Current Medical Imaging - Volume 17, Issue 5, 2021

Stroke is the most common cause of mortality and morbidity worldwide. The prognosis of stroke depends upon the area affected and its early treatment. Time is of the essence in the care of stroke patients as it is estimated that approximately 1.9 million neurons, 14 billion synapses, and 12 km myelinated nerve fibers are lost per minute. Therefore, early diagnosis and prompt treatment are necessary. The primary goal of imaging in acute stroke is to diagnose the underlying cause, estimate the area affected, predict response towards thrombolytic therapy and to exclude the conditions mimicking stroke. With advancements in radiology, multiple imaging modalities are available for diagnosis and predicting prognosis. None of them is considered alone to be perfect. In this era of multimodality imaging, the decision of choosing appropriate techniques depends upon purpose and availability. Non-Contrast Computed Tomography is time effective, and helps in excluding other causes, Trans Cranial Doppler is time-effective and cost-effective with wide availability, however, is operator dependent and less sensitive. It holds a great future in sonothrombolysis. Magnetic Resonance Imaging is so far considered to be the most superior one in terms of early diagnosis, planning for interventional treatment and predicting the response of treatment. However, it is limited due to high cost and lack of availability. The current review gives a detailed account of all imaging modalities available for imaging stroke and their associated pros and cons.

Objective: Several denoising methods for medical images have been applied, such as Wavelet Transform, CNN, linear and Non-linear methods. Methods: In this paper, A median filter algorithm will be modified and the image denoising method to wavelet transform and Non-local means (NLM), deep convolutional neural network (Dn- CNN), Gaussian noise, and Salt and pepper noise used in the medical image is explained. Results: PSNR values of the CNN method are higher and showed better results than different filters (Adaptive Wiener filter, Median filter, and Adaptive Median filter, Wiener filter). Conclusion: Denoising methods performance with indices SSIM, PSNR, and MSE have been tested, and the results of simulation image denoising are also presented in this article.

Objective: The purpose of this study is to clarify which morphologic variations of the hip on MRI are associated with the development of ischiofemoral impingement. Methods: Hip MRIs of patients who have been referred to our department between 2016-2017 were retrospectively reviewed and assessed for pathological signal changes in the quadratus femoris muscle and ipsilateral hip or buttock pain. After assessment, ischial angle, inclination angle, ischiofemoral space, quadratus femoris space, intertuberous distances and femur neck angle, femoral torsion angle and knee angle were measured and compared in 37 hips of 20 patients and 56 hips of 28 age-gender matched control subjects. Results: There were statistically significant differences between the patient and control groups in all MRI parameters except for intertuberous distances (p<0.05). Quadratus femoris space (p<0.001) and ischiofemoral space (p<0.001) were significantly lower and femoral torsion angle (p=0.02), femur neck angle (p=0.001), ischial angle (p=0.01) and inclination angle (p=0.03) values were significantly higher in patients compared with the control group. Conclusion: Decreased ischiofemoral space and quadratus femoris space, increased femoral torsion angle, femur neck angle, ischial angle and inclination angle are found to be associated with IFI on MRI. These pelvic anatomical variations may predispose to ischiofemoral impingement and should be kept in mind for patients with hip pain.

Background: The effectiveness of Diffusion Tensor Imaging (DTI) in demonstrating functional changes in the tumor in determining the response to treatment after radiosurgery in patients with vestibular schwannoma (VS) is not clear yet. Objective: The study aimed to determine the change in total tumor volume (TTV) in terms of radiological response in patients who had VS and were treated with radiosurgery and investigated the relationship between the TTV, follow-up times and DTI parameters. Methods: Thirty-one patients were assessed using DTI and MRI. TTV, apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were calculated. Patients were divided into three groups: those who responded to the treatment (group 1) (n=11), those who did not (group 0) (n=9) and those who remained stable (group 2) (n=11). Results: The mean duration of follow-up was 28.81±14 months. ADC values increased in patients with VS after radiosurgery (p=0.004). There was no statistical difference in the FA values. A significant reduction in TTV after radiosurgery was detected in group 1 (p=0.003). ADC values increased significantly after radiosurgery in group 2 (p=0.04). Although there were no significant differences, ADC values after radiosurgery increased in group 1 and group 0. Conclusions: ADC values continuously increase due to radiation damage in the period before the tumor volume shrinks after radiosurgery. We think that it is not appropriate to diagnose inadequate treatment or progression only when TTV is evaluated in terms of response to treatment in the early period after radiosurgery.

