High Signal Intensity Research Articles

Analysis of the results of optical coherence tomography to assess the effectiveness and safety of implantable bioresorbable stenting frames in the long term

Objective: to evaluate the effectiveness and safety of implantation of everolimus-coated bioabsorbable vascular scaffolds (BSCs) based on the results of optical coherence tomography (OCT) in patients with coronary artery disease who have previously undergone percutaneous coronary intervention (PCI). Materials and methods: OCT data from 23 patients with coronary artery disease (CAD) were studied 10 years or more after intervention with BVS implantation. Standard criteria based on OCT analysis were used to evaluate the efficacy of BVS. The stented segment, proximal zone before the stent, and distal zone after the stent were the areas of interest. Results: in the long-term period, the structure of the artery in the area of the installed biodegradable scaffolds is a combination of fragments of an atherosclerotic plaque, a resorbed scaffold, and neointima. When visualized using coherence tomography, this structure appears as a monolayer with high signal intensity. In 42.3% of patients, structures similar to fragments of the stenting frame were visualized, but smaller in size, with a disconnected structure, without clear contours and the absence of a typical shape. In 15.4% of cases, pronounced positive remodeling of the coronary artery in the area of the installation of the bioresorbable frame was noted. Conclusions: analysis of coherence tomography data showed that the use of biodegradable frames is effective and safe, the process of degradation of the frames occurs with an increase in diameter in the stented zone and the formation of a protective monolayer, while maintaining the patency of all side branches in the implantation zone.

A case of chronic contained rupture of abdominal aortic aneurysm mimicking a retroperitoneal tumor.

Chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) is a rare subtype of abdominal aortic rupturethat can mimic other retroperitoneal lesions. We report a case of CCR-AAA in a man in his sixties who presented witha 10-month history of right low back pain and weight loss. Contrast-enhanced computed tomography (CT) revealed alobulated retroperitoneal mass around the abdominal aorta, initially misdiagnosed as a possible hemorrhagicretroperitoneal tumor. Despite multiple imaging studies including CT, magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucosepositron emission tomography (FDG-PET)/CT, as well as a CT-guided biopsy, the correct diagnosisremained elusive for 34 months. Key findings included subtle aortic wall irregularity on CT, high signal intensity onT1-weighted MRI suggesting hematoma, peripheral FDG uptake on PET/CT, and histological findings of biopsy tissueconsistent with organizing hematoma. Surgery confirmed the diagnosis, revealing an organized hematoma with adefect in the right wall of the abdominal aortic aneurysm. This case demonstrates that CCR-AAA can present withatypical radiological features, potentially leading to misdiagnosis. When encountering a para-aortic mass with ahemorrhagic component, careful observation of the AAA morphology and aortic wall contour is crucial for anaccurate diagnosis of CCR-AAA.

An unusual cause of liver neoplasm in an older female.

We presented a 66-year-old woman with T2DM who had a liver mass discovered incidentally during hospitalization. She was asymptomatic with a right upper abdominal mass that was smooth, mobile, and non-tender. Hepatitis virus markers and tumor markers were normal. The computed tomography (CT) images showed a 4.7×4.0 cm lesion in the left liver lobe with indistinct borders. Further magnetic resonance imaging (MRI) revealed low T1 and high T2 signal intensity with ring-shaped enhancement following contrast administration. Surgical resection was performed, and histology confirmed hepatic angioleiomyoma with thick-walled vessels and spindle cell proliferation. Immunohistochemistry was positive for SMA, desmin, caldesmon, CD31, and CD34. The patient had no recurrence during 5 years follow-up.

Incidence of Tethered Cord Syndrome in Pediatric Patients With Neurofibromatosis Type 1

