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Open heart surgery requires a proper understanding of the endocardial surface of the heart and vascular structures. While modern four-dimensional (4D) imaging enables excellent dynamic visualization of the blood pool, endocardial surface anatomy has not routinely been assessed. 4D image data were post-processed using commercially available virtual reality (VR) software. Using thresholding, the blood pool was segmented dynamically across the imaging volume. The segmented blood pool was further edited for correction of errors due to artifacts or inhomogeneous signal intensity. Then, a surface shell of an even thickness was added to the edited blood pool. When the cardiac valve leaflets and chordae were visualized, they were segmented separately using a different range of signal intensity for thresholding. Using an interactive cutting plane, the endocardial surface anatomy was reviewed from multiple perspectives by interactively applying a cutting plane, rotating and moving the model. In conclusions, dynamic three-dimensional (3D) endocardial surface imaging is feasible and provides realistic simulated views of the intraoperative scenes at open heart surgery. As VR is based on the use of all fingers of both hands, the efficiency and speed of postprocessing are markedly enhanced. Although it is limited, visualization of the cardiac valve leaflets and chordae is also possible.

Adenomatoid tumors (ATs) are uncommon, benign tumors of mesothelial origin, most frequently found in the genital tracts of both sexes. Extragenital localization sites, such as adrenal glands, are extremely rare. Since patients with adrenal ATs have no obvious clinical symptoms, imaging examination has become important evidence for diagnosis. Although previous literature noted that the imaging findings of adrenal ATs were nonspecific, no relevant studies have confirmed this. We herein present two novel cases of adrenal ATs, confirmed by immunohistochemistry, and that were initially misdiagnosed as other, more common adrenal tumors based on clinical findings and preoperative imaging. Including our cases, we collected a total of 33 previously reported adrenal ATs and extracted all available imaging information from them, aiming to find some radiological characteristics of this rare tumor. Through the review, we identified some nonspecific imaging features of adrenal ATs; however, the final diagnosis still depends on pathology and immunohistochemistry results. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association of minimal levator ani hiatus area with age in female adults without pelvic floor dysfunction. Methods: 532 female subjects aged 18 ~ 90 years without pelvic floor dysfunction, divided into four groups (Group A, 18 ~ 29 years old; Group B, 30 ~ 39 years old; Group C, 40 ~ 49 years old; Group D, ≥ 50 years old) based on age, underwent traditional pelvic two-dimensional (2D) T2-weighted imaging (T2WI) axial to the body (AxB) for measuring the minimal levator ani hiatus area. 39 female volunteers were re-recruited to undergo both traditional pelvic 2D T2WI AxB and three-dimensional (3D) T2WI. An axial plane parallel to the direction of the puborectalis muscle (AxPRM) was acquired based on 3D T2WI. The difference of levator ani hiatus area measured on AxB and AxPRM images in 39 female volunteers was compared by one-sample t test, to verify if minimal levator ani hiatus area can be acquired on the traditional pelvic 2D T2WI AxB images. Spearman analysis evaluated the association of minimal levator ani hiatus area with age and the rank-sum test analyzed the area differences among four age groups. Results: Female age was positively correlated with minimal levator ani hiatus area (r = 0.23; p < 0.001). The minimal levator ani hiatus areas of 532 subjects were: 15.17 ± 1.77 cm2 in Group A, 15.52 ± 2.21 cm2 in Group B, 16.03 ± 2.16 cm2 in Group C, and 16.40 ± 2.10 cm2 in Group D. ANOVA showed significant statistical differences among four age groups (F = 7.519, p < 0.0001). Significant differences in minimal levator ani hiatus areas were found between Group A and Group C (p = 0.0491), Group A and Group D (p = 0.0007), and Group B and Group D (p < 0.001). There was no statistical difference in minimal levator ani hiatus areas measured on AxB and AxPRM images in 39 female volunteers (p = 0.1000). There were no statistical difference in minimal levator ani hiatus areas between nulliparous and multiparous group for each age group (all p > 0.05). Conclusions: Based on a large sample, this study summarized the minimum levator ani hiatus area of female adults without pelvic floor dysfunction in different age groups. We found significant differences among different age groups. In addition, a positive correlation was found between age and the minimum levator ani hiatus area. These findings can provide reference criteria for diagnosing pelvic organ prolapse in female adults of different age groups. [ABSTRACT FROM AUTHOR]

Hepatic hemangiomas are the most common benign liver tumors. Typically, small- to medium-sized hemangiomas are asymptomatic and discovered incidentally through the widespread use of imaging techniques. Giant hemangiomas (>5 cm) have a higher risk of complications. A variety of imaging methods are used for diagnosis. Cavernous hemangioma is the most frequent type, but radiologists must be aware of other varieties. Conservative management is often adequate, but some cases necessitate targeted interventions. Although surgery was traditionally the main treatment, the evolution of minimally invasive procedures now often recommends transarterial chemoembolization as the treatment of choice. [ABSTRACT FROM AUTHOR]

