Low Signal Intensity Research Articles

CNSC-50. PRIMARY INTRACRANIAL CONGENITAL GLIOBLASTOMA (PICG): A SYSTEMATIC REVIEW OF CASE REPORTS FROM 2000 TO 2023

Abstract BACKGROUND AND OBJECTIVE The most commonly reported congenital intracranial space occupying lesions are teratoma, glioma and neuroblastoma. Primary intracranial congenital glioblastoma (PICG) is one of the most lethal and extremely rare neoplasms. Most pediatricians and gynecologists are unable to detect it congenitally, posing an ominous risk of spread and disease severity. We aim to determine the clinical manifestations, number of reported cases, radiological findings and neuro-oncological management of PICG. MATERIALS AND METHODS A comprehensive literature search using PubMed Central and Google Scholar was done, retrieving 17 case reports and five case series of 31 patients with PICG and included using the Preferred Reporting items for Systematic Reviews and Meta-Analyses guidelines, published between 2000 and 2023. RESULTS The mean age at presentation was 86.00 ± 88.36 days, with both genders affected equally, i.e. 45.16%. The most common symptoms and signs at presentation were seizures (38.70%) and hydrocephalus (51.61%), respectively. Left hemispheric (48.38%), with frontoparietal involvement (16.12%) was the frequently affected site. MRI findings were suggestive of low intensity signal significant of hemorrhage or calcification and a heterogenous mass in 35.58% and 32.25% cases, respectively. Gross total resection (GTR) was achievable in 48.38% patients. Glial fibrillary acid protein and vimentin were positive in 45.16% and 29.03% cases, respectively. Intraoperative mortality and recurrence were noted in 25.80% and 9.68% of patients, respectively. The average follow up duration was 20.57 months. CONCLUSION PICG has an extremely aggressive course of natural progression. Congenital presentation and its lack of awareness among clinicians is itself a challenge for disease management. Adjuvant chemo-radiotherapy has proven fruitful along with GTR. Post-operative CSF diversion is warranted.

Zr-Doping Strategy of High-Quality Cu2O/β-Ga2O3 Heterojunction for Ultrahigh-Performance Solar-Blind Ultraviolet Photodetection.

β-Ga2O3, as an ultrawide band gap semiconductor, has emerged as the most promising candidate in solar-blind photodetectors. The practical application of β-Ga2O3, however, suffers from intrinsic defects and suboptimal crystal quality within the devices. In this work, high-quality β-Ga2O3 was successfully synthesized by employing the Zr-doping strategy, which has facilitated the development of ultrahigh-performance solar-blind photodetectors based on Cu2O/β-Ga2O3 heterostructures. Structural analyses indicate that the strong Zr-O covalent bond effectively stabilizes the material, thereby eliminating oxygen vacancy defects. The Cu2O/β-Ga2O3 heterostructure photodetector demonstrates an ultrahigh responsivity and detectivity coupled with an external quantum efficiency. Furthermore, the device exhibits a photocurrent-to-dark current ratio of 3 × 105, showcasing its superior capability in detecting low-intensity deep ultraviolet signals, markedly surpassing previous heterostructure ultraviolet photodetectors. These exceptional performances are attributed to the effective elimination of oxygen vacancy defects in β-Ga2O3 and the variation of band alignment at the interface, which facilitate rapid separation of photogenerated electron-hole pairs under reverse bias. This study not only provides an enhanced and easy route to mitigate oxygen vacancy defects in oxide materials but also propels further exploration into the next generation of flexible, high-performance, solar-blind ultraviolet photodetectors.

Desmoplastic Fibroblastoma (Collagenous Fibroma) of the Knee: A Case Report and Literature Review.

Desmoplastic fibroblastoma, also known as collagenous fibroma, is a rare benign mesenchymal neoplasm that primarily arises in the subcutaneous tissue of upper extremities and limb girdles. The knee is an uncommon location for desmoplastic fibroblastoma. Recent studies have demonstrated the presence of immunoreactivity for FOS like 1 (FOSL1) and rearrangements of FOSL1. A 70-year-old woman presented with a 1-year history of a palpable mass in the medial aspect of the right knee. Physical examination revealed a 4-cm, elastic hard, mobile, nontender mass. Magnetic resonance imaging (MRI) showed a well-defined mass with prominent low signal intensity on all pulse sequences. Contrast-enhanced MRI demonstrated mild internal enhancement with rim enhancement. After an open biopsy, the lesion was successfully treated by complete excision. Histologically, the tumor was composed of bland spindle or stellate-shaped cells embedded in an abundant collagenous stroma. Immunohistochemically, the tumor cells showed diffuse nuclear positivity for FOSL1. These findings were consistent with a diagnosis of desmoplastic fibroblastoma. The patient was asymptomatic and there was no evidence of local recurrence eight months after surgery. Desmoplastic fibroblastoma is a distinctive benign soft-tissue tumor with FOSL1 immunoreactivity and should be clearly distinguished from more biologically aggressive mesenchymal neoplasms.

