Low T2 Research Articles

T2 Mapping Values in Postmeniscectomy Knee Articular Cartilage after Running: Early Signs of Osteoarthritis?

Loading on the joints during running may have a deleterious effect on post-partial meniscectomy knee cartilage, leading to osteoarthritis. Utilizing T2-mapping measurements before and after running may enable the observation of changes in the articular cartilage of the postmeniscectomy knees compared with healthy knees. After medial partial meniscectomy, 12 volunteers underwent magnetic resonance imaging (MRI) of the both knees, before and immediately after 30 minutes of running. Quantitative assessment of articular cartilage was performed using a T2-mapping technique. In the medial compartment of the operated knees, significantly lower T2 values were found in anterior tibial plateau (pre- vs. postrun: 33.85 vs. 30.45 ms; p = 0.003) and central tibial plateau (33.33 vs. 30.63 ms; p = 0.007). Similar differences were found in lateral regions of central femur (post- vs. prerun: 35.86 vs. 40.35 ms; p = 0.015), posterior femur (34.89 vs. 37.73 ms; p = 0.001), and anterior tibia (24.66 vs. 28.70 ms, p = 0.0004). In lateral compartment, postrun values were significantly lower in operated compared with healthy knees, in central femur (34.89 vs. 37.59 ms; p = 0.043), posterior femoral (36.88 vs. 39.36 ms; p = 0.017), anterior tibia (24.66 vs. 30.20 ms; p = 0.009), and posterior tibia (28.84 vs. 33.17 ms; p = 0.006). No statistical difference was found while comparing postrun to prerun healthy knees. Lower T2 values were found in operated knees after 30 minutes of running. These changes were seen in medial and lateral compartments. We suspect that running may subject the articular cartilage to excessive loads in the post-partial meniscectomy knee, loads that in healthy knee do not cause any changes.

Cardiac Magnetic Resonance Reveals Incipient Cardiomyopathy Traits in Adult Patients with Phenylketonuria

Background: Phenylketonuria (PKU) is the most common inborn error of amino-acid metabolism, which, when untreated results to severe neuropsychological complications. . New born screenings programs and immediate beginning of phenylalanine-restricted diet, greatly ameliorate the prognosis. However, previous studies have shown that PKU patients have elevated levels of oxidative stress and collateral metabolic abnormalities such as dyslipidemia, predisposing to cardiovascular disease. The purpose of this study was to characterize the cardiac phenotype of adult subjects with PKU using advanced cardiac imaging. Methods: Thirty-nine adult patients with PKU (age 30.5±8.7 year old, median 10 year phenylalanine concentration (Phe) 924±330 µmol/L) and thirty-nine age- and gender- matched healthy controls were investigated. Participants underwent a comprehensive cardiac magnetic resonance imaging (CMR) and echocardiography examination to determine systolic and diastolic left (LV) and right (RV) ventricular function, LV mass, ventricular fibrosis, left atrial function and aortic distensibility. CMR parametric mapping was used to characterize structural tissue modification. All available quarterly plasma levels of Phe and tyrosine (Tyr) levels were averaged for 10 years prior to the CMR scan to evaluate therapeutic efficacy and compliance. Results: PKU patients had thinner LV walls (Septal end-diastolic (ED) thickness 7.0±17 vs 8.8±1.7 mm, p 1200µmol/L (909±48 ms). Both mean Phe (p=0.013) and Tyr (p=0.035) concentration levels were independently predictive for lower T1 values in a regression model. Conclusion: Taken together our findings indicate an early stage LV dysfunction in patients with PKU which associates lower T1 native levels probably reflecting an infiltration with lipids of the myocardium. These results suggest the importance of regular cardiac follow-up in clinical monitoring of the adult subjects with PKU. Funding Statement: Sebastian Kelle is supported by a grant from Philips Healthcare and received funding from the DZHK (German Centre for Cardiovascular Research) and by the BMBF (German Ministry of Education and Research). Declaration of Interests: None of the other authors reports a relationship with industry and other relevant entities – financial or otherwise – that might pose a conflict of interest in connection with the submitted article. The following authors report financial activities outside the submitted work: Radu Tanacli reports no conflict of interest. Burkert Pieske reports having received consultancy and lecture honoraria from Bayer Daiichi Sankyo, MSD, Novartis, Sanofi-Aventis, Stealth Peptides and Vifor Pharma; and editor honoraria from the Journal of the American College of Cardiology. Radu Tanacli and the other co-authors report no conflict of interest. Ethics Approval Statement: The study was approved by the Ethics Committee of the Charite University of Medicine in Berlin, complied with the Declaration of Helsinki and was registered at the German Register for Clinical Studies (DRK1120).

