Standard Imaging Techniques Research Articles

Single center experience in localization of insulinoma by selective intraarterial calcium stimulation angiography - a case series of 15 years

BackgroundInsulinomas are rare insulin-secreting neuroendocrine neoplasms of the pancreas. First-line treatment is the surgical removal of the tumor, however, the localization with standard imaging techniques is often challenging. With the help of selective intraarterial calcium stimulation the insulinoma’s localization can be narrowed down to one third of the pancreas which the selected artery supplies.ObjectiveWe aimed to prove the usefulness of the calcium stimulation test in case of 9 patients treated between 2006 and 2021 diagnosed with endogenous hyperinsulinemic hypoglycemia confirmed by fasting test, where conventional imaging methods, like transabdominal ultrasound, CT or MRI failed to detect the source of hyperinsulinemia.MethodsWe performed selective intraarterial calcium stimulation with angiography with calcium gluconate injected to the main supporting arteries of the pancreas (splenic, superior mesenteric and gastroduodenal arteries); blood samples were obtained from the right hepatic vein before, and 30, 60 and 120 seconds after calcium administration.ResultsWith selective angiography we found a significant elevation of insulin levels taken from the right hepatic vein in five of the nine cases. On histopathology, the lesions were between 1-2 cm, in one case malignancy was also confirmed. In four patients we found a significant rise of insulin levels obtained from all catheterized sites, which confirmed the diagnosis of nesidioblastosis. In three cases no surgery was performed, and the symptoms relieved with medical treatment.ConclusionsSelective intraarterial calcium stimulation remains an important tool in localization of the source of insulin excess, especially in cases where other diagnostic modalities fail.

Fibroblast activation protein inhibitor PET/CT as an emerging diagnostic modality in interstitial lung disease and other fibrotic conditions.

Interstitial lung diseases (ILD) encompass a wide range of disorders characterized by alveolar inflammation and fibrotic tissue remodeling, marked by significant morbidity and mortality. Systemic sclerosis (SSc), among other connective tissue diseases, is a frequent cause of ILD. Assessment of pulmonary fibrosis is frequently constrained by the delayed manifestations of profibrotic activation of fibroblasts, which results in late macroscopic alterations detectable by standard imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) scans. 68Ga-labeled fibroblast activation protein inhibitors (68Ga-FAPI [fibroblast activation protein inhibitor]) are novel radionuclides used in the selective positron emission tomography/computed tomography (PET/CT) detection of profibrotic fibroblasts, a key player in fibrotic tissue remodeling. Application of 68Ga-FAPI in different target organs undergoing fibrosis, such as lung and heart, highlights its efficacy in detecting ongoing fibrotic processes, since FAPI tracer uptake has been correlated with clinical disease progression markers in SSc-ILD. This feature could enable physicians to detect subclinical fibrotic activity and tailor an individualised therapy plan on a case by case basis. The use of 68Ga-FAPI in ILD and other fibrotic conditions may emerge as a novel tool in future clinical practice for both activity monitoring and treatment optimisation. Other tracers tested in ILD of different etiologies have shown promising results and may in future also be considered for potential application in SSc-ILD.

Prognostic evaluation using radiomics after stereotactic body radiotherapy in early-stage lung cancer

Non-small cell lung cancer (NSCLC), the leading cause of cancer-related deaths, is the most common subtype of lung cancer with an incidence of 85%. Stereotactic body radiotherapy (SBRT) is a curative treatment option for patients with early-stage NSCLC who cannot undergo surgery due to medical reasons or who refuse surgery. Radiomics non-invasively extracts advanced imaging features invisible to the human eye from medical images. Radiomics has prognostic value in predicting oncological outcomes after lung SBRT. Although studies on this subject are available in the literature, they are quite heterogeneous. There is a need for large-scale multicenter studies in which standard imaging techniques are used to obtain radiomic features, artificial intelligence-based segmentations are used to eliminate differences between contours, and SBRT dose schemes with appropriate therapeutic indexes are applied. This review aimed to interpret the existing studies and emphasize the clinical importance of radiomics, which can contribute to personalized treatment. A comprehensive literature search was conducted through the PubMed database using a wide range of keywords, which yielded 11 peer-reviewed articles published between 2017 and 2024. Seven articles evaluated computed tomography radiomics, and four evaluated fluorodeoxyglucose positron emission tomography-computed tomography radiomics. Oncological outcomes are not always identical in patients with a similar history receiving similar treatments at the same stage and age. Clinical, demographic, or treatment-related data are insufficient to predict prognosis and determine personalized treatment. Incorporating radiomics to these data can help establish models with higher accuracy and achieve personalized treatment.