Characterization of plaque hemorrhage with optical coherence tomography imaging in statin-treated patients with coronary artery disease: comparison with noncontrast T1-weighted MRI

Abstract Background Plaque hemorrhage is a phenotypic feature of coronary lesions associated with future coronary events. Noncontrast T1-weighted MRI has a potential to non-invasively identify plaque hemorrhage. Plaque to myocardium ratio (PMR) evaluated by noncontrast T1-weighted MRI has been shown to pathohistologically correspond to plaque hemorrhage. In several case reports comparing OCT images with coronary specimens, low intensity area without its attenuation was observed at lesions presenting plaque hemorrhage. However, whether the association of this OCT-derived feature with PMR remains to be elucidated yet. Purpose To characterize plaque hemorrhage in vivo by comparing with OCT and noncontrast T1-weighted MRI. Methods The current study prospectively enrolled 80 statin-treated patients with coronary artery disease requiring elective PCI. A total of 103 target lesions were imaged by both noncontrast T1-weighted MRI and OCT prior to PCI. Plaque hemorrhage on noncontrast T1-weighted MRI was defined as PMR>1.0. On OCT imaging analysis, low intensity area without attenuation (LIA) was defined according to the following criteria; (1) area presenting homogeneous low intensity signals, (2) clear border and (3) no signal attenuation behind its area. The maximum arc of LIA was manually measured. OCT-derived plaque features were compared in lesions with and without PMR>1.0. Results PMR>1.0 was observed at 49.5% of analyzed lesions. Patients with PMR>1.0 were more likely older (72 vs. 66 years, p=0.02), whereas there was no significant difference in on-treatment LDL-C levels (median: 80 vs. 77 mg/dL, p=0.62) (Table). On lesion-based analysis, while fibrous cap thickness was similar between the two groups (80 vs. 100um, p=0.10), a larger lipid arc (270 vs. 230º, p=0.02) and a greater frequency of macrophage (90.2 vs. 53.9%, p<0.01), layered plaque (62.8 vs. 32.7%, p=0.003) and cholesterol crystal (70.6 vs. 30.8%, p<0.001) were observed at lesions with PMR>1.0. Furthermore, lesions with PMR>1.0 more frequently exhibited LIA (66.7 vs. 19.2%, p<0.001) and its greater maximum arc (33 vs. 0º, p<0.001) (Figure). Of note, PMR was significantly correlated to the maximum arc of LIA (r=0.51, p<0.001) (Figure). Multivariate analysis demonstrated LIA and cholesterol crystal as independent OCT-derived features associated with PMR>1.0 (Table). Conclusion In statin-treated patients, 49.5% of analyzed lesions presented PMR>1.0. Coronary lesions with PMR>1.0 more frequently harbored LIA and cholesterol crystals, in addition to other vulnerable OCT features. Our findings suggest OCT-derived LIA as a potential signature of plaque hemorrhage. Given that cholesterol crystal was another feature of PMR>1.0, plaque inflammation driven by cholesterol crystallization may exist at plaque hemorrhage despite statin use. Whether anti-inflammation agent could modulate plaque hemorrhage requires future investigation.