ObjectiveThe link between Tethered Cord Syndrome (TCS) and Neurofibromatosis Type 1 (NF1) remains unclear. To date, only two studies have indicated a high occurrence of TCS in the pediatric NF1 patient population. Our study aims to ascertain the incidence of TCS among Chinese pediatric patients with NF1. MethodsA single-institution, 8-year retrospective analysis at a tertiary-level children's hospital was conducted for patients with NF1 who underwent surgery for TCS. The clinical features, imaging characteristics, genetic testing outcomes, and histopathological findings of pediatric NF1 patients with TCS were analyzed. ResultsDuring the study period, a total of 115 pediatric patients were diagnosed with NF1. Among these 115 NF1 patients, 11 individuals, accounting for 9.6% of the sample, were confirmed to have TCS. This rate of occurrence is significantly higher than the incidence rate of TCS in the general population, which stands at 0.17%. All 11 of the pediatric NF1 patients underwent surgery for TCS. Out of the 11 patients who were advised to have tethered cord release surgery, 4 (which is 36.4%) were girls, and the average age of these 11 patients was 8.6 years old, with ages ranging from 2 to 17 years old. The conus medullaris position of the 11 pediatric NF1 patients ranged from L1 to L2, and 10 of them (91%) had a filum terminale lipoma, characterized by high signal intensity on T1-weighted magnetic resonance (MR) images. Another patient was diagnosed with Occult Tethered Cord Syndrome (OTCS). All 11 pediatric NF1 patients exhibited symptoms associated with TCS, such as neuromotor dysfunction, abnormalities in urination, defecation, skeletal system abnormalities, or pain. Eight of the 11 pediatric NF1 patients had undergone genetic testing, which is a crucial part of the diagnostic process for NF1. The histopathological examination of the 11 pediatric NF1 patients who underwent surgery revealed that 10 patients had fatty infiltration of the filum terminale (FT), while the remaining patient exhibited fibrosis of the filum terminale (FT). ConclusionsIn the group of pediatric patients with NF1, the incidence of TCS, presenting to the pediatric neurosurgery clinic for any reason, is significantly higher than that of the general population. However, the pathophysiological relationship between NF1 and TCS is still not clear. It is essential to provide counseling to NF1 patients and their families about the symptoms of TCS to make sure they are aware and can seek the necessary care when needed. This underscores the importance of not only diagnosing NF1 but also staying alert for related conditions like TCS, which may have a higher occurrence in this demographic.

Clinical analysis of 21 cases of children with ectopic bronchogenic cyst

Objective: To analyze the clinical characteristics, treatment, and prognosis of ectopic bronchogenic cysts in children. Methods: A retrospective analysis was conducted on the data including the clinical characteristics, auxiliary examination and treatment of 21 children with ectopic bronchogenic cysts diagnosed pathologically at Children's Hospital Affiliated to Zhengzhou University from July 2015 to December 2023. There were 16 males and 5 females, with a male-female ratio of 3.2∶1, and the age ranged from 4 days to 8 years old (median age 2 years and 8 months). Results: Among the 21 cases of ectopic bronchogenic cysts, 11 cases were found in the pharynx, with symptoms including dyspnea (4 cases), snoring during sleep (3 cases), and choking on milk(4 cases).Ten cases were found in the head, neck or anterior chest, 5 of these cases had infection history, and 5 showed progressive mass growth.Imaging and endoscopy showed 9 patients underwent preoperative color ultrasonography revealed cystic masses with well-defined boundaries. CT examination was performed on 13 patients, which showed round or nearly round masses with homogeneous density, smooth margins, and regular cyst walls. CT attenuation values ranged from 2 to 52 Hounsfield Units (HU). Four cystic lesions were assessed via MRI, 3 cases demonstrated long T1 and long T2 signals, while 1 case had a slight short T1 and long T2 signal, with high signal intensity on fat-suppressed images. Eleven cases of pharyngopharyngeal cysts were examined by electronic nasopharyngoscopy. The cysts appeared as spherical or ovoid masses with smooth surfaces, close to or slightly light in color with the surrounding tissue, with one cyst presenting with a bluish blue in the oropharynx. All 11 pharyngeal cysts were excised using low-temperature plasma under general anesthesia and intubation assisted by a nasal endoscope. The cysts were pulled and excised as completely as possible.Ten cases of neck and anterior chest cysts were completely excised. Postoperative histopathology confirmed bronchogenic cyst. Twenty-one children were followed up postoperatively for 4 months to 7 years without recurrence, except for 1 patient who was lost to follow-up. Conclusions: Ectopic bronchogenic cysts are uncommon and lack of typical imaging and clinical features.Combination of ultrasonography, CT and MRI is recommended for cases occuered in neck and anterior chest, while electronic nasopharyngoscopy complements pharyngeal evaluations. Surgical intervention is the preferred treatment choice for this disease.

