Signal Intensity Measurements Research Articles

Echo-planar DWI variants: A comparative study in vertebral marrow pathology.

Single-shot echo-planar imaging (ss-EPI) has limited application in vertebral column imaging due to numerous artifacts. Therefore, we aimed to compare readout-segmented echo-planar imaging (rs-EPI) to ss-EPI and assess its value in the differential diagnosis of vertebral infectious, tumoral infiltrative, and degenerative disorders. Sixty-six adult patients with spondylodiscitis (SD, n = 26), tumoral infiltration (TI, n = 20), or Modic type I degeneration (DE, n = 20) findings on spinal magnetic resonance imaging (MRI) included in this retrospective study. Two radiologists scored images for quality on a 4-point scale (image resolution, degree of geometric distortion, lesion selectivity, and diagnostic reliability) and measured signal intensity (SI), apparent diffusion coefficient (ADC), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). DE and SD groups also united to form the benign group. In all groups, rs-EPI performed better than ss-EPI in image quality, SNR, and CNR (p < .05). The difference between mean pathological ADC (ADCP) in the two sequences was statistically significant (p < .05). There was no significant difference between the groups in terms of ADCP in rs-EPI (p = .229), unlike ss-EPI (p = .025). Pathological SI (SIP) and CNR in rs-EPI were significantly higher in the malignant group than benign group (p = .002, p < .001). In rs-EPI, no significant difference was found between malignant and benign groups' ADCP (p = .13). The rs-EPI is a diffusion-weighted imaging (DWI) method with higher image quality that diminishes motion-induced phase errors and increases resolution through phase corrections. However, the distinction of malignant and benign vertebral bone marrow pathologies is unsatisfactory for rs-EPI compared with ss-EPI.

The "Hypointense Focal Brain" on susceptibility-weighted imaging as a sign of venous congestion in cranial dural arteriovenous fistulas.

Cranial dural arteriovenous fistulas (dAVFs) are complex neurovascular malformations accounting for approximately 10%-15% of all intracranial arteriovenous malformations. The objective is to investigate the utility of susceptibility-weighted imaging (SWI) in identifying "hypointense focal brain" as an additional helpful sign of venous congestion in cranial dAVFs. A retrospective review of patients diagnosed with cranial dAVFs between January 2015 and June 2023 was conducted, and SWI was used to identify the "hypointense focal brain" sign within the venous drainage region of the dAVF. The "hypointense focal brain" on SWI was identified as a low-intensity signal within the venous drainage region, indicative of venous congestion. The presence of this imaging sign was assessed by two neuroradiologists and signal intensity measurements were performed to support the presence of the sign. The study included six patients with cranial dAVFs exhibiting cortical venous retrograde drainage and the "hypointense focal brain" on SWI. Follow-up imaging post-treatment revealed resolution or improvement of the hypointense signal, confirming its association with venous congestion. Signal intensity measurements further supported the presence of this imaging sign in pre-treatment scans. The study's findings demonstrate the presence of a reversible "hypointense focal brain" sign on SWI in patients with cranial dAVFs and CVR, which can be useful as an additional imaging sign for venous congestion.

Evaluation and clinical application of a bracketing calibration-based isotope dilution liquid chromatography-tandem mass spectrometry candidate reference measurement procedure for serum theophylline.

A candidate reference measurement procedure (RMP) for serum theophylline via isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. With a single-step precipitation pretreatment and a 6-min gradient elution, the method achieved baseline separation of theophylline and its analogs on a C18-packed column. A bracketing calibration method was used to ensure repeatable signal intensity and high measurement precision. The intra-assay and inter-assay imprecisions were 1.06%, 0.84%, 0.72% and 0.47%, 0.41%, 0.25% at concentrations of 4.22 µg/mL (23.40 µmol/L), 8.45 µg/mL (46.90 µmol/L), and 15.21 µg/mL (84.43 µmol/L), respectively. Recoveries ranged from 99.35 to 102.34%. The limit of detection (LoD) was 2 ng/mL, and the lowest limit of quantification (LLoQ) was 5 ng/mL. The linearity range extended from 0.47 to 60 µg/mL (2.61-333.04 µmol/L). No ion suppression and carry-over (< 0.68%) were observed. The relative bias for this candidate RMP that participated in 2023 External Quality Control for Reference Laboratories (RELA) conducted by the International Federation of Clinical Chemistry (IFCC) was within a range of 0.17 to 0.93%. Furthermore, two clinical immunoassay systems were compared with this candidate RMP, demonstrating good correlations. The results of the Trueness Verification Plan indicate significant differences among routine systems, highlighting the need for standardization efforts. The developed candidate RMP for serum theophylline serves as a precise reference baseline for standardizing clinical systems and assigning values to reference materials.

