a defined area on the posterior ilium. Arterial distributions indicated the presence of the superficial branch of SGA more frequently over the screw insertion area (at an intermuscular plane), while the deep branch ran closer to the ilium but antero‐inferior to the screw placement areas. This study proposes a new topographical perspective of visualizing SGA branches with respect to the cranial sacral segments. Precise localization of vascular anatomy may help to reduce potential risk of injury during sacroiliac screw placements.
Morphologie, Dec 1, 2014
The mamillary (MP) and the accessory (AP) processes are two important anatomical landmarks in the... more The mamillary (MP) and the accessory (AP) processes are two important anatomical landmarks in the lumbar vertebral morphology. These two processes form the mamillo-accessory notch (MAN) between them. In the living, the MP and the AP are connected together by the mamillo-accessory ligament (MAL). The medial branches of lumbar dorsal rami pass underneath the MAL. The MAL often undergoes varied degrees of ossification with diverse notching at the junction of these two processes, often with formation of a discrete foramen (MAF). Reports on the distribution of these notches (MAN) and foramina (MAF) are very few and most of them do not discuss such ossification in context of morphology of adjoining structures in the vertebrae. Lumbar vertebral and sacral specimens were screened for three different categories of narrowing at the mamillo-accessory junction: firstly >1/2 notch, secondly ¾ notch, and thirdly MAF and their distribution patterns were mapped along the lumbar spine. Transverse dimensions of superior facet articulating surfaces [length (a)] and widths of MPs [length (b)] were recorded. Relative widths of the MPs were calculated as index M (a/b). Results suggest associations between the degrees of assimilation of the MPs into the facet joints, the index M values, and the different types of mamillo-accessory junctional anatomy. This study may help to understand if MAN and MAF related dorsal rami entrapment neuropathies arise merely due to osteoarthritic ossification of the MAL or could also be accounted for by facet dimensions or degree of MP-facet fusions that abut close to the mamillo-accessory junctions.
Journal of Anatomy, Jun 7, 2018
MAHATO, NILADRI KUMAR, Ph.D., August 2016, Biological Sciences Development of Imaging and Image M... more MAHATO, NILADRI KUMAR, Ph.D., August 2016, Biological Sciences Development of Imaging and Image Modeling Techniques for the Assessment and Quantification of Inter-Vertebral Motion Using MRI Director of Dissertation: Brian C. Clark Low back pain (LBP) is the leading cause of disability worldwide with more than eight hundred billion dollars of direct and indirect costs associated with LBP being incurred annually in the US alone. About 80-90% of all LBP patients do not have a definitive diagnosis of the etiology of pain, and are grouped under the non-specific LBP cohort. A group of such patients with unspecified etiology for their back pain are believed to have their LBP due to un-controlled and often, more than normal segmental motion involving one or more of their lumbar vertebrae. As such, many surgical treatments for LBP are directed at reducing inter-vertebral motion at and around an affected segment. The most common approaches for quantifying vertebral motion are based on radiographic assessments, which in many cases preclude scientific inquiry (e.g., use of high radiation equipment is not permitted for scientific investigations in some states, and, even when permitted, presents a major roadblock for serial assessments). This project was undertaken to develop and examine the feasibility, reliability and accuracy of a technique that used magnetic resonance (MR) images, custom built 3-D models and animations of spine-segment motion to quantify displacements in a calibrated imaging space. Experiment 1 explored the feasibility of developing an MRI-based spine kinematics quantification technique that involved (i) creating MRI compatible solid-body objects, (ii) scanning axial images of the objects in the MRI machine to create static 3-D virtual models of the solid-bodies, (iii) scanning the solid bodies as they were displaced
Journal of Bangladesh Society of Physiologist, Mar 30, 2015
Neurophysiologic analysis of motor behavior has become one of the prime research areas in the dom... more Neurophysiologic analysis of motor behavior has become one of the prime research areas in the domain of Physiology and hence it has seen tremendous development integrated research in this field over the years. This short review discusses the broad approaches which favors to understand effective neural control of motor behavior. The focus of this review is to recognize the gradual evolution of basic ideas regarding execution of coordinated and effective movements. The integrated roles of the spinal cord, the cerebellum and the motor cortex in context of voluntary movements have been delineated with citation of important research observations made in the field of motor control. Internet database related to human motor behavior studies were extensively searched to map the chronological development of important research methods and newer findings in this field. The span of the text ranges from the development of the idea of Motor Primitives to Brain-Machine Interfaces. It is observed that several 'basic' neural modules are preserved through ontogeny and phylogeny. Different combination of hierarchical modular functioning provides a wide range of plasticity required for coordinated and effective skillful movements.
