Current Medical Imaging - Volume 17, Issue 7, 2021

Background: 3D printing is increasingly used in many fields of medicine. The broadening of knowledge in this field and the cooperation of doctors and engineers increase the interest in this technology and results in attempts to implement it at every stage of the treatment. Objective: The review aims to summarize the current literature on the use of 3D printing technology in the treatment of post-trauma patients. Methods: A review of available scientific publications in PubMed regarding 3D printing and its application in the context of posttraumatic procedures was carried out. Clinical Trials and Reviews from the period 2014-2019 (6-year period) were taken into consideration. The database was searched for “Printing”, “ThreeDimensional” [MAJR] [MeSH Term]. Finally, 48 studies have been included in our review article. Results: 3D printing technology has a number of applications in patients who have suffered injuries. 3D printing has found application in the preparation of procedures, accurate visualization of occurring injuries and complications, education of doctors and patients, prototyping, creation of synthetic scaffolding, production and implementation of target implants and rehabilitation. Conclusion: 3D printing is increasingly used in providing for posttraumatic patients. It is necessary to conduct further research in this area and to provide development opportunities regarding biopolymers and bioprinting. It is also necessary to improve cooperation between doctors and engineers and to create new centres that can comprehensively use 3D printing - from imaging diagnostics to the production of implants and their surgical use.

Background: When treating superficial tumors with external beam radiation therapy, bolus is often used. Bolus increases surface dose, reduces dose to underlying tissue, and improves dose homogeneity. Introduction: The conventional bolus types used clinically in practice have some disadvantages. The use of Three-Dimensional (3D) printing has the potential to create more effective boluses. CT data is used for dosimetric calculations for these treatments and often to manufacture the customized 3D-printed bolus. Purpose: The aim of this review is to evaluate the published studies that have compared 3D-printed bolus against conventional bolus types. Methods and Results: A systematic search of several databases and a further appraisal for relevance and eligibility resulted in the 14 articles used in this review. The 14 articles were analyzed based on their comparison of 3D-printed bolus and at least one conventional bolus type. Conclusion: The findings of this review indicated that 3D-printed bolus has a number of advantages. Compared to conventional bolus types, 3D-printed bolus was found to have equivalent or improved dosimetric measures, positional accuracy, fit, and uniformity. 3D-printed bolus was also found to benefit workflow efficiency through both time and cost effectiveness. However, factors such as patient comfort and staff perspectives need to be further explored to support the use of 3Dprinted bolus in routine practice.

Aims: Our aim is to develop 3D printed chitosan-gelatin-alginate scaffolds using a costeffective in house designed 3D printer followed by its characterization. To observe chondrocyte differentiation on 3D printed scaffolds as part of scaffold application. Background: Cartilage is considered to be a significant tissue in humans. It is present in between the rib cage, the lobe of the ear, nasal septum in the form of hyaline cartilage, in between ribs costal cartilage, intervertebral discs in the form of fibrocartilage, meniscus, larynx, epiglottis and between various joints of bones. To replace or repair damaged tissues due to disorders or trauma, thousands of surgical procedures are performed daily. 3D printing plays a crucial role in the development of controlled porous architectures of scaffolds for cartilage tissue regeneration. Advancement in 3D printing technology like inkjet, micro- extrusion in 3D bioprinting, Laser-assisted 3D Bioprinting (LAB), stereolithography combination with biomaterials plays a crucial role in the quick development of patient-specific articulating cartilage when need in a short period frame. Objective: Our objective is to develop different compositions of chitosan-gelatin-alginate composite hydrogel scaffolds with controlled porosity and architectures with the application of 3D printing and observe the growth of cartilage on it. To achieve as proposed, an in-house 3D paste extruder printer was developed, which is capable of printing porous composite chitosan hydrogel scaffolds of desired architecture layer by layer. After the characterization of 3D printed chitosan composite scaffolds, the differentiation of chondrocyte was observed using hMSC. Methods: In present paper process for the development of chitosan-alginate-gelatin composite hydrogel, 3D printing, morphological characterization, and observation for differentiation of chondrocytes cells on 3D printed chitosan composite hydrogels is presented. The present study is divided into three parts: in first part development of composite chitosan-alginate-gelatin hydrogel with the utilization of in house customized assembled paste extruder based 3D printer, which is capable of printing chitosan composite hydrogels. In the second part, the characterization of 3D printed chitosan composite scaffolds hydrogel is performed for evaluating the morphological, mechanical, and physical properties. The prepared composite scaffolds were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction(XRD), Scanning Electron Microscopy SEM, swelling property, mechanical testing, porosity, etc. In the last part of the study, the differentiation of chondrocytes cells was observed with human Mesenchymal Stem Cells (hMSC) on 3D printed scaffolds and showed positive results for the same. Results: Stereolithography (STL) files of 3D models for porous chitosan composite were developed using Computer-Aided Design (CAD) and printed with a hydrogel flow rate within the range of 0.2-0.25 ml/min. The prepared scaffolds are highly porous, having optimum porosity, optimal mechanical strength to sustain the cartilage formation. The 3D printed chitosan composite scaffolds show supports for the differentiation of chondrocytes. The above study is helpful for in-vivo regeneration of cartilage for patients having related cartilage disorders. Conclusion: This method helps in regeneration of degenerated cartilage for patient-specific and form above experiment we also concluded that 3D printed chitosan scaffold is best suited for the regeneration of chondrocyte cells.