Case Report: - Sudden sensorineural hearing loss and vertigo due to inner ear hemorrhage

Sudden deafness is a common cause of emergency consultation in otology. Usually, despite investigations, no etiology is known. Intracochlear hemorrhage is a rare cause of sudden sensorineural hearing loss (SSNHL) and may be associated with various labyrinthine disorders. In such cases, magnetic resonance imaging (MRI) is the clef of the diagnosis. We report the case of a 70-year-old patient who was referred to our department for sudden hearing loss, tinnitus, and vertigo. Otoscopic and neurological examinations were normal, and pure-tone audiometry revealed left profound sensorineural hearing loss. Videonystagmography (VNG) revealed left vestibular deficit. MRI demonstrated a high signal intensity inside the cochlea on unenhanced T1-weighted images, and no other abnormalities were found; in particular, no enhancement after intravenous administration of gadolinium. No etiology was identified. Vertigo disappeared rapidly with corticosteroid treatment and hyperbaric oxygen therapy, but hearing did not improve. Intra-labyrinthine hemorrhage causing SSNHL is rare, and the hearing prognosis is poor.

The Lateral Corticospinal Tract Sign: An MRI Marker for Amyotrophic Lateral Sclerosis.

Background Radially sampled averaged magnetization inversion-recovery acquisition (rAMIRA) imaging shows hyperintensity in the lateral corticospinal tract (CST) in patients with motor neuron diseases. Purpose To systematically determine the accuracy of the lateral corticospinal tract sign for detecting patients with amyotrophic lateral sclerosis (ALS) at rAMIRA MRI. Materials and Methods This study included prospectively acquired data from participants in ALS and other motor neuron disease imaging studies at the University Hospital Basel, Switzerland. All participants underwent 3-T axial two-dimensional rAMIRA imaging at four cervical intervertebral disk levels. The lateral CST sign was defined as spinal cord white matter hyperintensity dorsolateral to the anterior horns, with higher signal intensity than in the dorsal columns on axial rAMIRA images. Marker accuracy was assessed in a study data set and in an independent validation data set. Postmortem rAMIRA imaging and histopathologic analysis were performed in one participant who died during the study. Results Participants with ALS (study data set: 38 participants [mean age, 61 years; IQR, 15 years], 22 male participants; validation data set: 10 participants [mean age, 61 years; IQR, 21 years], seven male participants), post-polio syndrome (study data set: 25 participants [mean age, 68 years; IQR, 8 years], 12 male participants), spinal muscular atrophy (study data set: 10 participants [mean age, 43 years; IQR, 14 years], eight male participants; validation data set: five participants [mean age, 38 years; IQR, 19 years], two male participants), and healthy control participants (study data set: 60 participants [mean age, 57 years; IQR, 20 years], 36 male participants; validation data set: 10 participants [mean age, 44 years; IQR, 17 years], seven male participants) were included. The sensitivity and specificity of rAMIRA for ALS were 60% (23 of 38) and 97% (91 of 94) in the study data set and 100% (10 of 10) and 93% (14 of 15) in the validation data set, respectively. Histopathologic analysis showed distinct loss of myelinated axons in the localization of the hyperintensities observed at rAMIRA imaging performed in situ and after organ extraction. Conclusion The recently defined marker at rAMIRA MRI may be a promising tool for assessing upper motor neuron degeneration in the lateral CST in patients with ALS. Clinical trials registration no. NCT03561623, NCT05764434, NCT06137612 © RSNA, 2024 Supplemental material is available for this article.

High-risks drug adverse events associated with Cetirizine and Loratadine for the treatment of allergic diseases: A retrospective pharmacovigilance study based on the FDA adverse event reporting system database.

