Mean Number Of Pixels Research Articles

Diagnostic Ultrasound Shows Reversal of Supraspinatus Muscle Atrophy Following Arthroscopic Rotator Cuff Repair

Prospective study to assess ultrasonography (US) utility as an imaging tool for supraspinatus muscle atrophy diagnosis, establishing if there is any relationship between repairing supraspinatus tears and its eventual muscular recovery. Observational study. adults with a full-thickness reparable supraspinatus tear confirmed arthroscopically. Clinical and imaging data pre- and postoperatively with 12 months of follow-up were recorded, including demographic data, Constant scale, Patte classification, repair type, and supraspinatus muscle belly US images in both shoulders, recording height, diameter, echogenicity (mean number of pixels between 0-black and 255-white), and central tendon pennate angle (PA). In total, 110 supraspinatus tears underwent arthroscopic repair (2015-2018). Mean age was 61 ± 8 years (46-77). We detected a correlation between atrophy and age in terms of echogenicity and PA (P= .01). Echogenicity improved from 54.5 to 51.0 (P= .365) and slightly deteriorated on the contralateral side from 51.6 to 52.9 (P= .351). Supraspinatus echogenicity compared to trapezius muscle reduced from 0.43 to 0.36 (P < .001). PA augmented from 5.8 to 8.6 (P < .001). Mean PA on the contralateral side was 8.6 preoperatively. Patte II cases showed the most significant improvement in terms of imaging evaluation of atrophy. Although Patte III cases almost did not improve in terms of atrophy, they improved clinically. We observed improvement after surgery in Constant score from 35 to 85 (P < .001). Minimal clinically important differences for Constant and visual analog scale were 44.45 ± 12.87 and 6.54 ± 1.41, respectively. Recurrence of symptoms was 13%, related to worse results of PA and echogenicity compared to nonrecurrences. Supraspinatus atrophic muscle changes after repair can be reversed. It can be quantified using US imaging (histogram, histogram ratio and echogenicity reduction, pennate pattern, and PA augmentation). Patte II cases showed the best results after repair, demonstrated by US. The faster the repair, the better the results without being influenced by repair type. The bigger the tear and retraction, the more echogenicity and less PA, with worse clinical and US results. Level III, prospective therapeutic study.

Usefulness of subtraction pelvic magnetic resonance imaging for detection of ovarian endometriosis.

BackgroundTo minimize damage to the ovarian reserve, it is necessary to evaluate the follicular density in the ovarian tissue surrounding endometriosis on preoperative imaging. The purpose of the present study was to evaluate the usefulness of subtraction pelvic magnetic resonance imaging (MRI) to detect ovarian reserve.MethodsA subtracted T1-weighted image (subT1WI) was obtained by subtracting unenhanced T1WI from contrast-enhanced T1WI (ceT1WI) with similar parameters in 22 patients with ovarian endometriosis. The signal-to-noise ratio (SNR) in ovarian endometriosis, which was classified into the high signal intensity and iso-to-low signal intensity groups on the T2-weighted image, was compared to that in normal ovarian tissue. To evaluate the effect of contrast enhancement, a standardization map was obtained by dividing subT1WI by ceT1WI.ResultsOn visual assessment of 22 patients with ovarian endometriosis, 16 patients showed a high signal intensity, and 6 patients showed an iso-to-low signal intensity on T1WI. Although SNR in endometriosis with a high signal intensity was higher than that with an iso-to-low signal intensity, there was no difference in SNR after the subtraction (13.72±77.55 vs. 63.03±43.90, p=0.126). The area of the affected ovary was smaller than that of the normal ovary (121.10±22.48 vs. 380.51±75.87 mm2, p=0.002), but the mean number of pixels in the viable remaining tissue of the affected ovary was similar to that of the normal ovary (0.53±0.09 vs. 0.47±0.09, p=0.682).ConclusionThe subtraction technique used with pelvic MRI could reveal the extent of endometrial invasion of the normal ovarian tissue and viable remnant ovarian tissue.

