Lung ultrasound for the assessment of lung recruitment in neonates with massive pneumothorax during extracorporeal membrane oxygenation: a case report.

Bedside lung ultrasound may be an effective method for the assessment of lung recruitment in newborns with extracorporeal membrane oxygenation (ECMO). We report a case of a neonate who had severe hypoxemia with persistent pulmonary hypertension and massive pneumothorax due to meconium aspiration syndrome and was treated with ECMO. Positive pressure mechanical ventilation resulted in persistent massive air leakage from the disrupted pulmonary tissue. When ECMO was initiated, a "total lung rest" ventilation strategy was used to facilitate healing of the lung rupture and absorption of the pneumothorax. After complete absorption of the pneumothorax, lung recruitment was performed by progressively increasing the positive end-expiratory pressure under the guidance of lung ultrasound. Bedside lung ultrasound was successfully used to assess pneumothorax absorption and improvement of pulmonary inflammation and successfully guided the recruitment of collapsed alveoli and the withdrawal of ECMO.

Design of a low-cost MRI compatible plantarflexion force measurement device.

Investigating the neural correlates of ankles' joint rotation is critical to better understand the underlying deficit in balance or posture control in the clinical population. This work describes the design and characteristics of a low-cost MRI compatible isometric plantarflexion force measurement device. The device is fully adjustable to the particular height and shoe size of participants. Each individual force sensor has an operational linear range up to 80-100kg amounting to a force range up to 180kg when combining the two sensors, which is well above the maximal force for the majority of the population. Preliminary neuroimaging tests suggest that performing submaximal ankle plantar flexions on the device induce minimal motion artifacts on fMRI signal that are within an acceptable range.

[Three-dimensional localization and assessment of maxillary palatal impacted canines with cone-beam computed tomography].

PURPOSE: To evaluate the location of maxillary palatal impacted canines and resorption of neighboring incisors with cone-beam computed tomography (CBCT). METHODS: Twenty-two healthy adolescent patients who had received orthodontic treatments at Stomatological Hospital of Nanjing Medical University were selected and scanned by CBCT. Palatal impacted maxillary canines were reconstructed by Dolphin imaging 11.0 software. The impactions, spatial relationships and classification relative to adjacent structures and incisor resorption were assessed. RESULTS: Most of the maxillary palatal impacted canines inclinated mesially and palatally. Mesial malpositions were more significantly prevalent in Class I and IV, and the prevalence rates were 30.8% and 38.5% respectively. Mesial inclinations of the impacted canines to occlusal plane were mostly between 53.8° and 68.5°, and the distances from the impacted canines to median sagittal plane were between 5.4 and 8.4 mm. Older the patient was, further the impacted canines mesiopalatal displaced and mesial inclined. The roots of 84.6% of lateral incisors and 19.2% of central incisors contacted impacted canines; Root resorption occurred in 50% of lateral incisors and 15.4% of central incisors, which predominantly located in apical third of the lateral incisors and middle third of the central incisors. A inverse correlation was found between the resorption rates of adjacent incisors and minimum distances from impacted canines to adjacent incisors. CONCLUSIONS: CBCT allows three dimensional evaluation of impaction and spatial relationships relative to adjacent structures. In addition, 3 dimensional measurement contributes to more accurate exhibition of the adjacent root resorptions, inclinations and depths of the impacted canines, which leads to more efficient guidance of maxillary palatal impacted canines treatment.

Assessment of inter-hemispheric imbalance using imaging and noninvasive brain stimulation in patients with chronic stroke.

OBJECTIVE: To determine how interhemispheric balance in stroke, measured using transcranial magnetic stimulation (TMS), relates to balance defined using neuroimaging (functional magnetic resonance [fMRI], diffusion-tensor imaging [DTI]) and how these metrics of balance are associated with clinical measures of upper-limb function and disability. DESIGN: Cross sectional. SETTING: Laboratory. PARTICIPANTS: Patients with chronic stroke (N = 10; age, 63 ± 9 y) in a population-based sample with unilateral upper-limb paresis. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Interhemispheric balance was measured with TMS, fMRI, and DTI. TMS defined interhemispheric differences in the recruitment of corticospinal output, size of the corticomotor output maps, and degree of mutual transcallosal inhibition that they exerted on one another. fMRI studied whether cortical activation during the movement of the paretic hand was lateralized to the ipsilesional or to the contralesional primary motor cortex (M1), premotor cortex (PMC), and supplementary motor cortex (SMA). DTI was used to define interhemispheric differences in the integrity of the corticospinal tracts projecting from the M1. Clinical outcomes tested function (upper extremity Fugl-Meyer [UEFM]) and perceived disability in the use of the paretic hand (Motor Activity Log [MAL] amount score). RESULTS: Interhemispheric balance assessed with TMS relates differently to fMRI and DTI. Patients with high fMRI lateralization to the ipsilesional hemisphere possessed stronger ipsilesional corticomotor output maps (M1: r = .831, P = .006; PMC: r = .797, P = .01) and better balance of mutual transcallosal inhibition (r = .810, P = .015). Conversely, we found that patients with less integrity of the corticospinal tracts in the ipsilesional hemisphere show greater corticospinal output of homologous tracts in the contralesional hemisphere (r = .850, P = .004). However, an imbalance in integrity and output do not relate to transcallosal inhibition. Clinically, although patients with less integrity of corticospinal tracts from the ipsilesional hemisphere showed worse impairments (UEFM) (r = -.768, P = .016), those with low fMRI lateralization to the ipsilesional hemisphere had greater perception of disability (MAL amount score) (M1: r = .883, P = .006; PMC: r = .817, P = .007; SMA: r = .633, P = .062). CONCLUSIONS: In patients with chronic motor deficits of the upper limb, fMRI may serve to mark perceived disability and transcallosal influence between hemispheres. DTI-based integrity of the corticospinal tracts, however, may be useful in categorizing the range of functional impairments of the upper limb. Further, in patients with extensive corticospinal damage, DTI may help infer the role of the contralesional hemisphere in recovery.

Fractal dimension assessment of brain white matter structural complexity post stroke in relation to upper-extremity motor function.

Little is known about the association between brain white matter (WM) structure and motor function in humans. This study investigated complexity of brain WM interior shape as determined by magnetic resonance imaging (MRI) and its relationship with upper-extremity (UE) motor function in patients post stroke. We hypothesized that (1) the WM complexity would decrease following stroke, and (2) higher WM complexity in non-affected cortical areas would be related to greater UE motor function. Thirty-eight stroke patients (16 with left-hemisphere lesions) underwent MRI anatomical brain scans. Fractal dimension (FD), a quantitative shape metric, was applied onto skeletonized brain WM images to evaluate WM internal structural complexity. Wolf Motor Function Test (WMFT) and Fugl-Meyer Motor Assessment (FM) scores were measured to assess motor function of the affected limb. The WM complexity was lower in the stroke-affected hemisphere. The FD was associated with better motor function in two subgroups: with left-subcortical lesions, FD values of the lesion-free areas of the left hemisphere were associated with better FM scores; with right-cortical lesions, FD values of lesion-free regions were robustly associated with better WMFT scores. These findings suggest that greater residual WM complexity is associated with less impaired UE motor function, which is more robust in patients with right-hemisphere lesions. No correlations were found between lesion volume and WMFT or FM scores. This study addressed WM complexity in stroke patients and its relationship with UE motor function. Measurement of brain WM reorganization may be a sensitive correlate of UE function in people recovering from stroke.