Secrets for a Successful Surgical Systematization in the Treatment of Posterior Compartment Endometriosis

Study Objective Demonstrate the secrets of the laparoscopic systematization in the treatment of posterior compartment endometriosis. Design Video demonstrating the systematic technique step by step (Canadian Task Force classification III) Setting: Surgery performed in 30-year-old patient, G0P0, with progressive dysmenorrhea, dyspareunia, menometrorrhagia and infertility. Upon vaginal and rectal touch, palpable thickening of the uterosacral ligaments was noticed with pain on mobilization. The MRI scan showed a low T2 signal lesion over the uterosacral ligaments, resulting in extrinsic damage to the right ureter. Patients or Participants N/A Interventions The nerve sparing laparoscopic excision systematization technique was the following: 1) Carry out the inspection of the cavity without targeting the central disease at first. 2) Mobilization of the sigmoid colon, identifying the line of separation between the mesosigmoid and the parietal peritoneum, above the paracolic gutters. 3) Exposure of the left pararectal fossa, keeping the ureter and mesoureter as the lateral limit and the rectum as the medial limit, dissecting caudally until we surpass lesion. 4) Fixation of the ovaries, exposing the posterior leaflet of the broad ligament. 5) Left ureterolysis begins at level of the promontory, with craniocaudal and lateromedial movements over the ureter, until the proximity with the posterior leaflet of the broad ligament. We then lateralize the ureter to expose the left uterosacral ligament 6) Resection of the left uterosacral ligament, keeping the ureter and hypogastric nerve lateralized - exposing the rectovaginal space. 7) Target the rectovaginal septum from lateral to medial, facilitating the identification of the mesorectum, dissected in a posterior direction. The same steps are performed in the right hemi-pelvis respecting their anatomical differences. Measurements and Main Results: The lesions were excised without complications and with minimal blood loss. Conclusion The surgical systematization proposed is a viable and reproducible technique and may offer greater damage control.

Role of Cardiovascular Magnetic Resonance Imaging in Assessment of Myocardial Iron Overload in Thalassemic Patients

Background: Thalassemia major anemia patients require repeated blood transfusions, which improves their survival and quality of life, however it leads to iron overload and cellular damage. Serum ferritin and liver biopsy were used classically to measure iron overload and to monitor patient response to chelation therapy. Magnetic resonance imaging (MRI T2*) has proven to be a non-invasive, effective technique in detecting and quantifying iron in the heart and liver and in adjustment of iron chelation therapy. Objective: To assess myocardial siderosis among our patients using MRI T2* technique and correlate it with hepatic iron load and left ventricular ejection fraction (LVEF). Patients and methods: Our study included 42 cases of monthly transfused patients. Hepatic and myocardial iron overload were measured by multi-breath-hold MRI T2* technique and a cine view sequence was used to assess left ventricular function (EF). Results: Myocardial and hepatic iron overload were inter-correlated to each other and correlated to left ventricular function (LVEF). There was insignificant correlation between cardiac and hepatic T2* value results (k = 0.014, P > 0.05). However, there was a progressive and significant decline in left ventricular ejection fraction (r = 0·61, P < 0·001) in patients with low cardiac T2* values (T2* < 20 ms). Conclusion: MRI T2* technique is a precise, reproducible, and non-invasive technique for measuring tissue iron concentration and sparing the patients from an invasive biopsy technique. It also benefits in early detection of cardiac dysfunction and provides a follow up tool helping in chelation therapy adjustment.

Variations in native T1 values in patients with Duchenne muscular dystrophy with and without late gadolinium enhancement.

Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder leading to progressive skeletal and cardiac myopathy. Elevated myocardial T1 values correlate with fibrosis in most disease processes, but DMD skeletal and cardiac histopathology is defined by fibrofatty replacement that may result in a decrease in T1 values, due to the low T1 of fat. The study goal was to assess myocardial T1 values in DMD patients with and without late gadolinium enhancement (LGE). A retrospective analysis was performed on all patients with DMD referred for CMR at our institution from 7/5/2017 to 10/24/2018. T1 measurements were performed using breath-held modified Look Locker inversion recovery (MOLLI) sequences at the basal and mid-ventricular levels. The cohort was separated into patients without the presence of LGE (LGE-) and patients with current or previous LGE (LGE+). A total of 207 CMR studies were analyzed. The LGE- group comprised 88 patients while 119 patients were in the LGE+ group. The LGE+ group was older, had larger indexed LV end-diastolic volume and lower LV ejection fraction (LVEF) compared to the LGE- group. T1 values in the LGE+ group were lower compared to the LGE- group (mid T1 1012 ms vs. 1035 ms; p = 0.002), with 5 CMR studies demonstrating mid T1 values < 900 ms. There was no correlation between mid T1 and LVEF in the LGE- group. In the LGE+ cohort, lower T1 values correlated with worse LVEF (r = 0.34, p = 0.0002). The association between mid T1 values and LVEF remained statistically significant on multivariable analysis when accounting for number of LGE segments, LVEDVi, and age (p = 0.009). This is the largest study assessing native T1 values in patients with DMD. The results demonstrate that patients with LGE had lower T1 values than patients without LGE. In the LGE+ group, lower T1 values correlated with worse LV systolic function. These results are consistent with the evolving recognition of fibrofatty replacement in advanced stages of DMD myopathy. Furthermore, our study supports that there is not a simple linear relationship between increasing T1 values and advancing disease progression reported in most other cardiomyopathies.