Cetirizine and Loratadine are the two best-selling second-generation antihistamines for allergic diseases. This study aims to provide a comparative analysis of the differences in adverse drug events (ADEs) between these two medications, which can assist clinicians in making appropriate treatment decisions. ADE reports related to Cetirizine and Loratadine obtained from the FDA adverse event reporting system (FAERS) database were analyzed using disproportionality analysis and Bayesian analysis to evaluate and compare the ADE signals of both drugs. A total of 28,051 and 28,073 ADE reports were retrieved from the FAERS database related to Cetirizine and Loratadine, respectively, with both drugs showing a predominance of middle-aged females. Specifically, Loratadine was associated with respiratory symptoms, mainly nasal symptoms such as rhinorrhea (n=326, ROR 6.75), sneezing (n=251, ROR 15.24), and nasal congestion (n=185, ROR 4.25), while Cetirizine did not show this association. Notably, both drugs exhibited strong signals for somnolence in the nervous and psychiatric systems, especially Cetirizine (Cetirizine, n=2556, ROR 10.52 vs. Loratadine, n=1200, ROR 7.76). Additionally, Cetirizine itself showed strong signals for attention disturbance (n=233, ROR 3.3), while Loratadine was associated with nervousness (n=145, ROR 3.3). Further exploration revealed more severe adverse reactions closely associated with Cetirizine, including hallucinations, aggression, and abnormal behavior. Importantly, Cetirizine was significantly associated with the occurrence of pericarditis (n=138, ROR 8.13), potentially leading to serious adverse consequences. Compared to Loratadine, Cetirizine poses a greater potential risk in the nervous and psychiatric systems. Additionally, this study reveals previously underestimated potential cardiac toxicity of Cetirizine; albeit at a relatively low incidence rate, the high signal intensity warrants further attention and exploration. These findings highlight the need for enhanced patient monitoring and therapy optimization when prescribing these medications, ensuring better management of allergic diseases while minimizing risks.

Relationship between MRI findings and renal histopathology in IgG4-related tubulointerstitial nephritis.

MRI is expected to be a valuable tool for evaluating disease activity in immunoglobulin G4 (IgG4)-related tubulointerstitial nephritis (IgG4-TIN). However, the correlation between MRI findings and renal histopathological findings remains to be elucidated. This study aimed to clarify the correlation between MRI findings and renal histopathological findings in IgG4-TIN. This retrospective cross-sectional study investigated 26 patients with biopsy-proven IgG4-TIN who underwent simultaneous percutaneous kidney biopsies and abdominal MRI examinations at Toranomon Hospital or Toranomon Hospital Kajigaya between December 2007 and November 2022. We reviewed kidney biopsy specimens and scored the degree of inflammatory cell infiltration and interstitial fibrosis. We assessed abdominal MRI, specifically examining T1WI, T2WI, and DWI, for the presence of abnormal signals in the inferior pole of the kidney on the side where the kidney biopsy was performed. Spearman's correlation coefficient test was conducted to examine the relationship between the images and histological findings. For T1WI, eight cases showed a positive low-intensity signal, and 18 cases were negative. For T2WI, 19 cases were positive for a low-intensity signal, and seven cases were negative. In DWI, 23 cases were positive for a high-intensity signal, and one was negative. T1WI low-intensity signal and T2WI low-intensity signal were significantly correlated with interstitial fibrosis score (correlation coefficient 0.52 and 0.64). DWI revealed IgG4-TIN detected IgG4-TIN lesions with the highest sensitivity; however, the correlation with inflammatory cell infiltration score was not significant. Low-intensity signal on T2WI is useful for predicting the degree of fibrosis in IgG4-TIN.

The signal quality improvement of laser-induced breakdown spectroscopy due to the microwave plasma torch modulation

BackgroundLaser-induced breakdown spectroscopy (LIBS) is a versatile analytical technique for element determination in solids, liquids, and gases. However, LIBS suffers from low detection sensitivity and high relative standard deviation (RSD), restricting its large-scale applications. the process of a physical sampling can, in some cases, compromise the mechanical strength of the component under examination. It should be considered that too large laser energy is bound to cause damage to samples which cannot be tolerated in the process of safe production in the nuclear industry. It is necessary to find a method to obtain high elemental signal intensity in low energy laser. ResultsHere, we present a novel approach by integrating microwave plasma torch (MPT) with LIBS, referred to as MPT-LIBS, which effectively addresses the limitations associated with traditional LIBS. The MPT-LIBS technique is evaluated using Cu samples with a low laser pulse energy of 0.55 mJ. A remarkable enhancement factor of over 70 for Cu I 521.82 nm line is demonstrated, while that of Cu I 324.75 nm and 327.40 nm lines exceeding two orders of magnitude. Furthermore, the RSDs of all Cu spectral lines are reduced, especially for Cu I 521.82 nm, which is decreased from 11.48 % to 1.36 %. This indicates a significant improvement in signal stability. Characterization of the tested samples using con-focal microscopy reveals that the ablation area of MPT-LIBS is only 1.36 times of that of LIBS. The limit of detection of Cu I 324.75 nm line is reduced from 52.8 ppk to 319 ppm. Significance and noveltyThis study not only offers valuable guidance for improving signal stability and the limit of detection in LIBS, but also demonstrates minimal sample damage due to its low ablation amount. Consequently, the proposed methodology has the potential to significantly advance LIBS technology, expanding its applicability in industrial applications.