Background: Hyperthyroidism is a common systemic disorder where Graves’ disease is known as the leading cause of the disease. Thyroid stimulating hormone, T4 and T3 antibody assay is usually performed for the diagnosis of the pathology. However, with uncertainty in the results and in order to estimate the magnitude and the exact cause of the disease, radioactive iodine uptake (RAIU) test is recommended. The aim of this study is to evaluate underlying pathology in the patients presenting hyperthyroidism using RAIU test results. Methods: This is a cross-sectional retrospective study conducted on the patients with hyperthyroidism referred to Shahid Madani Hospital in Khorramabad. Data regarding the biochemical analysis and RAIU test was collected from the records and a questionnaire based on demographic and clinical information was completed for each patient. Results: Of 137 patients presenting hyperthyroidism, 62.04% presented with Graves’ disease, 24.08% with toxic multinodular goiter and 13.86% with toxic adenoma. 24-hour RAIU test showed that the percent of radioiodine uptake was most in toxic adenoma with 67.7%, Graves’ disease 53.5% and multinodular goiter 39%, respectively. From the age-based analysis, we found that Graves’ was most common in 20-30 years old individuals accounting for 34%, multinodular goiter in 50+ aged individuals with 36.3% and toxic adenoma was most prevalent in 30-40 and 50+ aged patients, with 26.3%. In our population of interest, 81.8% toxic multinodular goiter patients were females. Conclusion: Our study presents the outcome of RAIU tests in hyperthyroidism based on the underlying pathologies. We also conclude, in light of other findings, that Graves’ disease is the most common cause of hyperthyroidism in our population.

Background: Obstructive sleep apnea (OSA) is a chronic sleeping disorder. The analysis of the pharynx and its surrounding tissues can play a vital role in understanding the pathogenesis of OSA. Classification of the pharynx is a crucial step in the analysis of OSA. Methods: A visual analysis-based classifier is developed to classify the pharynx from MRI datasets. The classification pipeline consists of different stages, including pre-processing to select the initial candidates, extraction of categorical and numerical features to form a multidimensional features space, and a supervised classifier trained by using visual analytics and silhouette coefficient to classify the pharynx. Results: The pharynx is classified automatically and gives an approximately 86% Jaccard coefficient by evaluating the classifier on different MRI datasets. The expert’s knowledge can be utilized to select the optimal features and their corresponding weights during the training phase of the classifier. Conclusion: The proposed classifier is accurate and more efficient in terms of computational cost. It provides additional insight to better understand the influence of different features individually and collectively. It finds its applications in epidemiological studies where large datasets need to be analyzed.

Background: In this paper, we propose a new efficient method of radionuclide ventriculography image segmentation to estimate the left ventricular ejection fraction. This parameter is an important prognostic factor for diagnosing abnormal cardiac function. Methods: The proposed method combines the Chan-Vese and the mathematical morphology algorithms. It was applied to diastolic and systolic images obtained from the Nuclear Medicine Department of Salah AZAIEZ Institute. In order to validate our proposed method, we compare the obtained results to those of two methods present in the literature. The first one is based on mathematical morphology, while the second one uses the basic Chan-Vese algorithm. To evaluate the quality of segmentation, we compute accuracy, positive predictive value and area under the ROC curve. We also compare the left ventricle ejection fraction estimated by our method to that of the reference given by the software of the gamma-camera and validated by the expert, using Pearson’s correlation coefficient, ANOVA test and linear regression. Results: Static results show that the proposed method is very efficient for the detection of the left ventricle. The accuracy was 98.60%, higher than that of the other two methods (95.52% and 98.50%). Conclusion: Likewise, the positive predictive value was the highest (86.40% vs. 83.63% 71.82%). The area under the ROC curve was also the most important (0.998% vs. 0.926% 0.919%). On the other hand, Pearson's correlation coefficient was the highest (99% vs. 98% 37%). The correlation was significantly positive (p<0.001).