Conventional ultrasonography enabled with augmented reality needle guidance for percutaneous kidney access: An innovative methodologies randomized controlled trial.

Successful needle puncture of the renal collecting system is a critical but difficult procedure in percutaneous nephrolithotomy (PCNL). Although fluoroscopy and ultrasound are the standard imaging techniques to guide puncture during PCNL, both have known limitations. To assess the feasibility and safety of a new navigation system for needle puncture in ultrasound-guided PCNL. This study employed a single-center randomized controlled trial (RCT) design to assess the feasibility and safety of a new navigation system for needle puncture in ultrasound-guided PCNL. Conducted between May 2021 and November 2021, the trial utilized computer-generated random numbers for participant allocation to control for selection bias. The trial was executed at the *********, which serves as an academic medical center. All patients who met the inclusion criteria were randomly divided into two groups, with 29 patients in each group. One group underwent PCNL procedures using the new navigation system, while the control group underwent standard ultrasound-guided PCNL procedures. Included patients had renal pelvis or caliceal calculi larger than 2.0cm in diameter or had multiple or staghorn stones. The puncture procedure was performed with the support of real-time ultrasound imaging and visual guidance displayed on the screen. The primary outcome was system feasibility and puncture success rate. Secondary outcomes included puncture time, total surgical time, number of attempts, post-procedure complications, and one-year and three-year stone recurrence rates. Stone clearance was defined by postoperative CT. Descriptive statistics summarized patient demographics, stone size, and location. Independent samples t-tests analyzed puncture time and total surgical time. Chi-square or Fisher's exact tests compared stone clearance, complications, socioeconomic status, renal hydronephrosis, stone location, race, and medical history. Linear regression examined the correlation between BMI and puncture time. Significance was set at P<0.05. For all 58 patients undergoing PCNL, needle punctures of the renal collecting system were completed with a success rate of 100%. The average time from planning the puncture protocol to successful puncture was significantly shorter in the AcuSee guidance system group (3.12min, range 0.2-6.88min) compared to the standard ultrasound-guided group (7.58min, range 5.41-10.68min), representing a reduction of approximately 59%. The total surgical time was also shorter in the AcuSee group for patients with no and mild hydronephrosis (P<0.05). Complication rates were lower in the AcuSee group, with no major complications observed. However, 3 patients in the standard ultrasound-guided group have adverse effects after the PCNL procedure. The one-year stone recurrence rate was significantly lower in the AcuSee group (3.4%) compared to the standard group (24.1%), and the three-year recurrence rate was also lower (6.9% vs. 41.4%). Patient-specific factors such as BMI, renal morphology, and prior surgical history did not significantly affect the performance of the AcuSee system. We report the first clinical application of a new navigation system for needle puncture in ultrasound-guided PCNL. It has been demonstrated that it is feasible and safe compared to the standard ultrasound-guided group in percutaneous renal puncture. This technology provides intuitive and easy-to-use visual guidance, which may facilitate safe, accurate and fast needle puncture of the kidney.

A Review of 3D Modalities Used for the Diagnosis of Scoliosis.

Spine radiographs in the standing position are the recommended standard for diagnosing idiopathic scoliosis. Though the deformity exists in 3D, its diagnosis is currently carried out with the help of 2D radiographs due to the unavailability of an efficient, low-cost 3D alternative. Computed tomography (CT) and magnetic resonance imaging (MRI) are not suitable in this case, as they are obtained in the supine position. Research on 3D modelling of scoliotic spine began with multiplanar radiographs and later moved on to biplanar radiographs and finally a single radiograph. Nonetheless, modern advances in diagnostic imaging have the potential to preserve image quality and decrease radiation exposure. They include the DIERS formetric scanner system, the EOS imaging system, and ultrasonography. This review article briefly explains the technology behind each of these methods. They are compared with the standard imaging techniques. The DIERS system and ultrasonography are radiation free but have limitations with respect to the quality of the 3D model obtained. There is a need for 3D imaging technology with less or zero radiation exposure and that can produce a quality 3D model for diseases like adolescent idiopathic scoliosis. Accurate 3D models are crucial in clinical practice for diagnosis, planning surgery, patient follow-up examinations, biomechanical applications, and computer-assisted surgery.

