Current Medical Imaging - Volume 13, Issue 4, 2017

Background: Adipose or fat tissue measurement by MRI is a procedure that produces results similar to those of CT without exposing patients to harmful radiation. Discussion: This review explains the nature and value of adipose tissue (AT) measurements that can be performed with MRI. Conclusion: This paper attempts to provide a general understanding of the acquisition sequences and image processing methods used in measurement and analysis of body AT, as well as the validation and uses of such information. Current methods of MRI-based AT measurement are reviewed and explained in detail.

Background: This article reviews the latest radiological advances in the evaluation of small bowel disease. MRI and CT have been optimized in recent years for small bowel imaging including the development of enteric agents to distend the bowel, multiplanar thin-section imaging, advanced imaging applications, and radiation dose optimization techniques. Discussion: MR enterography, with the absence of ionizing radiation exposure, excellent tissue contrast, ultrafast breath-holding pulse sequences, and the ability to perform real-time functional imaging, has become the first-line imaging modality for the evaluation of the majority of small bowel disorders. Advanced MR applications including diffusion-weighted imaging, dynamic contrast-enhanced MRI, and motility imaging are becoming central in the imaging evaluation of small bowel disease. Conclusion: CT enterography is the preferred modality in patients with known or suspected inflammatory bowel disease in the acute setting to assess for extra-luminal complications. The enteroclysis technique is of use in selected cases in which adequate small bowel distention is not achieved with oral enteral contrast administration. Capsule endoscopy is reserved for patients in whom the clinical suspicion of small bowel disease remains high despite negative evaluations with endoscopy and imaging.

Purpose: Numbers of computed tomography (CT) examinations are increasing, so does the number of patients exposed to ionizing radiation. Our aim was to reveal the current usage of low dose CT protocols in pulmonary nodule follow up in Gaziantep, Turkey, and what is more important to create awareness to the issue. Materials and Methods: A survey was conducted with specialists of chest diseases, thoracic surgeons and radiologists, regarding pulmonary nodule follow-up. At the end of the interview, brief information was given to the participants about the benefits of low dose CT. Results: Among 81 participants, 16 of the 39 radiologists (41.02%) stated that their CT scanners had a previously established low dose chest CT protocols by vendors, while 14 (35.89%) responded that they did not have any and 9 (23.07%) stated they did not know if they had. Twenty nine (74.35%) of the radiologists answered that they have not used the low dose protocols in nodule follow up before. Ninety five percent of clinicians were following a nodule 2 years before they excluded patients from follow up. Only 10 clinicians (23.8%) stated that they have requested low dose chest CT before, while remaining 32 (76.2%) answered they did not ever. Requested mean CT examination numbers during a follow up (except initial CT) were 5.87±2.01, and 6.42±2.15 for pulmonologists and thoracic surgeons, respectively (p=0.437). Conclusion: Follow up strategies of clinicians are consisted with recent literature knowledge, but low dose CT protocols in nodule follow up have not gained enough recognition in our city, yet. Physicians must be enlightened, and steps must be taken to generalize the use of low dose CT, especially in public hospitals, where vast majority of CT examinations are performed.

Introduction: Although obstruction of osteomeatal area was not accepted as an important factor in the pathogenesis of sinus infections for years, recent studies point out the importance of this area. For the maintenance of normal functions of paranasal sinuses, ventilation and drainage of this area is necessary. The purpose of this study was to determine the effect of anomalies of the osteomeatal area on sinus diseases. Methods: This study included cone beam computed tomography scans of 200 patients. Osteomeatal area anomalies were classified as concha bullosa, septal deviation, paradox middle concha, deviation of uncinate process, uncinate bulla, Haller cells and Agger nasi cells. Ethmoid infundibulum and presence of sinus pathologies were recorded. Results: Pathologies were not determined in 243 (60.8%) of the evaluated 400 sinuses while detected in 157 (39.3%) sinuses. Pathologies were found to be more frequent in males than females (p<0.05). Sinus diseases were more prevalent in patients with an obstructed ethmoid infundibulum (p<0.05). Septum deviation was found in 64.5%, concha bullosa in 47%, Haller cells in 17%, paradox middle concha in 8%, deviation of uncinate process in 5.5%, over pneumatisation of agger nasi in 5%, and uncinate bulla in 5% of the investigated patients. Although we found a statistically significant link between ethmoid infundibulum clarity and pathology presence; there was no statistically significant relationship between sinus pathologies and evaluated anomalies. Conclusion: Although we found no relationship between these anomalies and sinus diseases, further studies including the dimensions of the osteomeatal area anomalies will be helpful to determine the effect of these anomalies on sinus diseases.

