Current Medical Imaging - Volume 15, Issue 10, 2019

Background: Image registration provides major role in real world applications and classic digital image processing. Image registration is carried out for more than one image and this image was captured from a different location, different sensors, different time and different viewpoints. Discussion: This paper deals with the comparative analysis of various registration techniques and here six registration techniques depending upon intensity, phase correlation, image feature, area, control points and mutual information are compared. Comparative analysis for different methodologies shows the advantages of one method over the other methods. The foremost objective of this paper is to deliver a complete reference source for the scholars interested in registration, irrespective of specific application extents. Conclusion: Finally performance analyses are evaluated for the medical datasets and comparison is graphically shown with the MATLAB simulation tool.

Background: Scoliosis is a three-dimensional deformity of the spine. It is usually assessed by measuring Cobb angle. Nowadays, due to increasing effectiveness of image processing and machine vision, willingness to apply these methods has improved considerably in determining scoliosis of Cobb angle. Methods: In accordance with the PRISMA guideline, a broad electronic search of all English language literature was conducted on the topic through four databases, including MEDLINE, Web of Science, Scopus, and the Cochrane Library from 2012 (last search date from earlier review) to 30 March 2017. Results: Twelve studies were included. 90% labeled high-quality were selected for analysis. Eighty percent of the selected studies were published in the period between 2012 and 2017. Three new procedures were used to measure the Cobb angle. One study used automated procedure (7%), two studies used smartphone procedure (14%), and nine studies used the semiautomatic procedure of Cobb measurement (79%). Seven studies reported reproducibility and repeatability. Reproducibility range was 0.72 to 1 in reporting of ICC. Repeatability has a high range in three separated methods. Conclusion: Computerized assessment method (Automatic and Semi-automatic) is most commonly performed in Cobb measurement. Semi-automatic is an effective measurement option for computerized assessment Cobb angle. There is no significant difference between manual, computer- based, and smartphone-based methods in described measures.

Purpose: To systematically review evidence regarding the association of multiparametric biomarkers with clinical outcomes and their capacity to explain relevant subcompartments of gliomas. Materials and Methods: Scopus database was searched for original journal papers from January 1st, 2007 to February 20th, 2017 according to PRISMA. Four hundred forty-nine abstracts of papers were reviewed and scored independently by two out of six authors. Based on those papers we analyzed associations between biomarkers, subcompartments within the tumor lesion, and clinical outcomes. From all the articles analyzed, the twenty-seven papers with the highest scores were highlighted to represent the evidence about MR imaging biomarkers associated with clinical outcomes. Similarly, eighteen studies defining subcompartments within the tumor region were also highlighted to represent the evidence of MR imaging biomarkers. Their reports were critically appraised according to the QUADAS-2 criteria. Results: It has been demonstrated that multi-parametric biomarkers are prepared for surrogating diagnosis, grading, segmentation, overall survival, progression-free survival, recurrence, molecular profiling and response to treatment in gliomas. Quantifications and radiomics features obtained from morphological exams (T1, T2, FLAIR, T1c), PWI (including DSC and DCE), diffusion (DWI, DTI) and chemical shift imaging (CSI) are the preferred MR biomarkers associated to clinical outcomes. Subcompartments relative to the peritumoral region, invasion, infiltration, proliferation, mass effect and pseudo flush, relapse compartments, gross tumor volumes, and highrisk regions have been defined to characterize the heterogeneity. For the majority of pairwise cooccurrences, we found no evidence to assert that observed co-occurrences were significantly different from their expected co-occurrences (Binomial test with False Discovery Rate correction, α=0.05). The co-occurrence among terms in the studied papers was found to be driven by their individual prevalence and trends in the literature. Conclusion: Combinations of MR imaging biomarkers from morphological, PWI, DWI and CSI exams have demonstrated their capability to predict clinical outcomes in different management moments of gliomas. Whereas morphologic-derived compartments have been mostly studied during the last ten years, new multi-parametric MRI approaches have also been proposed to discover specific subcompartments of the tumors. MR biomarkers from those subcompartments show the local behavior within the heterogeneous tumor and may quantify the prognosis and response to treatment of gliomas.