Temporal Changes on Postgadolinium MR Vessel Wall Imaging Captures Enhancement Kinetics of Intracranial Atherosclerotic Plaques and Aneurysms.

Analysis of vessel wall contrast kinetics (ie, wash-in/washout) is a promising method for the diagnosis and risk-stratification of intracranial atherosclerotic disease plaque (ICAD-P) and the intracranial aneurysm walls (IA-W). We used black-blood MR imaging or MR vessel wall imaging to evaluate the temporal relationship of gadolinium contrast uptake kinetics in ICAD-Ps and IA-Ws compared with normal anatomic reference structures. Patients with ICAD-Ps or IAs who underwent MR vessel wall imaging with precontrast, early postcontrast (5-15 minutes), and delayed postcontrast (20-30 minutes) 3D T1-weighted TSE sequences were retrospectively studied. ROIs of a standardized diameter (2 mm) were used to measure the signal intensities of the cavernous sinus, pituitary infundibulum, temporalis muscle, and choroid plexus. Point ROIs were used for ICAD-Ps and IA-Ws. All ROI signal intensities were normalized to white matter signal intensity obtained using ROIs of 10-mm diameter. Measurements were acquired on precontrast, early postcontrast, and delayed postcontrast 3D T1 TSE sequences for each patient.ajnr;45/9/1206/T1T1T1Table 1:MR-VWI parameters for ICAD-Ps and IAsParameterValueSequence3D TSEScan planeAxialFOV (mm)160TR/TE (ms)800/28-32BW (Hx/pixel)370θ120Acceleration2ETL42Matrix acquisition0.5 mm ×0.5 mmMatrix recon0.5 mm ×0.5 mmNo. of slices/thick120/0.5Note:-FOV indicates field of view; TR, the repetition time; TE, the echo time; BW, bandwidth; ETL, echo train length; Matrix recon, matrix reconstruction. Ten patients with 17 symptomatic ICAD-Ps and 30 patients with 34 IA-Ws were included and demonstrated persisting contrast uptake (P < .001) of 7.21% and 10.54% beyond the early phase (5-15 minutes postcontrast) and in the delayed phase (20-30 minutes postcontrast) on postcontrast MR vessel wall imaging. However, normal anatomic reference structures including the pituitary infundibulum and cavernous sinus demonstrated a paradoxical contrast washout in the delayed phase. In both ICAD-Ps and IA-Ws, the greatest percentage of quantitative enhancement (>70%-90%) occurred in the early phase of postcontrast imaging, consistent with the rapid contrast uptake kinetics of neurovascular pathology. Using standard MR vessel wall imaging techniques, our results demonstrate the effects of gadolinium contrast uptake kinetics in ICAD-Ps and IA-Ws with extended accumulating enhancement into the delayed phase (> 15 minutes) as opposed to normal anatomic reference structures that conversely exhibit decreasing enhancement. Because these relative differences are used to assess qualitative patterns of ICAD-P and IA-W enhancement, our findings highlight the importance of standardizing acquisition time points and MR vessel wall imaging protocols to interpret pathologic enhancement for the risk stratification of cerebrovascular pathologies.