Objectives: To evaluate the incremental value of diffusion weighted imaging (DWI) in addition to magnetic resonance cholangiopancreat-ography (MRCP) in diagnosing extrahepatic cholangiocarcinoma (EHCC); to determine the most appropriate b value for DWI on 3.0 T MRI. Methods: Preoperative MRI examinations were performed for 63 patients with suspected EHCC. The examinations included T2-weighted imaging, coronal fast imaging employing steady-state acquisition (FIESTA), MRCP and DWI sequence with different b values (500, 1000 and 1200s/mm2). All cases were confirmed by histopathological diagnosis. Two radiologists in consensus reviewed MRCP imaging and combined MRCP and DWI imaging with ADC maps, and apparent diffusion coefficient (ADC) value, signal-noise ratio (SNR), contrast-to-noise ratio (CNR) and signalintensity ratio (SIR) under various b values were calculated. Results: There were significant differences in sensitivity (74.4% vs. 94.9%), specificity (75% vs. 100%) and accuracy (74.6% vs. 96.8%) between MRCP alone and combined MRCP and DWI with a b value of 1000 s/mm2 (P<0.05). There was also a significant difference in ADC, SNR, CNR and SIR under various b values (P<0.05). Conclusion: For diagnosing EHCC, the combined use of MRCP and DWI shows a better diagnostic performance than MRCP alone; the b value of 1000 s/mm2 is the most appropriate for DWI on 3.0T MRI.

Background: Chronic pancreatitis is a progressive inflammatory disease of the pancreatic parenchyma and ductal structures. Typical MR imaging features of chronic pancreatitis include dilatation of the main pancreatic duct and irregularities of branch pancreatic ducts that can be evaluated with MRCP, loss of the normal high signal intensity of the pancreatic parenchyma on T1- weighted images, and decreased enhancement on dynamic contrast-enhanced sequences. Objective: The aim was to evaluate the parenchymal MRI findings of the pancreas in conjunction with MRCP in patients with chronic pancreatitis and normal healthy subjects. Methods: MRI and MRCP findings of 90 consecutive patients with chronic pancreatitis and 26 healthy volunteers were evaluated in this study. Patients were divided into five groups according to Cambridge classification system considering ERCP, MRCP, CT, US and EUS findings. On MRI, signal intensity ratios of the pancreas and the spleen on unenhanced T1 weighted fat saturated spoiled gradient echo images (SIR P/S) along with the enhancement ratio between the arterial phase and the portal venous phase (SIR A/V) were calculated and their frequency in each Cambridge score were documented. MRI findings in normal subjects were compared to patients with chronic pancreatitis. Results: MRCP findings were normal and pancreatic signal intensity was higher than spleen (SIR P/S > 1) in 26 healthy control subjects. Mean pancreas signal in control group (SIR P/S; 1.48±0.13) was significantly higher (P < 0,001) than mean signal intensity in patients with chronic pancreatitis (SIR P/S; 1.18±0.24). In the control group, the highest contrast enhancement occurred in arterial phase (SIR A; 1.7±0.32) and this was significantly higher (P < 0,001) than portal venous phase (SIR V; 1.45±0.28). In chronic pancreatitis group, the highest contrast enhancement occurred in portal venous phase (SIR V; 1.56±0.18) but there was no statistically significant difference (P = 0.06) compared to arterial phase (SIR A; 1.51±0.21). Mean SIR A/V values of control group were 1.18±0.08, and SIR A/V values of patients with chronic pancreatitis were 0.97±0.12 respectively. Mean SIR A/V value in control group was statistically higher than patients with chronic pancreatitis (P < 0.05). Between the control group and patients with chronic pancreatitis in terms of SIR statistically significant differences were found SIR P/S (Spearman correlation coefficient (rs) = - 0.76, P < 0.001), SIR A (rs = - 0.28, P = 0.003), SIR V (rs = 0.43, P < 0.001), SIR LV (rs = 0.54, P < 0.001) and SIR A/V (rs = - 0.68, P < 0.001). Conclusion: In our study, MRI findings were significantly different in subjects with chronic pancreatitis compared to the control group. MRI findings correlated well with the ductal changes according to Cambridge classification. However, MRI findings may occur prior to ductal changes.