MRI assessment of seminal vesicle involvement by prostate cancer using T2 signal intensity and volume.

Seminal vesicle involvement (SVI) in patients with newly diagnosed prostate cancer is associated with high rates of treatment failure and tumor recurrence; correct identification of SVI allows for effective management decisions and surgical planning. This single-center retrospective study analyzed MR images of the seminal vesicles from patients undergoing radical prostatectomy with confirmed T3b disease, comparing them to a control group without SVI matched for age and Gleason grade with a final stage of T2 or T3a. Seminal vesicles were segmented by an experienced uroradiologist, "raw" and bladder-normalized T2 signal intensity, as well as SV volume, were obtained. Among the 82 patients with SVI, 34 (41.6%) had unilateral invasion, and 48 (58.4%) had bilateral disease. There was no statistically significant difference in the degree of distension between normal and involved seminal vesicles (P = 0.08). Similarly, no statistically significant difference was identified in the raw SV T2 signal intensity (P = 0.09) between the groups. In the 159 patients analyzed, SVI was prospectively suspected in 10 of 82 patients (specificity, 100%; sensitivity, 12.2%). In all these cases, lesions macroscopically invaded the seminal vesicle, and the raw T2 signal intensity was significantly lower than that in the SVI and control groups (P = 0.02 and 0.01). While signal intensity measurements in T2-weighted images may provide insight into T3b disease, our findings suggest that this data alone is insufficient to reliably predict SVI, indicating the need for further investigation and complementary diagnostic approaches.

Simplified S1 vertebral bone quality score independently predicts proximal junctional kyphosis after surgery for degenerative lumbar scoliosis

ObjectiveOur study aimed to assess the effectiveness of the simplified S1 vertebral bone quality (VBQ) score in predicting the incidence of proximal junctional kyphosis (PJK) after surgery for degenerative lumbar scoliosis (DLS).MethodsWe reviewed 122 patients with DLS who underwent posterior lumbar decompression and long-segment fusion surgery in our hospital from January 2016 to December 2020. The patients were classified into PJK group and non-PJK group. S1 VBQ scores are determined by signal intensity measurements taken from the mid-sagittal plane of T1-weighted non-contrast MRI. Logistic regression analysis was used to identify factors associated with PJK. Receiver-operating characteristic curve (ROC) analysis was used to evaluate the value of S1 VBQ score in predicting pedicle PJK after DLS.Results122 DLS patients (90 females and 32 males) met the inclusion criteria. In addition, 27 patients (22.13%) had PJK at the time of last follow-up. VBQ was higher in PJK patients than non-PJK patients (3.58 ± 0.67 vs. 3.08 ± 0.54, p < 0.001). Preoperatively, patients in the PJK group had a greater TLK than those in the non-PJK group (20.00 ± 6.22 vs. 16.86 ± 5.38, p = 0.011). After surgery, patients in the PJK group had greater TLK (p < 0.001) and PJA (p < 0.001) compared with the non-PJK group. At final FU, patients in the PJK group had greater TK (p = 0.002), TLK (p < 0.001), SVA (p < 0.001), and PJA (p < 0.001) than patients in the non-PJK group (Table 4). In multivariate logistic regression analysis, higher VBQ score (OR 4.565, 95% CI 1.43–14.568, p = 0.010), advanced age (OR 1.119, 95% CI 1.021–1.227, p = 0.016), and larger TLK (OR 1.191, 95% CI 1.041–1.362, p = 0.011) were significant predictors of postoperative PJK in patients with DLS (Table 6). A statistically significant positive correlation existed between VBQ score and PJA change (r = 0.370, p < 0.001). We created ROC curves for VBQ scores as predictors of PJK with a diagnostic accuracy of 72.1% (95% CI 60.15–82.9%.The ideal limit for the VBQ score was 3.205 (sensitivity: 77.8%, specificity: 81.4%).ConclusionTo the best of our knowledge, this is the first study to evaluate the effectiveness of the S1 VBQ score in predicting postoperative PJK in DLS. Our study included major risk factors and found that S1 VBQ score was a significant predictor of PJK in patients undergoing DLS surgery. The higher the S1 VBQ score, the higher the probability of PJK.

