Current Medical Imaging - Volume 17, Issue 11, 2021

Bone metastases are a common source of malignancy in the skeleton and occur much more often than primary bone cancer. Several works were being performed to identify early markers for bone metastasis and novel drug targets to improve patients' quality of life. As some concerns exist with the [18F]sodiumfluoridein positron emission tomography (PET) bone imaging, there has been an increase in the number of targeted radiopharmaceutical markers for bone metastases imaging in its competitor, 68Ga. Since 18F properties are superior to those of 68Ga, there is a distinct motivation for developing 18F radiopharmaceuticals for bone metastases imaging.

Background: Magnetic Resonance Imaging (MRI) is frequently employed for the assessment of therapy in head and neck squamous cell carcinoma patients. Nonetheless, this technique has its limitations, the most apparent being the inability to differentiate between after therapy effects and the reoccurrence of tumor cells. Objective: This review was carried out to demonstrate the role of operative MRI in the treatment of head and neck squamous cell carcinoma patients, as well as the analysis of various methods like diffusion, perfusion, and spectroscopy when used in conjugation. Main Findings: Techniques such as diffusion-weighted imaging can augment the reliability of the detection of the main tumor site and local lymphatic nodes post-treatment. It was observed that diffusion is the most facile of the methods in question and can be easily implemented in follow-up sessions after therapy, though the evidential information is sometimes insufficient to validate. Perfusion factors may become elevated in the proliferation of tumors or their reoccurrence, but they are not employed for their accuracy in clinical settings. Spectroscopy methods pose some potential, but the case is the same as diffusion; insufficient data cannot be deemed enough to validate its application. Conclusion: These operative MRI methods can significantly help in the initial discernment of disease, thereby resulting in an improved therapeutic approach in patients. Prospective studies are necessary to layout standard specifications for using operative MRI in routine clinical applications.

Background: Schizotypal Personality Disorder (SPD) is a cluster A personality disorder affecting 1.0% of the general population, characterised by disturbances in cognition and reality testing dimensions, affected regulation, and interpersonal function. SPD shares similar but attenuated phenomenological, genetic, and neurobiological abnormalities with Schizophrenia (SCZ) and is described as part of schizophrenia spectrum disorders. Objective: The aim of this work was to identify major neural correlates of SPD. Methods: This is a systematic review conducted according to PRISMA statement. The protocol was prospectively registered in PROSPERO - International prospective register of systematic reviews. The review was performed to summarise the most comprehensive and updated evidence on functional neuroimaging and neurophysiology findings obtained through different techniques (DW- MRI, DTI, PET, SPECT, fMRI, MRS, EEG) in individuals with SPD. Results: Of the 52 studies included in this review, 9 were on DW-MRI and DTI, 11 were on PET and SPECT, 11 were on fMRI and MRS, and 21 were on EEG. It was complex to synthesise all the functional abnormalities found in a single, unified, pathogenetic pathway, but a common theme emerged: the dysfunction of brain circuits including striatal, frontal, temporal, limbic regions (and their networks) together with a dysregulation along the dopaminergic pathways. Conclusion: Brain abnormalities in SPD are similar, but less marked, than those found in SCZ. Furthermore, different patterns of functional abnormalities in SPD and SCZ have been found, confirming the previous literature on the ‘presence’ of possible compensatory factors, protecting individuals with SPD from frank psychosis and providing diagnostic specificity.

Background: An outbreak of coronavirus disease 2019 (COVID-19) has occurred worldwide. However, the small-airway disease in patients with COVID-19 has not been explored. Aim: This study aimed to explore the small-airway disease in patients with COVID-19 using inspiratory and expiratory chest high-resolution computed tomography (CT). Methods: This multicenter study included 108 patients with COVID-19. The patients were classified into five stages (0-IV) based on the CT images. The clinical and imaging data were compared among CT images in different stages. Patients were divided into three groups according to the time interval from the initial CT scan, and the clinical and air trapping data were compared among these groups. The correlation between clinical parameters and CT scores was evaluated. Results: The clinical data, including age, frequency of breath shortness and dyspnea, neutrophil percentage, lymphocyte count, PaO2, PaCO2, SaO2, and time interval between the onset of illness and initial CT, showed significant differences among CT images in different stages. A significant difference in the CT score of air trapping was observed between stage I and stage III. A low negative correlation was found between the CT score of air trapping and the time interval between the onset of symptoms and initial CT. No significant difference was noted in the frequency and CT score of air trapping among different groups. Conclusion: Some patients with COVID-19 developed small-airway disease. Air trapping was more distinguished in the early stage of the disease and persisted during the 2-month follow-up. Longer-term follow-up studies are needed to confirm the findings.

