Current Medical Imaging - Volume 15, Issue 1, 2019

Background: Sarcoidosis is an unknown etiology multisystem inflammatory disease in which noncaseating granulomas (a collections of inflammatory cells) form and grow in various organs, involving predominantly lungs, intrathoracic lymph node, skin and eyes. It most commonly affects patients between 20 and 40 years old of age but it could be observed at any age (female predominance; rare in Asians). Discussion: The areas of the body usually affected by sarcoidosis are lungs, skin, or lymph nodes; pulmonary and mediastinal involvement is seen in over of 90% of patients. Less commonly eyes, liver, heart, and brain are involved. Any organ, however, can be affected. Early diagnosis of sarcoidosis can be difficult due to few signs and symptoms in its early stages, and when disease does occur, it may mimic other pathologies, and is made up with chest X-ray, Computed Tomography (CT)-High Resolution CT (HRCT), gallium scans. Fluoro-Deoxy Glucose– Positron Emission Tomography (FDG-PET) is another useful tool to assess the extent of disease and has a potential to evaluate the clinical management of patients responding or not to the treatment. Conclusion: In this review, we would summarize in brief the clinical indications of PDG-PET in sarcoidosis and report the imaging features of the main organs involved in this disease.

Background: Sarcoidosis is a multisystem granulomatous disease with a neglected but high prevalence of life-threatening cardiac involvement. Discussion: The clinical presentation of Cardiac Sarcoidosis (CS) depends upon the location and extent of the granulomatous inflammation, with left ventricular free wall the most common location followed by interventricular septum. The lack of a diagnostic gold standard and the unpredictable risk of sudden cardiac death pose serious challenges for the validation of accurate and effective screening test and the management of the disease. In the last few years advanced cardiac imaging modalities such as Cardiac Magnetic Resonance (CMR) and Positron Emission Tomography (PET) have significantly improved our knowledge and understanding of CS, and have also contributed in risk stratification, assessment of inflammatory activity and therapeutic monitoring of the disease. Conclusion: In this review, we will discuss the state of the art in the diagnosis of CS focusing on the role and importance of multi-modality cardiac imaging.

Background: 18F-fluorodeoxyglucose positron emission tomography integrated with computed tomography (18-F-FDG-PET/CT) is getting wide consensus in the diagnosis and staging of neoplastic disorders and represents a useful tool in the assessment of various inflammatory conditions. Discussion: Sarcoidosis is an uncommon disease characterized by the systemic formation of noncaseating granulomas. Lungs are the sites most often affected, and investigation with high resolution computed tomography and biopsy is essential to achieve a correct diagnosis. 18-F-FDGPET/ CT is effective in the assessment of pulmonary sarcoidosis by demonstrating pulmonary and extrathoracic involvement and findings correlate well with pulmonary function in patients affected. Conclusion: This review would illustrate the usefulness and limits of 18-F-FDG-PET/CT in the assessment of pulmonary sarcoidosis.

Objective: To determine the prevalence of abdominal involvement, distribution pattern and evaluate role of hybrid molecular imaging in patients with abdominal sarcoidosis. Methods: Between January 2010 and December 2011, 98 patients with chronic sarcoidosis and presence of prolonged symptoms or other findings suggestive of active disease were referred to FDG PET/CT examination. Active disease was found in 82 patients, and they all were screened for the presence of abdominal sarcoidosis on FDG PET/CT. All patients also underwent MDCT and assessment of serum ACE level. Follow up FDG PET/CT examination was done 12.3±5.4 months after the baseline. Results: Abdominal sarcoidosis was present in 31/82 patients with active sarcoidosis. FDG uptake was present in: retroperitoneal lymph nodes (77%), liver (26%), spleen (23%), adrenal gland (3%). Majority of patients had more than two locations of disease. Usually thoracic disease was spread into the extrathoracic localizations, while isolated abdominal sarcoidosis was present in 10% of patients. After first FDG PET/CT examination therapy was changed in all patients. Eleven patients came to the follow up examination where SUVmax significantly decreased in the majority of them. Three patients had total remission, three had absence of abdominal disease but discrete findings in thorax and others had less spread disease. ACE levels did not correlate with SUVmax level. Conclusion: FDG PET/CT can be a useful tool for detection of abdominal sarcoidosis and in the evaluation of therapy response in these patients. Awareness of the presence of intra-abdominal sarcoidosis is important in order to prevent long-standing unrecognized disease.

