Current Medical Imaging - Volume 14, Issue 5, 2018

Background: Nano-Metal-Organic Frameworks (NMOFs) have stable pores in their assembly. In the recent era, these have been used in biomedicine, magnetic and electronic devices and sensors. MOFs also have a potential concern in biomedical applications, a new substitute of therapeutic and/or diagnostic materials, among others. Initially, NMOFs have been used as delivery vehicles for imaging contrast agents and molecular therapeutics. Discussion: Subsequently, several paramagnetic metal ions carrying capacity of NMOFs has been extensive explored as Magnetic Resonance Imaging (MRI) contrast agents. Gd3+ and Mn2+, both in NMOFs have shown brilliant efficiency as T1 -weighted contrast agents with large per metal- and per particle-based MR relaxivities. In this review, the focus is mostly over the uses of NMOFs in imaging techniques, also discussing some significant models of micrometric MOFs that have been discovered to date in the biomedical arena. Conclusion: The ready internalization of NMOFs by cells rendered their applications in sensing biologically relevant molecules such as Ca2+ and NO responsible for signal transduction, Na+/ K+ responsible for ion channels and proton pumps, Cl- responsible for osmotic pressure, and other processes in live cells.

Background: This paper attempts to identify suitable Machine Learning (ML) approach for image denoising of radiology based medical application. The Identification of ML approach is based on (i) Review of ML approach for denoising (ii) Review of suitable Medical Denoising approach. Discussion: The review focuses on six application of radiology: Medical Ultrasound (US) for fetus development, US Computer Aided Diagnosis (CAD) and detection for breast, skin lesions, brain tumor MRI diagnosis, X-Ray for chest analysis, Breast cancer using MRI imaging. This survey identifies the ML approach with better accuracy for medical diagnosis by radiologists. The image denoising approaches further includes basic filtering techniques, wavelet medical denoising, curvelet and optimization techniques. In most of the applications, the machine learning performance is better than the conventional image denoising techniques. For fast and computational results the radiologists are using the machine learning methods on MRI, US, X-Ray and Skin lesion images. The characteristics and contributions of different ML approaches are considered in this paper. Conclusion: The problem faced by the researchers during image denoising techniques and machine learning applications for clinical settings have also been discussed.

Background: “Computer Aided Diagnosis (CAD)” methods are today considered an important means to facilitate and speed-up the work of medical experts, namely in detection, segmentation, and classification of both healthy and pathologic structures in medical image data. Discussion: This paper provides an overview of such recently published methods aimed at analysing metastatic lesions in the spine using CT imaging. Moreover, common methods of evaluation and efficiency verification of the published CAD systems are also included. Conclusion: The methods of analysis and the respective CAD systems are mutually compared and their efficiencies, advantages, and drawbacks are discussed.

Background: Cardiac Magnetic Resonance (CMR) represents one of the most valuable modalities for the non-invasive diagnosis and characterization of cardiovascular diseases. CMR proton imaging is the state-of-the-art diagnostic tool for myocardial morphology and function evaluation. CMR Spectroscopy is a very powerful tool for exploration of tissue components and metabolism of the myocardium, through the use of nuclei including 1Hydrogen (1H), 31Phosphorus (31P), 13Carbon (13C) and 23Sodium (23Na). CMR requires high imaging speed and efficiency, due to the time constraints imposed by cardiac and respiratory motion. Discussion: The availability of dedicated Radio Frequency (RF) coils allows obtaining highly homogeneous field in a wide field of view for transmitter coils and high signal-to-noise ratio for receiver coils. Phased-array coils also make possible parallel imaging, a powerful mean for increasing acquisition speed. Conclusion: The aim of this review is to introduce a classification of cardiac coils, with a particular emphasis on phased-array coils largely used in CMR, and to describe cardiac coils dedicated to CMR spectroscopy. Finally, different strategies for simulation and design of cardiac coils are introduced and described.

Background: Knee bone diseases are rare but might be highly destructive. Magnetic Resonance Imaging (MRI) is the main approach to identify knee cancer and its treatment. Normally, the knee cancers are detected with the help of different MRI analysis techniques and later image analysis strategies assess these images. Discussion: Computer-based medical image analysis is getting researcher's interest due to its advantages of speed and accuracy as compared to traditional techniques. The focus of current research is MRI-based medical image analysis for knee bone disease detection. Accordingly, several approaches for features extraction and segmentation for knee bone cancer are analyzed and compared on benchmark database. Conclusion: Finally, the current state of the art is investigated and future directions are proposed.