Abstract Background Pituitary imaging is often required to exclude an adenoma suspected clinically or biochemically. Although magnetic resonance (MR) is the gold standard, computerised tomography (CT) is faster, cheaper and induces less claustrophobia. Our audit at Auckland City Hospital, New Zealand, investigated whether the use of CT of the pituitary as the first line imaging to assess for a pituitary macroadenoma reduces the need for MR. Methods We investigated the usefulness of CT pituitary imaging in the exclusion of pituitary macroadenoma between 2012 and 2020. A re-audit was then undertaken for a period of one year between March 2021 and March 2022 to assess outcomes once a departmental policy change was implemented. At Auckland City Hospital, 32 patients across eight years were eligible for this analysis, of which 31 had data available. In our re-audit, 29 patients were eligible for this analysis. We collected data on patient demographics, relevant hormone levels, indication for imaging and imaging results and subsequent management. Results After CT pituitary imaging, 28/31 (90%) of patients did not require further imaging because the clinical question had been addressed. One year after routine initial CT pituitary imaging was implemented by the Auckland City Hospital Endocrinology Department, 29 CT pituitary scans were performed to exclude a pituitary macroadenoma. Of these patients one required further imaging due to the finding of an expanded pituitary sella but not a pituitary macroadenoma. Conclusion CT pituitary imaging to exclude a pituitary macroadenoma is a useful test that may reduce the need for MR pituitary scans. Trial registration Not applicable. This was an audit as defined by the New Zealand National Ethics Advisory Committee guidelines. Please see ‘Declarations’ section.

Many wild otariids (sea lions and fur seals) strand along the California coast annually with seizures following presumed exposure to harmful algal blooms (HABs). This is a long-term case study of a stranded subadult male Guadalupe fur seal (Arctocephalus townsendi) that stranded in 2001 and within days after admission began demonstrating seizure activity. The epilepsy was stabilized with antiepileptic drug (AED) therapy and advanced imaging was performed. Magnetic resonance (MR) scans showed signs of encephalopathy consistent with domoic acid (DA) toxicosis. This fur seal was deemed “non-releasable” and over the following 19 years, he received supportive veterinary care and AED treatment at a permitted facility. In the summer of 2020, the fur seal showed progressive behavioral and functional deterioration whereupon humane euthanasia was performed. Post-mortem MR and diffusion tensor images (DTI) were acquired. A volumetric comparison with historic scans showed evidence of severe progressive unilateral right hippocampal atrophy. Histopathology confirmed severe chronic right and mild left hippocampal atrophy. The progressive degenerative brain changes demonstrate how adaptive brain function can be with neuronal atrophy secondary to DA exposure. This case highlights some considerations and decision-making processes needed for the rehabilitation and placement of wild stranded otariids with acquired epilepsy secondary to DA toxicity.

Many wild otariids (sea lions and fur seals) strand along the California coast annually with seizures following presumed exposure to harmful algal blooms (HABs). This is a long-term case study of a stranded subadult male Guadalupe fur seal (Arctocephalus townsendi) that stranded in 2001 and within days after admission began demonstrating seizure activity. The epilepsy was stabilized with antiepileptic drug (AED) therapy and advanced imaging was performed. Magnetic resonance (MR) scans showed signs of encephalopathy consistent with domoic acid (DA) toxicosis. This fur seal was deemed "non-releasable" and over the following 19 years, he received supportive veterinary care and AED treatment at a permitted facility. In the summer of 2020, the fur seal showed progressive behavioral and functional deterioration whereupon humane euthanasia was performed. Post-mortem MR and diffusion tensor images (DTI) were acquired. A volumetric comparison with historic scans showed evidence of severe progressive unilateral right hippocampal atrophy. Histopathology confirmed severe chronic right and mild left hippocampal atrophy. The progressive degenerative brain changes demonstrate how adaptive brain function can be with neuronal atrophy secondary to DA exposure. This case highlights some considerations and decision-making processes needed for the rehabilitation and placement of wild stranded otariids with acquired epilepsy secondary to DA toxicity. [ABSTRACT FROM AUTHOR]

White matter hyperintensities (WMHs) are found on magnetic resonance (MR) images of older individuals and are associated with many neurodegenerative disorders, although the exactrole of WMHs in Alzheimer's disease and other dementias remains an open area of research. Fluid-attenuated inversion recovery (FLAIR) MR imaging sequences show WMHs with good image contrast. Manual segmentation of WMHs on FLAIR images is the widely accepted "gold standard", however, this step is often time-consuming and has a high inter-rater variability. The absence of an automated, robust and accurate approach to segment WMHs remains a processing bottleneck. We explored convolutional neural networks (CNNs) for performing semantic segmentation of WMHs in FLAIR images. Two sets of experiments were conducted: (1) Variations of U-shaped CNNs (U-Nets) were evaluated in 186 individuals, specifically, four architectures (VGG16, VGG19, ResNet152 and EfficientNetB0) having three dimensionalities (2D, 2.5D and 3D). (2) New data from 60 individuals were added to test the generalizability of U-Net, LinkNet and Feature-Pyramid Network (FPN) variants. The first experiment showed that the 2.5D implementation with VGG16 or VGG19 was the most suitable configuration when segmenting WMH (F-measure > 95% and intersection-over-union > 90%). The second experiment confirmed generalizability of these variants when using unprocessed FLAIR images. [Display omitted] • Identification of the best feature-extracting architecture (VGG16 or VGG19) for WHM segmentation. • Identification of the best processing dimensionality implementation (2.5D) for WMH segmentation. • Demonstration of automatic segmentation and labeling of the WMH volume for the whole brain. • Confirmation of the generalizability of several CNN models (U-Net, LinkNet, FPN). [ABSTRACT FROM AUTHOR]