Evaluation of the Antibacterial Activity of Antibiotics with different Antibacterial Mechanisms using Electrochemical Signals of Heat‐Treated Escherichia Coli

AbstractElectrochemistry with purines as indicators may be a promising new method for antibiotic activity testing. However, the traditional electrochemical detection method (S‐LSV) requires a long accumulation time for purines and has low signal intensity. High‐temperature treatment of bacterial samples may significantly enhance the signal intensity and speed of detection. However, this process may also impact the structure and metabolism of bacteria. Further research is necessary to determine how electrochemical signals respond to antibiotic antibacterial activity. In this paper, the electrochemical detection method based on heat‐treated Escherichia coli (E. coli, H‐LSV) was used to investigate the effects of 11 antibiotics with four different antibacterial mechanisms on the electrochemical behavior of E. coli. The results showed that compared to the S‐LSV, the electrochemical signal of E. coli detected by the H‐LSV increased by 362%, and showed a strong linear relationship with bacterial counts up to 1.88×108 CFU/mL, with a detection limit of 1.15×106 CFU/mL. The electrochemical signal consistently correlated with changes in viable E. coli counts following treatment with the four different antibacterial mechanisms. HPLC analysis further confirmed that the changes in purine contents in bacteria after antibiotic treatment were consistent with the trends in electrochemical signals. The evaluation of antibiotic antibacterial ability by H‐LSV showed good consistency with results from plate counting and turbidity methods, but was closer to the results of plate counting. The inhibition rates of antibiotics on E. coli detected by H‐LSV and S‐LSV also showed high consistency, indicating that short‐term high‐temperature treatment of E. coli did not affect the response of the bacterium to the inhibitory activity of antibiotics.

Medical imaging for the diagnosis, recurrence and metastasis evaluation of clear cell sarcoma

Clear cell sarcoma (CCS) of soft tissue is extremely rare, accounting for approximately 1% of all soft tissue tumours. It is very difficult to diagnose CCS based on clinical manifestations. Magnetic resonance imaging (MRI) provides high-resolution images of soft tissues and pathological features such as mucus, necrosis, bleeding, and fat through high and low signals on T1 weighted image (T1WI) and T2 weighted image (T2WI). On the other hand, the paramagnetism of melanin in CCS shortens the relaxation time of T1 and T2, and high signal intensity on T1WI and low signal intensity on T2WI can be found. This is different from most other soft tissue sarcomas. At present, the treatment method for CCS is surgical resection. MRI can effectively display the tumour edge, extent of surrounding oedema, and extent of fat involvement, which is highly important for guiding surgical resection and predicting postoperative recurrence. As an invasive sarcoma, CCS has a high risk of metastasis. Regardless of the pathological condition of the resected tumour, MRI or computed tomography (CT) should be performed every 1-2 years to assess recurrence at the primary site and to screen for metastasis in the lungs, liver, and bones. If necessary, PET-CT can be performed to evaluate the overall condition of the patient.

6485 Unilateral Adrenal Metastasis From Unknown Primary Carcinoma Mimicking Primary Adrenocortical Carcinoma

Abstract Disclosure: S. Watanabe: None. S. Suzuki: None. K. Ishiwata: None. Y. Yamazaki: None. H. Sasano: None. K. Yokote: None. Background: Adrenal metastasis from carcinomas of the lung, breast, and melanoma are observed. However, isolated adrenal metastasis with unknown primary carcinoma origin has been rare, and the diagnosis is challenging. We encountered a case of unilateral adrenal tumor clinically diagnosed as non-functional primary adrenocortical carcinoma, but found to be a metastatic tumor on postoperative pathology. Clinical Case: A 68-year-old man was referred to our hospital for examination of an 8mm right adrenal incidentaloma. He underwent hormone therapy for prostate cancer four years ago, and the condition is in remission with no recurrence signs. Follow-up CT revealed that the adrenal tumor rapidly enlarged from 8 mm to 36 mm within six months, and its mean attenuation value was 38 HU. MRI showed that the adrenal tumor had a low signal intensity on T1 and a high signal on T2. At the same time, there is mediastinal lymphadenopathy and a 9-mm nodule in the lower lobe of the right lung, which was considered benign from the stable condition. FDG-PET/CT showed FDG uptake only in the right adrenal tumor (maximum standardized uptake value of 21.39). [1]23I-MIBG scintigraphy did not show any accumulations. The serum and urinary adrenal hormones were all within normal limits. Notably, tumor markers such as prostate-specific antigen (PSA), carcinoembryonic antigen (CEA), α-fetoprotein (AFP), and cancer antigen 19-9 (CA 19-9) were all within normal ranges. Therefore, we clinically suspected non-functional primary adrenocortical carcinoma, and the laparoscopic right adrenalectomy was performed. The resected right adrenal lesion was encapsulated and measured 79×54×22 mm. On histological analysis, the nodule comprised tumor cells with eosinophilic cytoplasm, and abundant tissue infiltrating lymphocytes. Immunohistochemical studies revealed that the tumor was not of adrenal origin due to negative steroidogenic factor-1 (SF-1) and inhibin alpha staining. From these results, the adrenal tumor was diagnosed as adrenal metastasis from unknown primary carcinoma. The tumor cells were positive for cytokeratin19, CEA, and thyroid transcription factor-1 but negative for PSA, p63, cytokeratin 5/6, insulinoma-associated protein-1, and synaptophysin. Genetically, the adrenal tumor harbored genomic abnormalities in CDKN2A, TP53, NF1, PBRM1, and KEAP1 genes. Conclusion: Isolated adrenal metastasis without a detectable primary tumor is rare but should be considered a differential diagnosis in the case of an enlarged, non-functioning adrenal tumor. Adrenalectomy or tumor biopsy may be actively considered to diagnose and determine the optimal course of treatment. Presentation: 6/3/2024