International Journal of Anatomical Variations, 2014
Detection of foramina at the sacral ala is not very uncommon and has been reported earlier in the... more Detection of foramina at the sacral ala is not very uncommon and has been reported earlier in the literature. It has also been suggested that occurrence of such a foramen may be associated with similar findings at adjacent lumbar transverse processes. This report documents detection of a similar occurrence and reviews commonly accepted embryological explanations of this phenomenon. Pedicle or alar instrumentations in these individuals warrants careful per-operative imaging of these foramina due to the likelihood of these formina containing remnants of longitudinally anastomosing vascular structures, in most instances.
Anatomical Science International, 2018
Genetics in Dentistry, 2010
Genetics in Dentistry, 2010
Journal of neurophysiology, Jan 15, 2014
We tested the hypothesis that the nervous system, and the cortex in particular, is a critical det... more We tested the hypothesis that the nervous system, and the cortex in particular, is a critical determinant of muscle strength/weakness and that a high level of corticospinal inhibition is an important neurophysiological factor regulating force generation. A group of healthy individuals underwent 4 wk of wrist-hand immobilization to induce weakness. Another group also underwent 4 wk of immobilization, but they also performed mental imagery of strong muscle contractions 5 days/wk. Mental imagery has been shown to activate several cortical areas that are involved with actual motor behaviors, including premotor and M1 regions. A control group, who underwent no interventions, also participated in this study. Before, immediately after, and 1 wk following immobilization, we measured wrist flexor strength, voluntary activation (VA), and the cortical silent period (SP; a measure that reflect corticospinal inhibition quantified via transcranial magnetic stimulation). Immobilization decreased s...
<b>Morphology-based Technique: MRI-only Approach for Joint Kinematics Assessment </b>
International Journal of Morphology, 2010
Neuro-vascular entrapments associated with variations observed in the origins of muscles in the a... more Neuro-vascular entrapments associated with variations observed in the origins of muscles in the arm are not uncommon. Though additional heads of biceps brachii muscle and extra fibres of brachialis muscles have been demonstrated earlier, bilateral additional heads of the biceps are rarely seen, especially with entrapment of the median nerve and the brachial arteries in both the arms. The present study reports conspicuous heads of the biceps brachii originating extensively from the medial inter-muscular septum, sharing its origin with the brachialis muscle. The extra origins of the muscle formed long musculo-aponeurotic tunnels. The tunnels measured eight centimeters in length extending from the lower arm to the cubital-fossa. Both the median nerve and the brachial arteries passed through the tunnel. The lower aspect of the left tunnel exhibited origins of fibres belonging to the superficial flexors of the forearm. The neuro-vascular structures did not give any branches in the tunnel. Awareness of such variations can aid clinicians in diagnosing and treating such neuropathies and vascular compromise.
Frontiers in aging, Mar 6, 2024
Asian spine journal, Jan 30, 2024
Testing between and within group differences and assessing reliability of measurements. Purpose: ... more Testing between and within group differences and assessing reliability of measurements. Purpose: To study and compare lumbar spine morphology in supine and weight-bearing (WB) magnetic resonance imaging (MRI). Overview of Literature: Upright lumbar MRI may uncover anatomical changes that may escape detection when using conventional supine imaging. This study quantified anatomical dimensions of the lumbar spine in the supine and WB MRI, compared specific morphometric differences between them, and tested the intra-rater reliability of the measurements. Repeated measures analysis was used to compare within-and between-session measurements performed on the supine and WB images. Reliability and agreement were assessed by calculating intraclass correlation (ICC) coefficient. Methods: Data from 12 adults without any history of back pain were used in this study. Sagittal T2-weighted images of the lumbar spine were acquired in the supine and WB positions twice (in two separate sessions scheduled within a week). Linear, angular dimensions, and cross-sectional areas (CSAs) were measured using proprietary software. Supine and WB data acquired from the two imaging sessions were tested for intra-rater reliability. Quantified data were normalized for each session to test the significance of differences. ICC was calculated to test the reliability of the measurements. Results: Linear, angular, and CSA measurements demonstrated strong within-position (supine and WB) correlations (r-values, 0.75-0.97). Between-position (supine vs. WB) differences were significant for all measured dimensions (p<0.05). Between-session measurements demonstrated a strong correlation (r-values, 0.64-0.83). Calculated ICC showed strong agreement among the measurements. Conclusions: Anatomical dimensions of the lumbar spine may demonstrate consistent and significant differences between supine and WB MRI for specific structural parameters.