Objective: The study aimed to investigate the relationship between the ratio of lymph node attenuation to primary lesion attenuation on contrast-enhanced CT and the PET/CT standard uptake value (SUVmax) in head and neck squamous cell cancer (HNSCC). Methods: Volunteers with advanced-stage, histopathologically proven HNSCC, indicated to have radiotherapy/chemoradiotherapy, were evaluated for CT and PET/CT for radiotherapy planning. The attenuation and SUVmax of the primary lesion and the largest, possibly metastatic lymph node, and the round index and volume of the lymph node were calculated. The relationship between lymph node/primary lesion attenuation and SUVmax ratios was investigated. The differences in CT findings between the SUVmax < and ≥3 groups were examined. Results: Thirty-two cases with adequate diagnostic quality were studied. There was a very strong positive correlation between the primary lesion and lymph node attenuation (r=0.817, p<0.001), a strong correlation between the lymph node volume and SUVmax (r=0.681, p<0.001), and a moderate negative correlation between lymph node/primary lesion SUVmax and attenuation (r=-0.503, p=0.004). In patients with ≥3 SUVmax, lymph node volume and lymph node/primary lesion SUVmax were significantly higher, and the attenuation ratio was close to 1 (PPV 94.1, 86.3%, respectively). Conclusion: In HNSCC, the lymph node/primary lesion attenuation ratio can be used instead of SUVmax if supported by other conventional CT findings. Metastasis should be considered if lymph node attenuation is similar to primary mass attenuation and excluded if higher. CT attenuation rate can be used as a supportive finding if PET/CT cannot be performed or lymph node SUVmax is close to the acceptable cut-off for metastasis.

Background: Though imaging manifestations of COVID-19 and other types of viral pneumonia are similar, their clinical treatment methods differ. Accurate, non-invasive diagnostic methods using CT imaging can help develop an optimal therapeutic regimen for both conditions. Objective: To compare the initial CT imaging features in COVID-19 with those in other types of viral pneumonia. Methods: Clinical and imaging data of 51 patients with COVID-19 and 69 with other types of viral pneumonia were retrospectively studied. All significant imaging features (Youden index >0.3) were included for constituting the combined criteria for COVID-19 diagnosis, composed of two or more imaging features with a parallel model. McNemar's chi-square test or Fisher's exact test was used to compare the validity indices (sensitivity and specificity) among various criteria. Results: Ground glass opacities (GGO) dominated density, peripheral distribution, unilateral lung, clear margin of lesion, rounded morphology, long axis parallel to the pleura, vascular thickening, and crazy-paving pattern were more common in COVID-19 (p <0.05). Consolidation-dominated density, both central and peripheral distributions, bilateral lung, indistinct margin of lesion, tree-inbud pattern, mediastinal or hilar lymphadenectasis, pleural effusion, and pleural thickening were more common in other types of viral pneumonia (p < 0.05). GGO-dominated density or long axis parallel to the pleura (with the highest sensitivity), and GGO-dominated density or long axis parallel to the pleura or vascular thickening (with the highest specificity) are well combined criteria of COVID-19. Conclusion: The initial CT imaging features are helpful for the differential diagnosis of COVID-19 and other types of viral pneumonia.

Background and Aims: Coronavirus Disease 2019 (COVID-19) pandemic has become a global health issue. This study aimed to explore the clinical characteristics and CT imaging features of patients with COVID-19 on admission. Methods: Consecutive patients with laboratory-confirmed COVID-19 were retrospectively recruited to this study from January 2020 to March 2020. According to the disease severity status on admission, patients were divided into two groups, the common group, and the severe group. Results: Forty-four patients (F/M 20/24) who were COVID-19 positive were enrolled in this study. The most common onset symptom was fever (90.9%), followed by cough (43.2%). As for the laboratory tests, common findings included increased C reactive protein (47.7%) and erythrocyte sedimentation rate (43.2%) and decreased lymphocyte (34.1%). The frequency of decreased lymphocyte count and increased lactate dehydrogenasewas higher in the severe group (n=14) than in the common group (n=30). About 86% of patients showed typical imaging findings of COVID-19 infection, including ground-glass opacity with ill-defined margins, air bronchogram, interlobular septal thickening, and consolidation. Lesions were mainly located in the peripheral and subpleural regions with diffused distribution and multiple lung lobes were found to be affected. Conclusion: Fever and cough were the most common onset symptoms of COVID-19. Increased C reactive protein and erythrocyte sedimentation rate were the most common laboratory findings. Typical signs of chest CT imaging of COVID-19 included ground-glass opacity with ill-defined margins, air bronchogram, interlobular septal thickening, and consolidation.