Focal fatty sparing areas of the pediatric steatotic liver: pseudolesions on hepatobiliary phase magnetic resonance images.

Focal fatty sparing in liver can be detected as hyperintense pseudolesions on hepatobiliary phase magnetic resonance imaging (MRI). Distinguishing these pseudolesions from liver lesions may make diagnosis challenging. The aim of this study was to evaluate the imaging features of fatty sparing areas on liver MRI in pediatric patients who have been administered gadoxetate disodium. A total of 63 patients between January 2018 and June 2023 underwent gadoxetate disodium-enhanced liver MRI, and 9 (14%) patients with a focal fatty sparing were included in the study. The fat spared areas were evaluated qualitatively and quantitatively including signal intensity measurements and fat fraction calculations. The liver MRI examinations of 9 patients (5 boys, 4 girls; aged 8-18 years, median age: 14.4) using gadoxetate disodium were evaluated. Based on in-phase and opposed-phase sequences, 13 areas of focal fatty sparing were identified. The mean fat fraction of the liver and fat spared areas were 26.2% (range, 15-47) and 9% (range, 2-17), respectively. All fat spared areas were hyperintense in the hepatobiliary phase images. The mean relative enhancement ratios of the liver and fat spared areas were 0.78 (range, 0.35-1.6) and 1.11 (range, 0.45-1.9), respectively. Focal fatty sparing in liver in children was observed as hyperintense on hepatobiliary phase MRI, and it should not be identified as a focal liver lesion.

The application value of LAVA-flex sequences in enhanced MRI scans of nasopharyngeal carcinoma: comparison with T1WI-IDEAL.

Magnetic resonance imaging (MRI) staging scans are critical for the diagnosis and treatment of patients with nasopharyngeal cancer (NPC). We aimed to evaluate the application value of LAVA-Flex and T1WI-IDEAL sequences in MRI staging scans. Eighty-four newly diagnosed NPC patients underwent both LAVA-Flex and T1WI-IDEAL sequences during MRI examinations. Two radiologists independently scored the acquisitions of image quality, fat suppression quality, artifacts, vascular and nerve display. The obtained scores were compared using the Wilcoxon signed rank test. According to the signal intensity (SI) measurements, the uniformity of fat suppression, contrast between tumor lesions and subcutaneous fat tissue, and signal-to-noise ratio (SNR) were compared by the paired t-test. Compared to the T1WI-IDEAL sequence, LAVA-Flex exhibited fewer artifacts (P<0.05), better visualization of nerves and vessels (P<0.05), and performed superior in the fat contrast ratio of the primary lesion and metastatic lymph nodes (0.80 vs. 0.52, 0.81 vs. 0.56, separately, P<0.001). There was no statistically significant difference in overall image quality, tumor signal-to-noise ratio (SNR), muscle SNR, and the detection rate of lesions between the two sequences (P>0.05). T1WI-IDEAL was superior to LAVA-Flex in the evaluation of fat suppression uniformity (P<0.05). LAVA-Flex sequence provides satisfactory image quality and better visualization of nerves and vessels for NPC with shorter scanning times.