This study aimed to analyze the applicability of the improved median filter in positron emission tomography (PET)/magnetic resonance (MR) fusion images based on parallel imaging using generalized autocalibrating partially parallel acquisition (GRAPPA). In this study, a PET/MR fusion imaging system based on a 3.0T magnetic field and 18F radioisotope were used. An improved median filter that can set a mask of the median value more efficiently than before was modeled and applied to the acquired image. As quantitative evaluation parameters of the noise level, the contrast to noise ratio (CNR) and coefficient of variation (COV) were calculated. Additionally, no-reference-based evaluation parameters were used to analyze the overall image quality. We confirmed that the CNR and COV values of the PET/MR fusion images to which the improved median filter was applied improved by approximately 3.32 and 2.19 times on average, respectively, compared to the noisy image. In addition, the no-reference-based evaluation results showed a similar trend for the noise-level results. In conclusion, we demonstrated that it can be supplemented by using an improved median filter, which suggests the problem of image quality degradation of PET/MR fusion images that shortens scan time using GRAPPA.

Hepatic hemangiomas are the most common benign liver tumors. Typically, small- to medium-sized hemangiomas are asymptomatic and discovered incidentally through the widespread use of imaging techniques. Giant hemangiomas (>5 cm) have a higher risk of complications. A variety of imaging methods are used for diagnosis. Cavernous hemangioma is the most frequent type, but radiologists must be aware of other varieties. Conservative management is often adequate, but some cases necessitate targeted interventions. Although surgery was traditionally the main treatment, the evolution of minimally invasive procedures now often recommends transarterial chemoembolization as the treatment of choice.

Magnetic resonance (MR) plays an essential role in chemical analysis and medical imaging. The reliable MR instrument is a prerequisite for MR related research. Foreign instrument companies have monopolized the MR instrument supply in China for a long time. Recently, the situation has witnessed impressive improvement due to progress made by Chinese domestic companies and institutions in developing and manufacturing MR instruments. This paper surveyed and reviewed the status and challenges of the domestic manufacturing of MR instruments in China.

The study was designed to assess the accuracy of contrast-enhanced balanced steady-state free precession (cine-SSFP) CMR imaging sequences to exhibit myocardial hyperemia in acute myocarditis, which has for a long time been investigated in some centers using early gadolinium enhancement (EGE) sequence. Contrast-enhanced cine-SSFP (CESSFP) sequences were compared to precontrast cine-SSFP sequences to calculate the early cine-contrast enhancement in 36 consecutive patients with acute myocarditis and 36 controls matched for age and gender. Four-chamber views images were obtained in each subject before and after gadolinium injection. Absolute and relative left ventricular myocardial enhancement of the overall myocardium, then separately of the lateral wall and interventricular septum was analyzed in telediastole. Myocarditis patients displayed higher cine-SSFP absolute enhancement than controls (overall left ventricular myocardium 2.38 ± 0.33 vs 1.84 ± 0.31; lateral wall 2.45 ± 0.35 vs 1.83 ± 0.32; and septum 2.26 ± 0.29 vs 1.82 ± 0.29, p < 0.0001 for all). Less significant differences were observed for the relative enhancement (p < 0.05 for all). Using ROC curves, the optimal threshold value of absolute enhancement to diagnose acute myocarditis was 2.05 (sensitivity: 86%; specificity: 81%). Given the simplicity of use, contrast-enhanced cine-SSFP sequences should be used as an additional diagnostic tool to detect hyperemia in acute myocarditis patients. [ABSTRACT FROM AUTHOR]

Intracranial tumors arise from constituents of the brain and its meninges. Glioblastoma (GBM) is the most common adult primary intracranial neoplasm and is categorized as high‐grade astrocytoma according to the World Health Organization (WHO). The survival rate for 5 and 10 years after diagnosis is under 10%, contributing to its grave prognosis. Early detection of GBM enables early intervention, prognostication, and treatment monitoring. Computer‐aided diagnostics (CAD) is a computerized process that helps to differentiate between GBM and low‐grade gliomas (LGG), using the perceptible analysis of magnetic resonance (MR) of the brain. This study proposes a framework consisting of a feature fusion algorithm with cascaded autoencoders (CAEs), referred to as FFCAEs. Here we utilized two CAEs and extracted the relevant features from multiple CAEs. Inspired by the existing work on fusion algorithms, the obtained features are then fused by using a novel fusion algorithm. Finally, the resultant fused features are classified with the Softmax classifier to arrive at an average classification accuracy of 96.7%, which is 2.45% more than the previously best‐performing model. The method is shown to be efficacious thus, it can be useful as a utility program for doctors. [ABSTRACT FROM AUTHOR]