Diagnostic Algorithm to Differentiate Benign Atypical Leiomyomas from Malignant Uterine Sarcomas with Diffusion-weighted MRI.

Background Improving the differentiation of uterine sarcomas from atypical leiomyomas remains a clinical challenge and is needed to avoid inappropriate surgery. Purpose To develop a diagnostic algorithm including diffusion-weighted MRI criteria to differentiate malignant uterine sarcomas from benign atypical leiomyomas. Materials and Methods This case-control retrospective study identified women with an atypical uterine mass at MRI between January 2000 and April 2017, with surgery or MRI follow-up after 1 year or longer. A diagnostic algorithm including T2-weighted MRI and diffusion-weighted imaging (DWI) signal and apparent diffusion coefficient (ADC) values was developed to predict for sarcoma. The training set consisted of 51 sarcomas and 105 leiomyomas. Two external validation sets were used to evaluate interreader reproducibility (16 sarcomas; 26 leiomyomas) and impact of reader experience (29 sarcomas; 30 leiomyomas). Wilson confidence intervals (CIs) were calculated for sensitivity and specificity. Results Evaluated were 156 women (median age, 50 years; interquartile range, 44-63 years). Predictive MRI criteria for malignancy were enlarged lymph nodes or peritoneal implants, high DWI signal greater than that in endometrium, and ADC less than or equal to 0.905 × 10-3 mm2/sec. Conversely, a global or focal area of low T2 signal intensity and a low or an intermediate DWI signal less than that in endometrium or lymph nodes allowed readers to confidently diagnose as benign a uterine mass demonstrating one or more of these signs (P < .001) in 100% cases in all three data sets. The sensitivities and specificities of the algorithm for diagnosis of malignancy were 98% (50 of 51 masses; 95% CI: 90%, 100%) and 94% (99 of 105 masses; 95% CI: 88%, 98%) in the training set; 88% (14 of 16 masses; 95% CI: 64%, 97%) and 100% (26 of 26 masses; 95% CI: 87%, 100%) in the validation set; and 83% (24 of 29 masses; 95% CI: 65%, 92%) and 97% (29 of 30 masses; 95% CI: 83%, 99%) for the less experienced reader, respectively. Conclusion A diagnostic algorithm with predictive features including lymphadenopathy, high diffusion-weighted imaging signal with reference to endometrium, and low apparent diffusion coefficient enabled differentiation of malignant sarcomas from atypical leiomyomas, and it may assist inexperienced readers. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Méndez in this issue.

Hemorrhage promotes chronic adverse remodeling in acute myocardial infarction: a T1 , T2 and BOLD study.

Hemorrhage is recognized as a new independent predictor of adverse outcomes following acute myocardial infarction. However, the mechanisms of its effects are less understood. The aim of our study was to probe the downstream impact of hemorrhage towards chronic remodeling, including inflammation, vasodilator function and matrix alterations in an experimental model of hemorrhage. Myocardial hemorrhage was induced in the porcine heart by intracoronary injection of collagenase. Animals (N = 18) were subjected to coronary occlusion followed by reperfusion in three groups (six/group): 8 min ischemia with hemorrhage (+HEM), 45 min infarction with no hemorrhage (I - HEM) and 45 min infarction with hemorrhage (I + HEM). MRI was performed up to 4 weeks after intervention. Cardiac function, edema (T2 , T1 ), hemorrhage (T2 *), vasodilator function (T2 BOLD), infarction and microvascular obstruction (MVO) and partition coefficient (pre- and post-contrast T1 ) were computed. Hemorrhage was induced only in the +HEM and I + HEM groups on Day 1 (low T2 * values). Infarct size was the greatest in the I + HEM group, while the +HEM group showed no observable infarct. MVO was seen only in the I + HEM group, with a 40% occurrence rate. Function was compromised and ventricular volume was enlarged only in the hemorrhage groups and not in the ischemia-alone group. In the infarct zone, edema and matrix expansion were the greatest in the I + HEM group. In the remote myocardium, T2 elevation and matrix expansion associated with a transient vasodilator dysfunction were observed in the hemorrhage groups but not in the ischemia-alone group. Our study demonstrates that the introduction of myocardial hemorrhage at reperfusion results in greater myocardial damage, upregulated inflammation, chronic adverse remodeling and remote myocardial alterations beyond the effects of the initial ischemic insult. A systematic understanding of the consequences of hemorrhage will potentially aid in the identification of novel therapeutics for high-risk patients progressing towards heart failure.

Assessing Response to Therapy in Neuroblastoma with MRI T1 Mapping.