Survival of the brightest? pIRIR dating of volcanic sediments in Sulawesi, Indonesia, using micro-aliquots of K-rich feldspar

Volcanic sediments are challenging to date with luminescence-based methods. Both main minerals used for dating—quartz and K-rich feldspar—commonly have suboptimal luminescence properties when of volcanic origins, primarily a low signal intensity and, for K-rich feldspars, high rates of anomalous fading. The present work provides a case study of sediment samples from the Leang Bulu Bettue (LBB) archaeological site in Indonesia, a key site in our understanding of the early human occupation of the island of Sulawesi. We show that currently available state-of-the-art methods can provide robust optical ages for volcanic sediments. Through various reliability tests, we establish the suitability of a post-IR IR stimulated luminescence (pIRIR) standardised growth curve (SGC) procedure for De estimation of ‘micro-aliquots’ containing 5–10 grains of K-rich feldspar, and then combine this method with estimates of environmental dose rate to determine 10 new reliable and finite optical ages for the sedimentary deposits at LBB. Furthermore, by applying the LnTn method to circumvent truncation of the De distribution caused by the non-linearity of the dose response curve in the higher dose range, we could extend the site's luminescence-based chronology to span the interval ∼15–210 ka. The new chronology is in keeping with previous radiocarbon and U-series ages for the site's upper layers. We show that the low fading rate of micro-aliquots relative to using large aliquots composed of hundreds of grains lies in a brightness-based selection. By targeting bright grains with low fading rates, the need for fading corrections is greatly reduced and they can be made with a smaller uncertainty propagated through into the final age estimate, resulting in optical ages of improved accuracy and precision for volcanic sediments.

Osteochondritis Dissecans of the Medial Femoral Condyle: MRI Findings of Instability.

BACKGROUND: Osteochondritis dissecans (OCD) of the medial femoral condyle (MFC), a common cause of pediatric chronic knee pain, is often found to be stable at arthroscopy. OBJECTIVE: To investigate the performance of MRI for identifying instability of MFC OCD in children. METHODS: This retrospective study included 59 children (37 boys, 22 girls; mean age, 12.5±2.2 years) with 69 MFC OCD lesions, who underwent knee MRI from January 2016 to October 2023. Two radiologists independently reviewed examinations to determine regional findings (effusion, skeletal maturity, secondary physis visibility, progeny composition), as well as direct (osteochondral defect, intraarticular body, cartilage alteration, bone plate disruption, receded ossification front) and indirect (progeny-parent bone interface, radius of curvature, parent-bone low-signal intensity (SI) marginal rim, perilesional marrow edema) findings of instability; disagreements were resolved through consensus. Two investigators assessed an additional indirect finding, cyst(s), in consensus. Demographic characteristics, and lesion volume were collected. The reference standard for lesion stability was arthroscopy (n=52) or follow-up evaluation (based on symptoms and imaging findings) in patients managed conservatively (n=17). Stable and unstable lesions were compared. RESULTS: Forty-nine lesions were stable, and 20 were unstable. Sensitivity and specificity for instability, among features showing significant associations with instability, were 70.0% and 100.0% for skeletal maturity, 75.0% and 75.5% for osteochondral progeny composition, 100.0% and 85.7% for cartilage alteration, 85.0% and 81.6% for presence of progeny-parent bone interface, 30.0% and 100.0% for extensive interface, 90.0% and 34.7% for cyst(s), 45.0% and 91.8% for altered radius of curvature, 80.0% and 89.8% for parent-bone low-SI rim, and 50.0% and 81.6% for extensive perilesional marrow edema. In multivariable analysis, factors independently associated with instability included larger lesion volume and indirect signs (presence of interface, cyst(s), altered radius of curvature, parent-bone low-SI rim, and extensive perilesional marrow edema). Frequency of instability was 0.0%, 7.4%, 16.7%, 75.0%, 83.3%, and 100.0% for lesions with 0, 1, 2, 3, 4, and 5 indirect signs. CONCLUSION: Lesion instability was associated with an increasing number of indirect MRI signs. CLINICAL IMPACT: Assessment of lesion stability by MRI can help guide decisions between arthroscopy and conservative management for MFC OCD in children.