P013 Magnetic Resonance Imaging-Based Average T2 Signal as A Non-Invasive Measure of Fibrosis In Enteric Crohn’s Disease

Abstract Background In Crohn’s Disease (CD), 10% of patients present with fibrostenosis with a further 10% progressing from inflammatory to a fibrostenotic disease behaviour over 7 years. 40% of fibrostenotic CD patients need surgery at 5 years compared to ~10% with inflammatory disease. Present non-invasive fibrosis biomarkers lack the required accuracy needed to be used routinely for clinical decision making. T1, T2, diffusion weighted imaging, motility and bowel volumes have shown promise in the non-invasive measure of fibrosis. Methods The primary objective of this study is to undertake biological validation of MRI measures as independent imaging biomarkers of histological fibrosis with the primary outcome being the correlation between MRI measures and histological fibrosis measures. GI-Seg (Motilent, London, UK) is an image analysis tool used to segment the gastrointestinal tract on T2W MRI scans. Patients with CD histological diagnosis and in need of surgical resection for stenosis attended a one-hour 3T MRI scanning session within 12 weeks prior to their intestinal resection surgery. Histological samples were scored by a specialized gastrointestinal pathologist for inflammation, fibrosis, and muscular hypertrophy. An expert radiologist with the help of the histopathologist located the strictures on DWI, quantitative T2&amp;T2 scans, and T2 weighted clinical MRI scans. GI-Seg was used to generate a 3D model of the stricture on T2W scans measuring bowel wall volume and average signal intensity of each stricture. Pearson correlation coefficient was used to quantify the correlation between the variables. Results A total of 10 CD patients, encompassing 20 strictures, were included in the study. The analysis revealed that the average T2 signal has a significant correlation with global fibrosis scores (r(20) = .563, p = .010) (Figure) and total inflammation scores (r(20) = .451, p = .046). Additionally, stricture volume showed a fair correlation with chronic inflammation component scores (r(20) = .453, p = .045). Notably, quantitative T1 values correlated with total inflammation scores (r(17) = .493, p = .045). Conclusion The study reveals fair correlations between the T2 signal average and both global fibrosis and global inflammation scores, as well as between stricture volume and chronic inflammation in CD strictures. While these findings indicate that the GI-seg tool's measurements of bowel wall volume and signal intensity have potential utility as imaging biomarkers for fibrosis and inflammation, the results also underscore the necessity for additional markers that are specifically correlated with fibrosis. Such markers are essential to distinctly identify fibrotic changes, independent of inflammatory processes.

Exploring enantioselective recognition of dTMP-Co-bpe coordination polymer for natural amino acids using molecular simulations and circular dichroism.

The 1D homochiral coordination polymer (CP-1) {[Co(dTMP)(bpe)2(H2O)3]·9H2O}n was constructed by using 2'-deoxy thymidine 5'-monophosphate disodium salt (dTMP·2Na), and auxiliary ligand bpe (1,2-bis(4-pyridyl)ethene) and characterized by single-crystal XRD, PXRD, IR, UV-visible, CD and TGA analyses. Molecular simulations revealed the selective chiral behaviour of CP-1 towards phenylalanine and histidine, as indicated by their higher binding free energies compared to other amino acids. Theoretical parameters were also compared with experimental UV-visible verdicts. Notably, the D-enantiomers of phenylalanine and histidine demonstrated strong bonding abilities and optimal configurations for probing and distinguishing them from their L-counterparts. These findings led to propositions suggesting that the dissimilarities between these D and L amino acid forms and their binding orientations with CP-1 may contribute to alterations in the CD signal. CP-1 exhibited a robust inherent circular dichroism (CD) signal in aqueous solutions, modulated by the presence of specific amino acids, namely D/L phenylalanine and D/L histidine. Leveraging the measurement of CD signal intensity, a sensor capable of detecting unmodified amino acids has been developed. Unlike previously reported approaches that relied on complex chemical reactions between initially CD-silent molecules and probed amino acids, this new method offers a more straightforward means of amplifying the CD signal. Consequently, this change facilitates a more accurate differentiation between the enantiomers of these specific amino acids compared to others.

Comparative Analysis of FSE T2 Weighted, Chemical Shift and Dynamic Contrast-Enhanced MR Imaging in the Characterization of Adrenal Masses Based on Qualitative and Quantitative Parameters.

