Can visual analogue scale be used in radiologic subjective image quality assessment?

Combining variational mode decomposition with regularisation techniques to denoise MRI data

In this paper, we propose a novel method for removing noise from MRI data by exploiting regularisation techniques combined with variational mode decomposition. Variational mode decomposition is a new decomposition technique for sparse decomposition of a 1D or 2D signal into a set of modes. In turn, regularisation is a method that can translate the ill-posed problem (e.g., image denoising) into a well-posed problem. The proposed method aims to remove the noise from the image in two steps. In the first step, the MR imaging data are decomposed by the 2D variational mode decomposition algorithm. In the second step, for effective suppression of Rician noise from MRI data, we used the fused lasso signal approximator with all modes acquired from the medical scan. The performance of the proposed approach was compared with state-of-the-art reference methods based on different metrics, that is, the peak signal-to-noise ratio, the structural similarity index metrics, the high-frequency error norm, the quality index based on local variance, and the sharpness index. The experiments were performed on the basis of both simulated and real images. The presented results prove the high denoising performance of the proposed algorithm; particularly under heavy noise conditions.

Performance of handheld ultrasound devices in diagnosis of pulmonary hypertension and right heart dysfunction in ICU patients

AIM

The use of handheld ultrasonography devices (HHUD) has increased recently but there are limited data about their performance in the evaluation of right heart dysfunction (RHD) and pulmonary hypertension (PHT). The aim of the study is to compare the performance of a HHUD with a conventional ultrasound device (CUD) in assessing PHT and RHD.

METHODS

This single-center prospective study was performed in a seven-bed teaching hospital intensive care unit (ICU). PHT and RHD criteria were compared by HHUD and CUD. Additional PHT criteria and right ventricle (RV) systolic and diastolic dysfunction criteria were also measured.

RESULTS

Forty-six patients were included in the study. There was no significant difference between the imaging rates and mean values of the parameters measured by both devices. When the positivity rates for additional PHT parameters and RHD criteria were compared, there were no significant differences between the devices. In Bland-Altman's analysis, there was good agreement and there was no bias between the measurements of the two devices but left ventricular end-systolic eccentricity index (LVSEI), right atrium area (RAA), and pulmonary artery diameter (PAD). Ninety percent of the patients had PHT probability, of whom 43% had a low, 37% had intermediate and 10% had a high probability of PHT. Ninety-two percent of the patients had RHD and there was no significant difference between the devices in the diagnosis of RHD (p = .212). When RV systolic and diastolic dysfunction evaluations of the devices were compared according to the British Society of Echocardiography (BSE) criteria there was no significant difference between the devices' measurements in the evaluation of systolic and diastolic function.

CONCLUSION

The imaging and measurement capabilities of the HHUDs for PHT and RHD parameters were similar to CUDs, and considering the inconsistent parameters, the HHUD can be useful in diagnosing these problems.

Electroacupuncture combined with extracorporeal shock wave therapy improves pain symptoms and inflammatory factor levels in knee osteoarthritis patients

Objective

To compare the clinical efficacy and safety of electroacupuncture combined with extracorporeal shock wave therapy (EESWT) and extracorporeal shock wave therapy (ESWT) in the treatment of knee osteoarthritis (KOA).

Methods

A total of 135 KOA patients who received EESWT treatment were selected as the EESWT group, and 135 KOA patients who received extracorporeal shock wave therapy (ESWT) were selected as the ESWT group. The clinical efficacy, inflammatory factors in joint synovial fluid and adverse events during treatment were compared before and after treatment.

Results

The clinical effective rate of patients in the EESWT group (89.63 %) after treatment was significantly higher than that of the ESWT group (74.81 %) (p < 0.01). The lysholm kness (LKSS) score and range of motion (ROM) of the patients in the EESWT group after treatment were higher than those of the ESWT group, while Lequesne index score, visual analogue scale (VAS) score and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were lower than those of the ESWT group (p < 0.01). Compared with ESWT group, the changes in the expression levels of nitric oxide (NO), superoxide dismutase (SOD), interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), matrix metalloproteinase-3 (MMP-3), and transforming growth factor β1 (TGF-β1) in the synovial fluid of the EESWT group after treatment were significantly greater than those of the ESWT group (p < 0.01). No significant difference in the incidence of adverse events between the EESWT group and the ESWT group (p > 0.05).

Conclusion

EESWT significantly improves pain symptoms and inflammatory factor levels in KOA patients and is an optional KOA treatment option worthy of clinical attention.