Background: Sarcoidosis is a multisystem granulomatous disorder of unknown origin characterized by nonspecific clinical symptomatology. 18F-FDG PET/CT can visualize activated inflammatory cells of sarcoidosis and simultaneously provide whole-body images. Objective: To evaluate the clinical usefulness of 18F-FDG PET/CT and its semiquantitative parameters for the assessment of treatment efficacy in patients with sarcoidosis. Methods: Thirty-one consecutive patients who performed 18F-FDG PET/CT for sarcoidosis assessment were selected. All subjects performed 18F-FDG PET/CT before any treatment (PET1) and after 6-12 months (PET2). SUVmax and SUVmean on PET1 and PET2 were collected. SUVs values were employed to evaluate the ratios with the liver (R-LIVERmax, R-LIVERmean) and the blood (R-BLOODmax, R-BLOODmean). The difference between the PET1 and PET2 values was evaluated (ΔSUVmax, ΔSUVmean, ΔR-LIVERmax, ΔR-LIVERmean, ΔR-BLOODmax, ΔR-BLOODmean). Patients were classified as Responders (R), Partial-Responders (PR) and Non- Responders (NR). Results: Seventeen patients (54.8%) had a complete metabolic response (R), 4 (12.9%) were PR while 10 (32.3%) had no Metabolic Response (NR). The chi-square test showed that response groups were related neither to the stage of disease (p=0.59) nor to therapy performed (p<0.079). The comparison between each Δ semiquantitative parameter showed a statistically significant decrease from PET1 to PET2 (0.0001 < p < 0.002). The comparison between Δ mean values in relation to response groups showed to be statistically significant (0.001 < p < 0.005). Conversely, they did not show statistical significance in relation to the clinical stage groups and to the kind of therapy performed (p>0.05). Pearson’s coefficient demonstrated a reverse correlation between a number of sites still involved in disease after therapy and each Δ semiquantitative parameters (p≤0.0001). Conclusion: 18F-FDG PET/CT should be considered a useful technique for the evaluation of sarcoidosis and semiquantitative parameters. Further studies are needed to determine the long-term impact of 18F-FDG PET/CT on clinical outcomes.

Background: Temporal Lobe Epilepsy (TLE) comprises the most common form of symptomatic refractory focal epilepsy in adults. Accurate lateralization and localization of the epileptogenic focus are a significant prerequisite for determining surgical candidacy once the patient has been deemed medically intractable. Structural MR imaging, clinical, electrophysiological, and neurophysiological data have an established role in the localization of the epileptogenic foci. Nevertheless, hippocampal sclerosis cannot be detected on MR images in more than 30% of patients with TLE, and the presurgical assessment remains controversial. Discussion: In the last years, advanced MR imaging techniques, such as 1H-MRS, DWI, DTI, DSCI, and fMRI, may provide valuable additional information regarding the physiological and metabolic characterization of brain tissue. MR imaging has shifted towards functional and molecular imaging, thus, promising to improve the accuracy regarding the lateralization and the localization of the epileptogenic focus. Additionally, nuclear medicine studies, such as SPECT and PET imaging modalities, have become an asset for the decoding of brain function and activity, and can be diagnostically helpful as well, since they provide valuable data regarding the altered metabolic activity of the seizure foci. Conclusion: Overall, advanced MRI, SPECT, and PET imaging techniques are increasingly becoming an essential part of TLE diagnostics, when the epileptogenic area is not identified on structural MRI or when structural MRI, clinical, and electrophysiological findings are not in concordance.

Background: This paper reviews segmentation techniques for 2D ultrasound fetal images. Fetal anatomy measurements derived from the segmentation results are used to monitor the growth of the fetus. Discussion: The segmentation of fetal ultrasound images is a difficult task due to inherent artifacts and degradation of image quality with gestational age. There are segmentation techniques for particular biological structures such as head, stomach, and femur. The whole fetal segmentation algorithms are only very few. Conclusion: This paper presents a review of these segmentation techniques and the metrics used to evaluate them are summarized.

Objective: The aim of the research was to determine the dependence of the blood flow velocity in the thyroid arteries in patients with Autoimmune Thyroiditis (AIT) on the presence of atherosclerotic carotid disease and the level of systemic blood pressure. Methods: The research involved 20 patients with AIT in euthyroid state, 30 patients AIT in euthyroid state with stable Coronary Heart Disease (CHD), 30 patients with stable CHD and 30 healthy individuals. Participants of the research were examined using ultrasound of carotid arteries and inferior thyroid arteries. Parameters of blood flow velocity were compared with the level of systemic blood pressure. Results: In AIT peak systolic velocity and resistance index in the inferior thyroid arteries were significantly higher than in healthy individuals and patients with CHD (p<0.05). In patients with CHD velocity parameters in carotid arteries were high, unlike in the healthy individuals and patients with AIT (p<0.05). In patients with AIT without CHD the atherosclerotic changes of carotid arteries were not found. Increased systemic blood pressure was noticed in all patients with CHD without significant differences between groups. Conclusion: The value of peak systolic velocity and resistance index of inferior thyroid arteries in autoimmune thyroiditis are noticed even with euthyroidism and do not depend on systemic blood pressure and atherosclerosis of carotid arteries. Increasing the thyroid arterial blood flow velocity parameters should be considered as sign of an active inflammatory period AIT, where advanced fibrosis is not present.