BIOM-14. UTILITY OF MIRNA-BASED LIQUID BIOPSY AND RADIOGRAPHIC IMAGING IN PEDIATRIC BRAIN TUMOR PATIENTS

Abstract BACKGROUND MRI is the current gold standard imaging technique for diagnostic evaluation and monitoring of pediatric CNS tumors; however, MRI measures can only provide inference into tumor biology and molecular stratification. miRNAs are an abundant and stable nucleic acid found circulating in blood and cerebrospinal fluid (CSF) and can be utilized as a tumor biomarker. METHODS We hypothesized that correlating miRNA biomarkers with radiological tumor measurements may provide improved diagnostic and monitoring for patients with pediatric brain tumors. Using a cohort of 54 pediatric brain tumors including low grade glioma, ependymoma, germ cell tumor, medulloblastoma, atypical teratoid rhabdoid tumor and high-grade glioma we attempted to combine MRI findings and circulating miRNA data. The miRNA expression was profiled in 33 CSF and 52 plasma samples using the HTG EdgeSeq platform. Clinically acquired, multi-parametric MRI scans at time-points close to liquid biopsy collection were collected retrospectively and used to generate volumetric tumor segmentations. Machine learning methods were implemented to evaluate combinatory features. RESULTS We identified unique miRNA targets that significantly correlated with MRI features, clinical findings, and patient outcomes. In both CSF and plasma, miRNA expression was found to correlate with diagnosis and clinical features including tumor grade and disease burden (p &amp;lt; 0.05). In CSF, miRNA expression was correlated with MRI features including cystic core presence, edema, leptomeningeal disease and tumor location (p &amp;lt;0.05). In plasma, differences in miRNA expression were related to MRI measurements including cystic core volume, location, and leptomeningeal disease (p &amp;lt; 0.05). Combination of miRNA targets for plasma or CSF with imaging-based features significantly improved histology specific multimodal diagnosis predictions. CONCLUSIONS These results demonstrate the potential utility of miRNAs as a pediatric brain tumor biomarker which when combined with imaging features can improve minimally and non-invasive diagnostics and the subsequent management of pediatric brain tumor patients.

Imaging of Intracranial Aneurysms: A Review of Standard and Advanced Imaging Techniques

Imaging of Intracranial Aneurysms: A Review of Standard and Advanced Imaging Techniques

Analysis of the Cellular Response to Different Dental Implant Surfaces: An In vitro Study.

Dental implant surfaces play a crucial role in determining the success of osseointegration and long-term stability. Understanding the cellular response to various implant surfaces is essential for optimizing implant design and clinical outcomes. In this in vitro study, we investigated the cellular response to different dental implant surfaces. Titanium implants with three distinct surface treatments (polished, acid-etched, and sandblasted) were prepared. Human osteoblast-like cells were cultured on these surfaces, and cellular behaviors including adhesion, proliferation, and morphology were evaluated using standard assays and imaging techniques. Our results revealed significant differences in cellular responses among the different implant surfaces. Cells exhibited higher adhesion and proliferation rates on the acid-etched and sandblasted surfaces compared to the polished surface. Furthermore, cells displayed a more spread-out morphology with well-defined filopodia and lamellipodia on the acid-etched and sandblasted surfaces, indicating enhanced cellular interaction and spreading. The cellular response to dental implant surfaces varies depending on surface characteristics. Acid-etched and sandblasted surfaces promote better cellular adhesion, proliferation, and spreading compared to polished surfaces. These findings underscore the importance of surface modifications in enhancing osseointegration and ultimately improving the success rates of dental implant procedures.

Integration of Artificial Intelligence into Chest Computed Tomography

The integration of Artificial Intelligence (AI) in radiology, especially for chest computed tomography (CT) scan analysis, marked a significant advancement in medical diagnostics, aiming to improve patient care and streamline the workflow for radiologists. This review article examined the role of current AI technologies, including machine learning (ML), deep learning (DL), convolutional neural networks (CNN), and radiomics, in enhancing the detection and characterisation of lung diseases. These technologies are instrumental in identifying complex patterns within imaging data and constructing more informed decisions regarding disease severity, progression, and potential treatment options. Deep learning and CNN have demonstrated effectiveness in analysing the intricate details present in chest CT scans, offering a high degree of accuracy. Radiomics complements these methods by extracting quantitative features from medical images, providing deeper insights into disease characteristics that are not visible through standard imaging techniques. The application of AI has shown promise in improving the diagnosis and management of interstitial lung diseases and lung cancers, contributing to the development of personalised treatment plans. However, this review also highlights limitations, such as small sample sizes in studies, which may impact the generalisability of AI applications in this field. Despite these challenges, the ongoing incorporation of AI into radiological practices is anticipated to significantly enhance the accuracy and efficiency of lung disease diagnostics, setting a foundation for future research and improvements in clinical practice.