Background: ‘Sella turcica’ was first described in 1543. The “De humani corporis fabrica” is the name of a book by Andreas Vesalius that first described the ‘sella turcica’. After this date, it was called the ‘sella ephippi’, ‘sphenoidis sella’, or ‘sella equine’. In 1627, the famous anatomist Adrianus Spigelius developed the current definition of the term. Discussion: The Ottoman military power was at its highest level and a serious threat to Europe at the time so it was indicative of the sense of Turkish power to use ‘sella turcica’ as a medical term. Spigelius had investigated Turkish daily life, art, and culture in the sixteenth century, and Turks were common exemplars of an orientalist fashion that was being pioneered in Europe, which may be how this term came about. ‘Sella’ was used because of its similarity to the Turkish saddle; other such similarities included the amygdala and pear, hippocampus and almond, and priformis and seahorse. Conclusion: In this study, the anatomical, hormonal, and historical characteristics of ‘sella turcica’ are reviewed.

Objectives: The objectives of this study were to: 1) compare the size and T2 signal intensity of the trigeminal nerves on the symptomatic side and asymptomatic side of the patients with idiopathic trigeminal neuralgia and to correlate these morphological findings with each other in order to assess whether Magnetic Resonance Imaging (MRI) can provide evidence of microstructural changes in the affected trigeminal nerve that could be potential imaging markers for diagnosis and monitoring trigeminal neuralgia 2) correlate these data with the pain score of the patients in order to search a quantitative evaluation method of the pain in patients with Trigeminal Neuralgia (TN). Materials and Methods: The subjects were 18 adults with clinically diagnosed trigeminal neuralgia. We compared the trigeminal nerve size and T2 signal intensity on the symptomatic side and asymptomatic side for each patient via three-dimensional constructive interference in steady-state (3D-CISS) MRI. Then, we correlated these structural changes with pain score of the patients. Results: The mean diameter of the trigeminal nerve on the affected side was significantly smaller than the mean diameter on the unaffected side (p=0.004). The mean T2 signal intensity of the trigeminal nerve on the affected side was significantly higher than the unaffected side (p=0.004). There was a significant negative correlation between T2 signal intensity and diameter of the nerve (p=0.001). However, there was no significant correlation between the nerve atrophy, T2 signal intensity and pain score. Conclusion: On the affected side the size of the trigeminal nerve was smaller and T2 signal intensity of the nerve on the affected side was higher and these two findings strongly correlated with each other. These microstructural changes that defined noninvasively via 3D CISS MRI can provide new insight about the trigeminal neuralgia pathogenesis and also can be useful reliable markers for diagnosis and follow-up of treatment response in TN.

Background: Fine needle biopsies are used to diagnose thyroid cancer. Nevertheless most thyroid nodules are benign so FNA is performed too often. It is very important to recognize which echographic features can help to predict benignity and avoid unnecessary biopsies. Purpose: To prospectively evaluate several ultrasonographic patterns, and the presence of comet tail artifacts, for predicting thyroid nodule benignity. Material and Methods: US findings in 1326 nodules (1079 patients) that underwent fine needle biopsies in our institution from April 2013 to February 2015 were prospectively reviewed. FNA was performed jointly by the cytology and radiology department. Nodules were assessed searching for the following US pattern appearances: spongiform, macrocystic “Honeycomb” (HC), Entirely Cystic (EC), cyst with spongiform avascular colloid clot (CCC), echogenic nodule and giraffe pattern in a thyroiditis background and presence of comets tail artifacts. Positive Predictive Value (PPV) and specificity to predict benignity were achieved. Results: 1252 nodules were included in our study, 1167 were benign and 85 malignant (confirmed by surgery). Ultrasound patterns of the 1167 benign nodules were distributed as: 17.9% spongiform, 3.8% CCC, 1.8 % HC and 1.9 % EC. In thyroiditis background, 4.1% showed echogenic nodule and 0.8% giraffe pattern. Also, 168 benign nodules showed comet tail artifacts. All nodules that presented any of the ultrasound patterns described before were benign. None of the malignant nodules showed any of the patterns evaluated. The occurrence of any pattern described when strictly evaluated, had 100% PPV and specificity to predict benignity. Conclusion: A significant number of thyroid nodule biopsies can be avoided when adequate ultrasound approach patterns are used.