The purpose of our study was to investigate the role of different magnetic resonance imaging (MRI) parameters in the characterization of adrenal masses. A total of 150 patients who presented with 186 adrenal tumors were retrospectively evaluated in this study. Final patient cohort consisted of 17 pheochromocytomas, 3 adrenocortical carcinomas, 24 metastases, 31 lipid-poor adenomas and 111 lipid-rich adenomas. We carried out a visual assessment on FSE (Fast spin echo)T2 weighted images and also calculated T2 signal intensity ratio of all adrenal masses and also performed a qualitative assessment on chemical shift imaging (CSI) together with quantitative calculation using Adrenal to spleen signal intensity (si) ratio and Adrenal si index formulas. On dynamic contrast-enhanced sequences, visual assessment based on enhancement patterns on late-arterial phase images was performed and also mean signal intensity measurements were carried out. All examinations were interpreted by two abdominal radiologists in consensus who were blinded to the clinical and pathological findings. Statistical analysis was performed. On FSE T2 weighted imaging, isointense to liver and slightly hyperintense than liver was found higher in benign cases, however, in malignant cases moderately and strikingly hyperintense than liver was higher than in benign cases (p=0.001, p<0.01). There was a statistically significant difference between the T2 signal intensity ratio values of adrenal tumor groups (p=0.001, p<0.01). In lipid-rich and lipid-poor adenoma groups, T2 signal intensity ratio values was significantly lower than in pheochromocytoma and metastasis cases. In malignant group, T2 signal intensity ratio values were found statistically significantly higher than in the benign group (p=0.001, p<0.01). There was a statistically significant difference between CSI visual assessment of adrenal tumor groups (p=0.001, p<0.01). Although moderate and significant signal intensity loss was usually detected in lipid-rich adenoma group, never detected in other tumor groups. There was also a statistically significant difference between benign and malignant adrenal tumor groups (p=0.001, p<0.01). In the malignant group, Adrenal to spleen si ratio values were found significantly higher whereas, Adrenal si index values were significantly lower compared to benign tumors (p=0.001, p<0.01). Based on malignancy, there was a statistically significant difference between adrenal tumor groups (p=0.001, p<0.01). Although capillary blush and homogenous type enhancement were more common in benign cases than in malignant ones, peripheral-patchy and strikingly capillary blush type enhancement was more frequent in malignant tumors. Based on malignancy, mean arterial signal intensity values of malignant tumors were statistically higher than benign tumors (p=0.001; p<0.01). Dynamic contrast-enhanced MRI protocol including CSI aids in the characterization of indeterminate adrenal masses. Herein, the combined use of qualitative and quantitative parameters enables more tumors to be recognized that otherwise would be indeterminate.

Comparison of automated and manual quantification methods for neuromelanin-sensitive MRI in Parkinson's disease.

Neuromelanin-sensitive magnetic resonance imaging quantitative analysis methods have provided promising biomarkers that can noninvasively quantify degeneration of the substantia nigra in patients with Parkinson's disease. However, there is a need to systematically evaluate the performance of manual and automated quantification approaches. We evaluate whether spatial, signal-intensity, or subject specific abnormality measures using either atlas based or manually traced identification of the substantia nigra better differentiate patients with Parkinson's disease from healthy controls using logistic regression models and receiver operating characteristics. Inference was performed using bootstrap analyses to calculate 95% confidence interval bounds. Pairwise comparisons were performed by generating 10,000 permutations, refitting the models, and calculating a paired difference between metrics. Thirty-one patients with Parkinson's disease and 22 healthy controls were included in the analyses. Signal intensity measures significantly outperformed spatial and subject specific abnormality measures, with the top performers exhibiting excellent ability to differentiate patients with Parkinson's disease and healthy controls (balanced accuracy = 0.89; area under the curve = 0.81; sensitivity =0.86; and specificity = 0.83). Atlas identified substantia nigra metrics performed significantly better than manual tracing metrics. These results provide clear support for the use of automated signal intensity metrics and additional recommendations. Future work is necessary to evaluate whether the same metrics can best differentiate atypical parkinsonism, perform similarly in de novo and mid-stage cohorts, and serve as longitudinal monitoring biomarkers.