A Unique Time-Reversal Algorithm-Enabled Flexible Ultrasound Transducer with a Controllable Acoustic Field.

Flexible ultrasonic devices represent a feasible technology for providing timely signal detection and even a non-invasive disease treatment for the human brain. However, the deformation of the devices is always accompanied by a change in the acoustic field, making it hard for accurate focusing. Herein, we report a stable and flexible transducer. This device can generate a high-intensity acoustic signal with a controllable acoustic field even when the device is bent. The key is to use a low-impedance piezoelectric material and an island-bridge device structure, as well as to design a unique time-reversal algorithm to correct the deviation of signals after transcranial propagation. To provide an in-depth study of the acoustic field of flexible devices, we also analyze the effects of mechanical deformation and structural parameters on the corresponding acoustic response.

Contrast of muscle magnetic resonance imaging and pathological findings of muscle tissue in patients with anti-aminoacyl transfer RNA synthetase antibodies.

Methods: Patients with idiopathic inflammatory myopathies (IIMs) diagnosed using the 2017 EULAR/ACR classification criteria in our university between 2005 and 2020 were retrospectively reviewed. IIMs were subclassified into the anti-ARS syndrome (ASSD), immune-mediated necrotizing myositis (IMNM), Dermatomyositis DM and others. Fat-suppressed T2-weighted MRI and muscle biopsy specimens were assessed in IIMs followed by the comparison among the four subgroups. MRI findings were available for 62 patients and histopathological findings were available for 27 patients. Perifascicular atrophy or necrosis in the muscle tissues from the patients with IIM was more frequently observed in patients with subcutaneous and fascial high signal intensity (HSI) on MRI than those without. Four-group comparison among ASSD, IMNM, DM and others revealed HSI in fasciae on MRI was more frequently observed in patients with ASSD and DM than others. Perifascicular atrophy or necrosis in muscle tissues was more frequently observed in patients with ASSD than in others. Patients with ASSD had distinct MRI features compared with anti-ARS negative patients. The fascial high signal intensity on MRI may reflect distinctive pathological features of muscles.

MRI Evaluation and Characterization of Ovarian Lesions Based on Ovarian-Adnexal Reporting and Data System MRI.