Background and Purpose: The clinical diagnosis of Binswanger’s disease (BD), a chronic progressive form of subcortical vascular dementia, remains challenging. 3D pseudo-continuous arterial-spin-labeling (pcASL) and diffusion kurtosis imaging (DKI) can quantitatively reveal the microcirculation changes and heterogeneity of white matter (WM), respectively. We thus aimed to determine the diagnostic value of the combined 3D-pcASL and DKI in BD. Materials and Methods: A total of 35 patients with BD and 33 healthy controls underwent 3D-ASL and DKI experiments. The perfusion parameter of cerebral blood flow (CBF), diffusion parameters of fractional anisotropy (FA), mean/axial/radial diffusivity (MD/Da/Dr), and kurtosis parameters of anisotropy fraction of kurtosis (FAk) and mean/axial/radial kurtosis MK/Ka/Kr were obtained to quantitatively measure the parametric distributions of functional brain subregions. One-way analysis of variance and post hoc t-test were applied to explore the different distributions of DKI/ASL-derived parameters among brain subregions of BD. In addition, all region-specific DKI/ASL parameters were separately analyzed in Pearson correlation analysis to investigate the relationship with Mini-Mental State Examination (MMSE), a typical clinical scale for cognitive function assessment in patients with BD. Results: FA/FAk/MK/Ka/Kr was significantly declined in all WM hyperintensities (WMHs) of BD compared with healthy controls, while the corresponding MD/Da/Dr was significantly increased (all p < 0.005). In addition, significant changes, similar to the WMHs of patients with BD, were also observed in almost all DKI parameters in WM normal areas and genu/splenium of the corpus callosum (GCC/SCC) in BD (p < 0.005). Finally, CBF was significantly reduced in all of the above regions we measured in patients with BD (p < 0.005). For patients with BD, MMSE showed a negative correlation with MD/Da in thalamus (r = −0.42/−0.58; p < 0.05), and a positive correlation with CBF in PWM/TWM (r = 0.49/0.39; p < 0.05). Using receiver operating characteristic (ROC) analysis, FA/FAk/Kr in GCC, CBF/FA/Dr/FAk in SCC, MD/Da/Ka in thalamus, and the combined FA/MD/Dr/CBF in TWM showed high accuracy [area under the curves (AUCs) 0.957/0.946/0.942/0.986] in distinguishing patients with BD from healthy controls. Conclusion: We found that combined DKI and 3D-ASL are helpful in diagnosing patients with BD, especially with FA, MD, Dr, and CBF in the temporal WM region. Additionally, the kurtosis parameters of DKI can sensitively monitor the potentially damaged WM areas in patients with BD patients, adding complementary clinical value. [ABSTRACT FROM AUTHOR]

We aimed to comprehensively characterize degenerative findings associated with various types of lumbosacral transitional vertebra (LSTV) on magnetic resonance images. Three hundred and fifty patients with LSTV (52.3 ± 10.9 years), including 182 Castellvi type I, 107 type II, 43 type III, and 18 type IV, and 179 controls without LSTV (50.6 ± 13.1 years), were studied. Discs, endplates, and posterior vertebral structures were assessed and compared to those of controls for the most caudal three discs on MRIs. There were no differences in degenerative findings between patients with type I LSTV and controls. For types III and IV, the transitional discs had smaller sizes, lower Pfirrmann scores, and lower rates of disc bulging (2.3% and 5.6% vs. 39.1%), osteophytes (2.3% vs. 15.1%), disc herniation (2.3% and 5.6% vs. 31.8%), and Modic changes (2.3% and 5.6% vs. 16.8%) than controls. However, the cranial discs had more severe Pfirrmann scores, disc narrowing and spinal canal narrowing, and greater rates of disc herniation (41.9% and 50.0% vs. 25.7%), endplate defects (27.9% and 33.3% vs. 14.4%) and spondylolisthesis (18.6% vs. 7.3%) than controls. Type II LSTV was associated with degenerative findings in the cranial segments but to a lesser degree, as compared with type III/IV LSTV. Thus, Castellvi type III/IV LSTV predisposed the adjacent spinal components to degeneration and protected the transitional discs. Type II LSTV had significant effects in promoting transitional and adjacent disc degeneration. Type I LSTV was not related to spinal degeneration. [ABSTRACT FROM AUTHOR]

Most multiphase flow separation detection methods used commonly in oilfields are low in efficiency and accuracy, and have data delay. An online multiphase flow detection method is proposed based on magnetic resonance technology, and its supporting device has been made and tested in lab and field. The detection technology works in two parts: measure phase holdup in static state and measure flow rate in flowing state. Oil-water ratio is first measured and then gas holdup. The device is composed of a segmented magnet structure and a dual antenna structure for measuring flowing fluid. A highly compact magnetic resonance spectrometer system and intelligent software are developed. Lab experiments and field application show that the online detection system has the following merits: it can measure flow rate and phase holdup only based on magnetic resonance technology; it can detect in-place transient fluid production at high frequency and thus monitor transient fluid production in real time; it can detect oil, gas and water in a full range at high precision, the detection isn't affected by salinity and emulsification. It is a green, safe and energy-saving system.

Myosteatosis has emerged as an important concept in muscle health as it is associated with an increased risk of adverse health outcomes, a higher rate of complications, and increased mortality associated with ageing, chronic systemic and neuromuscular diseases, cancer, metabolic syndromes, degenerative events, and trauma. Myosteatosis involves ectopic infiltration of fat into skeletal muscle, and it exhibits a negative correlation with muscle mass, strength, and mobility representing a contributing factor to decreased muscle quality. While myosteatosis serves as an additional biomarker for sarcopenia, cachexia, and metabolic syndromes, it is not synonymous with sarcopenia. Myosteatosis induces proinflammatory changes that contribute to decreased muscle function, compromise mitochondrial function, and increase inflammatory response in muscles. Imaging techniques such as computed tomography (CT), particularly opportunistic abdominal CT scans, and magnetic resonance imaging (MRI) or magnetic resonance spectroscopy (MRS), have been used in both clinical practice and research. And in recent years, ultrasound has emerged as a promising bedside tool for measuring changes in muscle tissue. Various techniques, including CT-based muscle attenuation (MA) and intermuscular adipose tissue (IMAT) quantification, MRI-based proton density fat fraction (PDFF) and T1-T2 mapping, and musculoskeletal ultrasound (MSUS)-based echo intensity (EI) and shear wave elastography (SWE), are accessible in clinical practice and can be used as adjunct biomarkers of myosteatosis to assess various debilitating muscle health conditions. However, a stan¬dard definition of myosteatosis with a thorough understanding of the pathophysiological mechanisms, and a consensus in assessment methods and clinical outcomes has not yet been established. Recent developments in image acquisition and quantification have attempted to develop an appropriate muscle quality index for the assessment of myosteatosis. Additionally, emerging studies on artificial intelligence (AI) may provide further insights into quantification and automated assessment, including MRS analysis. In this review, we discuss the pathophysiological aspects of myosteatosis, all the current imaging techniques and recent advances in imaging assessment as potential biomarkers of myosteatosis, and the most common clinical conditions involved., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-24-365/coif). The special issue “Advances in Diagnostic Musculoskeletal Imaging and Image-guided Therapy” was commissioned by the editorial office without any funding or sponsorship. X.T. served as the unpaid Guest Editor of the issue. The authors have no other conflicts of interest to declare., (2024 AME Publishing Company. All rights reserved.)