Background: Dynamic Magnetic Resonance Imaging (MRI) can be used to diagnose organs' motion, so it is useful and has been used widely. Reconstructing dynamic MRI from undersampled measurements can accelerate the imaging speed, this has attracted the attention of many researchers. For dynamic MRI, there is much global and local correlation in spatial and temporal dimensions, and if the spatial and temporal redundancy can be utilized efficiently in the reconstruction process, higher spatial and temporal resolutions can be achieved. Methods: In this paper, we propose a novel reconstruction method which utilizes the redundancy in spatial and temporal domains jointly. In particular, a 2-D matrix is obtained by vectorizing the images of every frame of a 3-D dynamic MRI sequence, and we extract overlapping 2-D patches from this matrix. Similar patches will be searched from these 2-D patches, and a non-convex function is used to approximate the low-rank matrices formed by these similar patches. At the present stage, only local correlation in the temporal dimension is employed. Discussion: To obtain better image quality, the global correlation in the temporal dimension is utilized by a low-rank penalty which is relaxed by the nuclear norm. Conclusion: We validate the proposed algorithm by using retrospectively undersampled in vivo cardiac datasets, and the proposed algorithm shows superior reconstruction performance compared to existing state-of-the-art methods such as k-t FOCUSS, k-t SLR, and L+S.

Objective: The present study was aimed at investigating the correlation of MRI characteristics of Cerebral Palsy (CP) pediatric patients with their gestational age, type of CP and Gross Motor Function Classification System (GMFCS). Methods: 120 cases of children with cerebral palsy admitted to our hospital from May 2015 to May 2016 were selected as study subjects. MRI data were observed and the correlation of MRI characteristics was studied with the gestational age, CP type and GMFCS. Results: The MRI manifestations were recorded with respect to Periventricular White Matter Injury (PWMI), diffuse brain injury, cerebral dysplasia, focal cerebral vascular accident and normal state. They were noticed to be statistically significant (P <0.05). Among 120 cases of children with CP in the group, there were 30 cases with grade I GMFCS (25%), 44 cases with grade II (36.67%), 15 cases (12.5%) with grade III, 25 cases with grade IV (20.83%) and 6 cases with grade V (5%). The differences between the mild/moderate (grade I-III) GMFCS and severe (grade IV-V) GMFCS in the distribution were statistically significant (P <0.05). Moreover, the MRI abnormal rate of premature infants was significantly higher than the MRI abnormal rate of term infants. Conclusion: The MRI characteristics of children with cerebral palsy were closely correlated with CP type, GMFCS and gestational age. MRI could be used for the early diagnosis and prognosis of such pediatric patients.

Background: For the cerebrovascular Digital Subtraction Angiography (DSA), how to restrain the patient motion artifact to improve the quality of subtraction image has an important effect on the clinical diagnosis. Methods: Currently, image registration is the main way to extract the blood vessels. However, there is usually massive calculation in the registration process. And it is usually only suitable for simple rigid motion artifact. Instead of registration way, a novel cerebrovascular segmentation method was proposed to extract blood vessels in this paper. In this method, the geometrical feature points of mask image and live image were firstly detected by SIFT algorithm under same restrain parameters. Secondly, the feature points were clustered and the subtraction of clustered point set was implemented. Then, the coordinates of the residual feature points were adjusted based on gray gradient. Lastly, the vessel image was segmented based on region growing and local threshold. Result: Experiments for the sequential cerebrovascular DSA images illustrate the applicability of this method. The quality of the vessel image after segmentation was satisfactory. The interdependency of geometrical feature information for both mask image and live image was adequately utilized in this new method. Conclusion: This method can provide accurate vessel image data for the clinical operation based on DSA interventional therapy.

Introduction: We present in this paper an automatic detection system of brain aneurysms in Digital Subtraction Angiography (DSA) images. Methods: The approach proposed here relies on two main steps: A region-based segmentation using the Otsu method is first employed in order to extract the vascular structure. Then a combination of the Zernike moments and MSER detector is used to detect aneurysms. Result: In our experiments, the evaluation results over 14 DSA images have given very satisfactory results. Conclusion: The achieved sensitivity of the proposed cerebral aneurysm detection method was 100% with 0.78 false positive rate.

Background: This study does the qualitative analysis of segmentation technique with compression and authentication to provide improved and advanced e–health care system. This study addresses three main problems of brain tumor detection, one is to find the region of interest, second is to authenticate patient information and third is to minimize memory space for a large dataset of medical images. Methods: The proposed approach combines a region based segmentation using support vector machine, authentication using discrete cosine transformation and compression using Huffman coding. Storing image data is the major and longtime problem associated with images, especially when the sizes of the images are large. The size of the image is directly reflected with the storing size, more space it will require to be stored when the size of the image is large. The main aim of this work is to open a new way of diagnosing tumor detection under the compressed domain and so making suitability for mobile computing and internet based medical analysis. Discussion: The proposed algorithm combines in such a way that it will improve the performance parameters and also reduce the space for storage, without sacrificing the quality of pixels or image. Conclusion: To evaluate the performance of our proposed mechanism, we conducted simulations on different medical images. The simulation results prove the significance in terms of quality parameters and imperceptibility.