Unveiling the Potential of Single‐Cell Encapsulation in Biomedical Applications: Current Advances and Future Perspectives

The encapsulation of single cells has emerged as a promising field in recent years, owing to its potential applications in cell‐based therapeutics, bioprinting, in vitro cell culture, high‐throughput screening, and diagnostics. Single‐cell units offer several advantages, including compatibility with standard imaging techniques, superior diffusion rates, and lower material‐to‐cell volume ratios. They also serve as effective carriers for targeted drug delivery, allowing precise administration of therapeutics in cell‐mediated quantities. Moreover, single‐cell units exhibit improved circulation potential throughout the vasculature, with a reduced likelihood of entrapment compared to multicell strategies. However, the production of single‐cell units from random dispersion of cells follows the Poisson distribution, requiring the separation of empty and multicell units from single‐cell ones. Various methods have been developed to address this challenge; nevertheless, the majority of these strategies are either expensive or time‐consuming. This review provides an in‐depth analysis of the advantages and limitations of single‐cell units and their applications, as well as a comprehensive overview of the most used techniques for single‐cell encapsulation and sorting strategies.

Multiscale in-situ characterization of static recrystallization using dark-field X-ray microscopy and high-resolution X-ray diffraction

Dark-field X-ray microscopy (DFXM) is a high-resolution, X-ray-based diffraction microstructure imaging technique that uses an objective lens aligned with the diffracted beam to magnify a single Bragg reflection. DFXM can be used to spatially resolve local variations in elastic strain and orientation inside embedded crystals with high spatial (~ 60 nm) and angular (~ 0.001°) resolution. However, as with many high-resolution imaging techniques, there is a trade-off between resolution and field of view, and it is often desirable to enrich DFXM observations by combining it with a larger field-of-view technique. Here, we combine DFXM with high-resolution X-ray diffraction (HR-XRD) applied to an in-situ investigation of static recrystallization in an 80% hot-compressed Mg–3.2Zn–0.1Ca wt.% (ZX30) alloy. Using HR-XRD, we track the relative grain volume of > 8000 sub-surface grains during annealing in situ. Then, at several points during the annealing process, we “zoom in” to individual grains using DFXM. This combination of HR-XRD and DFXM enables multiscale characterization, used here to study why particular grains grow to consume a large volume fraction of the annealed microstructure. This technique pairing is particularly useful for small and/or highly deformed grains that are often difficult to resolve using more standard diffraction microstructure imaging techniques.

129Xe Dynamic Nuclear Polarization Demystified: The Influence of the Glassing Matrix on the Radical Properties.

129Xe dissolution dynamic nuclear polarization (DNP) is a controversial topic. The gold standard technique for hyperpolarized xenon magnetic resonance imaging (MRI) is spin exchange optical pumping, which received FDA approval in 2022. Nevertheless, the versatility of DNP for enhancing the signal of any NMR active nucleus might provide new perspectives for hyperpolarized 129Xe NMR/MRI. Initial publications about 129Xe DNP underlined the increased complexity in the sample preparation and lower polarization levels when compared to more conventional 13C-labeled molecules, at same experimental conditions, despite very close gyromagnetic ratios. Herein, we introduce, using a Custom Fluid Path system, a user-friendly and very robust sample preparation method. Moreover, investigating the radical properties at real DNP conditions by means of LOngitudinal Detected Electron Spin Resonance, we discovered a dramatic shortening of the electron spin longitudinal relaxation time (T1e) of nitroxyl radicals in xenon DNP samples' matrices, with respect to more commonly used water:glycerol ones. Mitigating those challenges through microwave frequency modulation, we achieved over 20% 129Xe polarization without employing any deuterated solvent.

Dynamic Contrast Enhanced-MRI and Apparent Diffusion Coefficient Quantitation for Differentiate Hepatocellular Carcinoma from Hepatocellular Adenoma.