Early penumbral FLAIR changes predict tissue fate in patients with large vessel occlusions.

In patients with an acute ischemic stroke, the penumbra is defined as ischemic tissue that remains salvageable when reperfusion occurs. However, the expected clinical recovery congruent with penumbral salvage, is not always observed. We aimed to determine if the Magnetic Resonance Imaging (MRI) defined penumbra includes irreversible neuronal loss that impedes expected clinical recovery after reperfusion. In the prospective French Acute Multimodal Imaging Study to Select Patients for Mechanical Thrombectomy (FRAME) and an observational cohort of patients with large vessel occlusions undergoing endovascular treatment, we quantified penumbral integrity by FLAIR changes. We studied the influence of recanalization status on the evolution of penumbral FLAIR changes and studied penumbral FLAIR changes as predictor of tissue fate and functional outcome on the 90 days modified Rankin Scale (mRS). Recanalization status did not modify the evolution of rFLAIR signal intensity (SI) over time in the total cohort, but was associated with lower SI in the FRAME subset (b=-0.06, p for interaction=0.04). Median rFLAIR SI was higher at baseline in the subsequently infarcted penumbra compared to the salvaged (ratio=1.07, standard deviation [SD] 0.07 vs 1.03, SD 0.06 p<0.0001, n=150). The severity and extent of rFLAIR SI changes did not predict 90 day functional outcome in univariate (p=0.09) and multivariate logistic regression (p=0.4). Recanalization status did not influence the evolution of penumbral FLAIR changes. FLAIR SI changes in the baseline penumbra were associated with tissue fate, but not functional outcome. The data supporting the study are available upon reasonable request; following a signed data access agreement.

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.

Integrating lateral flow device with controllable gold in situ growth for sensitive detection of staphylococcal enterotoxin A in milk

Gold nanoparticle-based lateral flow immunoassays (AuNP-LFIA) are widely used for pathogen monitoring to prevent foodborne illness outbreaks. However, conventional AuNP-LFIA exhibits poor sensitivity and limited quantitative capacity due to the low colorimetric signal intensity of AuNPs. Herein, we introduced a low-background gold in situ growth (GISG) strategy by lowering the pH of the growth solution to weaken the reducibility of hydroxylamine, thereby enhancing the sensitivity of AuNP-LFIA. Additionally, we developed a universal and manufacturable lateral flow device to streamline the GISG process. We applied this device to detect staphylococcal enterotoxin A (SEA), an exotoxin produced by Staphylococcus aureus. Under optimal conditions, the proposed device demonstrated superior practicality and excellent sensitivity for SEA detection, achieving a detection limit of 0.061 ng/mL with the total detection time of 37 min, showing 311 times more sensitive than the unamplified AuNP-LFIA. Furthermore, SEA detection in milk samples showed a strong correlation (R2 = 0.8845) with results obtained from a conventional ELISA kit. Therefore, this promising LFIA device offers a novel strategy with high sensitivity and practicality for in-field detection of Staphylococcus aureus and can be easily adapted for screening other foodborne pathogens.

Ultrashort-Echo-Time MRI of the Disco-Vertebral Junction: Modulation of Image Contrast via Echo Subtraction and Echo Times.