Colour Doppler Ultrasound Assessment of the Normal Neonatal Hip

Objective To determine the morphology and hemodynamic characteristics of the arterial vessels of the proximal femur according to specific anatomic regions in asymptomatic neonates in 2 pediatric-based health care institutions. Methods Forty-three neonates (29 female, 14 male; age range, 2 d–3 mo; median age, 3 d) were enrolled in the study. Thirty-two (37%) of 86 hips were classified as Graf type IIA joints (mean alpha angle, 56.0° ± 2.7°), and 54 (63%) were classified as type I joints (mean alpha angle, 65.0° ± 4.6°). Results Colour and spectral Doppler imaging identified vessels running along the acetabular labrum, epiphyseal vessels, and femoral neck. We showed 4 different patterns of vascularity of the hips: radial, parallel, mixed radial–parallel, and indeterminate, however, they were not related to the hip maturity ( P = .3, coronal plane; P = .62, transverse plane) or to the amount of colour pixels identified in each region ( P = .35). The mean number of pixels in the ligamentum teres region was significantly higher than that in other regions of interest ( P = .03). Except for the acetabular labrum arteries, Doppler spectrum waveforms of proximal femur arteries presented with low resistivity. There was a tendency towards females' acetabular arteries presenting with lower peak systolic velocities than males' acetabular arteries ( P = .06). Conclusions Colour Doppler spectrum waveforms and intensity of vascularity in normal neonatal hips differ according to the anatomic region under evaluation. This observation deserves further investigation on its role on the physiopathogenesis of neonatal hip disorders.

Phase I and DCE-MRI evaluation of NGR-TNF, a novel vascular targeting agent, in patients with solid tumors (EORTC 16041)

3521 Background: NGR-TNF is a novel agent exploiting a tumor homing peptide (cNGRCG) that selectively targets CD13 that is expressed on tumor neovasculature. Preclinical data show that its antitumor activity is achieved by a change of vascular permeability (at low doses) and damage of tumor-associated blood vessels (at high doses). This phase I study was conducted to assess its safety, PK, PD, MTD, and optimal biological dose in patients (pts) with advanced solid tumors. Methods: NGR-TNF was administered once every 3 weeks by an IV infusion in 20 min in the first 18 pts and in 1 hr IV infusion in the other pts, to cohorts of 3–6 pts. The starting dose was 0.2 μg/m2. Dose escalation was performed with a doubling of the dose until G2 toxicity was observed; thereafter a modified Fibonacci schedule was used. DCE-MRI was performed in Cy 1 at baseline and 2 hours after start of the infusion at each DL. Results: 70 pts were treated with in total 179 Cy (1–12). 17 DLs have been visited (0.2 to 60 μg/m2). 4 DLTs (bronchospasm at 1.3 μg/m2; abdominal pain with hypotension at 8.1 μg/m2; dyspnea and acute infusion reaction at 60 μg/m2 - all G3) were observed. The MTD was 45 μg/m2 with no DLT in 9 pts. Most frequently related adverse events were chills (81%) and fever (58%). No objective responses were observed, 21 pts had SD. DCE-MRI data of 31 pts were available. At dose-levels ≥1.3 μg/m2 the majority of pts showed a decrease in Ktrans compared to baseline. Although the mean kep and Ktrans were not significantly different at baseline and follow-up, at dose-levels ≥1.3 μg/m2 the mean Ktrans significantly decreased (.015 vs .012 a.u. s-1; p <.05). For all DLs, the mean number of pixels with a low fraction of kep and Ktrans significantly increased (p<0.01), as seen with other anti- vascular agents. The change in Ktrans was not related with DL. AUC and Cmax increased dose proportional. TNF-RI and II increased with dose, but a plateau was seen ≥25.4 μg/m2. A dose-dependent increase of MIP-1β and MCP- 1 and decrease of EGF was seen. Generation of anti-NGR-TNF antibodies was not observed. Conclusions: NGR-hTNF is well tolerated; the MTD is 45 μg/m2. The DCE-MRI results suggest an anti-vascular effect of NGR-TNF. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration MolMed S.p.A. MolMed S.p.A.