HomeRadiology: Imaging CancerVol. 2, No. 5 Previous Research HighlightsFree AccessAssessing Response to Therapy in Neuroblastoma with MRI T1 MappingGary D. LukerGary D. LukerGary D. LukerPublished Online:Sep 25 2020https://doi.org/10.1148/rycan.2020209026MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Take-Away Points■ Major Focus: Investigating T1 mapping as a quantitative, functional MRI marker for response to targeted therapy in neuroblastoma.■ Key Result: Regions with high T1 corresponded with undifferentiated neuroblasts, which decreased with successful therapy.■ Impact: Clinical translation of T1 mapping may help improve precision medicine for children with neuroblastoma and other malignancies with similar pathologic features.Neuroblastoma is a childhood malignancy that arises from neural crest cells in the sympathetic nervous system. Amplification of the gene MYCN, the most common genetic abnormality in this cancer, marks patients with aggressive disease and poor prognosis. Trials with drugs designed to destabilize MYCN protein require functional imaging methods to measure response to therapy earlier and with greater sensitivity than changes in tumor volume. Imaging cell membrane transporters for norepinephrine or metabolism with metaiodobenzylguanidine (MIBG) or fluorine-18 2-fluoro-2-deoxyglucose PET/CT, respectively, provide functional information but expose children to additional radiation and imaging studies. Since the soft-tissue delineation of MRI makes it the preferred method for anatomic imaging of neuroblastoma, an MRI-based functional imaging method would streamline evaluation.Using a genetically engineered mouse model of MYCN neuroblastoma, Zormpas-Petridis et al discovered that T1 mapping from MRI detects tumor heterogeneity. Regions with high and low T1 signal corresponded to areas in tumors with large numbers of undifferentiated neuroblasts and more differentiated cancer cells, respectively. Treatment with targeted inhibitors against aurora A kinase (alisertib) or mTOR (vistusertib) reduced T1 signal due to death of undifferentiated neuroblasts. The authors proposed that undifferentiated neuroblasts produce high T1 signal because these cells have very large nuclei and minimal cytoplasm, similar to other “small round blue cell tumors” including medulloblastoma, Ewing sarcoma, and small cell lung cancer. These data support clinical trials using T1 mapping to monitor response to targeted therapies in neuroblastoma and suggest this MRI method may extend to other tumors in the group of small round blue cell tumors.Highlighted ArticleZormpas-Petridis K, Poon E, Clarke M, et al. Noninvasive MRI native T1 mapping detects response to MYCN-targeted therapies in the Th-MYCN model of neuroblastoma. Cancer Res 2020;80:3424–3435. doi: 10.1158/0008-5472.CAN-20-0133.Highlighted ArticleZormpas-Petridis K, Poon E, Clarke M, et al. Noninvasive MRI native T1 mapping detects response to MYCN-targeted therapies in the Th-MYCN model of neuroblastoma. Cancer Res 2020;80:3424–3435. doi: 10.1158/0008-5472.CAN-20-0133. Crossref, Medline, Google ScholarArticle HistoryPublished online: Sept 25 2020 FiguresReferencesRelatedDetailsRecommended Articles Updates in Diagnosis, Management, and Treatment of NeuroblastomaRadioGraphics2018Volume: 38Issue: 2pp. 566-580Extraskeletal Ewing Sarcoma from Head to Toe: Multimodality Imaging ReviewRadioGraphics2022Volume: 42Issue: 4pp. 1145-1160Current and Emerging Roles of Whole-Body MRI in Evaluation of Pediatric Cancer PatientsRadioGraphics2019Volume: 39Issue: 2pp. 516-534Pediatric Brain Tumor Genetics: What Radiologists Need to KnowRadioGraphics2018Volume: 38Issue: 7pp. 2102-2122MIBG in Neuroblastoma Diagnostic Imaging and TherapyRadioGraphics2016Volume: 36Issue: 1pp. 258-278See More RSNA Education Exhibits Big List of Malignant Small Round Cell Tumors: A Pictorial Exhibit on CTDigital Posters2018Stain Your Brain: Neuropathology of Pediatric Brain TumorsDigital Posters2018Li Fraumeni Syndrome: Genomics, Oncogenesis and Where to Look on Whole-Body Surveillance ImagingDigital Posters2019 RSNA Case Collection Ewing's sarcomaRSNA Case Collection2020Metastatic MedulloblastomaRSNA Case Collection2021Desmoplastic Small Round Cell Tumor RSNA Case Collection2021 Vol. 2, No. 5 Metrics Altmetric Score PDF download

Increasing partner communication and understanding during pregnancy: evaluation of ‘The Great Pregnancy Quiz’

ABSTRACT Objective To evaluate a Quiz designed to enhance communication and understanding in expectant parents. Background A supportive and understanding relationship is associated with better maternal mental health outcomes. Many services therefore advocate that couples should communicate openly with each other, particularly about worries or concerns either have. To facilitate this a quiz (The Great Pregnancy Quiz) was developed and evaluated in this project. Method English-speaking women (N = 442) and men (N = 146) were recruited from antenatal clinics or classes and were given the ‘Great Pregnancy Quiz’ to complete at home. Approximately 2–4 weeks (T2) later they participated in either a phone interview, an online survey, or a face-face interview, still during the pregnancy, concerning the impact of the Quiz. Data were available from 90 women and 46 men. Data were analysed using a mixed-methods single group post-test only design. Results Most women (78 of the 90: 87%) and men (35 of the 46: 76%) reported that the Quiz had positively impacted either their understanding or knowledge of each other. For 30 of the 90 women (33%) and 3 of the 46 men (7%) one or other had implemented some new supportive behaviour due to the Quiz. Qualitative comments highlight the impacts of the Quiz. Conclusion Most couples who did the Quiz reported positive impacts on their communication and understanding. While the issue of low T2 contact rates may have skewed the results, the benefits associated with the quiz make this resource an inexpensive and easily implemented health promotion strategy.