Due to their overlapping radiological characteristics, hepatic lesions, such as hepatocellular carcinoma (HCC) and hepatocellular adenoma (HCA), present a substantial diagnostic challenge. Accurate differentiation between HCC and HCA is essential for the best clinical treatment and therapeutic decision-making. This study aims to assess the potential role of DCE-MRI and Apparent Diffusion Coefficient (ADC) quantitation in the diagnosis of hepatocellular carcinoma (HCC) from hepatocellular adenoma (HCA). 103 patients (56 HCC, 47 HCA) with histopathologically proven hepatocellular lesions were the subjects of a cross-sectional investigation. A standardized imaging technique was used for DCE-MRI on all patients. Diffusion-weighted imaging (DWI) provided the ADC values. The diagnostic efficacy of DCE-MRI and ADC in differentiation was evaluated using statistical analyses, such as t-tests and receiver operating characteristic (ROC) curve analysis. SPSS VER 16 was used for the analysis of the collected data. A total of 103 patients (female: male= 52:51, 57.14±3.09 years) were included in the study. The study revealed significant differences in DCE-MRI parameters and ADC values between HCC and HCA lesions. ADC value was significantly lower in HCC than in HCA (p < 0.001). The area under the curve (AUC) was 0.78 (95% CI: 0.69-0.87) for ADC, 0.84 (95% CI: 0.76-0.91) for Ktrans, and 0.72 (95% CI: 0.62-0.82) for Ve. Sensitivity and specificity for ADC were 76.59% and 71.42%, respectively. Also, PPV and NPV of ADC were 69.23% and 78.43%, respectively. Sensitivity and specificity for Ktrans were 82.14% and 76.59%, respectively. Also, PPV and NPV of Ktrans were 80.7% and 78.26%, respectively. In conclusion, DCE-MRI-derived parameters, along with ADC values, exhibit promise as non-invasive tools for differentiating HCC from HCA.

Current status of optoacoustic breast imaging and future trends in clinical application: is it ready for prime time?

Optoacoustic imaging (OAI) is an emerging field with increasing applications in patients and exploratory clinical trials for breast cancer. Optoacoustic imaging (or photoacoustic imaging) employs non-ionizing, laser light to create thermoelastic expansion in tissues and detect the resulting ultrasonic emission. By combining high optical contrast capabilities with the high spatial resolution and anatomic detail of grayscale ultrasound, OAI offers unique opportunities for visualizing biological function of tissues in vivo. Over the past decade, human breast applications of OAI, including benign/malignant mass differentiation, distinguishing cancer molecular subtype, and predicting metastatic potential, have significantly increased. We discuss the current state of optoacoustic breast imaging, as well as future opportunities and clinical application trends. CLINICAL RELEVANCE STATEMENT: Optoacoustic imaging is a novel breast imaging technique that enables the assessment of breast cancer lesions and tumor biology without the risk of ionizing radiation exposure, intravenous contrast, or radionuclide injection. KEY POINTS: • Optoacoustic imaging (OAI) is a safe, non-invasive imaging technique with thriving research and high potential clinical impact. • OAI has been considered a complementary tool to current standard breast imaging techniques. • OAI combines parametric maps of molecules that absorb light and scatter acoustic waves (like hemoglobin, melanin, lipids, and water) with anatomical images, facilitating scalable and real-time molecular evaluation of tissues.

Quality and Diagnosis on the Lateral View of Pediatric Upper Gastro-Intestinal Series.

The standard imaging technique for the diagnosis of intestinal malrotation remains the upper gastro-intestinal series (UGIS). The lateral view is promoted as important for making a diagnosis. For this, the lateral view should be of adequate quality, and radiologists must know the normal appearance as well as the appearance of duodenal variants, as misdiagnosis may lead to unnecessary surgery. We aimed to evaluate the quality, findings including the prevalence of the "descending staircase" configuration and its correspondence to a diagnosis of duodenum redundum. This was a retrospective study and was conducted in a large tertiary children's hospital in the United States. A retrospective review of UGI fluoroscopy exams in children aged ≤ 18 years between January and December 2018 was performed by a pediatric radiologist. First, the lateral view images/cine-loops were assessed independently, followed by the anteroposterior (AP) view. The studies which were designated to have an adequate lateral view were evaluated for configuration of the duodenum and recorded as: normal, abnormal, or normal variant. Also, the presence of a descending staircase configuration was correlated with an AP view for a diagnosis of duodenum redundum. A total of 26 children (26%) (males:16; females:10) with age range 0 to 16 years had adequate lateral views during UGI exams for inclusion. Of the 26, 18 (69%) were reported as normal, 7 (27%) were reported as having a descending staircase and 1 (4%) was reported as abnormal. The AP view demonstrated 2 abnormal studies (1 malrotation and 1 non-rotation), 6 duodenum redundum and 18 normal exams. The one abnormal lateral duodenum was confirmed as a non-rotation on AP view; the second patient with an abnormal AP view had a normal appearance on the lateral view. A total of 26% of UGI studies had adequate lateral views for interpretation. Of these, nearly a quarter (23%) demonstrated the descending stair-case sign corresponding to a diagnosis of duodenum redundum on the AP view. If the lateral view had been used alone, there would have been a missed diagnosis in one patient.