Aim: This study aims to determine a printing material that has both elastic property and radiology equivalence close to the real aorta for simulation of endovascular stent-graft repair of aortic dissection. Background: With the rapid development of Three-Dimensional (3D) printing technology, a patient- specific 3D printed model is able to help surgeons to make a better treatment plan for Type B aortic dissection patients. However, the radiological properties of most 3D printing materials have not been well characterized. This study aims to investigate the appropriate materials for printing human aorta with mechanical and radiological properties similar to the real aortic Computed Tomography (CT) attenuation. Objective: Quantitative assessment of CT attenuation of different materials used in 3D printed models of aortic dissection for developing patient-specific 3D printed aorta models to simulate type B aortic dissection. Methods: A 25-mm length of aorta model was segmented from a patient’s image dataset with a diagnosis of type B aortic dissection. Four different elastic commercial 3D printing materials, namely Agilus A40 and A50, Visijet CE-NT A30 and A70 were selected and printed with different hardness. Totally four models were printed out and CT scanned twice on a 192-slice CT scanner using the standard aortic CT angiography protocol, with and without contrast inside the lumen. Five reference points with the Region Of Interest (ROI) of 1.77 mm2 were selected at the aortic wall, and intimal flap and their Hounsfield units (HU) were measured and compared with the CT attenuation of original CT images. The comparison between the patient’s aorta and models was performed through a paired-sample t-test to determine if there is any significant difference. Results: The mean CT attenuation of the aortic wall of the original CT images was 80.7 HU. Analysis of images without using contrast medium showed that the material of Agilus A50 produced the mean CT attenuation of 82.6 HU, which is similar to that of original CT images. The CT attenuation measured at images acquired with the other three materials was significantly lower than that of the original images (p<0.05). After adding contrast medium, Visijet CE-NT A30 had an average CT attenuation of 90.6 HU, which is close to that of the original images without a statistically significant difference (p>0.05). In contrast, the CT attenuation measured at images acquired with other three materials (Agilus A40, A50 and Visiject CE-NT A70) was 129 HU, 135 HU and 129.6 HU, respectively, which is significantly higher than that of original CT images (p<0.05). Conclusion: Both Visijet CE-NT and Agilus have tensile strength and elongation close to actual patient’s tissue properties producing similar CT attenuation. Visijet CE-NT A30 is considered the appropriate material for printing aorta to simulate contrast-enhanced CT imaging of type B aortic dissection. Due to the lack of body phantoms in the experiments, further research with the simulation of realistic anatomical body environment should be conducted.

The aim of this paper is to discuss the use of transcranial doppler in the pre-hospital management of stroke. In the pre-hospital organization, neurological defect scales are used, but they are often indicative of the occlusions of anterior circulation and not of the posterior circulation. Patients with posterior circulation stroke are sometimes not diagnosed and clinically treated. In the pre-hospital phase, the transcranial doppler may identify an occlusion of the large cerebral vessels and be useful for stroke patients, in particular those with posterior occlusions, for a more precise diagnosis and consequently for adequate treatment in the excellence centers for stroke.