The disco-vertebral junction (DVJ) of the lumbar spine contains thin structures with short T2 values, including the cartilaginous endplate (CEP) sandwiched between the bony vertebral endplate (VEP) and the nucleus pulposus (NP). We previously demonstrated that ultrashort-echo-time (UTE) MRI, compared to conventional MRI, is able to depict the tissues at the DVJ with improved contrast. In this study, we sought to further optimize UTE MRI by characterizing the contrast-to-noise ratio (CNR) of these tissues when either single echo or echo subtraction images are used and with varying echo times (TEs). In four cadaveric lumbar spines, we acquired 3D Cones (a UTE sequence) images at varying TEs from 0.032 ms to 16 ms. Additionally, spin echo T1- and T2-weighted images were acquired. The CNRs of CEP-NP and CEP-VEP were measured in all source images and 3D Cones echo subtraction images. In the spin echo images, it was challenging to distinguish the CEP from the VEP, as both had low signal intensity. However, the 3D Cones source images at the shortest TE of 0.032 ms provided an excellent contrast between the CEP and the VEP. As the TE increased, the contrast decreased in the source images. In contrast, the 3D Cones echo subtraction images showed increasing CNR values as the second TE increased, reaching statistical significance when the second TE was above 10 ms (p < 0.05). Our study highlights the feasibility of incorporating UTE MRI for the evaluation of the DVJ and its advantages over conventional spin echo sequences for improving the contrast between the CEP and adjacent tissues. Additionally, modulation of the contrast for the target tissues can be achieved using either source images or subtraction images, as well as by varying the echo times.

Solitary Fibrous Tumors: A Rare Tumor Arising from Ubiquitous Anatomical Locations.

Solitary Fibrous Tumors (SFTs) are uncommon mesenchymal tumors of fibroblastic/myofibroblastic origin that stem from various anatomical sites. Most SFTs are asymptomatic and noticed incidentally by various imaging modalities. Although SFTs were initially identified in the pleura and erroneously considered to originate solely from serosal layers, extrapleural SFTs have been reported more commonly than their pleural counterparts. Imaging features are similar in different anatomical locations and are mainly related to the tumor's size and collagen content, characteristically displaying low signal intensity on Magnetic Resonance Imaging (MRI). Smaller tumors typically exhibit uniform enhancement, yet necrotic regions may become evident as the tumor size increases, resulting in heterogeneous enhancement. Less than 30% of SFTs demonstrate unfavorable clinical outcomes regardless of their histological features, warranting surgery as the preferred treatment with long-term follow-up. In this article, we have reviewed the clinical manifestations and imaging features of SFTs, discussed their differential diagnosis based on anatomical site, and provided diagnostic pearls.

Magnetic resonance imaging of the dromedary camel carpus

BackgroundThe dromedary camel (Camelus dromedarius) carpal joint presents multiple joints and constitutes several bones and soft tissues. Radiography and/or ultrasonography of the carpus are challenging due to structural superimposition. High-field magnetic resonance imaging (MRI) technique precludes superimposed tissues and offers high soft tissue contrast in multiple sequences and planes. Hence, understanding the normal MRI anatomy is crucial during clinical investigations. Magnetic resonance imaging is highly sensitive for investigation of soft tissues and articular cartilage; therefore, it is extensively used for outlining joint anatomy and evaluation of a wide range of musculoskeletal conditions. MRI images of a specific anatomical region acquired by using multiple sequences in various planes are necessary for a complete MRI examination. Given the dearth of information on the MRI features of the dromedary camel carpus, the current study demonstrates the MRI appearance of the clinically significant structures in the camel carpus in various sequences and planes using a high-field 1.5 Tesla superconducting magnet. For this purpose, twelve cadaveric forelimbs, obtained from 6 clinically sound lameness free adult dromedary camels, were examined.ResultsThe cortex and medulla of the radius, carpal bones and metacarpus were evaluated. Articular cartilage of the carpal joints was depicted and showed intermediate intensity. Carpal tendons expressed lower signal intensity in all pulse sequences. The collateral and inter-carpal ligaments showed mixed signal intensity.ConclusionsThe obtained data outlines the validation of MRI for investigation of the camel carpus and could set as a reference for interpretation in clinical patients.

Association of Microbleeds on Susceptibility-Weighted Imaging with Ferroptosis and Prognosis in Rabbits with Spinal Cord Injury.