New-generation maximum entropy method: a Lagrangian-based algorithm for dynamic reconstruction of interferometric data

ABSTRACT Imaging interferometric data in radio astronomy requires the use of non-linear algorithms that rely on different assumptions on the source structure and may produce non-unique results. This is especially true for very long baseline interferometry (VLBI) observations, where the sampling of Fourier space is very sparse. A basic tenet in standard VLBI imaging techniques is to assume that the observed source structure does not evolve during the observation. However, the recent VLBI results of the supermassive black hole at our Galactic Centre (Sagittarius A*), recently reported by the Event Horizon Telescope Collaboration, require the development of dynamic imaging algorithms, since it exhibits variability at minute time-scales. In this paper, we introduce a new non-convex optimization problem that extends the standard maximum entropy method (MEM), for reconstructing intra-observation dynamical images from interferometric data that evolve in every integration time. We present a rigorous mathematical formalism to solve the problem via the primal–dual approach. We build a Newton strategy and we give its numerical complexity. We also give a strategy to iteratively improve the obtained solution and, finally, we define a novel figure of merit to evaluate the quality of the recovered solution. Then, we test the algorithm, called the new-generation MEM (ngMEM), in different synthetic data sets, with increasing difficulty. Finally, we compare it with another well-established dynamical imaging method. Within this comparison, we have identified a significant improvement of the ngMEM reconstructions. Moreover, the evaluation of the integration time evolution scheme and the time contribution showed that this method can play a crucial role in obtaining good dynamic reconstructions.

Post-mortem feasibility of dual-energy computed tomography in the detection of bone edema-like lesions in the equine foot: a proof of concept.

In this proof-of-concept study, the post-mortem feasibility of dual-energy computed tomography (DECT) in the detection of bone edema-like lesions in the equine foot is described in agreement with the gold standard imaging technique, which is magnetic resonance imaging (MRI). A total of five equine cadaver feet were studied, of which two were pathological and three were within normal limits and served as references. A low-field MRI of each foot was performed, followed by a DECT acquisition. Multiplanar reformations of DECT virtual non-calcium images were compared with MRI for the detection of bone edema-like lesions. A gross post-mortem was performed, and histopathologic samples were obtained of the navicular and/or distal phalanx of the two feet selected based on pathology and one reference foot. On DECT virtual non-calcium imaging, the two pathological feet showed diffuse increased attenuation corresponding with bone edema-like lesions, whereas the three reference feet were considered normal. These findings were in agreement with the findings on the MRI. Histopathology of the two pathologic feet showed abnormalities in line with bone edema-like lesions. Histopathology of the reference foot was normal. DECT virtual non-calcium imaging can be a valuable diagnostic tool in the diagnosis of bone edema-like lesions in the equine foot. Further examination of DECT in equine diagnostic imaging is warranted in a larger cohort, different locations, and alive animals.

Fast reconstruction of SMS bSSFP myocardial perfusion images using noise map estimation network (NoiseMapNet): a head-to-head comparison with parallel imaging and iterative reconstruction.