Development of non-contact foreign body imaging base on photoacoustic signal intensity measurement.

It is challenging to visually identify tiny and concealed foreign objects within the body due to their small size and subcutaneous location while they can cause infections. A non-contact photoacoustic system based on Rosencwaig-Gersho photoacoustic theory and dual modulator method is developed for detecting foreign objects in meat. The experiments conducted validate the successful development of this measurement technique with 10μm spatial resolution and its corresponding mathematical model, demonstrating an 11% Mean Absolute Percentage Error (MAPE) in comparison to the experimental results. Dual modulator successfully regulates laser energy at MPE limit. The utilization of non-contact photoacoustic signal intensity measurements enables the identification of foreign objects within the body. Further, the application of mathematical modelling can validate the measurement outcomes. These findings serve as a foundation for creating an affordable and straightforward foreign body detector.

Development of normalized quantitative measures of lumbar disc degeneration.

Lumbar disc degeneration (DD) is widely regarded as a likely contributor to low back pain (LBP), but the association between DD and LBP is relatively weak. No known studies have normalized quantitative measures of DD severity relative to multiple variables such as age, height, and disc level. This study developed normalized quantitative measures (z-scores) of disc signal intensity (DSI) and disc height (DH) to rate relative severity of DD. Raw (unnormalized) quantitative measures of DSI and DH alongside potential normalization variables were acquired from MRI scans and clinical data of 76 patients. The associations between the raw quantitative measures and potential normalization variables were investigated to develop the normalized quantitative measures (z-scores) of DSI and DH. Construct validity was assessed by comparing the normalized measures to an experienced radiologist's subjective measures of relative severity of DSI and DH loss. CSF signal intensity, age, and disc level were significantly associated with raw DSI (R 2 = 0.06, 0.25, and 0.09, respectively). Lumbar height and disc level were significantly associated with raw DH (R 2 = 0.13 and 0.31). Normalizing DSI and DH by these variables resulted in stronger relationships (R 2 = 0.39 and 0.37) than raw DSI and DH (R 2 = 0.24 and 0.31) with the radiologist's subjective measures. Normalized DSI and DH were both normally distributed (p = 0.32 and 0.12). Construct validity and the distributions suggested that normalized quantitative measures of DSI and DH are better than existing measures of DSI and DH at rating relative DD severity. Determining whether normalized quantitative measures are more predictive of clinical outcomes is important future research.

Contribution of contrast-enhanced ultrasound in the diagnosis of adnexal torsion (AGATA): protocol for a prospective comparative study

IntroductionAdnexal torsion is a surgical emergency and its prognosis depends on the time elapsed prior to treatment. The diagnosis relies on pelvic ultrasound in which sensitivity remains low and may...

Nondestructive Measurement of the Water Content in Building Materials by Single-Sided NMR-MOUSE

Water has a significant impact on the properties of building materials. A nuclear magnetic resonance (NMR) spectrometer can be used to detect water in materials and measure its distribution nondestructively, rapidly, and accurately. In this paper, a novel method is introduced for using single-sided NMR to measure the water content (WC) of building materials, including brick, sandstone, mortar, and concrete. The NMR signal intensity and water content of these building materials were measured using a single-sided NMR-MOUSE PM25 and a high-precision electronic scale, respectively. A total of 80 groups of NMR signal intensity and water content data were obtained in two different measurement environments. The NMR signal intensity and water content data for each of the four building materials were fitted by the least squares method. The similarity of the coefficients of the determined correlations demonstrated that these relations are universal for building materials and independent of the NMR signal intensity and water content measurement environments.

Added value of zoomed-echo-planar imaging diffusion-weighted imaging for evaluation of periampullary carcinomas.