Background: Viral pneumonia (VP) often leads to the development of deep vein thrombosis (DVT) in hospitalized patients. The aim of the study was to investigate the incidence of DVT in discharged patients with VP, and whether new and old DVT differ in transverse relaxation time., Methods: In this prospective cohort study in Wuhan, China, 338 consecutive discharged VP patients from February 2021 to March 2023 who underwent T2 weighted Sampling Perfection with Application Optimized Contrast Evolution (SPACE) were recruited to detect DVT. T2 mapping and T2* mapping were performed for the patients with DVT detected by magnetic resonance imaging (MRI). The minimum, maximum, mean of T2 time and T2* time of DVT were recorded as T2min, T2max, T2mean, T2*min, T2*max, and T2*mean, respectively. Clinical data and laboratory findings were compared between new and old DVT cases, which were defined based on the examination results before and after discharge. A Mann-Whitney test was used to compare transverse relaxation time parameters between new and old DVT., Results: Twelve percent of VP patients (40/338) developed new DVT after discharge. Thirty-three out of 104 DVTs did not resolve after discharge. Compared with patients with new DVT, patients with old DVT were older (67 vs. 59 years, P=0.003); and had a higher proportion of bedridden time >72 hours (72.7% vs. 37.0%, P<0.001). Patients with old DVT had a lower lymphocyte count (0.67×10 9 /L vs. 0.97×10 9 /L, P=0.01), higher C-reactive protein (59 vs. 35 mg/L, P=0.019), and higher levels of D-dimer (6.7 vs. 0.9 µg/mL, P<0.001) than patients with new DVT. Patients with old DVT received more invasive mechanical ventilation (30.3% vs. 7.4%, P<0.001) and had a higher proportion of acute respiratory distress syndrome (75.8% vs. 51.9%, P<0.001), and a higher proportion of cardiac injury (39.4% vs. 14.8%, P=0.033) than patients with new DVT. T2min, T2max, T2mean, and T2*max of new DVT were significantly greater than old DVT (17.6±10.4 vs. 13.2±5.9 ms, 94.9±44.9 vs. 42.3±23.6 ms, 46.8±24.0 vs. 25.0±12.6 ms, 22.5±12.4 vs. 10.7±3.5 ms, P<0.05 for all). There was no significant difference in T2*min or T2*mean between new and old DVT (3.2±0.4 vs. 3.1±0.4 ms, 8.2±4.9 vs. 5.5±1.5 ms, P>0.05 for both)., Conclusions: T2 weighted SPACE magnetic resonance (MR) is valuable in the follow-up of thrombosis of discharged VP patients. T2 mapping distinguishes between new and old DVT., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-23-1607/coif). The authors have no conflicts of interest to declare., (2024 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

Background: Contrast leakage after arthrography is common. We sought to investigate if immobilization could prevent it. Purpose: The purpose of this study was to determine the effects on contrast extravasation and image quality produced by strict immobilization of the shoulder between arthrography puncture and subsequent MR imaging. Material and methods: Fifty patients underwent shoulder MR arthrography using a standard shoulder puncture in the anteroinferior quadrant. Ten milliliters of contrast mixture of saline, iodinated contrast, and gadolinium contrast was injected by a senior musculoskeletal (MSK) radiologist using a 21G needle. Half of the patients were immediately immobilized using a shoulder sling, and the other half were allowed to move their shoulder and arm freely during the time before MR imaging. MR arthrography was performed with a 3 T system using standard T1 and PD weighted sequences. The MR images were reviewed independently by 2 MSK radiologists and graded for extravasation using a five-point scale (1: none, 2: less than 2 cm, 3: 2-5 cm, 4: 5-10 cm, 5: more than 10 cm) and for image quality using a 5 point scale (1: poor, 5: good). The Pearson correlation was calculated to assess the correlation between leakage and image quality. Results: There was no significant difference in amount of leakage between both groups, and global image quality was found equal in both groups. A negative correlation was found between leakage and quality assessment. Conclusion: This study shows that it cannot be avoided by strict shoulder immobilization and that it negatively affects image quality and interpretation. [ABSTRACT FROM AUTHOR]