Electronic structure and magnetic exchange interactions in Zn diluted CuFe2O4 magneto-ceramics

We report a detailed study on the electronic structure and temperature (1.9K≤T≤900K) dependence of magnetization in Zn diluted cuprospinel [Cu1−xZnxFe2O4 (0≤x≤0.6)]. The electronic structure determined from the x-ray photoelectron spectroscopy and Rietveld analysis of the x-ray diffraction patterns reveals the structure to be (Cu(1−x)/5ZnxFe4(1−x)/5)A [Cu4(1−x)/5Fe2−4(1−x)/5]BO4. Beyond a specific dilution limit (0.05≤xp≤0.1), a sudden phase-change from tetragonal (I41/amd) to cubic (Fd3m) is noticed with an alteration in the A–O–A (3.29%) bond angle and A–O bond length (0.67%). Our analysis shows that all these compounds order ferrimagnetically below the Néel temperature (TFN) due to dissimilar site-specific magnitudes of spins, yet, they undergo a second transition at low temperatures T1∼66K with asymptotic Curie temperature TA(=C/χ0) as high as −547.2K for the undoped case. Dilution with Zn cause quadratic decay (b2x2+b1x+yo) of the ferrimagnetic ordering temperature from 743 K to 370.5 K for x=0 and 0.6, respectively. On the contrary, a significant increase in the saturation magnetization (MS) was observed with increasing x until the critical composition xc∼0.4 beyond which MS decreases continuously (MS=1.64μB and 4.73μB for x=0 and 0.4, respectively). From the temperature dependence of inverse paramagnetic susceptibility [χ−1(T&amp;gt;TFN)] data and Néel’s expression for ferrimagnets, we evaluated the molecular field constants and exchange interactions (J) between the tetrahedral A- and octahedral B-sites. A systematic compositional dependence of this analysis yields that JAB (∼25kB for x=0) is the dominant exchange interaction in comparison to JBB and JAA; however, JAB decreases significantly with increasing the composition (JAB∼−5.5kB for x=0.6). The isothermal magnetization data and law of approach to saturation analysis reveals that the investigated system possesses very high anisotropy field HK ≥5.5kOe with cubic anisotropy constant K1≥1.6×106erg/cc at xc.

Noninvasive MRI Native T1 Mapping Detects Response to MYCN-targeted Therapies in the Th-MYCN Model of Neuroblastoma.

Noninvasive early indicators of treatment response are crucial to the successful delivery of precision medicine in children with cancer. Neuroblastoma is a common solid tumor of young children that arises from anomalies in neural crest development. Therapeutic approaches aiming to destabilize MYCN protein, such as small-molecule inhibitors of Aurora A and mTOR, are currently being evaluated in early phase clinical trials in children with high-risk MYCN-driven disease, with limited ability to evaluate conventional pharmacodynamic biomarkers of response. T1 mapping is an MRI scan that measures the proton spin-lattice relaxation time T1. Using a multiparametric MRI-pathologic cross-correlative approach and computational pathology methodologies including a machine learning-based algorithm for the automatic detection and classification of neuroblasts, we show here that T1 mapping is sensitive to the rich histopathologic heterogeneity of neuroblastoma in the Th-MYCN transgenic model. Regions with high native T1 corresponded to regions dense in proliferative undifferentiated neuroblasts, whereas regions characterized by low T1 were rich in apoptotic or differentiating neuroblasts. Reductions in tumor-native T1 represented a sensitive biomarker of response to treatment-induced apoptosis with two MYCN-targeted small-molecule inhibitors, Aurora A kinase inhibitor alisertib (MLN8237) and mTOR inhibitor vistusertib (AZD2014). Overall, we demonstrate the potential of T1 mapping, a scan readily available on most clinical MRI scanners, to assess response to therapy and guide clinical trials for children with neuroblastoma. The study reinforces the potential role of MRI-based functional imaging in delivering precision medicine to children with neuroblastoma. SIGNIFICANCE: This study shows that MRI-based functional imaging can detect apoptotic responses to MYCN-targeted small-molecule inhibitors in a genetically engineered murine model of MYCN-driven neuroblastoma.

Quantitative magnetic resonance imaging: differentiating soft tissue implants and fillers used in cosmetic and reconstructive surgery.