Objective: While liver biopsy is the golden standard for liver-fibrosis diagnosis, it is also invasive and has many limitations. Non-invasive techniques such as Magnetic Resonance Imaging (MRI) need to be further developed for liver fibrosis staging. This study aimed to evaluate the diagnostic accuracy of Gadolinium Ethoxybenzyl Diethylenetriamine Penta-acetic Acid (Gd-EOBDTPA)- enhanced MRI for liver fibrosis through systematic review and meta-analysis. Methods: This study comprehensively searched relevant article in PubMed, Embase, and the Cochrane Library published from 2004 to 2018 to find studies analyzing the diagnostic accuracy of Gd-EOB-DTPA-enhanced MRI for liver fibrosis. Two reviewers independently screened the retrieved articles, extracted the required data from the included studies, and evaluated the methodological quality of the studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and Summary Receiver Operating Characteristics (SROC) curve were assessed. Results: This study finally included 16 studies (n = 1,599) and selected a random-effects model based on the results of the I² statistic to combine them. The areas under the SROC curve for the detection of F1 or greater, F2 or greater, F3 or greater, or F4 liver fibrosis were 0.8669, 0.8399, 0.8481, and 0.8858, respectively. Conclusion: Gd-EOB-DTPA-enhanced MRI showed a good diagnostic performance for staging liver fibrosis, especially for F4 liver fibrosis.

Background: McCune-Albright Syndrome (MAS) is a genetic disorder with a triad of endocrine diseases, café-au-lait macules and fibrous dysplasias. Craniofacial fibrous dysplasia is a term that is used to describe the fibrous dysplasia, which was localized at the craniofacial skeleton and is common in MAS patients. Objective: The objective of this review is to determine the involvement frequency of cranial and facial bones in patients with MAS and CFD. Methods: Articles in PubMed was searched with the following details “(mccune[Title/Abstract] OR albright[Title/Abstract]) OR (“craniofacial fibrous dysplasia”[MeSH Terms] OR (“craniofacial”[ All Fields] AND “fibrous”[All Fields] AND “dysplasia”[All Fields]) OR “craniofacial fibrous dysplasia”[All Fields])”. The articles in which the authors did not state the involved bones or did not add any radiographic images were excluded from the study. Results: 26 cases in 25 articles met the inclusion criteria. Among the 26 cases and our case, sphenoid and frontal bones were involved in 17 cases, parietal and occipital bones were involved in 15 cases, mandible and ethmoid bone were involved in 14 cases, maxilla-zygoma-temporal and palate was involved in 13, 11, 6 and 3 cases, respectively. Palate was involved in cases where maxilla was also involved. Our case was the only case that was evaluated with CBCT. Conclusion: Routine follow-ups are important since new CFDs can occur in different cranial or facial bones. 2D imaging techniques may not be able to demonstrate early CFDs; thus, an advanced imaging technique should be used after MAS diagnosis.

Background: The importance of pre-treatment Diffusion Tensor Imaging (DTI) parameters in determining the response to treatment after radiosurgery in patients with meningioma has not yet been clearly revealed. Objective: This study was conducted to determine tumor volume changes in terms of radiological response in patients with meningioma treated with Gamma Knife Radiosurgery (GKR) and to analyze the relationship between Total Tumor Volume (TTV) and Diffusion Tensor Imaging (DTI) parameters. In addition, we investigated whether the response to treatment can be predicted by pre-radiosurgery DTI findings. Methods: Fifty-four patients were assessed using MRI and DTI before and after GKR. Mean Diffusivity (MD), Fractional Anisotropy (FA), Radial Diffusivity (RD), and TTV of tumour were determined. Patients with 10% or more decrease in TTV after GKR were classified as group 1 and those with less than 10% decrease in volume or increase in volume were considered group 2. The relationships between MD, RD, and FA values and TTV were investigated. Results: A decrease of 46.34% in TTV was detected in group 1 after GKR, while TTV increased by 42.91% in group 2. The lowest pre-treatment FA value was detected in group 1. In addition, after GKR, FA values showed a significant increase in group 1. MD and RD values increased in both groups after radiosurgery. There was a negative correlation between pre-treatment FA, RD, and MD values after radiosurgery. Conclusion: Detection of low FA values due to the poor fiber content in meningioma before radiosurgery may be a guide in predicting the response to treatment. Further studies are required to have a better understanding of the relationship between pre- and post-treatment follow-up FA values and tumor volume in determining the efficacy of GKR in patients with meningioma.