International Journal of Anatomical Variations, 2014
The power of the mind: the cortex as a critical determinant of muscle strength/weakness [PDF] [Fu... more The power of the mind: the cortex as a critical determinant of muscle strength/weakness [PDF] [Full Text]
Indian Journal of Radiology and Imaging, May 6, 2023
Clinical Anatomy, Jan 24, 2023
Latrogenic vascular injuries at the posterior ilium during sacroiliac screw placements are not un... more Latrogenic vascular injuries at the posterior ilium during sacroiliac screw placements are not uncommon. Though intra‐operative imaging reduces the risk of such injuries, anatomical localization of the sacral segments using discrete topographical landmarks is not currently available. This descriptive study proposes the use of an anatomical grid system to localize the sacroiliac articulation on the posterolateral ilium. It also investigates the positional variability of the branches of the superior gluteal artery (SGA) within areas defined by the grid. 48 dried adult hip bones were examined to determine the position of the sacral articular surface on the posterolateral surface of the ilium. A novel grid‐system was defined and used to map the positions of the articulation of the first two sacral segments on the posterolateral ilium. Superficial and deep branches of the SGA were dissected in donor cadavers and their courses were virtually overlayed on the grid system. The grid system localized the sacral articular surfaces within a defined area on the posterior ilium. Arterial distributions indicated the presence of the superficial branch of SGA more frequently over the screw insertion area (at an intermuscular plane), while the deep branch ran closer to the ilium but antero‐inferior to the screw placement areas. This study proposes a new topographical perspective of visualizing SGA branches with respect to the cranial sacral segments. Precise localization of vascular anatomy may help to reduce potential risk of injury during sacroiliac screw placements.
Morphologie, Dec 1, 2014
The mamillary (MP) and the accessory (AP) processes are two important anatomical landmarks in the... more The mamillary (MP) and the accessory (AP) processes are two important anatomical landmarks in the lumbar vertebral morphology. These two processes form the mamillo-accessory notch (MAN) between them. In the living, the MP and the AP are connected together by the mamillo-accessory ligament (MAL). The medial branches of lumbar dorsal rami pass underneath the MAL. The MAL often undergoes varied degrees of ossification with diverse notching at the junction of these two processes, often with formation of a discrete foramen (MAF). Reports on the distribution of these notches (MAN) and foramina (MAF) are very few and most of them do not discuss such ossification in context of morphology of adjoining structures in the vertebrae. Lumbar vertebral and sacral specimens were screened for three different categories of narrowing at the mamillo-accessory junction: firstly >1/2 notch, secondly ¾ notch, and thirdly MAF and their distribution patterns were mapped along the lumbar spine. Transverse dimensions of superior facet articulating surfaces [length (a)] and widths of MPs [length (b)] were recorded. Relative widths of the MPs were calculated as index M (a/b). Results suggest associations between the degrees of assimilation of the MPs into the facet joints, the index M values, and the different types of mamillo-accessory junctional anatomy. This study may help to understand if MAN and MAF related dorsal rami entrapment neuropathies arise merely due to osteoarthritic ossification of the MAL or could also be accounted for by facet dimensions or degree of MP-facet fusions that abut close to the mamillo-accessory junctions.