To evaluate the value of synthetic magnetic resonance imaging (MRI) and T2 mapping in distinguishing between different types of fillers in soft tissues. Ex vivo fillers of buttock soft tissues (silicone, collagen, and different types of hyaluronic acid) were scanned using a synthetic MRI sequence at 1.5 and 3T and an optimized T2 mapping sequence to measure the T2 relaxation times of the fillers ex vivo. Three patients addressed to assess complications with buttock fillers underwent MRI with the standard morphological sequences and an additional synthetic MRI sequence; T2 mapping was not performed for the patients. Two patients had silicone fillers, whereas the exact filler composition for the third patient was unknown. Measurements of T1 and T2 relaxation times of ex vivo fillers at 1.5 and 3T using synthetic MRI showed that the silicone, collagen, and hyaluronic acid had distinct relaxation time characteristics. In vivo, the synthetic MRI correctly identified silicone in the two patients with known silicone fillers, showing low T1 and T2 values, whereas in the third patient with an unknown filler type, the synthetic MRI suggested a collagen filler, with intermediate relaxation time values. Quantitative sequences have the potential to differentiate between filler types in a noninvasive fashion.

The Negative Predictive Value of a PI-RADS Version 2 Score of 1 on Prostate MRI and the Factors Associated With a False-Negative MRI Study.

OBJECTIVE. The purpose of this study was to calculate the negative predictive value of a prostate MRI study with a Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) score of 1 (hereafter referred to as a PI-RADS 1 MRI study) and to explore the patient characteristics and MRI-based factors associated with an MRI study with false-negative results. MATERIALS AND METHODS. A total of 542 consecutive patients with a PI-RADS 1 MRI study obtained between January 2016 and July 2019 were retrospectively identified. Patient charts were examined to identify those patients who subsequently underwent systematic prostate biopsy within 1 year of undergoing MRI or at any later date if the biopsy was negative. Patient characteristics and MRI-specific factors were recorded. Two blinded radiologists evaluated the quality of the axial T2-weighted, DWI, and apparent diffusion coefficient sequences; measured the volume of the bladder, the prostate gland, and rectal gas; and determined whether the peripheral zone was avidly enhancing and whether low signal intensity was seen in 50% or more of the peripheral zone on T2-weighted images. Interobserver agreement was tested. Univariable and multivariable logistic regression models were built. RESULTS. A total of 150 patients (median age, 63 years; interquartile range, 56-70 years) were included. Of these patients, 19 (13%) had prostate cancer with a Gleason score of 3 + 4 or greater, yielding a negative predictive value of 87%. Both low T2 signal intensity in the peripheral zone and the prostate-specific antigen level were associated with a false-negative PI-RADS 1 assessment (odds ratio, 4.9 [95% CI, 1.6-14.9; p = 0.006] and 1.1 [95% CI, 1.0-1.2; p = 0.03], respectively). A cutoff prostate-specific antigen level of 3.97 ng/mL resulted in sensitivity and specificity of 89% and 21%, respectively. There was moderate interobserver agreement for low T2 signal intensity in the peripheral zone (κ coefficient = 0.75). CONCLUSION. Even among select patients who undergo subsequent biopsy because of a high clinical suspicion of prostate cancer, a PI-RADS 1 prostate MRI study has a high negative predictive value. A T2-hypointense peripheral zone and an elevated prostate-specific antigen level are significantly associated with a false-negative MRI study.

Significant Association between the T2 Values of Vertebral Cartilage Endplates and Pfirrmann Grading.

ObjectiveThe T2 value of lumbar cartilage endplates was measured using the T2 mapping imaging technique, aiming to explore the correlation between the T2 value and Pfirrmann grading of intervertebral discs.MethodsA total of 130 patients with lumbar spine MR examination due to persistent low back pain were enrolled, including 71 men and 59 women (age: 21–63 years). Lumbar Modic changes and Schmorl nodules were recognized by conventional T1WI and T2WI images in 49 patients, and these patients were excluded from the study. A total of 81 patients were enrolled in this study, including 45 men (45.16 ± 12.20 years) and 36 women (43.33 ± 11.27 years). Pfirrmann (Pm) grading of each lumbar disc was performed based on conventional T2WI median sagittal images and the position of cartilage endplates (CEP) was determined by IDEAL‐SPGR images. Meanwhile, the T2 mapping technique was used to obtain T2 values of cartilage endplates. The T2 values of CEP corresponding to different Pm grade discs were compared, and the correlation between the T2 value and the Pm grade of intervertebral discs was analyzed.ResultsThe T2 values of cephalic and caudal CEP of L1–2 in Pm grades I–II, Pm grades III, and Pm grades IV–V were 61.96 ± 5.89 ms, 54.45 ± 3.29 ms, 42.47 ± 3.69 ms and 64.35 ± 5.93 ms, 55.28 ± 3.97 ms, 44.75 ± 2.12 ms, respectively. For cephalic and caudal CEP of L2–3, the T2 values in Pm grades I–II, Pm grades III, and Pm grades IV–V were 62.96 ± 6.93 ms, 55.19 ± 4.02 ms, 48.67 ± 4.56 ms and 65.51 ± 6.49 ms, 57.16 ± 5.55 ms, 52.05 ± 4.20 ms, respectively. The T2 values of cephalic and caudal CEP from L3–4 to L5–S1 in Pm grades I–II, Pm grades III, and Pm grades IV–V were (63.72 ± 5.76 ms, 53.96 ± 6.52 ms, 48.05 ± 5.00 ms), (65.46 ± 6.37 ms, 55.70 ± 7.50 ms, 48.10 ± 3.27 ms); (66.34 ± 7.68 ms, 56.76 ± 9.48 ms, 47.80 ± 4.33 ms), (64.44 ± 4.65 ms, 59.30 ± 8.80 ms, 47.30 ± 5.78 ms), (65.32 ± 5.11 ms, 55.33 ± 6.65 ms, 48.18 ± 5.37 ms), and (63.47 ± 4.92 ms, 50.32 ± 8.86 ms, 44.77 ± 4.69 ms), respectively. There were significant differences in T2 values of cartilage endplates between the Pm grades I–II, III, and IV–V of intervertebral discs (P = 0.000). T2 values corresponding to Pm I–II grades were higher than those in Pm III grade, while T2 values in Pm grades IV–V were lowest. The T2 value of the L4–5, L5–S1 segment endplates was highly correlated with the Pm grades (r = −0.711, −0.721, −0.796, −0.745; P = 0.000) and that of L1–2, L2–3 endplates were moderately correlated (r = −0.542, −0.562, −0.637, −0.612; P = 0.000).ConclusionThe T2 values of cartilage endplates revealed varying degrees of degeneration of intervertebral discs, and more severe degeneration corresponded to lower T2 values. Measurement of changes in the T2 value through cartilage endplates can be useful for the diagnosis of early intervertebral disc degeneration and the prevention of disc degeneration.