The traditional level set algorithm selects the position of the initial contour randomly and lacks the processing of edge information. Therefore, it cannot accurately extract the edge of the brain tissue. In order to solve this problem, this paper proposes a level set algorithm that fuses partition and Canny function. Firstly, the idea of partition is fused, and the initial contour position is selected by combining the morphological information of each region, so that the initial contour contains more brain tissue regions, and the efficiency of brain tissue extraction is improved. Secondly, the canny operator is fused in the energy functional, which improves the accuracy of edge detection of rhesus monkey brain tissue while retaining the advantage of the traditional level set algorithm in processing an uneven gray image. Experimental results show that the algorithm can accurately extract the brain tissue of rhesus monkeys with an accuracy of up to 86%. [ABSTRACT FROM AUTHOR]

The incidence of nervous system and soft tissue is getting higher, and nuclear magnetic resonance is the preferred method of examination and is widely used. The segmentation of brain magnetic resonance (MR) images is the key to the subsequent operations such as three-dimensional reconstruction, quantitative analysis of normal tissues and diseased tissues. The accuracy of image segmentation is critical in the doctor's assessment with the location, shape, and size of the lesion tissue, as well as the determination of the disease and the correct diagnosis plan. The results of this study indicate that the multi-scale convolutional neural network (MSCNN) model can segment brain tumors accurately and effectively. Through multi-scale input, this paper overcomes the need to select specific input scales according to the size of the tumor, accommodate more neighborhood information from various angles, and adapt to different tumor sizes, thus improving the segmentation accuracy of brain tumors. Based on the same accuracy, the segmentation speed is accelerated to ensure the real-time segmentation further. This method can effectively segment the brain lesion tissue in the nuclear magnetic resonance image, which improves the generalization ability. It can be used for identifying the brain lesion tissue of the nuclear magnetic resonance medical image.

Purpose: We introduce a MR imaging technique, balanced T1 relaxation‐enhanced steady‐state (bT1RESS), that provides the unique capability to efficiently impart a flexible amount of T1 weighting to a balanced steady‐state free precession acquisition using periodically applied contrast‐modifying RF pulses. Leveraging this capability to suppress the signal intensity of background tissues, we implemented a 3D noncontrast MR angiography technique that continuously acquires thin overlapping 3D volumes and tested it for evaluation of the peripheral arteries. Methods: bT1RESS used a fast interrupted steady‐state readout with a 45° cslab‐selective ontrast‐modifying RF pulse applied at 262 msec intervals. A series of 16.4‐mm thick overlapping 3D volumes was acquired using a radial stack‐of‐stars k‐space trajectory. The combination of slice oversampling, slab overlap, and averaging of edge slices was helpful to reduce venetian blind artifact. Spatial resolution was near isotropic with reconstructed slice thickness = 0.7 mm and in‐plane resolution = 0.5 mm. Results: Pilot studies in the peripheral arteries demonstrated improved vessel sharpness compared with cardiac‐gated quiescent interval slice‐selective noncontrast MR angiography. bT1RESS noncontrast MR angiography reliably identified stenotic and occlusive arterial disease in a small cohort of patients with peripheral artery disease. Conclusions: bT1RESS provides the basis for a simplified, completely "push button" approach for noncontrast MR angiography that obviates the need for contrast agents, electrocardiographic gating, scout imaging, breath holding, or tailoring of imaging parameters for the individual patient. Further work is needed for technical optimization and clinical validation. [ABSTRACT FROM AUTHOR]

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Magnetic resonance (MR) identification and grading of subjects with liver fibrosis and inflammation represents a clinical challenge. MR elastography plays a well-defined role in fibrosis estimation, but its use is not widely available in clinical settings. Given that liver MR is becoming the reference standard for fat and iron quantitation, there is a need to clarify whether there is any role for MR imaging in the concomitant evaluation of fibrosis and inflammation in this setting. This review summarizes the diagnostic estimations of different MR imaging parameters obtained from conventional non-contrast-enhanced multiple b values diffusion-weighted acquisitions, variable flip angles T1 relaxation maps and STIR images. Although some derived parameters have shown a significant correlation to histological scores, a small magnitude of effect with wide overlap across severity grades is the rule. Contrary to fat and iron quantification, the low precision and reproducibility of MR imaging metrics limits its clinical relevance in fibrosis and inflammation assessment. In a sequential clinical approach combining different methodologies, MR imaging has no applicability for ruling-out and low accuracy for ruling-in advanced fibrosis. Thereby, MR elastography remains as the only image method with high diagnostic accuracy for the detection of advanced fibrosis. Until date, inflammation remains in a gray zone where biopsy cannot be replaced, and further investigations are needed. The present review offers an in-depth discuss of the MR imaging diagnostic performance for the evaluation of liver fibrosis and inflammation, highlighting the need for scientific improvements. [ABSTRACT FROM AUTHOR]

Use of magnetic fields (MFs) for underwater wireless communication is very promising nowadays due to its advantages such as low power, low cost, no multipath, no Doppler effect, and instant communication. Considering the importance and potential of MF communication for underwater wireless sensor networks, this article presents a review on the fundamental concepts and theory of MF communication by identifying the main blocks, describing the limitation of each block and mentioning the advancements being done. The three fundamental blocks identified are: 1) the transmit and receive coils; 2) the matching network; and 3) the channel characteristics of the MFs. The first block explains how a single-dimensional coil is used to establish a directional communication link between a transmitter and a receiver and then the method by which the directionality problem is solved using multidimensional coils and metamaterial coils. Furthermore, the matching network explains the difference between the induction and resonance phenomena and their effect on the range and capacity. In the third block, the factors affecting the MFs are mentioned, which are critical to underwater wireless communication with MFs. Finally, this article introduces the recent advancements at the physical, MAC, and network layers. [ABSTRACT FROM AUTHOR]