To assess the image quality feasibility and diagnostic value of zoomed diffusion-weighted imaging (z-EPI DWI) using echo-planar imaging (EPI) compared with conventional DWI (c-EPI DWI) in patients with periampullary disease. Thirty-six patients with periampullary carcinomas and fifteen with benign periampullary disease were included in this study. All the subjects underwent MR cholangiopancreatography (MRCP), c-EPI DWI, and z-EPI DWI. Two radiologists independently assessed image quality of the two image sets, including overall image quality and lesion conspicuity. In addition, signal intensity and ADC measurements of DWIs in the periampullary lesions were conducted. Diagnostic accuracies of the combined image sets of MRCP and z-EPI DWI were compared with those of a combined set of MRCP and c-EPI DWI. z-EPI DWI showed significantly better image quality scores (anatomic structure visualization, 2.94 ± 0.24; overall image quality, 2.96 ± 0.17) compared to that with c-EPI DWI (anatomic structure visualization, 2.02 ± 0.22; overall image quality, 2.04 ± 0.24) (both P < 0.01). For all the periampullary malignant lesions and small lesions (≤20 mm), there was better delineation of lesion conspicuity and the lesion margin, as well as diagnostic confidence with z-EPI DWI (all P<0.05). The rate of periampullary malignancy's hyperintense signal on z-EPI DWI was increased to 91.7% (33/36) compared to c-EPI DWI (69.4% (25/36)) (P = 0.023). For all malignant lesions and small lesions, the diagnostic accuracy scores were increased using the MRCP and z-EPI DWI combined set, compared to the MRCP and c-EPI DWI combined set (P<0.05). Diagnostic accuracy for detection and differentiation of malignant lesions from benign lesions significantly improved for the MRCP and z-EPI DWI combined set compared with MRCP and c-EPI DWI combined set (P<0.05). There were no significant differences between c-EPI DWI and z-EPI DWI in the ADC values of periampullary malignant and benign lesions (P>0.05). z-EPI DWI has an advantage that could lead to remarkable image quality improvements and enhanced lesion visualization of periampullary carcinomas. z-EPI DWI was superior to c-EPI DWI for detecting, delineating, and diagnosing the lesions, particularly for small challenging lesions.

The utility of arterial spin labelled perfusion-weighted magnetic resonance imaging in measuring the vascularity of high grade gliomas – A prospective study

BackgroundDynamic susceptibility contrast (DSC) perfusion weighted imaging (PWI) currently remains the gold standard technique for measuring cerebral perfusion in glioma diagnosis and surveillance. Arterial spin labelling (ASL) PWI is a non-invasive alternative that does not require gadolinium contrast administration, although it is yet to be applied in widespread clinical practice. This study aims to assess the utility of measuring signal intensity in ASL PWI in predicting glioma vascularity by measuring maximal tumour signal intensity in patients based on pre-operative imaging and comparing this to maximal vessel density on histopathology. MethodsPseudocontinuous ASL (pCASL) and DSC images were acquired pre-operatively in 21 patients with high grade gliomas. The maximal signal intensity within the gliomas over a region of interest of 100 mm2 was measured and also normalised to the contralateral cerebral cortex (nTBF-C), and cerebellum (nTBF-Cb). Maximal vessel density per 1 mm2 was determined on histopathology using CD31 and CD34 immunostaining on all participants. ResultsUsing ASL, statistically significant correlation was observed between maximal signal intensity (p < 0.05) and nTBF-C (p < 0.05) to maximal vessel density based on histopathology. Although a positive trend was also observed nTBF-Cb, this did not reach statistical significance. Using DSC, no statistically significant correlation was found between signal intensity, nTBF-C and nTBF-Cb. There was no correlation between maximal signal intensity between ASL and DSC. Average vessel density did not correlate with age, sex, previous treatment, or IDH status. ConclusionsASL PWI imaging is a reliable marker of evaluating the vascularity of high grade gliomas and may be used as an adjunct to DSC PWI.