Chemical abundances of Seyfert 2 AGNs – III. Reducing the oxygen abundance discrepancy

ABSTRACT We investigate the discrepancy between oxygen abundance estimations for narrow-line regions of active galactic nuclei (AGNs) type Seyfert 2 derived using direct estimations of the electron temperature (Te-method) and those derived using photoionization models. In view of this, observational emission-line ratios in the optical range ($3000 \: \lt \: \lambda (\mathring{\rm A}) \: \lt 7000$) of Seyfert 2 nuclei compiled from the literature were reproduced by detailed photoionization models built with the cloudy code. We find that the derived discrepancies are mainly due to the inappropriate use of the relations between temperatures of the low (t2) and high (t3) ionization gas zones derived for H ii regions in AGN chemical abundance studies. Using a photoionization model grid, we derived a new expression for t2 as a function of t3 valid for Seyfert 2 nuclei. The use of this new expression in the AGN estimation of the O/H abundances based on Te-method produces O/H abundances slightly lower (about 0.2 dex) than those derived from detailed photoionization models. We also find that the new formalism for the Te-method reduces by about 0.4 dex the O/H discrepancies between the abundances obtained from strong emission-line calibrations and those derived from direct estimations.

Gadolinium-hyaluronic acid nanoparticles as an efficient and safe magnetic resonance imaging contrast agent for articular cartilage injury detection

Accurate detection of cartilage injuries is critical for their proper treatment because these injuries lack the self-healing ability and lead to joint dysfunction. However, the low longitudinal T1 relaxivity (r1) and non-specificity of contrast agents (such as gadolinium(III)-diethylenetriamine-pentaacetic acid (Gd-DTPA)) significantly limit the efficiency of clinical magnetic resonance imaging (MRI) applications. To overcome these drawbacks, we integrated hyaluronic acid (HA) with Gd to synthesize a Gd-DTPA-HA composite, which was subsequently freeze-dried to produce nanoparticles (NPs). The resultant Gd-HA NPs demonstrated a greater r1 value (12.51 mM−1 s−1) compared with the bulk Gd-DTPA-HA (8.37 mM−1 s−1) and clinically used Gd-DTPA (3.88 mM−1 s−1). Moreover, the high affinity of HA to the cartilage allowed these NPs to penetrate deeper beyond the cartilage surface. As a result, Gd-HA NPs considerably increased the quality of cartilage and lesion MR images via their intra-articular injection in vivo. Specifically, 2 h after NP administration, the signal-to-noise ratio at the injured cartilage site was 2.3 times greater than the value measured before the injection. In addition, Gd-HA NPs exhibited good biosafety properties due to the absence of adverse effects in the blood or on the main organs. It was also showed that Gd NPs were first metabolized by the kidney and liver and then excreted from the body with urine. Thus, Gd-HA NPs can potentially serve as an efficient MRI contrast agent for improved detection of cartilage injuries.