Effect of acoustic noise reduction technology on image quality: a multivendor study

The purpose of this study was to clarify the appropriate use of a combination of pulse sequences and acoustic noise reduction technology in general-purpose brain magnetic resonance imaging. Five pulse sequences commonly used in brain magnetic resonance imaging examinations-turbo spin-echo T2-weighted imaging, T1-weighted fluid-attenuated inversion recovery, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted imaging, and magnetic resonance angiography-were performed on healthy participants at three vendors where acoustic noise reduction technology was available. The results showed that acoustic noise reduction technology reduced sound pressure levels and altered image quality in all pulse sequences across all vendors' magnetic resonance imaging scanners. Although T2-weighted imaging and T1-weighted fluid-attenuated inversion recovery resulted in little image quality degradation, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted imaging, and magnetic resonance angiography had significant image degradation. Therefore, acoustic noise reduction technology should be used with caution.

Double inversion recovery MRI versus contrast-enhanced MRI for evaluation of knee synovitis in juvenile idiopathic arthritis

BACKGROUND

Double inversion recovery (DIR) MRI has the potential to accentuate the synovium without using contrast agents, as it allows simultaneous signal suppression of fluid and fat. The purpose of this study was (1) to compare DIR MRI to conventional contrast-enhanced (CE) MRI for delineation of the synovium in the knee in children with juvenile idiopathic arthritis (JIA) and (2) to assess the agreement between DIR MRI and CE-MRI regarding maximal synovial thickness measurements.

RESULTS

In this prospective study, 26 children with JIA who consecutively underwent 3.0-T knee MRI between January 2018 and January 2021 were included (presence of knee arthritis: 13 [50%]; median age: 14 years [interquartile range [IQR]: 11-17]; 14 girls). Median confidence to depict the synovium (0-100 mm visual analogue scale; scored by 2 readers [consensus based]) was 88 (IQR: 79-97) for DIR MRI versus 100 (IQR: 100-100) for CE-MRI (p value = < .001). Maximal synovial thickness per child (millimeters; scored by 4 individual readers) on DIR MRI was greater (p value = < .001) in the children with knee arthritis (2.4 mm [IQR: 2.1-3.1]) than in those without knee arthritis (1.4 mm [IQR: 1.0-1.6]). Good inter-technique agreement for maximal synovial thickness per child was observed (r_s = 0.93 [p value = < .001]; inter-reader reliability: ICC DIR MRI = 0.87 [p value = < .001], ICC CE-MRI = 0.90 [p value = < .001]).

CONCLUSION

DIR MRI adequately delineated the synovium in the knee of children with JIA and enabled synovial thickness measurement similar to that of CE-MRI. Our results demonstrate that DIR MRI should be considered as a child-friendly alternative to CE-MRI for evaluation of synovitis in children with (suspected) JIA.

Tarsier Anterior Chamber Cell Grading: Improving the SUN Grading Scheme with a Visual Analog Scale

PURPOSE

To compare an analog visual scale in grading anterior chamber cells (ACC) to a modified Standardization of Uveitis Nomenclature (SUN) ACC scale.

METHOD

A graphical representation of anterior chamber cells as a reference and a test set was created and shown to two groups of experienced uveitis experts. Group 1 was given the analog scale in written format, while group two was given the reference images for comparison. Each test subject was asked to provide the best approximation for each grade.

RESULTS

Eleven graders participated in phase 1. Correct grading occurred in 87.4% of cases. Discrepancies were seen at all grades. Only 3 of 11 graders were able to achieve a perfect score. Seven graders participated in phase 2. Agreement was 95.2% with 4/7 graders achieving a perfect score. Discrepancies were seen at higher grades only.

CONCLUSIONS

ACC grading is improved by a visual grading scale, and interobserver variability is reduced.

Clinical efficacy and learning curve of posterior percutaneous endoscopic cervical laminoforaminotomy for patients with cervical spondylotic radiculopathy