Susceptibility-weighted imaging (SWI) is a common imaging technique used to identify cerebral microbleeds. Given that spinal cord injury (SCI) often creates an environment that favors ferroptosis, a type of cell death driven by iron, this study aimed to explore the relationship between microbleeds on SWI and ferroptosis, and explore the effect of deferoxamine on SCI. Thirty-six rabbits were divided into three groups: sham, SCI, and SCI with deferoxamine (DFO, a ferroptosis inhibitor) treatment (SCI+DFO). Following 48 hours of SCI modeling, the rabbits underwent magnetic resonance imaging (MRI) and SWI examinations. Ferroptosis markers and spinal cord tissue morphology were examined, and the modified Tarlov's score was used to assess neurological function. SWI analysis revealed that rabbits in the SCI group exhibited lower signal intensities and larger microbleed areas compared to the those in the SCI+DFO group (p < 0.05). The SCI+DFO group demonstrated significantly decreased iron and malondialdehyde (MDA) levels, coupled with increased glutathione (GSH) and glutathione peroxidase 4 (GPX4) levels, along with attenuated ferroptosis (p < 0.05). This group also displayed greater Neuronal Nuclei (NeuN) expression, Tarlov's scores, and neurological recovery rates (all p < 0.05). A significant positive correlation was found between the microbleed area and iron content (r = 0.59, p = 0.04), MDA (r = 0.75, p = 0.01), and mitochondrial damage (r = 0.90, p < 0.01). Conversely, a negative correlation was established between the microbleed area and GPX4 levels (r = -0.87, p < 0.01), as well as neurological function recovery (r = -0.62, p = 0.03). The extent of microbleeds on SWI following SCI is closely correlated with ferroptosis, and the inhibition of ferroptosis could improve neurologic function. These findings suggest that the area of microbleeds on SWI could potentially serve as a predictive marker for ferroptosis in spinal cord injury.

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.

Optimizing agitated saline volume for contrast echocardiography: Balancing diagnostic performance and operator fatigue

AbstractBackgroundAgitated saline contrast echocardiography, essential for patent foramen ovale detection, typically uses a 10‐mL saline protocol, which may lead to operator fatigue and compromise diagnostic accuracy. This study aimed to identify an optimal saline volume that balances diagnostic efficacy and minimizes operator fatigue.MethodsFifty‐three patients with suspected patent foramen ovale underwent echocardiography using three saline protocols: 10 mL (9 mL saline + 1 mL air), 7 mL (6.4 mL saline + 0.6 mL air), and 5 mL (4.6 mL saline + 0.4 mL air). The protocols were evaluated for their impact on microbubble signal intensity in the right atrium, right‐to‐left shunt grading, and operator fatigue, as assessed by the Borg CR10 scale.ResultsThe signal intensities were comparable between the 10‐mL and 7‐mL protocols, while the 5‐mL protocol showed significantly lower signal intensities at all time points (p &lt; 0.001). The 7‐mL protocol achieved 100% right‐to‐left shunt grading concordance with the 10‐mL protocol, while the 5‐mL protocol showed decreased accuracy and recall. Operator fatigue significantly decreased with the reduction in saline volume (p &lt; 0.001), and the 7‐mL protocol demonstrated optimal diagnostic accuracy and reduced fatigue.ConclusionA 7‐mL agitated saline volume is recommended for contrast echocardiography to maintain diagnostic accuracy while significantly reducing operator fatigue, offering a practical balance between diagnostic precision and operator comfort.

Optimising in-cell NMR acquisition for nucleic acids.

Understanding the structure and function of nucleic acids in their native environment is crucial to structural biology and one focus of in-cell NMR spectroscopy. Many challenges hamper in-cell NMR in human cell lines, e.g. sample decay through cell death and RNA degradation. The resulting low signal intensities and broad line widths limit the use of more complex NMR experiments, reducing the possible structural and dynamic information that can be extracted. Here, we optimize the detection of imino proton signals, indicators of base-pairing and therefore secondary structure, of a double-stranded DNA oligonucleotide in HeLa cells, using selective excitation. We demonstrate the reproducible quantification of in-cell selective longitudinal relaxation times (selT1), which are reduced compared to the in vitro environment, as a result of interactions with the complex cellular environment. By measuring the intracellular selT1, we optimize the existing proton pulse sequences, and shorten measurement time whilst enhancing the signal gained per unit of time. This exemplifies an advantage of selective excitation over conventional methods like jump-return water suppressionfor in-cell NMR. Furthermore, important experimental controls are discussed, including intracellular quantification, supernatant control measurements, as well as the processing of lowly concentrated in-cell NMR samples. We expect that robust and fast in-cell NMR experiments of nucleic acids will facilitate the study of structure and dynamics and reveal their functional correlation.

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.