Background: The aim of this study was to compare sensitivity, specificity and accuracy of 18F-FDG PET/CT and bone scintigraphy (BS) in detection of bone metastases in breast cancer patients; particularly according to anatomical regions, CT characteristics, tumor markers and hormone receptor status. Methods: Fifty patients, who received both FDG PET/CT and BS were retrospectively analyzed. Patients’ information including age, histological tumor type, hormone receptor positivity, c-erb B-2 oncogenes, tumor markers, clinical stages and subsequent clinical courses were reviewed. Lesion by lesion, regional and overall analyses was performed. The extent of metastases was assessed with twelve regions segmented bone scan index (BSI). The final diagnosis was established by histopathology, imaging and follow-up. Results: Overall sensitivity, specificity and accuracy were 83.2%, 100% and 87.6% for PET/CT, and 69.8%, 76.1% and 71.5% for BS. PET/CT was found to be more sensitive, specific and accurate for all regions, except cranium. While PET/CT was more sensitive in detecting osteolytic lesions, BS was more sensitive in detecting osteoblastic lesions. CA 15-3 levels were correlated with number of metastases for both techniques (P<0.05). Although PET/CT detected more metastatic lesions, the number of lesions detected with both techniques and the calculated BSI’s were not significantly different (p= 0.061, p= 0.053, respectively). BSI and number of totally detected metastases with both techniques were correlated with the final assessment. Conclusion: The sensitivity, specificity and accuracy of PET/CT in detecting overall and subregional bone lesions were significantly higher. Although PET/CT detected more metastatic lesions, both techniques seemed to supply complementary information to each other.

Objectives: The purpose of the study is predicting the sites of the recurrence with PET/CT by serum CA-125 level and detecting the cut-off value of CA-125 for metastatic ovarian cancer (OC) in comparison with Fluorine-18 FDG PET/CT. Materials & Methods: For 38 patients with histological stage III-IV OC, F-18 FDG PET/CT studies (n=59) referred for suspicion of relapsing of OC were conducted. PET/CT images were assessed as positive/negative in 4 categories based on similar location as local recurrence, peritoneal metastasis, lymph node metastases and distant metastases. Patients were divided into five groups according to the levels of CA-125. The results of PET/CT imaging were compared with the level of CA-125. Results: Recurrence was confirmed in all FDG-PET/CT studies. In 7 of them (11.9%) CA-125 levels were normal (mean: 18.9±5.9) whereas in 52 of them (88%) were high (mean: 433.9±798.3). Moderate but highly significant positive correlation between CA-125 level and the number of metastatic foci detected by PET/CT was found. There was no statistically significant difference between CA-125 level subgroups and metastatic sites. However, the difference between CA-125 levels and location of metastasis was statistically significant only for distant metastasis and peritoneal metastasis with moderate accuracy (71% and %66, respectively). Conclusion: Since CA-125 has moderate but highly significant positive correlation with the number of metastatic foci, it is important in clinical management of OC patients. However, it may not predict the localization of the recurrence. When suspicious findings were reported at radiodiagnostic techniques in OC patients, FDG-PET is a useful technique for detecting recurrent ovarian carcer regardless of CA-125 level.