In this study, we aimed to investigate the clinical efficacy and learning curve of posterior percutaneous endoscopic cervical laminoforaminotomy (PPECLF) in patients with cervical spondylotic radiculopathy (CSR). A total of 64 patients with CSR received PPECLF. Clinical outcome scores included the visual analog scale, Japanese Orthopedic Association score, neck disability index, and modified Macnab criteria. Radiological outcomes included the disc height, C2 to C7 Cobb angle, and range of motion. The learning curve was evaluated using cumulative sum analysis. Patients were divided into accumulation phase and mastery phase groups (A and B), and general data and surgical efficacy were compared between the 2 groups. Follow-up ranged from 12 to 24 months. Clinical outcome scores improved significantly at the final follow-up, and there were no differences in radiological outcomes. Surgical efficacy was excellent and good in 82.8% of patients. The operative time showed a decreasing trend with the accumulation of cases. Patients were divided and the 26th case was the cutoff point according to the learning curve. No significant differences were found in the clinical outcomes between the 2 groups. Decompression with PPECLF was safe and effective in the treatment of CSR. With the accumulation of cases, the operative time was gradually shortened, and the clinical efficacy was significant. The PPECLF procedure can be performed efficiently and safely to treat CSR.

Quantitative Analysis for the Delineation of the Subthalamic Nuclei on Three-Dimensional Stereotactic MRI Before Deep Brain Stimulation Surgery for Medication-Refractory Parkinson’s Disease

Delineation of the subthalamic nuclei (STN) on MRI is critical for deep brain stimulation (DBS) surgery in patients with Parkinson’s disease (PD). We propose this retrospective cohort study for quantitative analysis of MR signal-to-noise ratio (SNR), contrast, and signal difference-to-noise ratio (SDNR) of the STN on pre-operative three-dimensional (3D) stereotactic MRI in patients with medication-refractory PD. Forty-five consecutive patients with medication-refractory PD who underwent STN-DBS surgery in our hospital from January 2018 to June 2021 were included in this study. All patients had whole-brain 3D MRI, including T2-weighted imaging (T2WI), T2-weighted fluid-attenuated inversion recovery (FLAIR), and susceptibility-weighted imaging (SWI), at 3.0 T scanner for stereotactic navigation. The signal intensities of the STN, corona radiata, and background noise were obtained after placing regions of interest (ROIs) on corresponding structures. Quantitative comparisons of SNR, contrast, and SDNR of the STN between MR pulse sequences, including the T2WI, FLAIR, and SWI. Subgroup analysis regarding patients’ sex, age, and duration of treatment. We used one-way repeated measures analysis of variance for quantitative comparisons of SNR, contrast, and SDNR of the STN between different MR pulse sequences, and we also used the dependent t-test for the post hoc tests. In addition, we used Mann–Whitney U test for subgroup analyses. Both the contrast (0.33 ± 0.07) and SDNR (98.65 ± 51.37) were highest on FLAIR (all p < 0.001). The SNR was highest on SWI (276.16 ± 115.5), and both the SNR (94.23 ± 31.63) and SDNR (32.14 ± 17.23) were lowest on T2WI. Subgroup analyses demonstrated significantly lower SDNR on SWI for patients receiving medication treatment for ≥13 years (p = 0.003). In conclusion, on 3D stereotactic MRI of medication-refractory PD patients, the contrast and SDNR for the STN are highest on FLAIR, suggesting the optimal delineation of STN on FLAIR.

Automated segmentation of magnetic resonance bone marrow signal: a feasibility study

BACKGROUND

Manual assessment of bone marrow signal is time-consuming and requires meticulous standardisation to secure adequate precision of findings.

OBJECTIVE

We examined the feasibility of using deep learning for automated segmentation of bone marrow signal in children and adolescents.

MATERIALS AND METHODS

We selected knee images from 95 whole-body MRI examinations of healthy individuals and of children with chronic non-bacterial osteomyelitis, ages 6-18 years, in a longitudinal prospective multi-centre study cohort. Bone marrow signal on T2-weighted Dixon water-only images was divided into three color-coded intensity-levels: 1 = slightly increased; 2 = mildly increased; 3 = moderately to highly increased, up to fluid-like signal. We trained a convolutional neural network on 85 examinations to perform bone marrow segmentation. Four readers manually segmented a test set of 10 examinations and calculated ground truth using simultaneous truth and performance level estimation (STAPLE). We evaluated model and rater performance through Dice similarity coefficient and in consensus.

RESULTS

Consensus score of model performance showed acceptable results for all but one examination. Model performance and reader agreement had highest scores for level-1 signal (median Dice 0.68) and lowest scores for level-3 signal (median Dice 0.40), particularly in examinations where this signal was sparse.

CONCLUSION

It is feasible to develop a deep-learning-based model for automated segmentation of bone marrow signal in children and adolescents. Our model performed poorest for the highest signal intensity in examinations where this signal was sparse. Further improvement requires training on larger and more balanced datasets and validation against ground truth, which should be established by radiologists from several institutions in consensus.