Background: Digital Signal Processing (D.S.P) is an evolutionary field. It has a vast variety of applications in all fields. Bio medical engineering has various applications of digital signal processing. Digital Image Processing is one of the branches of signal processing. Medical image modalities proved to be helpful for disease diagnosis. Higher expertise is required in image analysis by medical professional, either doctors or radiologists. Methods: Extensive research is being done and has produced remarkable results. The study is divided into three main parts. The first deals with introduction of mostly used imaging modalities such as, magnetic resonance imaging, x-rays, ultrasound, positron emission tomography and computed tomography. The next section includes explanation of the basic steps of digital image processing are also explained in the paper. Magnetic Resonance imaging modalities is selected for this research paper. Different methods are tested on MRI images. Discussion: Brain images are selected with and without tumor. Solid cum Cystic tumor is opted for the r esearch. Results are discussed and shown. The software used for digital image processing is MATLAB. It has in built functions which are used throughout the study. The study represents the importance of DIP for tumor segmentation and detection. Conclusion: This study provides an initial guideline for researchers from both fields, that is, medicine and engineering. The analyses are shown and discussed in detail through images. This paper shows the significance of image processing platform for tumor detection automation.

Background: Mediastinal bronchial artery aneurysms are uncommon, with fewer than 40 published case reports. This study objective was to evaluate the short term follow up of two cases ruptured Bronchial Artery Aneurysm (rBAA) treated with aneurysm embolization and subsequent aortic stent graft. Methods: Two cases of rBAA were treated with a combination of an aortic stent-graft and aneurysm embolization. With rBAA, aneurysm embolization could be performed with sodium polymannuronate until the aneurysm was almost completely packed. One of the limitations of aneurysm embolization is spontaneous recanalization of previously occluded aneurysm. So a stent-graft was deployed to isolate the feeding artery of the rBAA from the descending aorta. The 3 months follow- up after the procedure included chest or back pain and computed tomographic angiography. Results: The hospital stays of the 2 cases were 5 and 7 days. Chest or back pain was disappeared. There were no hospital deaths and late deaths. Computed tomographic angiogram showed no recanalization and no hemothorax. These 2 patients have not reported any complications up to now. Conclusion: Aortic stent graft combined with aneurysm embolization is a minimally invasive, effective and safe method for rBAA.

Background: Recurrent episodes of isolated pericardial effusion due to tuberculosis, leading to reduced Left Ventricle Ejection Fraction (LVEF), are uncommon. Methods: This is a case report of a previously healthy 32-years old male with tuberculous induced pericardial effusion as isolated manifestation. The only known exposure of tuberculosis was a brother with whom the patient did not have physical contact during the last year. The pericardial effusion repeatedly appeared after being drained a total of three times. Due to recurrent episodes of pericardial effusion, severe thickening of the pericardium, pericardial adherences and increasing affection on the heart, pericardiectomy was ultimately performed. Results: Biochemical examination, chest X-ray, computed tomography of thorax and abdomen and cytology report did not reveal any signs of malignancy, connective tissue disease or other infections including extra-pulmonary/pulmonary tuberculosis. However, the pericardial biopsy was Polymerase Chain Reaction positive (PCR) for tuberculosis DNA and showed granulomatous inflammation with necrosis. After 6 months anti-tuberculous therapy, biochemical parameters, LVEF and the clinical condition of the patient were normalized. Conclusion: Tuberculosis can be difficult to diagnose when it only manifests as pericardial effusion especially if the time for exposure is long before the appearance of symptoms and admission.

Background: Lung lesions often appear in patients with sarcoidosis; however, miliary opacities are rare. We present the case of a 55-year-old Indian man who presented with dyspnea and low-grade fever. Discussion: Miliary Tuberculosis (TB) was initially suspected, despite the direct microscopic examination from bronchoalveolar lavage was negative for acid-fast bacilli because imaging showed miliary opacities, and transbronchial lung biopsy revealed the presence of typical caseating granulomas. Antitubercular treatment with the classic four-drug regimen was initiated. However, the patient did not improve and cultures were negative for Mycobacterium growth. The diagnosis of sarcoidosis was made only after a negative culture and clinical and histopathological re-evaluation of the case. Conclusion: Although miliary sarcoidosis is rare, physicians should consider sarcoidosis in the differential diagnosis with conditions like tuberculosis, malignancy, and pneumoconiosis when patients present with miliary opacities who do not respond to the traditional treatment.