Dark papillary muscles sign: a novel prognostic marker for cardiac magnetic resonance

Abstract Funding Acknowledgements Type of funding sources: None. Background the prognostic role of left ventricular (LV) papillary muscle abnormalities in patients with preserved LV systolic ejection fraction (LVEF) is unknown. Aim to evaluate the prevalence and the clinical and prognostic impact of papillary muscle abnormalities by CMR in patients with ventricular arrhythmias, preserved LVEF with no cardiac disease. Methods 391 patients with &amp;gt;500/24h premature ventricular complexes and/or with non-sustained ventricular tachycardia (NSVT), preserved LVEF and no cardiac disease, were enrolled. Different features of LV papillary muscles were considered: supernumerary muscles, papillary thickness, the attachment, late gadolinium enhancement (LGE). The end-systolic hypointensity was defined when its measured signal intensity (SI) was lower than the SI of the septum in early post-contrast cine CMR images. Dark-Paps was defined when both the main papillary muscles had systolic hypointensity. Mitral valve prolapse, mitral annular disjunction (MAD), myocardial LGE were considered. The outcome of hard cardiac events was define as a composite of cardiac death, resuscitated cardiac arrest, and appropriate implantable cardioverter defibrillator (ICD) shock, sustained ventricular tachycardia (lasting ≥30 s at ≥100 beats/min). Results Dark-Paps was found in 79 (20%) patients and was more frequent in females. It was associated with higher prevalence of mitral valve prolapse and MAD. During a median follow-up of 2534 days, 22 hard cardiac events occurred. At Kaplan-Meier curve (Figure) analysis patients with Dark-Paps were at higher risk of events than those without (p&amp;lt;0.0001). Dark-Paps was significantly associated with hard cardiac events in all the multivariate models performed. Dark-Paps improved prognostic estimation when added to NSVT (p = 0.0006), to LGE (p = 0.005) and to a model including NSVT+LGE (p = 0.014). Dark-Paps allowed a significant net reclassification when added to NSVT (NRI 0.30, p =0.03), to LGE (NRI 0.25, p =0.04), and to NSVT + LGE (NRI 0.32, p =0.02). Conclusions Dark-Paps sign could be considered a novel imaging prognostic marker in patients with ventricular arrhythmias and preserved ejection fraction.

Use of quantitative indocyanine green near-infrared fluorescence imaging in bariatric surgery: early results

Introduction Indocyanine green fluorescence angiography (ICG-FA) is commonly used in general surgery, but its use in bariatric surgery is still marginal. Moreover, post-operative leaks remain a dramatic complication after this surgery and the leak tests available have poor performance preventing them. The aim of the present paper is to assess the use and utility of a new innovative technology based on quantitative measures of fluorescence signal intensity. Material and methods From January 2022 to June 2022, 40 consecutive patients with a median age of 51 years and a preoperative median body mass index of 45.2 kg/m2 underwent bariatric surgery with quantitative ICG fluorescence angiography in our center. Two different types of surgery, based on the multidisciplinary evaluation, were performed: laparoscopic sleeve gastrectomy (LSG) and one anastomosis gastric bypass (OAGB). For ICG visualization, quantitative laparoscopic ICG platform was used to identify the vascular supply. Results Thirteen patients underwent LSG and 27 patients underwent OAGB. ICG was performed in all patients with no adverse events. An adequate and satisfactory blood supply was assessed in each case. No case of post-operative leak was detected. Conclusions The quantitative ICG-FA seems to be a useful and promising tool for the prevention of complications in bariatric surgery but further studies are mandatory.

Characteristics of electromagnetic vector field generated from rock fracturing

Rock fracturing is often accompanied by electromagnetic phenomenon. As a vector field, in addition to the intensity that is widely concerned, the generated electromagnetic field also has obvious directionality. To this end, a set of electromagnetic antennas capable of simultaneous three-axis measurement is used to monitor the electromagnetic vector field generated from rock fracturing based on Brazilian tests. The signal amplitude on each axis can represent the magnitude of actual magnetic flux density component on the three axes. The intensity and directional characteristics of electromagnetic signals received at different positions are studied using vector synthesis. The directionality of electromagnetic radiation measured using a three-axis electromagnetic antenna shows that the direction of the magnetic flux intensity generated by rock fracturing tends to be parallel to the crack surface, and the measured signal intensity is greater in a direction closer to the crack surface.