Respiratory Motion-Registered Isotropic Whole-Heart T2 Mapping in Patients With Acute Non-ischemic Myocardial Injury

Background: T₂ mapping is a magnetic resonance imaging technique that can be used to detect myocardial edema and inflammation. However, the focal nature of myocardial inflammation may render conventional 2D approaches suboptimal and make whole-heart isotropic 3D mapping desirable. While self-navigated 3D radial T₂ mapping has been demonstrated to work well at a magnetic field strength of 3T, it results in too noisy maps at 1.5T. We therefore implemented a novel respiratory motion-resolved compressed-sensing reconstruction in order to improve the 3D T₂ mapping precision and accuracy at 1.5T, and tested this in a heterogeneous patient cohort. Materials and Methods: Nine healthy volunteers and 25 consecutive patients with suspected acute non-ischemic myocardial injury (sarcoidosis, n = 19; systemic sclerosis, n = 2; acute graft rejection, n = 2, and myocarditis, n = 2) were included. The free-breathing T₂ maps were acquired as three ECG-triggered T₂-prepared 3D radial volumes. A respiratory motion-resolved reconstruction was followed by image registration of the respiratory states and pixel-wise T₂ mapping. The resulting 3D maps were compared to routine 2D T₂ maps. The T₂ values of segments with and without late gadolinium enhancement (LGE) were compared in patients. Results: In the healthy volunteers, the myocardial T₂ values obtained with the 2D and 3D techniques were similar (45.8 ± 1.8 vs. 46.8 ± 2.9 ms, respectively; P = 0.33). Conversely, in patients, T₂ values did differ between 2D (46.7 ± 3.6 ms) and 3D techniques (50.1 ± 4.2 ms, P = 0.004). Moreover, with the 2D technique, T₂ values of the LGE-positive segments were similar to those of the LGE-negative segments (T_2LGE-= 46.2 ± 3.7 vs. T_2LGE+ = 47.6 ± 4.1 ms; P = 0.49), whereas the 3D technique did show a significant difference (T_2LGE- = 49.3 ± 6.7 vs. T_2LGE+ = 52.6 ± 8.7 ms, P = 0.006). Conclusion: Respiratory motion-registered 3D radial imaging at 1.5T led to accurate isotropic 3D whole-heart T₂ maps, both in the healthy volunteers and in a small patient cohort with suspected non-ischemic myocardial injury. Significantly higher T₂ values were found in patients as compared to controls in 3D but not in 2D, suggestive of the technique's potential to increase the sensitivity of CMR at earlier stages of disease. Further study will be needed to demonstrate its accuracy.

Three-dimensional gait quantitative analysis in postoperative rehabilitation of lumbar degenerative diseases: a self-controlled before-after study

OBJECTIVE

To evaluate the efficacy of three-dimensional (3-D) gait quantitative analysis in the surgical treatment and postoperative rehabilitation in patients with lumbar degenerative diseases.

METHODS

This is a prospective study with self-controll before -after. A total of 48 patients with lumbar degenerative diseases and treated in our hospital were enrolled in the observation group, 40 healthy individuals were included in the control group. Gait analysis was carried out with 3-D motion acquisition and analysis system. The 3-D gait quantitative parameters of the two groups were compared preoperatively. These include time-distance parameters (gait speed, stride frequency, stride length, support phase), hip joint flexion angle and gait deviation index (GDI). The 3-D gait quantitative parameters in the observation group were analyzed post operation and during rehabilitation. Pearson correlation coefficient was used to evaluate the correlation between 3-D gait quantitative parameters and the patient's visual analog score (VAS), Japanese Orthopedic Association (JOA) score and Oswestry Disability Index (ODI).

RESULTS

Compared with the healthy group, the time-distance parameters and the kinematics parameters of lower extremity joints in the observation group were significantly decreased (both P<0.001). The gait index indicated that there were significant gait abnormalities in the observation group (P<0.001). Two weeks after operation, the patient's VAS score, JOA score and ODI were significantly improved compared to the results preoperatively, as well as the 3-D gait quantitative parameters (all P<0.05). Further improvement was then observed after 12 weeks of rehabilitation training (all P<0.05), and the patient's gait was close to normal. Pearson correlation analysis showed that the improvement of the 3-D gait quantitative parameters positively correlated with VAS score, JOA score and ODI (all P<0.001).

CONCLUSION

The 3-D gait quantitative analysis can effectively evaluate the effect of operation and rehabilitation training.