Background: In recent years, there has been a massive increase in the number of people suffering from psoriasis. For proper psoriasis diagnosis, psoriasis lesion segmentation is a prerequisite for quantifying the severity of this disease. However, segmentation of psoriatic lesions cannot be evaluated just by visual inspection as they exhibit inter and intra variability among the severity classes. Most of the approaches currently pursued by dermatologists are subjective in nature. The existing conventional clustering algorithm for objective segmentation of psoriasis lesion suffers from limitations of premature local convergence. Objective: An alternative method for psoriatic lesion segmentation with objective analysis is sought in the present work. The present work aims at obtaining optimal lesion segmentation by adopting an evolutionary optimization technique that possesses a higher probability of global convergence for psoriasis lesion segmentation. Methods: A hybrid evolutionary optimization technique based on the combination of two swarm intelligence algorithms, namely Artificial Bee Colony and Seeker Optimization algorithm, has been proposed. The initial population for the hybrid technique is obtained from the two conventional local- based approaches, i.e., Fuzzy C-means and K-means clustering algorithms. Results: The initial population selection from the convergence of classical techniques reduces the effect of population dynamics on the final solution and hence yields precise lesion segmentation with a Jaccard Index of 0.91 from 720 psoriasis images. Conclusion: The performance comparison reflects the superior performance of the proposed algorithm over other swarm intelligence and conventional clustering algorithms.

Background: Ultrasonography is a diagnostic resource that serves as a complement in the evaluation of patients with carpal tunnel syndrome. The correlation of ultrasonography findings with nerve conduction studies can serve to classify new phenotypes and to evaluate therapeutic responses. Objectives: To determine the diagnostic sensitivity of ultrasound, the correlation between the diameter of the nerve (CSA) against the motor and sensitive latencies, and the capacity to differentiate the mild, moderate and severe degrees of the electrophysiological classification of carpal tunnel syndrome. Methods: A cross-sectional study with prospective data collection was carried out. An ultrasonography system with a 15 MHz transducer was used. Nerve conduction studies of the median nerve were performed with conventional techniques. Data from the most symptomatic hand were used. Determination of the correlations of nerve diameter with motor and sensitive latencies of the median nerve was performed in four age groups: <40(n=11), 40-54 (n=47), 55-70 (n=42) y >70(n=27). Results: A total of 127 patients were evaluated (average age = 58.2 years: minimum = 26; maximum = 85; SD = 13.4); 109 (85.8%) were female patients. According to the electrophysiological classification, 40 (31.5%) were mild ; 60 (47.2%) were moderate ; and 27 (21.3%) were severe . Significant differences in the area of the median nerve were found between the electrophysiological types (mild, moderate and severe; p = 0.000). The diagnostic sensitivity of ultrasonography differed for each age group. In general, the diagnostic sensitivity was high in patients with severe cases and low for mild cases. The capacity for ultrasonography to classify the degrees of electrophysiological severity was different for each age group. For patients above 70 years and in the age group of 40 to 54 years, the CSA did not differentiate the electrophysiologically moderate cases from the severe ones. Conclusion: There is a well-defined and significant correlation between nerve conduction studies and median nerve diameter in patients with Carpal Tunnel Syndrome. However, it shows that the exclusive use of the ultrasonographic measurement of the cross-sectional area through the inlet of the carpal tunnel would not be enough to confirm or rule out an entrapment of the median nerve through the carpal tunnel, nor to predict in every case their electrophysiological severity.