The hemangioma is the most common solid lesion of the liver. Therefore, radiologists must know the typical and atypical imaging findings of this lesion in order to reach a correct diagnosis and avoid diagnostic errors. However, only few papers have comprehensively described the entire spectrum of atypical and uncommon imaging features. In this updated review, we provide the imaging features of hepatic hemangioma, in both typical and atypical forms, as well as its association with abnormalities in the adjacent hepatic parenchyma and other hepatic lesions, and its complications. [ABSTRACT FROM AUTHOR]

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Abstract Image segmentation plays a vital role in MRI abnormality detection. This paper presents a robust MRI segmentation method to outline potential abnormality blobs. Thresholding and boundary tracing strategies are employed to remove background noises, and hence, the ROIs in the whole process are set. Subsequently, a polyfit surface evolution is proposed to approximately estimate bias field, which makes segmentation robust to image noises. Simultaneously, customized initial level set functions are devised so as to detect subtle bright and dark blobs which are highly potential abnormality regions. The proposed method improves bias field estimation and level set method to acquire fine segmentation with low computational complexities. Analysis of experimental results and comparisons with existing algorithms demonstrates that the proposed method can segment weak-edged, low-resolution MR brain images, and its performance prevails in accuracy and effectiveness.

We sought to develop an activity nomogram for magnetic resonance (MR)–planned permanent seed prostate brachytherapy to improve quality assurance through a secondary dosimetric check. Patients undergoing MRI-assisted radiosurgery (MARS), whereby MRI is used for preoperative planning and postimplant dosimetry, were reviewed from May 2016 to September 2018. Planned activity (U) was fitted by MR-prostate volume (cc) via simple linear regression. Resulting monotherapy nomograms were compared with institutional nomograms from an ultrasound-planned cohort. Dosimetric coverage and external urinary sphincter (EUS) dose were also assessed for MR-planned patients. We identified 183 patients treated with MARS: 146 patients received palladium-103 (103Pd; 102 monotherapy and 44 boost), and 37 received iodine-125 (125I) monotherapy. Median prostate volume was 28 cc (interquartile range: 22–35). Lines of best fit for implant activity were U = 4.344 × (vol) + 54.13 (R2: 95%) for 103Pd monotherapy, U = 3.202 (vol) + 39.72 (R2: 96%) for 103Pd boost and U = 0.684 (vol) + 13.38 (R2: 96%) for 125I monotherapy. Compared with ultrasound, MR-planned nomograms had lower activity per volume (p < 0.05) for both 103Pd monotherapy (∼6%) and 125I monotherapy (∼11%), given a median size (30 cc) prostate. Across all MARS implants, postimplant dosimetry revealed a median V100% of 94% (interquartile range: 92–96%). Median EUS V125 was <1 cc for all patients, regardless of isotope. We developed a quality assurance nomogram for MR-planned prostate brachytherapy. When compared with ultrasound-planned, MR-planned monotherapy resulted in a lower activity-to-volume ratio while maintaining dosimetric coverage, likely secondary to EUS-sparing and reduced planning target margins. [ABSTRACT FROM AUTHOR]

Magnetic resonance (MR) images denoising is important in medical image analysis. Denoising methods based on deep learning have shown great promise and outperform all of the other conventional methods. However, deep-learning methods are limited by the number of training samples. In this article, using a small sample size, we applied a wider denoising neural network to MR images with Rician noise and trained several denoising models. The first model is specific to a certain noise, while the other applies to a wide range of noise levels. We considered the noise range as one interval, two sub-intervals, three sub-intervals, or even more sub-intervals to train the corresponding models. Experimental results demonstrate that for MR images, the proposed deep-learning models are efficient in terms of peak-signal-to-noise ratio, structure-similarity-index metrics and normalized mutual information. In addition, for blind noise, the effect of the three sub-intervals is better than that of the other sub-intervals. [ABSTRACT FROM AUTHOR]

To describe the most common hamstring injury scenarios and outcomes in elite rugby union. Retrospective investigation. Hamstring injury data from an elite rugby union team was collected over five seasons and retrospectively analysed. 74 professional rugby players. Injuries were classified as new or recurrent. Injury severity, activity, player position, and whether the injury occurred during a match or training was determined for each injury. Injury location and grade were determined for more clinically severe injuries where Magnetic Resonance Imaging (MRI) data was available (15 injuries). Thirty hamstring injuries were sustained over the five seasons. The majority of injuries were new (93%), moderate in severity (60%) and occurred during running (77%). For more clinically severe injuries, the biceps femoris long head (BFlh) was the most commonly injured muscle (73%) and the distal myofascial junction (DMFJ) was the most common injury site (58% of BFlh injuries). Hamstring injuries most commonly occurred while running and in the BFlh muscle, which is similar to other sports. However, the most common intramuscular injury site was the DMFJ, which contrasts with reports from other cohorts. Future studies should ensure to include the myofascial junction when classifying injury location. • The DMFJ of the BFLH is the most common hamstring injury site for more clinically severe injuries in rugby athletes. • Findings from this study contrast reports from other sports. • Hamstring injury prevention strategies should consider the most common injury site. • Future studies should include the MFJ when classifying hamstring injury location. [ABSTRACT FROM AUTHOR]