Background: We hypothesized that postoperative lymph node status would affect I-131 uptake (RIU) due to pathophysiological behavior of benign and malign thyroidal tissue. This retrospective study was designed to assess whether RIU would predict the presence of lymph node metastasis (LNM). Methods: Data for differentiated thyroid cancer patients who received postoperative I-131 therapy at our institution between 2013 and 2016 were reviewed. Age, histopathology, TSH, Tg, anti-Tg, 2 and 24 hour RIU (2-24RIU), ultrasonography, I-131 dose, scans were reviewed. Patients were divided into groups according to lymph node status. The ΔRIU was calculated (ΔRIU=24RIU-2RIU) to define different metabolic behavior of I-131. Patients were grouped according to ΔRIU to assess the sensitivity, specificity, negative/positive predictive values, accuracy of ΔRIU predicting LNM. Results: 198 patients (38 males /160 females, age: 47±14 years) who received mean: 118±27 mCi I- 131 were enrolled in the study. There was no difference between ages, TSH level, 2RIU values and the I-131 therapy dose of patients with and without LNM. Tg, anti-Tg, 24RIU, ΔRIU values were higher in patients with LNM. Patients with ΔRIU≥1% had higher Tg values (mean±std: 16.63±46.53 vs. 6.70±31.18, p: 0.04). When ΔRIU≥1% was used for predicting LNM, sensitivity, specificity, positive, negative predictive values, diagnostic accuracy were, 66%, 72%, 64%, 74 %, and 70% respectively. Conclusion: RIU was evaluated to predict neck LN status in this study. The sensitivity and specificity were comparable with modalities which are commonly used for determination of LNM. In light of the results of this study, when a pre-therapy RIU increase in time is observed, carrying out further investigation protocols for LNM, would contribute to pre-therapy staging.

Background: In this paper, we propose a fully automatic intelligent computer vision based method for extracting soft tissue tumor from ultrasound images. Accurate soft tissue tumor area extraction is vital in developing reliable automatic diagnosing tool from ultrasonography. Methods: The proposed method uses many image processing algorithms including intelligent methods such as fuzzy stretching and ART2 clustering algorithm in forming soft tissue tumor object from ultrasonography. Results: In the experiment, the proposed system successfully extracts the target without human intervention in 55 of 60 cases (91.7% accuracy). 51 of such successful extractions have no larger than 20% discrepancy from human experts' manual extractions in size and 28 cases are highly matched to those of human experts' results (less than 10 % discrepancy in size). Conclusion: Such relatively small discrepancy from human expert's judgement is an evidence of the competence of this work.

Background: One of the important functions of blood vessels and retinal vessels is that to extract the information in tissue of the retina for the diagnosis and treatment of various diseases such as glaucoma, hyper tension, blood pressure, cardiovascular diseases (CVD) etc. While the retinal image has to segment the blood vessels and optic disc are proposed in this novel method. Methods: Modern ophthalmology can support non-intrusive diagnosis of this proposed method while the first step is implemented by graph cut technique in the retina vascular tree of extraction. Optic Disc (OD) has been used to locate the blood vessel information and it is the high intensity part of an eye. In this paper, ellipse fitting technique has been used to find the cup boundary of optical disc in an efficient manner. Conclusion: Experimental results have successfully shown the diagnosis of the glaucoma, cardio vascular and other diseases.