Objectives: We retrospectively investigated the relationship between olfactory fossae depth, septal deviation angle, paranasal sinuses and the distance between infraorbital foramens (IOFs). Methods: Computerized Tomography (CT) images of 315 adult subjects were used. Paranasal sinus dimensions; Keros classification of olfactory fossae, length of Crista Galli (CG), the distance between IOFs (ZP), The distance between inferior part of crista galli and basal-inferior part of the nasal septum at the midline (CG-Sbasal) (XY), ZP/XY ratio, septal deviation side and angle were measured. Results: Keros type I was detected in males (50.3%) and Keros type II was detected in females (59.5%) mainly. In females, Keros type was highly related to the males. Both right-deviated and left deviated subjects, Keros type II (49.7% and 54.3% respectively) was the most detected Keros-type for olfactory fossae. Higher ethmoid sinus-height, maxillary sinus-width; and lower maxillary sinusheight values were related to higher Keros types. As IOFs (ZP) distance increased, Keros type also increased. Conclusion: When Endoscopic Sinus Surgery (ESS) is performed in patients having nasal septal deviation, surgeons should be careful for Keros type II olfactory fossae to avoid intracranial penetration. If possible, navigation systems should be used in these patients.

Background: Cone-beam Computed Tomography (CBCT) scans obtained with larger field of view let us see various incidental findings, anatomical variations and pathologies, like intracranial and soft tissue calcifications. Objective: The purpose of this retrospective study was to determine the prevalence of intracranial and soft tissue calcifications via CBCT. Methods: Full volume (maxillofacial region) scans of 290 patients achieved for various reasons were investigated by blinded two dentomaxillofacial radiologists. Demographic data of the patients were saved. The findings were categorized and statistically analyzed with descriptive statistics, crosstabs and chi-square tests. Results: Totally 290 patients aged between 24 and 81 years old (mean age ± standard deviation: 49±14) consisting of 155 females (53.4%) and 135 males (46.6%) were examined in the study. The most common calcifications were pineal gland calcification (64.5%), followed by tonsillolith (34.1%), petroclinoid ligament calcification (33.4%), Intracranial Internal Carotid Artery Calcifications (IICAC) (18.3%), Extracranial Internal Carotid Artery Calcifications (EICAC) (8.3%) and the others (1.7%, equally sialolith, antrolith and choroid plexus calcification), respectively. Conclusion: Tonsillolith, EICAC and IICAC showed an increase with age. EICAC was seen more in females, conversely petroclinoid ligament calcification was seen more in males. There was a statistically significant correlation between EICAC and IICAC.

Objectives: In this study, Digital Infrared Thermal Imaging (DITI) was designed based on a noninvasive system that could display and detect the relative temperature variations in patients suffering from thyroid nodules especially nonpalpables. Methods: In this prospective clinical trial, Infrared Thermal Camera (IRC) was used alternative to conventional clinical thermometers. 32 patients confirmed with thyroid nodules and volunteers as control were studied. Ultrasonography (US) was used for confirming the thyroid nodules while the DITI of thyroid surface skin temperature was obtained using the IRC. Results: The thermal image shows the variation of the patient thyroid surface skin temperature according to hypoechoic and hyperechoic nodules. The DITIs showed higher temperature for hypoechoic nodul sides and it correlated with nodule size. There was no significant temperature difference on the sex distribution. Conclusion: DITI is a valuable auxiliary to ultrasound, especially in thyroid hypoechoic nodul and if used in combination with other imaging modality, could play an extra role in the non-invasive diagnosis of thyroid nodules.

Background: T1, T2 and PD weighted images are the three bands of magnetic resonance image and they provide complementary information of the structure of the part being imaged. It is more useful for diagnosis and analysis if they are fused into MRI triplet. Discussion: This paper proposes a novel fusion method using Selective Frequency Localization Contourlet Transform to combine these three bands into one. Conclusion: From the qualitative and quantitative evaluation using average pixel intensity, standard deviation, mutual information and edge information based objective criteria, the fused image is found to be more informative.