Background Managing ovarian lesions requires differentiating between benign and malignant cases. The development of a multiparametric MRI approach combining anatomical and functional criteria has led to the creation of the Ovarian-Adnexal Reporting and Data System (O-RADS) MRI scoring system, which enhances diagnostic accuracy. Objectives To study ovarian lesions and their characteristics, along with their risk stratification based on MRI O-RADS. Methods A prospective study used the O-RADS MRI criteria to categorize ovarian lesions. Clinical findings and MRI results were compared with histopathological outcomes to assess diagnostic accuracy. Results We identifiedabdominal pain as the most prevalent clinical finding among our cases (64, 91.43%), followed by a lump in the abdomen (33, 47.5%), dysmenorrhea (33, 47.5%), bleeding per vaginal (15, 21.43%), and weight loss (11, 15.71%). A total of 80 ovarian lesions were examined and characterized on the basis of the O-RADSMRI risk stratification system.Among the 80 ovarian lesions, 54 were histopathologically confirmed ovarian lesions (39 (72.22%) were benign, and 15 (27.77%) were malignant). The most common benign lesions were ovarian serous cystadenoma (28.20%) and ovarian mucinous cystadenoma (20.51%), while the most common malignant lesions were serous carcinoma (33.33%) and mucinous carcinoma (20%). Using the O-RADS MRI scoring system, we categorized six lesions (7.5%) as O-RADS 1 (all benign), 34 lesions (42.50%) as O-RADS 2 (32 benign and 2 malignant), 24 lesions (30%) as O-RADS 3 (23 benign and 1 malignant), seven lesions (8.75%) as O-RADS 4 (four benign and three malignant), and nine lesions (11.25%) as O-RADS 5 (all malignant). Our findings revealed significant differences in the size of lesions, the presence of thick septa, high T2-weighted signal intensity within solid tissue, and patterns of solid component enhancement and wall irregularity between malignant and benign lesions. The MRI cut-off score of ≥4 for malignancy demonstrated a sensitivity of 94.59%, a specificity of 97.5%, an accuracy of 97.62%, a positive predictive value of 94.5%, and a negative predictive value of 97.5%. The positive likelihood ratio was 32.7, while the negative likelihood ratio was 0.025. These results affirm the high diagnostic accuracy of the O-RADS MRI scoring system in distinguishing benign from malignant ovarian lesions. Conclusion The O-RADS MRI score is a highly accurate tool for differentiating between benign and malignant ovarian lesions. Its application can significantly enhance the management and treatment outcomes for patients with adnexal masses. The study confirms the scoring system's high sensitivity, specificity, and overall diagnostic accuracy.

Adverse drug reactions of intravesical instillation therapy for bladder cancer: based on FDA adverse event reporting system

ABSTRACT Background Intravesical chemotherapy and immunotherapy are common adjuvant treatments for non-muscle invasive bladder cancer post-surgery. Analyzing adverse events linked to these therapies, can assist in clinical decision-making and risk assessment. Study design and methods Disproportionality analysis was conducted to analyze data from the Food and Drug Administration Adverse Event Reporting System database from the first quarter of 2004 to the first quarter of 2024, exploring potential positive signals between Bacillus Calmette-Guérin, mitomycin-C, epirubicin, gemcitabine, and adverse events. Results The database retrieved 2018, 140, 31, and 85 adverse event reports associated with Bacillus Calmette-Guérin, mitomycin-C, epirubicin, and gemcitabine, respectively. Adverse reactions not mentioned in the label, such as aortic aneurysm and ocular congestion, were observed in preferred term level related to Bacillus Calmette-Guérin. Mitomycin-C exhibited specificity in skin and subcutaneous tissue diseases not reflected in the package insert. Gemcitabine-induced adverse drug reactions showed signals in vascular and lymphatic diseases meeting the screening criteria of all 4 indicators, with capillary leakage syndrome being the preferred term with the highest signal intensity. Conclusion This study observed new adverse event signals, providing important assistance for drug selection in adjuvant therapy for non-muscle invasive bladder cancer postoperatively.

Treatment Outcomes of PED for Unruptured Aneurysms of Internal Carotid Artery: Comparison of PED-Flex and PED-Shield.

There is a lack of data regarding the safety and effectiveness of implanting the Pipeline Embolization Device with Shield technology (PED-Shield) compared with the previous generation of Pipeline (PED-Flex). This retrospective single-center study aimed to compare treatment outcomes between the PED-Shield and PED-Flex for treating unruptured internal carotid artery aneurysms. The PED-Flex was used in 62 procedures (67 aneurysms, 59 patients) and the PED-Shield in 53 procedures (59 aneurysms, 58 patients). The mean aneurysm diameter was significantly lower in the PED-Shield group than in the PED-Flex group (11.9 ± 7.0 mm vs. 15.2 ± 6.9 mm, p < 0.001). At the 12-month follow-up, the complete angiographic occlusion rate was 72.1% and 72.3% in the PED-Flex and PED-Shield groups, respectively (p = 0.9808). Limited to aneurysms larger than 10 mm, 70.6% and 68.0%, respectively (p = 0.8175). The incidence of more than three high signal intensity areas on diffusion-weighted imaging after treatment was significantly lower in the PED-Shield group than in the PED-Flex group (27.7% vs. 67.7%; p < 0.001). Limited to aneurysms larger than 10 mm, 41.1% and 69.6%, respectively (p < 0.0117). Symptomatic ischemic complications occurred within 30 days of four PED-Flex procedures (6.5%) and one PED-Shield procedure (2.0%) (p = 0.2315). Limited to aneurysms larger than 10 mm, 1.8% and 3.2%, respectively (p = 0.6677). The incidence of mRS score worsening at 6 months was 3.2% and 1.9% in the PED-Flex and PED-Shield groups, respectively (p = 0.6534). The PED-Shield can achieve outcomes equivalent to or better than the PED-Flex. Further large-scale studies are warranted to confirm our findings.