Background: The aetiology of anterior knee pain is multifactorial, and any patellofemoral structure can be the cause of the symptoms. Introduction: For the last decades, the suprapatellar fat pad is studied as a potential cause of anterior knee pain. Since the results in the literature are contradictory, in this study, we tried to reevaluate the role of the suprapatellar fat pad in the development of anterior knee pain. Methods: Total 156 knee MRIs of 150 patients from December 2015 to July 2019 were retrospectively evaluated by a radiologist for the configuration of the suprapatellar fat pads. The population was divided into two groups according to the presence of anterior knee pain. Maximum craniocaudal, anteroposterior and oblique diameters, and relative signal intensity indexes of the suprapatellar fat pads were measured and compared between the groups. Configurations of the fat pads were recorded, and measurements of the triangular-shaped and convex posterior bordered suprapatellar fat pads were compared. A student t-test was used for statistical analysis. Statistically, significant differences and correlations were defined as p<0.05. Results: The diameters and relative signal intensity indexes of the fat pads showed no significant difference between the groups (p=0.588, 0.744, 0.874, and 0.201, respectively). Anteroposterior and oblique diameters and relative signal intensity indexes of the suprapatellar fat pads were correlated with the convex posterior border (p=0.001, 0.003, and 0.000, respectively). Conclusion: Oedema-like changes of the suprapatellar fat pad seen at knee MRIs are correlated with the configuration of the fat pad but are rarely associated with anterior knee pain.

Purpose: Kidney, Ureter, and Bladder radiography (KUB) has frequently been used in suspected urolithiasis, but its performance is known to be lower than that of Computed Tomography (CT). This study aimed to investigate the diagnostic performance of digitally KUB in the detection of ureteral stones. Materials and Methods: Thirty patients who underwent digital KUB and CT were included in this retrospective study. The original digital KUB underwent post-processing that involved noise estimation, reduction, and whitening in improving the visibility of ureteral stones. Thus, 60 digital original or post-processed KUB images were obtained and ordered randomly for blinded review. After a period, a second review was performed after unblinding stone laterality. The detection rates were evaluated at both initial and second reviews, using CT as a reference standard. The objective (size) and subjective (visibility) parameters of ureteral stones were analyzed. Fisher’s exact test was used to compare the detection sensitivity between the original and post-processed KUB data set. Visibility analysis was assessed with a paired t-test. The correlation of stone size between CT and digital KUB data sets was assessed with the Pearson’s correlation test. Results: The detection rate was higher for most reviewers once stone laterality was provided and was non-significantly better for the post-processed KUB images (p > 0.05). There was no significant difference in stone size among CT and digital KUB data sets. In all reviews, visibility grade was higher in the post-processed KUB images, irrespective of whether stone laterality was provided. Conclusion: Digital post-processing of KUB yielded higher visibility of ureteral stones and could improve stone detection, especially when stone laterality was available. Thus, digitally post-processed KUB can be an excellent modality for detecting ureteral stones and measuring their exact size.

Background: Portal vein velocity (PVV) has shown a reasonable correlation with the presence of portal hypertension in patients with cirrhosis. This study aims to evaluate the value of PVV for diagnosing clinically significant portal hypertension (CSPH) and predicting the risk of variceal hemorrhage (VH) in patients with hepatitis B virus (HBV)-related cirrhosis. Materials and Methods: A cohort of 166 consecutive adult patients with HBV-related cirrhosis was recruited in this retrospective study from two high-volume liver centers in China between April 2015 and April 2017. The performance of PVV and other non-invasive parameters for diagnosing CSPH and predicting the risk of VH was studied. Results: PVV demonstrated the best performance for diagnosing CSPH (defined as an HVPG ≥10 mmHg) in patients with HBV-related cirrhosis among the included non-invasive predictors with the area under the receiver operating characteristic curve (AUC), specificity, and sensitivity of 0.745, 50%, and 93.5%, respectively. Other non-invasive markers, including APRI, AAR, LS, FIB-4, and diameter of the portal vein, did not show sufficient performance with the AUCs of 0.565, 0.560, 0.544, 0.529, and 0.474, respectively. With regard to predicting the risk of VH (defined as an HVPG ≥12 mmHg), PPV also exhibited a moderate performance with an AUC of 0.762, which was superior to that of the aforementioned markers. By using two cutoff values of PVV to rule-out (11.65 cm/s) and rule-in (20.20 cm/s) CSPH, 30 (33.7%) patients showed definite results categories, with 23 (76.7%) patients were well classified and 7 (23.3%) were misclassified. Fifty-nine (66.3%) patients were with indeterminate results. By using PVV values of 13.10 cm/s and 21.40 cm/s to rule-out and rule-in HVPG ≥ 12mmHg, 34 (38.2%) patients has definite results, among whom 26 (76.5%) were well classified and 8 (23.5%) were misclassified. And 55 (61.8%) patients required further evaluation. Conclusion: PPV is insufficient to serve as a non-invasive parameter for identifying CSPH and predicting the risk of VH in patients with HBV-related cirrhosis.