Introduction: Cerebrospinal Fluid (CSF) is produced mainly by the choroid plexus but with a substantial influence by the ependymal lining of the ventricles in the brain. Hydrocephalus occurs as a result of discrepancy in the production as well as circulation of CSF as a result of congenital and acquired conditions. Nevertheless, studies on the differences between CSF dynamics according to age and gender are still insufficient. Thus, this study evaluated the volume of intracranial CSF in healthy people and hydrocephalus patients taking into account the differences between CSF dynamics according to age and gender using Sampling Perfection with Application optimised Contrast using different flip-angle Evolution (SPACE) sequence. Methods: 120 healthy volunteers and 60 patients with hydrocephalus were included in this study. SPACE sequence was used to evaluate intracranial CSF with a 3.0T magnetic resonance machine. The total volume of intracranial CSF and the amount of CSF in the ventricle were obtained using a software, and the volume ratio of CSF in the subarachnoid space, the ventricle and the subarachnoid space were calculated. Results: The mean volume of intracranial CSF, ventricular CSF, and subarachnoid CSF of male volunteers were (206.9±47.7) cm3, (33.0±10.7) cm3, (173.9±37.9) cm3 respectively. The average volume of intracranial CSF, ventricular CSF, and subarachnoid CSF of female volunteers were (199.7±44.9) cm3, (30.8±9.4) cm3, and (168.9±37.0) cm3, respectively. Thus, no significant statistically (P>0.05) difference between males and females was found. (3) The mean values of intracranial CSF, ventricle CSF and subarachnoid CSF, ventricle and subarachnoid CSF volume ratio in patients with hydrocephalus were significantly greater than health volunteers. Thus, the difference between the two groups was statistically significant (P<0.05). Conclusion: SPACE sequence can quantitatively determine the content of CSF. The change of CSF volume has nothing to do with gender but with age. It is feasible to use SPACE sequence to evaluate the spatial distribution and volume of intracranial CSF.

Background : Temporal bone is a region where fat suppression is difficult due to the inhomogeneity of various structures with different molecular properties. Introduction:: We aimed to determine the most effective fat suppression sequence in order to increase the visibility of the inner ear region. Materials and Methods: The hybrid techniques and T1-Weighted mDIXON images of 40 patients with Magnetic Resonance (MR) imaging of the inner ear were prospectively compared by two experienced radiologists in terms of fat suppression efficacy. In all fat-suppressed sequences, the Signal to Noise Ratio (SNR), the spinal cord signal intensity / mean fat signal intensity ratio and spinal cord signal to noise ratio were calculated. The suppression efficacy of MR techniques for fat areas in the inner ear was visually graded. Results: Qualitative assessment of image quality due to fat suppression in the inner ear was made; the Dixon technique performed significantly better than SPAIR and SPIR techniques (p<0.0001). The mean signal intensity of the inner ear fat and SNR for the Dixon technique were significantly lower than that for SPIR and SPAIR techniques (p<0.0001). Inter-observer agreement regarding the assessment of the inner ear fat, mean signal intensity values and mean SNR values for fat suppression techniques was significant. Conclusion: The Dixon technique exhibited higher image quality and fat suppression efficiency than the hybrid techniques in the MR imaging of the inner ear.

Background: Callosal Angle (CA) and Evans Index (EI) are considered as imaging biomarkers to diagnose normal-pressure hydrocephalus using traditional MR measurement methods. Objective: The current study aimed to evaluate the differential diagnostic value of CA and EI in Mild Cognitive Impairment (MCI) and Alzheimer’s Disease (AD). Methods: Five-hundred and two subjects were selected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, which included 168 Normal Controls (NC), 233 MCI and 101 AD patients. The structural MR images were interactively applied with multiplanar reconstruction to measure the CA and EI. Results: CA presented no significant difference among NC, MCI and AD groups (H value = 3.848, P value = 0.146), and EI demonstrated higher value in MCI and AD groups than that in NC groups (P = 0.000 and 0.001, respectively). MCI group had significant larger EI (0.29±0.04) than (0.27±0.03) NC group in 70-75 years old sub-groups. ROC showed that the area under the curve was 0.704±0.045 for NC-MCI in 70-75 years old groups. The correlation analysis indicated that EI was significantly negatively related to MMSE scores of MCI patients (r = -0.131, P = 0.046). Conclusion: EI might serve as a screening imaging biomarker for MCI in 70-75 years old patients, and show limited differential value for the diagnosis of AD. CA could present no diagnostic value for MCI and AD in the current study.