Background: Image fusion has been grown as an effectual method in diseases related diagnosis schemes. Methods: In this paper, a new method for combining multimodal medical images using spatial frequency motivated parameter-adaptive PCNN (SF-PAPCNN) is suggested. The multi- modal images are disintegrated into frequency bands by using decomposition NSST. The coefficients of low frequency bands are selected using maximum rule. The coefficients of high frequency bands are combined by SF-PAPCNN. Methods: In this paper, a new method for combining multimodal medical images using spatial frequency motivated parameter-adaptive PCNN (SF-PAPCNN) is suggested. The multi-modal images are disintegrated into frequency bands by using decomposition NSST. The coefficients of low frequency bands are selected using maximum rule. The coefficients of high frequency bands are combined by SF-PAPCNN. Results: The fused medical images is obtained by applying INSST to above coefficients. Conclusion: The quality metrics such as entropy ENT, fusion symmetry FS, deviation STD, mutual information QMI and edge strength QAB/F are used to validate the efficacy of suggested scheme.

Introduction: Aneurysm of the communicating vein between the left renal vein and left ascending lumbar vein is extremely rare, with only anecdotal reported cases. Unless detected and recognized promptly, this rare condition may give rise to severe bleeding in patients undergoing retroperitoneal surgery. It may also closely mimic enlarged retroperitoneal lymph nodes, paragangliomas, adrenal masses, or renal artery aneurysms. Case Report: In this case study, we reported the imaging findings of this rare entity, which was falsely diagnosed as an enlarged retroperitoneal lymph node in an outside medical center, reported to be consistent with metastatic disease in a patient with newly diagnosed testicular cancer. Conclusion: The aneurysm of the communicating vein should be considered in the differential diagnosis in patients with testicular cancer and other disease processes where lymph nodes are commonly affected.

Introduction: Neurocysticercosis (NCC), a major contributor to the burden of seizure disorders and epilepsy in the world, is one of the most common parasitic infections of the central nervous system, which is usually located in the brain. Medical therapy for NCC should initially cover appropriate symptom control and then the use of antiparasitic agents should be considered. Antiparasitic treatment is of benefit in most cases of viable and degenerating NCC. Nevertheless, cysticercosis of the spinal cord is very uncommon. Case Series: In this article, we recorded 5 cases of extramedullary-intradural lumbar spinal cysticercosis, in which one case displayed cystic lesions in both brain and spine, one case showed an independent cystic lesion in the spine, and three remaining cases showed diffuse lesions in the spinal canal. Conclusion: Thus, in any case of single or numerous cystic lesions or dispersed lesions entering the spinal canal, spinal cysticercosis should be considered.

Introduction: Meningiomas are the third most common intracranial tumors in adults after glial tumors and metastases. Olfactory groove meningiomas often grow without symptoms due to their slow growth rates and location in the frontal lobe. Optic nerve sheath meningiomas are benign neoplasms of the meninges surrounding the optic nerve. The coexistence of olfactory groove and optic nerve sheath meningiomas without any history of neurofibromatosis or radiotherapy has never been reported in the literature. Case Report: A 36-year-old female patient was reported with anosmia, headache, memory disturbance, and visual impairment and with the diagnosis of olfactory groove meningioma. In the postoperative period, optic nerve sheath meningioma was detected in the imaging performed due to persistence of visual impairment. Conclusion: Olfactory groove and optic nerve sheath meningiomas are rare tumors and can be diagnosed late because they progress slowly. Early diagnosis and treatment may affect the prognosis and morbidity of these patients favorably.

Background: Neurosarcoidosis manifests symptomatically in 5% of patients with sarcoidosis and diagnosis can be challenging if not clinically suspected. Cerebral mass-like presentation of neurosarcoidosis rarely reported in the literature. We presented a woman with neurosarcoidosis who had a cerebral mass-like lesion which completely disappeared after medical treatment. Discussion: A 37-year-old woman with history of pulmonary sarcoidosis referred to the emergency service of our hospital with a one-month history of progressive dizziness, nausea and seeing flashing lights. At neurologic examination, numbness and weakness on the left side of the body, deviation of uvula toward the right side was seen. Cranial MRI demonstrated a 2.5x2 cm in size mass lesion which hypointense on T1 WI, heterogeneous hyperintense on T2 and FLAIR sequence with peripheral vasogenic edema and heterogeneous, irregular contrast enhancement simulating brain tumor. Also, leptomeningeal and nodular contrast enhancement was seen on brainstem, cerebellar vermis, perimesencephalic cistern and left frontal, bilateral parietooccipital sulcus. In laboratory tests; The level of serum angiotensin-converting enzyme (ACE) was 53 IU/mL (N:8-52 IU/mL) and cerebrospinal fluid (CSF) ACE was 23 IU/mL (N:0-2.6 IU/mL). CSF cytology analysis was normal. Pattern 2 oligoclonal bands were present. With these clinical, laboratory and radiological findings, cerebral involvement of sarcoidosis was suspected. Biopsy was not performed due to the high risk of morbidity caused by the deep location of the lesion.Patient was treated with methylprednisolone and Azathioprine for a month.On post-treatment control imaging; lesion disappeared completely without residual leptomeningeal and nodular contrast enhancement.Also, neurologic symptoms were decreased remarkably. Conclusion: Multi-system inflammatory disorders like sarcoidosis, can present with mass-like lesion in the brain parenchyma. While early diagnosis is important to prevent unnecessary interventions like biopsy and surgery, it is crucial to initiate the necessary treatment with the aim of recovery without sequelae. Radiological and clinical follow-up are fundamental in differential diagnosis.