Sweet corn in no-tillage system on cover crop residues in the Brazilian Cerrado

In recent years, the growth of the cultivated area with sweet corn in conventional tillage system in Brazil expanded, although crops can be grown on different residues of cover crops, which improve nutrient cycling and crop productivity. The objective of this study was to evaluate the biomass production and to quantify the rate of plant residues decomposition of different cover crops, and correlate the results with the production and grain yield of sweet corn in an area located in the Cerrado biome. The experimental design used was randomized blocks with eight treatments: PM - pearl millet; SH - sunn hemp; SG - signal grass; PM + SH; PM + SG; SH + SG; PM+ SH + SG; FW - fallow (spontaneous vegetation), which preceded the cultivation of sweet corn. Fresh biomass (FB) and dry biomass (DB) of the cover crops were evaluated, as well as the rate of plant residue decomposition. Sweet corn productivity, straw and corncob weight, and grain yield were also determined. Pearl millet presented a better performance in FB production, decomposition rate, residue half-life (T½ life) in soil, yield, corn cob strawweight and yield of sweet corn. Pearl millet, when mixed with other plants, presented reduced rate of residue decomposition and increased residue T½ life. The FW presented the lowest biomass production, with great rate of decomposition and low T½ life. Cover crops grown before sweet corn in soils of good fertility did not affect crop agronomic characteristics. Pearl millet is the best cover crop adapted to Cerrado Brazilian climatic conditions to be used in monoculture or in mixtures with other plants.

Clinical study of 21 cases of sacral cysts containing fila terminale

To summarize the characteristics of sacral cysts containing fila terminale and to explore the surgical treatment methods. The clinical features, imaging characteristics and surgical methods of 21 cases of sacral cysts containing fila terminale from July 2010 to March 2017 were reviewed and analyzed. Lumbosacral and perineal pain, weakness of the lower limbs and bladder and bowel dysfunction were the common clinical symptoms. MRI showed that the cysts located in the sacral canal. The lower T1 and higher T2 signals were found on MRI. There were fila terminale within the cysts which tethered the spinal cord. No enhancement was visible within the lesion. The key steps of operation included the resection of the cyst wall, the cutting off of the fila terminale, the release of the tethered cord and the reconstruction of the cisterna terminalis. The total and subtotal resections of cyst walls were achieved in 14 and 7 cases, respectively. The fila terminales were separated and cut off in all the cases, and the tethered cords were released completely. The reconstructions of the cisterna terminalis were accomplished in all the cases. There was no new-onset dysfunction except for 7 cases of mild numbness around anus postoperatively. Pathological examinations confirmed that the cyst wall was fibrous connective tissue, and hyperplasia of fibrous tissue and/or adipose tissue was found within the thickened fila terminale. The lumbosacral and perineal pain disappeared. The weakness of the lower extremities and the bladder and bowel dysfunction gradually improved. The period of follow-up ranged from 3 months to 7 years (average: 2.25 years). The spinal function of all the patients restored to McCormick grade Ⅰ. Only 1 case encountered recurrence of cyst. The sacral cysts containing fila terminale are rare. The common symptoms include lumbosacral and perineal pain and symptoms of tethered cord. MRI is helpful to the diagnosis, which shows the signal of cerebrospinal fluid and the fila terminale in the cyst as well as tlow-placed conus medullaris. Microsurgery should remove the cyst wall, cut off the fila terminale, release the tethered cord and reconstruct the cisterna terminalis.

Cardiac T2* MR in patients with thalassemia major: a 10-year long-term follow-up.

The consequence of regular blood transfusion in patients with thalassemia major (TM) is iron overload. Herein, we report the long-term impact of chelation on liver iron concentration (LIC) and cardiac T2* MR in patients with TM. This is a retrospective cohort study over 10years of adolescents and adults with TM aged at least 10years who had their first cardiac T2* MR between September 2006 and February 2007. One-year chelation therapy was considered the unit of analysis. A total of 99 patients were included in this study with a median age of 18years. The median cardiac T2* MR and LIC at baseline were 19ms and 11.6mg/g dw, respectively. During follow-up, 18 patients died and six underwent successful bone marrow transplantation. Factors associated with decreased survival were older age (HR 1.12, p= 0.014) and high risk cardiac T2* (HR 8.04, p= 0.004). The median cardiac T2* and LIC significantly improved over the 10-year follow-up period (p= 0.000011 and 0.00072, respectively). In conclusion, this long-term "real-life" study confirms that low cardiac T2* adversely impacts the overall survival in patients with TM. Higher baseline LIC predicts a larger reduction in LIC, and lower baseline cardiac T2* predicts a larger improvement in T2*.

Is There A Role for Limited Parotid Resections for Primary Malignant Parotid Tumors?

(1) Background: Lateral or total parotidectomy are the standard surgical treatments for malignant parotid tumors. However, some authors have proposed a more limited procedure. (2) Methods: We performed a review of the literature on this topic. Studies were included that met the following criteria: malignant parotid tumors, information about the extent of surgical resection, treated with less than a complete lateral lobectomy, and information on local control and/or survival. Nine articles fulfilled the inclusion criteria. (3) Results: Eight of the nine series reported favorable results for the more limited approaches. Most used them for small, mobile, low-grade cancers in the lateral parotid lobe. Most authors have used a limited partial lateral lobectomy for a presumed benign lesion. The remaining study analyzed pediatric patients treated with enucleation with poor local control. (4) Conclusions: There is weak evidence for recommending less extensive procedures than a lateral parotid lobectomy. In the unique case of a partial lateral parotidectomy performed for a tumor initially thought to be benign but pathologically proved to be malignant, close follow-up can be recommended for low grade T1 that has been excised with free margins and does not have adverse prognostic factors.