Bone Imaging of the Knee Using Short-Interval Delta Ultrashort Echo Time and Field Echo Imaging.

Background: Computed tomography (CT) is the preferred imaging modality for bone evaluation of the knee, while MRI of the bone is actively being developed. We present three techniques using short-interval delta ultrashort echo time (δUTE), field echo (FE), and FE with high resolution-deep learning reconstruction (HR-DLR) for direct bone MRI. Methods: Knees of healthy volunteers (n = 5, 3 females, 38 ± 17.2 years old) were imaged. CT-like images were generated by averaging images from multiple echoes and inverting. The bone signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined. Results: The δUTE depicted a cortical bone with high signal intensity but could not resolve trabeculae. In contrast, both the FE and FE HR-DLR images depicted cortical and trabecular bone with high signal. Quantitatively, while δUTE had a good bone SNR of ~100 and CNR of ~40 for the cortical bone, the SNR for the FE HR-DLR was significantly higher (p < 0.05), at over 400, and CNR at over 200. Conclusions: For 3D rendering of the bone surfaces, the δUTE provided better image contrast and separation of bone from ligaments and tendons than the FE sequences. While there still is no MRI technique that provides a perfect CT-like contrast, continued advancement of MRI techniques may provide benefits for specific use cases.

Meibography signal intensity as a novel image biomarker for meibomian gland function: evidence from cross-sectional and longitudinal analyses.

Meibomian gland dysfunction (MGD), one of the most common ocular surface diseases, can induce dry eye and reduce patients' quality of life. Methodological limitations have resulted in contradictory interpretations of gland function. This study sought to investigate the correlation between meibography signal intensity (SI) and meibomian gland (MG) function and to validate an MGD classification strategy based on different levels of SI. A multicenter, cross-sectional analysis was conducted on 817 eyes from 361 patients with MGD and 52 healthy controls. Additionally, 78 eyes from 39 patients with MGD who had undergone LipiFlow treatment were recruited for longitudinal analyses. The SI value was obtained via meibography using an automated analyzer, and all participants underwent ocular surface examinations. A cross-sectional analysis was performed to determine SI distribution and its relationship to clinical characteristics via a generalized estimating equation model. Longitudinal analyses were conducted on the treatment cohort using a mixed-effects model to explore the outcome in different SI levels. Regression analysis revealed significant correlations between SI and lipid layer thickness (β=0.016), meibum expressibility (β=-0.676), meibum quality (β=-0.251), and fluorescein-stained tear-film break-up time (FBUT) (β=0.064) (all P values <0.001 for the above associations). Low-level SI MGD cases exhibited the most severe clinical signs, including the worst meibum expressibility (16% for level 3) and quality scores (19% for level 3), the shortest FBUT (3.82±0.13 s), and the thinnest lipid layer (65.68±2.58 nm), (all P values <0.05, respectively). Patients with medium SI showed the lowest ocular surface disease index (OSDI) value (26.64±1.06), the longest FBUT (4.56±0.08 s), and the thickest lipid layer (80.20±2.90 nm). After treatment, the high SI values reduced significantly at each follow-up point compared to baseline (all P values <0.05). The medium SI group demonstrated the greatest improvement in symptoms and signs, followed by the high SI group, and the low SI group. Automated measurements of SI can effectively reflect MG secretory activity. The proposed low, medium, and high SI classifications represent different functional subtypes of MGD.

Prospective close monitoring of the effect of vascular-targeted photodynamic therapy and high intensity focused ultrasound of localized prostate cancer by multiparametric magnetic resonance imaging.