Background: Breast cancer is the most prevalent cancer and the second leading cause of cancer death among women. Recently, computerized methods have proved to be an extraordinary tool for radiologists for diagnosing breast cancer. In recent years, data mining techniques and image mining of digital mammography have played a significant role in diagnosing breast cancer. Mammography is considered to be an efficient tool for the early diagnosis of breast cancer. Methods: Mammography images are classified into three groups of benign, malignant, and normal images. This paper proposes a method for optomizing breast cancer diagnosis in digital mammography using Gray Level Co-occurrence Matrix (GLCM) and cumulative histogram features. In the proposed method, a combination of Imperialist Competitive Algorithm (ICA) and decision tree method was introduced for classifying mammogram images by means of GLCM and cumulative histogram features. The proposed approach is referred to as DC-MICs algorithm. Results: In this study, midified imperialist competitive algorithm was implemented for selecting and reducting useless features. Decision tree method was aimed at classifying images based on extracted features. Conclusion: The efficiency of this method was investigated on Digital Database for Screening Mammography (DDSM) breast cancer through the accuracy criterion and the selection of appropriate features for classification. The obtained results indicated that the proposed DC-MICs algorithm has remarkably improved the accuracy, sensitivity, specificity and F-score measures

Background: Blood vessel segmentation plays an important role in medical image analysis. Modern blood vessel segmentation algorithms attempts to attempts to increase patient safety by providing better diagnosis and support to more accurate medical decisions. Methods: In 3D image processing techniques leads to an emerging area, and voxel classification. Most of the voxel classification algorithms are a manual classification. This work introduces a novel fully automatic blood vessel segmentation algorithm from 3D images using Hessian-based multi-scale filters (Frangi's filter) and Chan-Vese model with level-set framework. Parameters of Frangi's filter are adjusted by means of an evolutionary computation method, particle swarm optimization (PSO). 3D synthetic and real CTA clinical image database is used to test the proposed algorithm and show a correct voxel classification. Conclusion: The proposed algorithm shows results that are more accurate.

Background: Sphenoethmoid cells may be above the sphenoid sinus with/ or without contact to optical nerve. Although sphenoethmoid cells are theoretically considered to possibly influence the sphenoid sinus volume, we could not find any study in the literature on this issue. Aims: The aim of our study was to detect sphenoethmoid cells and measure the sphenoid sinus volume using multiplanar computerized tomography and also investigate the correlation between the presence of sphenoethmoid cells and the sphenoid sinus volume. Methods: Retrospectively 141 patients who had available paranasal computerized tomography images were included in this study. The sphenoid sinus volumes of each patient were calculated individually for each side, and the relationship between the presence of sphenoethmoid cell and sphenoid sinus volume was investigated. Results: Sphenoethmoid cells were detected at 106 (37.5%) of the total 282 sides in 141 patients. No gender difference was observed. The total sphenoid sinus volume was significantly lower in the group of patients who had bilateral sphenoethmoid cells than in the sphenoethmoid cell negative group. In patients with a unilateral sphenoethmoid cell, a significant decrease in the sphenoid sinus volume was observed only for the side where the sphenoethmoid cell was located. Conclusion: It was observed that the sphenoethmoid cells caused a significant reduction in the sphenoid sinus volume on the side where they were located. In the case of low sphenoid sinus aeration, the sphenoethmoid cell should be kept in mind. Further studies with an extended patient series are required to explore this issue.

Background: In this paper, we propose a new image denoising technique which combines two denoising approaches. Methods: The first one is a curvelet transform (cvt) based denoising technique. The second one is a two-stage image denoising by principal component analysis with local pixel grouping (LPG-PCA). This proposed technique consists at first step in applying the first approach to the noisy image in order to obtain a first estimate of the clean image. The second step consists in estimating the level of noise corrupting the original image. This estimation is performed by using a method of noise estimation from noisy images. The third step consists in using this first clean image estimation, the noisy image and this noise level estimate as inputs of the second image denoising system (LPGPCA based image denoising) in order to obtain the final denoised image. Conclusion: The proposed image denoising technique was applied on a number of noisy images and the obtained results from PSNR and SSIM computations show its performance.