EFFECT OF INTERTROCHANTERIC OSTEOTOMY ON THE PROXIMAL FEMUR OF RABBITS: ASSESSMENT WITH POWER DOPPLER SONOGRAPHY AND SCINTIGRAPHY

In bone injury, repair results in local increased vascularity and bone marrow remodeling. Characterizing the vascular and metabolic imaging patterns of the proximal femur following an intertrochanteric osteotomy may help clinicians decide proper management of the patient. Our objective was to measure Doppler sonography and scintigraphy interval changes in the proximal femur following intertrochanteric osteotomy and compare imaging and histomorphometric measurements in the late post-operative stage (6 weeks after surgery) in a rabbit model of bone injury. Both hips of 12 adult rabbits were imaged with power Doppler sonography and scintigraphy prior to and after (7 days and 6 weeks) unilateral osteotomy. Accuracy of the imaging methods was evaluated using hip operative status and histomorphometric results (vascular fractional area and number of vessels per area unit) as reference standard measures. A significant difference in the mean number of pixels was noted between operated and non-operated femura in late post-operative power Doppler examinations (P=0.049). Although without reaching statistical significance, the AUC of Doppler measurements (AUC=0.99) was numerically greater than the AUC of scintigraphy measurements (AUC=0.857+/-0.099) (P=0.15) in differentiating proximal femura with regard to their fractional vascular areas in the late post-operative stage. In contrast, scintigraphy tended to perform better (AUC=0.984+/-0.022) than Doppler ultrasound (AUC=0.746+/-0.131) to demonstrate the vascularity intensity per area unit (P=0.07) in the late stage. Our results warrant further investigation to determine the value of different imaging modalities for assessment of pathologic changes following hip surgery. Power Doppler sonography demonstrated larger AUCs (representing higher accuracy) for the discrimination of vascular fractional areas and scintigraphy, for discrimination of the number of vessels per area unit.

L‐DOPA‐induced dyskinesia in adult rats with a unilateral 6‐OHDA lesion of dopamine neurons is paralleled by increased c‐fos gene expression in the subthalamic nucleus

In the recently published paper of Soghomonian (2006), the key to Fig. 5 was incorrect (‘ipsilateral’ and ‘contralateral’ were reversed). The corrected Fig. 5 is reproduced here, with its original legend for completeness. Average c-fos mRNA labeling in the STN of adult rats with a unilateral 6-OHDA lesion of dopamine neurons. Values are mean number of pixels ± SEM per cell for the side ipsi- or contralateral to the 6-OHDA lesion, and were obtained by computerized image analysis as described in the Materials and methods. Labeling was quantified in 6-OHDA-lesioned rats injected with vehicle (vehicle), once (acute) or chronically with L-DOPA (chronic), or sham-operated rats injected chronically with L-DOPA (shamchronic). Values in the acute group are shown for all rats included (all-acute) or for rats that did not show dyskinetic movements (nd-acute). *P < 0.0001 (chronic) and P < 0.05 (acute-all) with a Mann–Whitney non-parametric test. The author apologizes for any confusion that this may have caused.

Broadening of the variance of the number of upsets in a read-cycle by MBUs

This work presents A technique for establishing the proportion of multiple bit upsets (MBUs) in single event effects (SEE) test results based on a more sophisticated analysis of existing trial data and not requiring a memory map. The technique is demonstrated and verified with reference to recent neutron SEE results in charge coupled devices, since multi-pixel events are plentiful in these data and the mean number of pixels per event can be independently established through image analysis. This technique is most easily applied when the fraction of MBUs is relatively large, so it is predicted to become increasingly important in the future, as feature size reduction is expected to increase the proportion of MBUs.

Differential effects of p-chlorophenylalanine on indoleamines in brainstem nuclei and spinal cord of rats. II. Identification of immunohistochemically stained structures using computer-assisted image enhancement techniques

Following intraperitoneal injection of p-chlorophenylalanine (PCPA, 400 and 600 mg/kg) on 3 consecutive days, the brainstem and lumbar cord of rats were removed, frozen-sectioned and immunohistochemically stained (PAP method) for serotonin (5-HT). Using computer-assisted image analysis, the density of 5-HT staining in control, 400 and 600 mg/kg PCPA groups was determined. The mean number of pixels (representing 5-HT staining) was determined in 6 areas in the brainstem containing 5-HT cell bodies (nuclei raphe pallidus, raphe obscurus, rostral and caudal raphe magnus, raphe dorsalis and paragigantocellularis lateralis) and in the dorsal and ventral spinal cord. The resultssuggest a differential depletion of 5-HT within brainstem nuclei following PCPA treatment in that the most marked dose-related reductions were observed in nucleus raphe obscurus and caudal magnus. Furthermore, a computer program designed to isolate terminal structures in the spinal cord identified a differential depletion of 5-HT terminals in the dorsal horn versus the ventral horn. The present study describes 3 analytical approaches combining immunohistochemistry with the computer-assisted image analysis technique and allows comparison between groups of animals which received the same or different drug treatments.