The aim of this study is to describe the anatomical and functional changes observed in multiparametric magnetic resonance imaging (mpMRI) during follow-up after focal therapy (FT) for localized prostate cancer (PCa). In this prospective study, we analyzed pre- and postoperatively acquired mpMRI of 10 patients after FT (7days; 3, 6, 9, 12months). 7/10 (70%) patients underwent vascular-targeted photodynamic therapy (VTP). 3/10 (30%) patients underwent high-intensity focused ultrasound (HIFU). MpMR image analysis was performed using a semi-automatic software for segmentation of the prostate gland (PG) and tumor zones. Signal intensities (SI) of T2-weighted (T2w), T1-weighted (T1w),diffusion-weighted (DWI) and dynamic contrast-enhanced (DCE) images as well as volumes of the prostate gland (PGV) and tumor volumes (TV) were evaluated at each time point. The results showed a significant increase of PGV 7days after FT (p = 0.042) and a significant reduction of PGV between 7days and 6, 9 and 12months after FT (p < 0.001). The TV increased significantly 7days after FT (p < 0.001) and decreased significantly between 7days and 12months after FT (p < 0.001). There was a significant increase in SI of the ADC in the ablation zone after 6, 9 and 12months after FT (p < 0.001). 1/9 patients (11%) had recurrent tumor on rebiopsy characterized as a a small focal lesion on mpMRI with strong diffusion restriction (low SI on ADC map and high SI on b-value DWI). MpMRI is able to represent morphologic changes of the ablated zone after FT and might be helpful to detect recurrent tumor.

Optimizing magnetic sensor placement and probe design for high-speed rail RCF crack detection

This study investigates the impact of the trailing effect on the accuracy of crack detection under high-speed conditions. Finite element simulation analysis was used to explore the effects of the trailing effect on the magnetic field distribution on the rail surface and compare the signal intensity and sensitivity at different detection positions. The optimal detection position with higher signal intensity and sensitivity was identified, and a probe structure suitable for electromagnetic non-destructive testing at high speeds was proposed. Experimental results show that at a detection speed of 20.0 m/s, this probe structure effectively quantifies cracks deeper than 1.0 mm, with relative errors and standard deviations within 10 %.

Preoperative Increases in T2-Weighted Fat-Suppressed Magnetic Resonance Imaging Signal Intensities Associated With Advanced Tissue Degeneration and Mitochondrial Dysfunction in Rotator Cuff Tears

PurposeThe purpose of this study was to investigate the relationship between magnetic resonance imaging (MRI) signal intensities and mitochondrial function in patients undergoing arthroscopic rotator cuff repair, assessed through histological and genetic profiling of tendon tissue. MethodsThis study, conducted between April 2022 and January 2023, included 20 patients undergoing rotator cuff repair for atraumatic/degenerative tears. Rotator cuff tendon edge samples were obtained during arthroscopic rotator cuff repair. Patients were classified based on signal intensity from preoperative T2-weighted fat suppressed MRI. Specifically, they were categorized as having either high or low signal intensity at the rotator cuff tendon edge, with the deltoid muscle serving as a reference. Comparative analyses specifically compared the histological features and genetic profiles of the tendon tissue at the rotator cuff tendon edge. Histological evaluation of harvested tendon specimens during arthroscopic rotator cuff repair employed the modified Bonar score. Real-time polymerase chain reaction was used to assess expression of various mitochondrial and apoptosis-related genes. The mitochondrial morphology of the rotator cuff torn site was examined using electron microscopy. ResultsThe higher signal intensity group showed significantly higher modified Bonar scores (p=0.0068), decreased mitochondrial gene expression, increased TUNEL-positive cells (p=0.032), lower SOD activity (p=0.011), reduced ATP5A (p=0.031), and increased cleaved caspase-9 activity (p=0.026) when compared to the lower signal intensity group. Electron microscopy revealed fewer mitochondrial cristae in the higher signal intensity group. ConclusionOur results suggest correlations between high MRI signal intensities and the presence of degeneration, mitochondrial dysfunction, and increased apoptosis in rotator cuff tissues. This underscores the utility of MRI signal intensity as an indicator of tissue condition. Clinical RelevanceBuilding on the established premise that elevated preoperative MRI signal intensities may indicate higher rates of postoperative rotator cuff re-tears, the current study substantiates these findings from a mitochondrial function perspective.