Background: Isolated iliac artery aneurysms are rare and occur predominantly in men at an older age. Such aneurysms can rupture into an adjacent organ (such as the bowel, bladder or ureter) or into the adjacent common iliac vein, resulting in an arteriovenous fistula. INTRODUCTION: Formation of an internal iliac arteriovenous fistula caused by spontaneous rupture of an atherosclerotic iliac artery aneurysm wall is an exceedingly rare yet serious complication. Case Presentation: This article presents a case of an internal iliac arteriovenous fistula caused by rupture of an atherosclerotic giant iliac artery aneurysm. Conclusion: Rapid diagnosis and meticulous surgical technique improve outcomes in patients with this rare vascular complication.

Background: The utility of gadobutrol (GAD) which is higher r1 value contrast media for evaluating abdominal solid organ have not been fully evaluated. Objective: To compare the contrast enhancement of abdominal organs on dynamic MRI using 0.1 mmol/kg 1.0 M GAD or 0.5 M meglumine gadoterate (MG) in patients with a liver hemangioma. Methods: A phantom study was performed at different concentrations (0.05, 0.1, 0.3, 0.5, 0.7, 0.9, 1.0, 5.0 and 10 mmol/L) of GAD and MG. Sixty-two patients with a liver hemangioma were enrolled. Contrast media was injected at a rate of 2 mL/s followed by 40 mL of saline. Two arterial phases, a portal phase and an equilibrium phase were obtained. One certified radiologist set regions of interest on the abdominal aorta, liver, pancreas, spleen and the liver hemangioma. The relative enhancement ratio (RER) was calculated. Results: In the phantom study the signal intensity of both contrast media was similar at lower concentrations. However, the signal intensity of MG was higher at concentrations of more than 5.0 mmol/L. In the clinical study the RER of the abdominal viscera during the portal and equilibrium phases was higher with GAD. The hemangioma had a higher equilibrium phase enhancement with GAD. The aortic RER was equivalent during all phases and the liver RER during the 2nd arterial phase was higher with GAD. The arterial phase during GAD imaging might have been measured later than was optimal. Conclusion: When the same injection protocol was used for an abdominal dynamic MRI, arterial phase imaging was late when GAD was used. The higher T1 relaxation value was significantly higher in the abdominal viscera during the portal and equilibrium phases, while the liver hemangioma also had significantly higher contrast enhancement during the equilibrium phase. Clinical trial registration number: 3186.

The Artery of Percheron (AOP) is an uncommon anatomic variant that provides arterial supply to the paramedian region of the thalami and bilaterally to the rostral part of the midbrain; it is a solitary arterial trunk that branches from a proximal segment of the posterior cerebral artery (PCA). Although AOP infarction results in a characteristic pattern of ischemia—namely bilateral paramedian thalamic infarct with or without midbrain involvement—it may cause diagnostic difficulties due to the variety of its clinical presentations and wide differentials, as well as its small diameter and the difficulty of obtaining visualization through diagnostic imaging. Early neuroimaging of AOP infarction and correct diagnosis are mandatory for early initiation of the appropriate treatment and better patient outcomes. In this study, we discuss imaging the patterns of AOP infarction and its differentials and clinical presentation.

Due to an oversight of the author, the principal author’s name was published incorrectly in the author list and in the Fig. (3): Shakeel et al. (2019) have been changed to Shakeel et al. (2020) and Palani and Venkata-lakshmi (2019) have been changed to Palani and Venkatalakshmi (2018) in the article entitled “A Review on Lung Cancer Diagnosis Using Data Mining Algorithms” in “Current Medical Imaging”, 2021; 17(1), [1]. The original article can be found online at https://www.eurekaselect.com/183148/article