Aims: To demonstrate the prevalence, accompanying pathologies, imaging and follow up findings of Duodenal Diverticula (DD) with Multidetector Computed Tomography (MDCT). Materials and Methods: Consecutive 2910 abdominal MDCTs were retrospectively reviewed on axial, coronal and sagittal planes. DD were evaluated for prevalence, location, number, size, contents, diverticular neck, accompanying pancreaticobiliary pathologies, jejunal and colonic diverticula, respectively. Results: DD were diagnosed in 157 cases (5.4%) and found mostly in the second part of the duodenum. Juxta-ampullary DD was the most common type (78.3%) and mostly located ventral (n:86, 69.9%) to the ampulla of Vater. DD was solitary in 123 patients (78.3%) and more than one in 34 patients (21.7%). The median diameter of DD was 2.5 cm (range 1.5-3.6 cm) in the long-axis. The lumen of DD contains air and contrast agent (n:96, 61.1%); air, contrast agent and debris (n:42, 26.7%) in most cases. Colonic diverticula (n:36, 22.9%), cholelithiasis (n:32, 20.4%), choledocholithiasis (n:7, 4.4%), and biliary dilatation (n:8, 5.1%) were the most common additional findings. Median follow-up time was 23 months (range 11 to 41 months). In three cases, new findings (cholelithiasis, n:3, choledocholithiasis, n:1) were detected. Conclusion: Accompanying pathologies with DD diagnosis are valuable for physicians in order to manage the patients. Following clinical and radiological features of well-diagnosed DD might reduce the possible complications.

Background: The detection of recurrence or metastasis might be challenging in patients, who underwent total thyroidectomy and radioactive iodine therapy for Differentiated Thyroid Carcinoma (DTC), with increased serum Thyroglobulin (Tg) levels and negative 131I whole body scan (131I-WBS) results. Aims: The purpose of this study was to compare the ability of Magnetic Resonance Imaging (MRI) and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F FDG PET-CT) to detect recurrence or cervical and upper mediastinal metastases in postoperative DTC patients who had negative 131I-WBS despite elevated serum Tg levels. Study Design: This study has a retrospective study design. Methods: We evaluated cervical and upper mediastinal MRI and 18F FDG PET-CT of 32 postoperative patients with DTC (26 patients with papillary thyroid carcinoma and 6 patients with follicular thyroid carcinoma). Results: We evaluated 44 lesions in 32 patients. For all lesions, the Positive Predictive Value, (PPV) Negative Predictive Value (NPV), sensitivity, specificity, and accuracy of MRI were 81.4%, 76.4%, 84.6%, 72.2%, and 79.5% respectively. The PPV, NPV, sensitivity, specificity, and accuracy of 18F FDG PET-CT were 100.0%, 85.7%, 88.4%, 100.0%, and 93.1%, respectively. Conclusion: Although we could not replace 18F FDG PET-CT, MRI might be used as an adjunct to 18F FDG PET-CT for the evaluation of recurrent or cervical and upper mediastinal metastatic thyroid cancers; however, MRI is inadequate for the detection of metastases in small lymph nodes.

Background: Gastric cancer is the second leading cause of cancer death worldwide. Aims: In the benign and malign gastric pathologies, we measured the Apparent Diffusion Coefficient (ADC) value from the thickened section of the stomach wall. We assessed the diagnostic value of ADC and we wanted to see whether this value could be used to diagnose gastric pathologies. Study Design: This study has a prospective study design. Methods: A total of 90 patients, 27 with malign gastric pathologies 63 with benign gastric pathologies with Gastric Wall (GW) thickening in multidector CT, were evaluated by T2 weighted axial MR imaging and Diffusion-Weighted Imaging (DWI). Measurements were made both from the thickened wall and from the normal GW. Also, a new method called GW/spine ADC ratio was performed in image analysis. The value found after ADC measurement from the GW was proportioned to the spinal cord ADC value in the same section. Results: The ADC values measured from the pathological wall in patients with gastric malignancy (1.115 ± 0.156 x10-3 mm2/s) were significantly lower than the healthy wall measurements (1.621 ± 0.292 x 10-3 mm2/s) and benign gastric diseases (1.790± 0.359 x10-3 mm2/s). GW/spine ADC ratio was also lower in gastric malignancy group. Conclusion: ADC measurement in DWI can be used to distinguish between benign and malign gastric pathologies.

Background: The application of image processing algorithms for medical image analysis has been found effectual in the past years. Imaging techniques provide assistance to the radiologists and physicians for the diagnosis of abnormalities in different organs. Objectives: The proposed algorithm is designed for automatic computer-aided diagnosis of liver cancer from low contrast CT images. The idea expressed in this article is to classify the malignancy of the liver tumor ahead of liver segmentation and to locate HCC burden on the liver. Methods: A novel Fuzzy Linguistic Constant (FLC) is designed for image enhancement. To classify the enhanced liver image as cancerous or non-cancerous, fuzzy membership function is applied. The extracted features are assessed for malignancy and benignancy using the structural similarity index. The malignant CT image is further processed for automatic tumor segmentation and grading by applying morphological image processing techniques. Results: The validity of the concept is verified on a dataset of 179 clinical cases which consist of 98 benign and 81 malignant liver tumors. Classification accuracy of 98.3% is achieved by Support Vector Machine (SVM). The proposed method has the ability to automatically segment the tumor with an improved detection rate of 78% and a precision value of 0.6. Conclusion: The algorithm design offers an efficient tool to the radiologist in classifying the malignant cases from benign cases. The CAD system allows automatic segmentation of tumor and locates tumor burden on the liver. The methodology adopted can aid medical practitioners in tumor diagnosis and surgery planning.