Objectives: Our study aimed to investigate the role of infrared thermal imaging in differential diagnosis of Lumbar Disc Herniation (LDH). 180 patients with lumbocrural pain and clinically suspected of having LDH were selected from January 2015 to March 2016 during their hospitalization in Xiangyang No. 1 People's Hospital, Hubei University of Medicine. Methods: 62 of those cases were diagnosed by X-ray Computed Tomography (CT), 70 by Magnetic Resonance Imaging (MRI), and 48 by both. The signal value of infrared thermal images was estimated by comparing the images of patients with LDH with that of control patients. Results: In this study, LDH were found in 120 cases by infrared thermal imaging. The infrared thermal images of lumbosacral area of all those 120 cases showed a diamond-shaped asymmetric high temperature zone with deepened color compared with surrounding area. Among the 120 cases, 30 cases showed unchanged temperature of affected leg compared with control group; 48 cases showed decreased temperature of the affected limb; 17 cases showed increased body temperature of the affected limb; 25 cases showed both decreased and increased temperatures found in different areas of the affected limb. Discussion: Analyses of the combined data of infrared thermal images, clinical histories and physical examinations resulted in 60 cases to be more accurately diagnosed with different conditions which share the same symptom with LDH (28 cases of myofascial syndrome, 11 cases of coxitis, 16 cases of joint osteoarthritis, 3 cases of femoral head necrosis, and 2 cases of varicose veins). Conclusion: Compared with the conventional imaging examination, such as CT and MRI, infrared thermal imaging showed a higher diagnostic value for LDH.

Background: Uterine Fibroids are common non-cancerous cell growth in muscular wall of the uterus and these do not create any symptoms, but the size and location of these fibroids lead to several problems for women such as pain and heavy bleeding during the menstrual cramps. Many algorithms have been developed and each one has its own merits and demerits. However, none of the algorithms has reached 100% accuracy in identification of fibroids. Methods: The proposed system will identify fibroids by using the Magnetic Resonance Imaging (MRI) and Bio Inspired Xenogenetic based Extreme Learning Neural Networks (BIXELNN) classification algorithm. Initially, Adaptive Median Filtering technique (AMF) is applied to MRI image to remove the noise. Improved Multi- scale Segmentation is used to segment the images into different regions. From the segmented region, shape, intensity and texture features are extracted and then the Improved Fireflies algorithm with Hausdorff Distance (IFHD) is applied to optimize those features for classification process. Conclusion: Finally, the classification is performed by using BIXELNN, achieving high accuracy than other approaches, i.e., 97.3%.

Background: The aim of the study was to investigate the metabolic activity of aneurysms of the main arteries. It has been done in retrospective analysis of routine oncological 18FDG PET-CT. Materials and Methods: In our material (2 925 FDG PET/CT studies), aneurysms were found in 26 patients (8 F/18 M), 5 of whom had inflammatory aneurysms. The diameter of the aneurysm was measured at its widest point, while the metabolic activity was determined by SUV max. No significant correlation between the size of the aneurysm and its activity was found. Results: When comparing inflammatory aneurysms to non-inflamed ones no significant differences in maximum size were found. Conclusion: However, notable differences in maximum activity were observed (p <0.01). There were no relation between the size and metabolic activity of aneurysms.

Background: Prolonged hyperammonemia, as a result of its toxic effect, may cause irreversible damage in the central nervous system. Objective: We aimed to determine whether there were DTI changes in brains of pediatric subjects with acute hyperammonemic encephalopathy due to Urea Cycle Defects (UCD) and Organic Acidemia (OA). Methods: Eleven children with acute hyperammonemic encephalopathy (UCD, n=5; OA, n=6) and 9 controls were included in study. Routine MRI and diffusion-weighted images at b= 0 s mm -2 and b= 1000 s mm -2 were applied. Then, DTI sequence was performed. ADC and FA comparisons of all subjects were performed by nonparametric tests (the Mann-Whitney test, Kruskal-Wallis test). Results: The mean ADCs of the perirolandic cortex (p=0.037), cerebellar white matter (p=0.006), cingulum (p=0.017), temporal and frontal periventricular white matter (p=0.030) (p=0.020), and parietal subcortical white matter (p=0.037) were statistically higher in all subjects than controls. FAs of nucleus caudatus (p=0.034), putamen (p=0.004), perirolandic cortex (p=0.026), corpus callosum genu (p=0.031), temporal periventricular white matter (p=0.003), and occipital periventricular and subcortical white matter (p=0.045, p=0.026) were lower in both subjects with UCD and OA than controls. FAs of splenium of the corpus callosum (p=0.012) in subjects with UCD were lower compared to subjects with OA and the control group. FAs of hippocampus and parietal subcortical white matter in subjects with OA were lower compared to subjects with UCD and the control group (p=0.031). Conclusion: On DTI, both UCDs and OAs demonstrated similar DTI changes in same regions compared to controls. These changes in ADC and FA values in both conditions may indicate microstructural damage. In this context, DTI findings may contribute to a better understanding of the underlying pathophysiology of disease.