Introduction: The aim of this study was to gain an understanding of radiology professionals' awareness of, and approach towards e-portfolio use. A further aim was to monitor the effect of the training intervention, and individuals' views and attitudes towards e-portfolio usage in their continuous professional development. Materials and Methods: Questionnaires were initially distributed to 142 radiology professionals in the pre-intervention phase to investigate individuals' knowledge and understanding of e-portfolios. An intervention phase was then carried out consisting of training such as lectures, handouts, and group discussions relative to the benefits of e-portfolio use. Post-intervention questionnaires were then distributed to those participants who had responded to the initial survey and had experienced training during the intervention phase. Quantitative data were collected through the pre and postintervention questionnaires using attitudinal questions with Likert scales. Results were then analyzed to determine any significant correlations following the intervention. Results: Ninety-nine respondents completed the questionnaire in the pre-intervention phase resulting in a response rate of 70%. The response rate decreased to 55% in the post-intervention phase. Statistically, significant post-intervention results indicate that radiology professionals' perceptions towards e-portfolios improved following training and enhanced their interest to adopt it for lifelong learning. Discussion: It is evident that individuals' understanding of what e-portfolios are and how they can help to develop an individual both professionally and personally is lacking. Following the intervention period the positive responses from participants increased significantly indicating that in order to encourage the future use of e-portfolios amongst those who work in radiology, either clinically or academically, prior training and awareness sessions would be beneficial.

Background: Ovarian torsion occurs when the ovary twists on its pedicle. This uncommon cause of acute abdomen is usually accompanied by ovarian abnormalities in postmenarchal girls. In prepubertal girls, the diagnosis is even less common. Discussion: The signs and symptoms of ovarian torsion are often vague and non-specific, especially in young girls who have difficulty explaining themselves. Ultrasound is the first line imaging modality and can diagnose ovarian torsion, as well as some of the differential diagnosis. In an equivocal case, computed tomography and especially magnetic resonance imaging, can help in making the correct diagnosis. Here, we report the imaging findings of 3 prepubertal girls with ovarian torsion, who had similar clinical presentation. In the first two cases, the diagnosis was made relatively fast. In the third case, the findings of the ultrasound examination were not specific enough and additional examination with computed tomography and magnetic resonance imaging was needed; consequently, the damage to most of the adnexa was irreversible. Conclusion: It is important to remember the ultrasound signs of ovarian torsion when examining young girls with acute abdomen, since early diagnosis followed by prompt surgery enables successful treatment, preservation of the adnexa and of fertility, and prevention of complications.

Background: Cardiac Inflammatory Myofibroblastic Tumor (IMT) is extremely rare, currently considered a tumor of borderline malignancy, with unpredictable clinical expression. IMT mimics malignant tumor in clinical presentation, imaging information, and histologic features, making diagnosis troublesome especially in the heart for its rarity. Histopathology is the gold standard for the diagnosis of cardiac IMT. Cardiovascular magnetic resonance (CMR) imaging is a useful tool for the diagnosis of IMT. It can also assist with intraoperative planning. Discussion: However, few researches report the application of CMR imaging in IMT. In our case, CMR results showed typically abundant vascularity and hemorrhage, which may be the characteristic manifestations of IMT. These possible CMR characteristics of IMT could provide basic information for further studies. To date, only 58 cases of cardiac IMT including 4 recurrence cases were reported in the published English paper. We herein present an adolescent girl who presented with similar entity involving left atrium and early recurrence at the same site after subtotal surgical resection. Conclusion: Moreover, recurrence was more likely to occur in patients with incomplete resection. Key Points: Key point 1: Cardiac Inflammatory Myofibroblastic Tumor (IMT) is extremely rare. Key point 2: CMR imaging is a useful tool for the diagnosis and intraoperative planning. Keypoint 3: Few research reports the application of CMR imaging in IMT.