Background: Bone Age Assessment (BAA) refers to a clinical procedure that aims to identify a discrepancy between biological and chronological age of an individual by assessing the bone age growth. Currently, there are two main methods of executing BAA which are known as Greulich-Pyle and Tanner-Whitehouse techniques. Both techniques involve a manual and qualitative assessment of hand and wrist radiographs, resulting in intra and inter-operator variability accuracy and time-consuming. An automatic segmentation can be applied to the radiographs, providing the physician with more accurate delineation of the carpal bone and accurate quantitative analysis. Methods: In this study, we proposed an image feature extraction technique based on image segmentation with the fully convolutional neural network with eight stride pixel (FCN-8). A total of 290 radiographic images including both female and the male subject of age ranging from 0 to 18 were manually segmented and trained using FCN-8. Results and Conclusion: The results exhibit a high training accuracy value of 99.68% and a loss rate of 0.008619 for 50 epochs of training. The experiments compared 58 images against the gold standard ground truth images. The accuracy of our fully automated segmentation technique is 0.78 ± 0.06, 1.56 ±0.30 mm and 98.02% in terms of Dice Coefficient, Hausdorff Distance, and overall qualitative carpal recognition accuracy, respectively.

Background: The middle ear cavity is ventilated through the aditus ad antrum. Aditus blockage contributes to the pathology of otitis media. Objective: To determine the normal values of the aditus ad antrum diameter on computed tomography and to investigate its relationship with chronic otitis media and related pathologies (tympanosclerosis and myringosclerosis). Methods: The temporal CT images of 162 individuals were evaluated retrospectively. In the axial sections, the inner diameter of the aditus was measured at the narrowest point at the cortex. The differences in diameter were compared between diseased and healthy ears. Results: In healthy individuals, the diameter was narrower in women. There was no difference between the right and left ears in healthy subjects. No correlation was found between age and diameter. In male patients with myringosclerosis, the diameter was slightly narrower on both sides but more marked on the left. In female patients with myringosclerosis, the diameter in both ears was slightly narrower. In cases of otitis media and tympanosclerosis, the diameter was less than that of healthy individuals, despite the lack of statistically significant result in all cases. Conclusion: The aditus ad antrum was narrower in diseased ears, indicating that a blocked aditus may contribute to the development of otitis media, as well as mucosal diseases.

Background: Cranial ultrasonography is the main neuroimaging technique for very low birth weight infants. Low brain volume is associated with poor neurologic outcome. This study aimed to calculate brain volumes of preterm infants with two-dimensional measurements of cranial ultrasonography. Methods: Intracranial height, anteroposterior diameter, bi-parietal diamater, ventricular height, thalamo-occipital distance and ventricular index were measured with routine cranial ultrasonographic scanning. Brain considered a spheric, ellipsoid model and estimated brain volume (EBV) was calculated by subtracting two lateral ventricular volumes from the total brain volume. Results: One hundred and twenty-one preterm infants under a birth weight of 1500 g and 32 weeks of gestational age were included in this study. The mean gestational age of study population was 27.7 weeks, and mean birthweight was 1057 grams. Twenty-two of 121 infants had dilated ventricle, in this group, EBV was lower than normal group (202 ± 58 cm3 vs 250 ± 53 cm3, respectively, p<0.01). Advanced resuscitation, bronchopulmonary dysplasia and late-onset sepsis were found to be independent risk factors for low brain volume in our data. Conclusion: Estimated brain volume can be calculated by two-dimensional measurements with cranial ultrasonography.

Background: Supernumerary kidney is an accessory organ with its own encapsulated parenchyma, blood vessels and ureters, either separated from the normal kidney or connected to it via fibrous tissue and ectopic kidney is a migration abnormality of the kidney. Here, we have evaluated a rare case of the supernumerary and ectopic kidney with DMSA, MAG3 and also CT fusion of the images. Methods: The absolute divided renal function was calculated for each kidney by DMSA. The MAG3 scintigraphy showed no obstruction in the ureteropelvic junction. Furthermore, the renogram curve and Tmax and time to ½ values were assessed. Two months after the conventional scintigraphies, the patient was referred to a CT scan and the fusion of DMSA SPECT and CT data was generated on a workstation. Results: The ectopic supernumerary kidney was functioning very well except a small hypoactive area, visible on DMSA, which was possibly a minimal pelvicalyceal dilatation. However, consequent CT scan did not show any pathology. Conclusion: It is important to evaluate particularly complicated or rare cases with multimodality systems with 3D or fusion techniques for the accurate diagnosis.