Journal of Anatomy, Jun 7, 2018
MAHATO, NILADRI KUMAR, Ph.D., August 2016, Biological Sciences Development of Imaging and Image M... more MAHATO, NILADRI KUMAR, Ph.D., August 2016, Biological Sciences Development of Imaging and Image Modeling Techniques for the Assessment and Quantification of Inter-Vertebral Motion Using MRI Director of Dissertation: Brian C. Clark Low back pain (LBP) is the leading cause of disability worldwide with more than eight hundred billion dollars of direct and indirect costs associated with LBP being incurred annually in the US alone. About 80-90% of all LBP patients do not have a definitive diagnosis of the etiology of pain, and are grouped under the non-specific LBP cohort. A group of such patients with unspecified etiology for their back pain are believed to have their LBP due to un-controlled and often, more than normal segmental motion involving one or more of their lumbar vertebrae. As such, many surgical treatments for LBP are directed at reducing inter-vertebral motion at and around an affected segment. The most common approaches for quantifying vertebral motion are based on radiographic assessments, which in many cases preclude scientific inquiry (e.g., use of high radiation equipment is not permitted for scientific investigations in some states, and, even when permitted, presents a major roadblock for serial assessments). This project was undertaken to develop and examine the feasibility, reliability and accuracy of a technique that used magnetic resonance (MR) images, custom built 3-D models and animations of spine-segment motion to quantify displacements in a calibrated imaging space. Experiment 1 explored the feasibility of developing an MRI-based spine kinematics quantification technique that involved (i) creating MRI compatible solid-body objects, (ii) scanning axial images of the objects in the MRI machine to create static 3-D virtual models of the solid-bodies, (iii) scanning the solid bodies as they were displaced
Journal of Bangladesh Society of Physiologist, Mar 30, 2015
Neurophysiologic analysis of motor behavior has become one of the prime research areas in the dom... more Neurophysiologic analysis of motor behavior has become one of the prime research areas in the domain of Physiology and hence it has seen tremendous development integrated research in this field over the years. This short review discusses the broad approaches which favors to understand effective neural control of motor behavior. The focus of this review is to recognize the gradual evolution of basic ideas regarding execution of coordinated and effective movements. The integrated roles of the spinal cord, the cerebellum and the motor cortex in context of voluntary movements have been delineated with citation of important research observations made in the field of motor control. Internet database related to human motor behavior studies were extensively searched to map the chronological development of important research methods and newer findings in this field. The span of the text ranges from the development of the idea of Motor Primitives to Brain-Machine Interfaces. It is observed that several 'basic' neural modules are preserved through ontogeny and phylogeny. Different combination of hierarchical modular functioning provides a wide range of plasticity required for coordinated and effective skillful movements.
International Journal of Anatomical Variations, 2014
Detection of foramina at the sacral ala is not very uncommon and has been reported earlier in the... more Detection of foramina at the sacral ala is not very uncommon and has been reported earlier in the literature. It has also been suggested that occurrence of such a foramen may be associated with similar findings at adjacent lumbar transverse processes. This report documents detection of a similar occurrence and reviews commonly accepted embryological explanations of this phenomenon. Pedicle or alar instrumentations in these individuals warrants careful per-operative imaging of these foramina due to the likelihood of these formina containing remnants of longitudinally anastomosing vascular structures, in most instances.
Anatomical Science International, 2018
Genetics in Dentistry, 2010
Genetics in Dentistry, 2010
Journal of neurophysiology, Jan 15, 2014
We tested the hypothesis that the nervous system, and the cortex in particular, is a critical det... more We tested the hypothesis that the nervous system, and the cortex in particular, is a critical determinant of muscle strength/weakness and that a high level of corticospinal inhibition is an important neurophysiological factor regulating force generation. A group of healthy individuals underwent 4 wk of wrist-hand immobilization to induce weakness. Another group also underwent 4 wk of immobilization, but they also performed mental imagery of strong muscle contractions 5 days/wk. Mental imagery has been shown to activate several cortical areas that are involved with actual motor behaviors, including premotor and M1 regions. A control group, who underwent no interventions, also participated in this study. Before, immediately after, and 1 wk following immobilization, we measured wrist flexor strength, voluntary activation (VA), and the cortical silent period (SP; a measure that reflect corticospinal inhibition quantified via transcranial magnetic stimulation). Immobilization decreased s...
<b>Morphology-based Technique: MRI-only Approach for Joint Kinematics Assessment </b>
International Journal of Morphology, 2010
Neuro-vascular entrapments associated with variations observed in the origins of muscles in the a... more Neuro-vascular entrapments associated with variations observed in the origins of muscles in the arm are not uncommon. Though additional heads of biceps brachii muscle and extra fibres of brachialis muscles have been demonstrated earlier, bilateral additional heads of the biceps are rarely seen, especially with entrapment of the median nerve and the brachial arteries in both the arms. The present study reports conspicuous heads of the biceps brachii originating extensively from the medial inter-muscular septum, sharing its origin with the brachialis muscle. The extra origins of the muscle formed long musculo-aponeurotic tunnels. The tunnels measured eight centimeters in length extending from the lower arm to the cubital-fossa. Both the median nerve and the brachial arteries passed through the tunnel. The lower aspect of the left tunnel exhibited origins of fibres belonging to the superficial flexors of the forearm. The neuro-vascular structures did not give any branches in the tunnel. Awareness of such variations can aid clinicians in diagnosing and treating such neuropathies and vascular compromise.