Objective: The purpose of the study was to determine DTI properties of brain metastases in subjects with Non-Small Cell Lung Carcinoma (NSCLC) to evaluate whether there was a correlation between DTI findings and Programmed Cell Death Ligand-1 (PD-L1). Methods: The study population (n:22) was assigned to PD-L1 negative (Group 1: PD-L1 expression<% 50) (n=11) or positive (Group 2: PD-L1 expression ≥%50) (n=11). We compared ADC and FA values measured from the enhanced solid metastases and peritumoral edema area with PD-L1 protein status. Results: The mean ADC values were lower in group 2 compared to group 1. The peritumoral ADC values were higher in group 2 compared to group 1. Mean peritumoral edema FA values were lower in group 2 compared to group 1. The peritumoral edema nADC values were higher in group 2 compared to group 1. As PD-L1 expression frequency increased, ADC values in the peritumoral edema area increased and FA values decreased. Conclusion: We thought that the existence of PD-L1 protein does not affect ADC and FA values of brain metastasis (BM) originating from NSCLC. DTI characteristics of the peritumoral edema area could be a guide in determining the PD-L1 protein status of brain metastases of NSCLC. The relationship between PD-L1 expression status and DTI features in BM from NSCLC could help us to have an idea regarding the response to immunotherapy.

Background: In recent years, Deep Learning (DL) algorithms have emerged endlessly and achieved impressive performance, which makes it possible to accelerate Magnetic Resonance (MR) image reconstruction with DL instead of Compressed Sensing (CS) methods. However, a DL-based MR image reconstruction method has always suffered from its heavy learning parameters and poor generalization ability so far. Therefore, an efficient, light-weight network is still in desperate need of fast MR image reconstruction. Methods: We propose an efficient and light-weight MR reconstruction network (named RecNet) that uses a Convolutional Neural Network (CNN) to fast reconstruct high-quality MR images. Specifically, the network is composed of cascade modules, and each cascade module is further divided into feature extraction blocks and a data consistency layer. The feature extraction block can not only effectively extract the features of MR images, but also do not introduce too many parameters for the whole network. To stabilize the training procedure, the correction information of image frequency is adopted in the Data Consistency (DC) layer. Results: We have evaluated RecNet on a public dataset and the results show that the image quality reconstructed by RecNet is the best on the Peak Signal-To-Noise Ratio (PSNR) and structural similarity index (SSIM) evaluation standards. In addition, the pre-trained RecNet can also reconstruct high-quality MR images on an unseen dataset. Conclusion: The results demonstrate that the RecNet has superior reconstruction ability in various metrics than comparative methods. The RecNet can quickly generate high-quality MR images in fewer parameters. Furthermore, the RecNet has an excellent generalization ability on pathological images and different sampling rates data.

Background: This study was conducted to measure the entrance skin dose in radiographic examinations of pediatric patients in King Khalid Hospital, Majmaah, Saudi Arabia. Introduction: Children have been given special attention since they are often regarded as especially vulnerable to potential hazards. The pediatric population is more susceptible to radiation than the adult population for certain tumor types. Objective: The aim of this study is to determine the amount of Entrance Surface Dose (ESD) received by pediatric patients attending the emergency department. Methods: Traumatic department registers for pediatric patients admitted to the King Khalid hospital (Majmaah, Saudi Arabia) between 1st February and 31st December 2018 were retrospectively studied for all diagnostic (plain radiographs examinations) imaging did on pediatric (<18 years old) trauma patients. The entrance surface dose was used to calculate the total radiation dose for each patient. One hundred and twenty patients encountered the inclusion criteria of the study and their doses (chest, skull, and extremities) were assessed. Results: The mean of radiation exposure factors were 65.4 ± 7.9 (71.3 – 89.9) and 1.3 ± 0.2 (0.3–2.5) for X-ray tube potential (kVp) and current (mAs), respectively. The measured dose for pediatric patients were 0.10 ± 0.02 (0.09 – 0.37), 0.18 ± 0.04 (0.06 -0.59) and 0.09 ± 0.03 (0.03 -0.45) for chest, skull, and extremities, respectively. The mean Entrance surface dose received by trauma patients was 0.03-0.59 mGy. 51.7% (62 patients) of the patients received ≤ 0.25 mGy while around 48.3% (58 patients) received ≥ 0.26 mGy radiation dose from those examinations. Conclusion: Trauma patients attending to traumatic radiology department obtain substantial Entrance surface dose from chest, skull, and extremities imaging procedures within their initial assessment. The radiation exposure can also be lowered by optimizing each examination, therefore more studies are recommended for this task. The results obtained can be used as the basis for local reference dosages for X-ray examinations.