Background: Greater Saphenous Vein (GSV) courses within saphenous compartment, an adipose-filled space bound by fasciae provides structural support. Ultrasound Shear-Wave Elastography (SWE) provides objective and quantitative data on tissue shear elasticity modulus. Objective: This study aims to analyze possible associations between early stage GSV insufficiency and saphenous intracompartmental SWE measurements. Methods: Two-hundred consecutive patients, ages 22 to 81 (mean=44.3) years, with venous insufficiency symptoms underwent Doppler and SWE examinations. Patients had no visible or palpable sign of venous disease or had telangiectasia and reticular veins only. Analyses regarding patient age, gender, presence of venous insufficiency of GSV proper and intracompartmental connective tissue elasticity were performed. Results: Ninety-six patients had Doppler evidence for either bilateral or unilateral insufficiency of GSV proper at mid-thigh level. Intracompartmental elasticity of patients with venous insufficiency (mean=4.36±2.24 kilopascals; range 1.55 to 10.44 kPa) did not differ significantly from those with normal veins (mean=4.82±2.61 kPa; range 2.20 to 12.65 kPa) (p=0.231). No threshold for predicting the presence of venous insufficiency could be determined. Neither were there any correlations between age, gender and intracompartmental elasticity. In patients with unilateral insufficiency, however, elastography values around insufficient veins were significantly lower compared to contralateral normal GSV (p<0.001). Conclusion: Many intrinsic and patient factors affect intracompartmental connective tissue elastography measurements; thus, cut-off values obtained from specific populations have limited generalizability. Nevertheless, statistically significant intrapatient differences of intracompartmental elasticity among diseased and normal saphenous veins indicate that lack of elastic support from surrounding connective tissues contributes to venous insufficiency in early stages.

Background: Differentiation of brain lesions by conventional MRI alone is not enough. The introduction of sophisticated imaging methods, such as MR Spectroscopy (MRS), will contribute to accurate differentiation. Objective: To determine the diagnostic accuracy of MRS in differentiating neoplasm and non-neoplastic brain lesion. Methodology: This is a cross-sectional descriptive study conducted at Khartoum State from the period of 2015 to 2017. Thirty cases with brain lesions were included in the study investigated with MRS (Single-voxel spectroscopy) and conventional MRI. A comparison of MRS findings and histopathologic analysis was performed. The ratios of Cho/Cr and Cho/NAA were analyzed and compared between neoplastic and non-neoplastic brain masses. Data were analyzed using SPSS version 23. Results: Out of the 30 patients affected with brain lesions, there were 16 females and 14 males with a mean age of 44 +- 18 years. The ratios of Cho/Cr and Cho/NAA were higher in gliomas, astrocytoma, and meningioma than non-neoplastic lesions. Kappa statistical value (K) showed a good agreement between MRS and histopathological analysis (K= 0.60). The diagnostic accuracy of MRS was 100%, with 82.60% sensitivity, 85.71% specificity, 95% PPV, and 60% NPV. Conclusion: MRS has high diagnostic accuracy in differentiating neoplasm from non-neoplastic brain tumors. The elevation ratios of Choline-to- N-acetyl aspartate and choline-to- creatine can help neurosurgeons and clinicians differentiate benign from malignant masses.

Introduction: Although Computed Tomography (CT) is the most convenient technology for the diagnosis of gastric lipoma, it also has a high rate of missed diagnosis of gastric lipoma. Objective: To analyze the causes of missed diagnosis of gastric lipomas by CT. Methods: We retrospectively studied the CT images and CT diagnosis reports of 25 cases of gastric lipoma confirmed by surgery or clinical follow-up at the Affiliated Hospital of North Sichuan Medical College and Nanchong Central Hospital from 2016 to 2020 and analyzed the causes of missed diagnosis of gastric lipomas. Results: Among the 25 cases of gastric lipomas included in this study, 17 cases (68.0%) were correctly diagnosed by CT, and 8 cases (32.0%) were missed, but there was no case of misdiagnosis. Eighteen cases (72.0%) of gastric lipomas were located in the gastric antrum, 2 cases (8.0%) at the junction of the gastric body and antrum, 5 cases (20.0%) at the fundus of the stomach, 23 cases (92.0%) under the gastric mucosa, and 2 cases (8.0%) under the gastric serous membrane. All gastric lipoma cases were manifested as round or oval-shaped low-density shadows with clear boundaries on CT. 22 cases (88.0%) showed homogeneous low-density shadows while 3 cases (12.0%) mainly showed low-density shadows containing medium-density strips. There was no obvious enhancement in the contrast-enhanced CT scan. The gastric lipoma cases missed by CT were all located under the gastric mucosa of the gastric antrum. When reading the CT images on the default upper abdominal window width and window level, all the missed lesions were similar to the gas image. And the straight meridian of the three lesions was less than 2 cm. Conclusion: Fat density shadow in gastric antrum area was mistaken for gastrointestinal gas. Improper CT image window width and window levels and small gastric lipoma volume, along with insufficient knowledge of gastric lipomas imaging by the clinician, might be the main causes of missed diagnosis of gastric lipomas by CT. Familiarity with the CT manifestations of gastric lipomas and rich clinical experience can improve the rate of correct diagnosis of gastric lipomas by CT.