Purpose: In a curved vessel such as the aortic arch, the velocity profile closer to the aortic root is normally skewed towards the inner curvature wall, while further downstream along the curve, the velocity profile becomes skewed towards the outer wall. In an aortic dissection (AD) disease, blood velocities in the true lumen (TL) and false lumen (FL) are hypothesized to depend on the proximity of the entry tear to the root of aortic arch. Faster velocity in the FL can lead to higher hemodynamic loading, and pose tearing risk. Furthermore, the luminal velocities control the perfusion rate of radiological contrast media during diagnostic imaging. The objective in this study is to investigate the effect of AD disease morphology and configuration on the blood velocity field in the TL and FL, and on the relative perfusion of radiological enhancement agents through the dissection. Methods: Eight in vitro models were studied, including patent and non-patent FL configurations. Particle image velocimetry (PIV) was used to quantify the AD velocity field, while laser-induced fluorescence (LIF) was implemented to visualize dynamical flow phenomena and to quantify the perfusion of injected dye, in mimicry of contrast-enhanced computed tomography (CT). Results: The location of the proximal entry tear along the aortic arch in a patent FL had a dramatic impact on whether the blood velocity was higher in the TL or FL. The luminal velocities were dependent on the entry/reentry tear size combination, with the smaller tear (whether distal or proximal) setting the upper limit on the maximal flow velocity in the FL. Upon merging near the distal reentry tear, the TL/FL velocity differential gave rise to the roll up and shedding of shear layer vortices that convected downstream in close proximity to the wall of the non-dissected aorta. In a non-patent FL, the flow velocity was practically null with all the blood passing through the TL. LIF imaging showed much slower perfusion of contrast dye in the FL compared to the TL. In a patent FL, however, dye had a comparable perfusion rate appearing around the same time as in the TL. Conclusions: Blood velocities in the TL and FL were highly sensitive to the exact dissection configuration. Geometric case A1R, which had its proximal entry tear located further downstream along the aortic arch, and had its entry and reentry tears sufficiently sized, exhibited the highest FL flow velocity among the tested models, and it was also higher than in the TL, which suggest that this configuration had elevated hemodynamic loading and risk for tearing. In contrast-enhanced diagnostic imaging, a time-delayed acquisition protocol is recommended to improve the detection of suspected cases with a non-patent FL. [ABSTRACT FROM AUTHOR]

PurposeTo assess the relative accuracies of computed tomography (CT) and magnetic resonance (MR) imaging in the local staging of primary malignant bone and soft-tissue tumors.Materials and methodsAt four institutions, 367 eligible patients (aged 6-89 years) with malignant bone or soft-tissue neoplasms in selected anatomic sites were enrolled. Patients underwent both CT and MR imaging within 4 weeks before surgery. In each patient, CT scans were interpreted independently by two radiologists and MR images by two other radiologists at the enrolling institution. The CT and MR images were then interpreted together by two of those radiologists and subsequently reread at the other institutions. Imaging and histopathologic findings were compared and were supplemented when needed with surgical findings. Receiver operating characteristic curve analysis and descriptive statistical analysis were performed.ResultsCases were analyzable in 316 patients: 183 had primary bone tumors; 133 had primary soft-tissue tumors. There was no statistically significant difference between CT and MR imaging in determining tumor involvement of muscle, bone, joints, or neurovascular structures. The combined interpretation of CT and MR images did not statistically significantly improve accuracy. Interreader variability was similar for both modalities.ConclusionCT and MR imaging are equally accurate in the local staging of malignant bone and soft-tissue neoplasms in the specific anatomic sites studied.

Background: The use of magnetic resonance linear accelerators (MR-LINACs) for clinical treatment has opened up new possibilities and challenges in the field of radiation oncology. However, annual quality assurance (QA) is relatively understudied due to practical considerations. Thus, to overcome the difficulty of measuring the dose with a small water phantom for TRS-398 or TG-51 in all external beam radiation treatment unit environments, such as MR compatibility, we designed a remote phantom with a three-axis changeable capacity for QA., Methods: The designed water phantom was tested under an MR environment. The water phantom system comprised of three parts: a phantom box, a dose measurement tool, and a PMD401 drive system. The UNIDOSE universal dosimeter was used to collect beam data. The manufacturer's developer tools were utilized to position the measurement. To ensure magnetic field homogeneity, a distortion phantom was prepared using sixty fish oil capsules aligned radially to distinguish the oil and free air. The phantom was scanned in both the MR simulator and computed tomography (CT), and the acquired images were analyzed to determine the position shift., Results: The dimensions of the device are 30 cm in the X-axis, 20 cm in the Y-axis, and 17 cm in the Z-axis. Total cost of materials was no more than $10,000 US dollars. Our results indicate that the device can function normally in a regular 1.5 T MR environment without interference from the magnetic field. The water phantom's traveling speed was found to be approximately 5 mm/s with a position difference confined within 6 cm intervals during normal use. The distortion test results showed that the prepared MR environment has uniform magnetic field homogeneity., Conclusions: In this study, we constructed a prototype water phantom device that can function in an MR simulator without interference between the magnetic field and electronic components. Compared to other commercially available MR-LINAC water phantoms, our device offers a more cost-effective solution for routine monthly QA. It can shorten the duration of QA tests and relieve the burden on medical physicists., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-23-189/coif). The authors have no conflicts of interest to declare., (2023 Quantitative Imaging in Medicine and Surgery. All rights reserved.)