Simultaneous multi-slice (SMS) bSSFP imaging enables stress myocardial perfusion imaging with high spatial resolution and increased spatial coverage. Standard parallel imaging techniques (e.g., TGRAPPA) can be used for image reconstruction but result in high noise level. Alternatively, iterative reconstruction techniques based on temporal regularization (ITER) improve image quality but are associated with reduced temporal signal fidelity and long computation time limiting their online use. The aim is to develop an image reconstruction technique for SMS-bSSFP myocardial perfusion imaging combining parallel imaging and image-based denoising using a novel noise map estimation network (NoiseMapNet), which preserves both sharpness and temporal signal profiles and that has low computational cost. The proposed reconstruction of SMS images consists of a standard temporal parallel imaging reconstruction (TGRAPPA) with motion correction (MOCO) followed by image denoising using NoiseMapNet. NoiseMapNet is a deep learning network based on a 2D Unet architecture and aims to predict a noise map from an input noisy image, which is then subtracted from the noisy image to generate the denoised image. This approach was evaluated in 17 patients who underwent stress perfusion imaging using a SMS-bSSFP sequence. Images were reconstructed with (a) TGRAPPA with MOCO (thereafter referred to as TGRAPPA), (b) iterative reconstruction with integrated motion compensation (ITER), and (c) proposed NoiseMapNet-based reconstruction. Normalized mean squared error (NMSE) with respect to TGRAPPA, myocardial sharpness, image quality, perceived SNR (pSNR), and number of diagnostic segments were evaluated. NMSE of NoiseMapNet was lower than using ITER for both myocardium (0.045 ± 0.021 vs. 0.172 ± 0.041, p < 0.001) and left ventricular blood pool (0.025 ± 0.014 vs. 0.069 ± 0.020, p < 0.001). There were no significant differences between all methods for myocardial sharpness (p = 0.77) and number of diagnostic segments (p = 0.36). ITER led to higher image quality than NoiseMapNet/TGRAPPA (2.7 ± 0.4 vs. 1.8 ± 0.4/1.3 ± 0.6, p < 0.001) and higher pSNR than NoiseMapNet/TGRAPPA (3.0 ± 0.0 vs. 2.0 ± 0.0/1.3 ± 0.6, p < 0.001). Importantly, NoiseMapNet yielded higher pSNR (p < 0.001) and image quality (p < 0.008) than TGRAPPA. Computation time of NoiseMapNet was only 20s for one entire dataset. NoiseMapNet-based reconstruction enables fast SMS image reconstruction for stress myocardial perfusion imaging while preserving sharpness and temporal signal profiles.

DIAGNOSTIC CORRELATION OF ULTRASOUND AND THYROID FUNCTION TESTS IN EARLY THYROID DISEASES: A CROSS SECTIONAL STUDY

BACKGROUND: Thyroid disease is a growing problem in young people and adolescents. Ultrasonography (US) serves as an optimal imaging modality for thyroid gland evaluation due to its ease of use, cost-effectiveness, non-invasiveness, and absence of ionizing radiation. It is used for detecting the growth of lumps in the neck or adjacent structures and serves as a valuable tool for uncovering thyroid gland abnormalities and detecting lesions that cannot be felt manually alongside the use of thyroid function tests. OBJECTIVES: The purpose of this study was to determine if thyroid function tests (TFTs) and ultrasound characteristics are correlated in patients who report with palpable masses and neck swelling. This would allow for an evaluation of the usefulness of ultrasonography as a thyroid problem diagnostic tool. METHODOLOGY: A cross-sectional study with 126 participants was carried out with an emphasis on symptomatic candidates who were 12 years of age or older. Participants had ultrasound exams and TFTs performed. Using standardized imaging techniques, ultrasound impressions were gathered, and the results were correlated with TFT reports. RESULTS: The results of the study showed that the TFT reports, and ultrasound characteristics had a very strong positive link (Pearson correlation coefficient = 0.694, p &lt; 0.01). Among 126 participants, 69.8% exhibited abnormal thyroid function. Ultrasound identified various thyroid pathologies, including nodules, hyperthyroidism, thyroiditis, Hashimoto's disease, cysts, goiter, and thyroid atrophy. CONCLUSION: The study underscores the clinical utility of ultrasound in diagnosing thyroid disorders. The strong correlation observed emphasizes ultrasound's complementary role in thyroid disease diagnosis. Integrating ultrasound into routine assessments can enhance diagnostic accuracy, enabling early intervention and personalized treatment plans. These insights advocate for a holistic approach to thyroid disease management, ensuring optimal outcomes and improved quality of life for affected individuals. KEYWORDS: Thyroid disorders, thyroid function tests, ultrasound, diagnosis, correlation.