Purpose To investigate the role of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in the prediction of histological differentiation and local invasion (T stage) of rectal non-mucinous adenocarcinoma for appropriate treatment planning. Material and methods Pre-operative magnetic resonance imaging (MRI) and IVIM-DWI examinations were prospectively performed in patients with rectal non-mucinous adenocarcinoma. A total of 36 patients with a mean age of 61 ± 8 years (range: 26-85 years) were included. Size, signal intensities and enhancement pattern of tumors, lymphadenopathy, serosal involvement, adjacent organ invasion, and metastasis were noted. IVIM-DWI parameters were estimated. Relationships between IVIM-DWI parameters and histopathological results were analyzed using Mann-Whitney U and Kruskal-Wallis tests. Receiver operating characteristic analysis was performed for optimal cut-off values. Results In our study, a total of 36 patients were enrolled. There was a negative relationship between tumor differentiation and perfusion (f) (p < 0.05). A negative relationship was detected between T staging and true diffusion (D), pseudo-diffusion coefficient (D*) and apparent diffusion coefficient (ADC) values (p < 0.05). Lower D, D*, and ADC values were detected in late stage (T3-T4) rectal tumors and nodal metastasis (p < 0.05). Lower f values were achieved in higher histological grades (p < 0.05). In differentiation of poorly from well- and moderately differentiated tumors, cut-off value of < 20.89 showed 88.5% sensitivity and 85.7% specificity (area under the curve: 0.771, p < 0.05). Conclusions Aggressive tumors with low histological differentiation and metastatic lymphadenopathy exhibit lower diffusion and perfusion values. As a perfusion indicator, f provides valuable information regarding tumor differentiation. IVIM-DWI can be used as an adjunctive modality to routine abdominal MRI in the local staging of rectal carcinoma.

Purpose Our aim was to evaluate the diagnostic efficacy of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) parameters [D, D*, f, and apparent diffusion coefficient (ADC) values] in the detection and staging of liver fibrosis in patients with hepatitis B virus (HBV). Material and methods In this prospective study, a patient group of 64 consecutive patients (with a mean age of 43 years, 30 women and 34 men) with HBV, who scheduled liver biopsy, and a control group of 30 healthy individuals without liver disease underwent IVIM-DWI scan. A total of 94 IVIM-DWI examinations were analysed. IVIM-DWI parame­ters were measured in the right lobe of the liver. The IVIM-DWI parameters of the patient and control groups were compared by Mann-Whitney U test. The patient group was classified into subgroups according to fibrosis stage of histopathological results. Receiver operating characteristic (ROC) analysis was conducted to assess the sensitivity and specificity of each parameter for detection and staging fibrosis. Results D and ADC values were significantly lower in the patient group compared to the control group (p < 0.05), while D* values were significantly higher (p < 0.05). No significant difference was observed in f values between the 2 groups. D* had the highest diagnostic performance, with a sensitivity of 78.1% and specificity of 73.3%, with a cut-off value of 1.4 × 10–3 mm2/s in the differentiation of fibrosis stages. Conclusions IVIM-DWI, particularly the D, D*, and ADC parameters, is an adjunctive non-invasive alternative to biopsy in the staging of HBV-related liver fibrosis, especially for the prediction of advanced fibrosis.

Metastases from ovarian cancer to the central nervous system (CNS) are rare, in particular, isolated leptomeningeal metastases (LM) are extremely rare. The gold standard in the diagnosis of leptomeningeal carcinomatosis (LC) is the detection of malignant cells in cerebrospinal fluid (CSF) cytology. A 58-year-old woman diagnosed with ovarian cancer 2 years ago underwent lumbar puncture and CSF cytology in recent months due to new weakness, loss of strength in the lower extremities, and speech disorders. Magnetic resonance imaging CNS was simultaneously visualized and linear leptomeningeal enhancement was demonstrated. CSF cytology showed tumor cells as isolated cells or small clusters of tumor cells with large, partially vacuolated, and abundant cytoplasm, mostly with centrally located nuclei. Given her history of high-grade clear cell ovarian cancer,CSF cytology was positive for malignant cells and a diagnosis of leptomeningeal carcinomatosis was made by the neuro-oncology multidisciplinary tumor board. Since LM also implies a systemic disease, the prognosis is very poor, CSF cytology will play an important role in rapid diagnosis and will be useful both in the right choice of treatment and in the early initiation of palliative care.

PurposeTo investigate the role of non-echo planar diffusion weighted imaging (DWI) using "periodically rotated overlapping parallel lines with enhanced reconstruction" (PROPELLER) sequence for the diagnosis of cholesteatoma compared to surgical and histopathological results in an attempt to determine the factors causing false negative and false positive diagnoses.MethodsPatients who had PROPELLER DWI before ear surgery were retrospectively reviewed. The presence of a lesion with diffusion restriction on PROPELLER DWI was accepted as positive for cholesteatoma, and the results were compared to the intraoperative and histopathological findings.ResultsA total of 112 ears in 109 patients were reviewed. On PROPELLER DWI, a lesion with diffusion restriction was found in 101 (90.2%) ears, while in 11 (9.8%) of the patients, no diffusion restriction was found. Surgery and histopathological analysis revealed a cholesteatoma in 100 (89.3%) ears, while in 12 (10.7%) ears, no cholesteatoma was found surgically. There were 96 (85.7%) true positives, 7 (6.2%) true negatives, 5 (4.5%) false positives and 4 (3.6%) false negatives. The accuracy, sensitivity, specificity, positive predictive and negative predictive values of non-echo planar DWI were calculated to be 91.96%, 96%, 58.33%, 95.05%, and 63.64%, respectively.ConclusionNon-echo planar DWI using PROPELLER sequence has high accuracy, sensitivity and positive predictive value and can be used for the detection of cholesteatoma. The external auditory canal, postoperative ears and small lesions should be evaluated with caution to avoid false results.

OBJECTIVE:Because of the immature bone marrow signal in children, assessment of the sacroiliac joint is more difficult than in adults. Aim of this study is to evaluate the efficacy of diffusion-weighted imaging (DWI) in sacroiliac joint magnetic resonance imaging (MRI).METHODS:Sacroiliac joint MRI, including DWI sequences, were evaluated by two pediatric radiologists in 54 patients with sacroiliitis and 85 completely normal controls. In MRI evaluation, subchondral bone marrow edema and contrast enhancement in the sacroiliac joints were considered as active sacroiliitis. Apparent diffusion coefficient (ADC) measurements were made in six areas from each sacroiliac joint. A total of 1668 fields were evaluated retrospectively without their diagnosis being known.RESULTS:When the postcontrast T1W series were referenced, the sensitivity, specificity, positive predictive value, and negative predictive value of short time inversion recovery (STIR) images in the diagnosis of sacroiliitis were 88%, 92%, 83% and 94% respectively, compared to contrast-enhanced images. False positive results in STIR images were observed secondary to the flaring signal in the immature bone marrow. ADC measurements obtained from diffusion-weighted images were recorded in all patients and healthy groups. The ADC values were 1.35x10-3 mm2/s (SD: 0.21) in the areas of sacroiliitis, 0.44x10-3 mm2/s (SD: 0.71) in the normal bone marrow and 0.72x10-3 mm2/s (SD: 0.76) in the immature bone marrow areas.CONCLUSION:Although STIR studies are an effective sequence in the diagnosis of sacroiliitis, they cause false positive results in immature bone marrow in children in inexperienced hands. DWI is an objective method that prevents errors in the assessment of sacroiliitis by means of ADC measurements in the immature skeleton. In addition, it is a short and effective MRI series that makes important contributions to the diagnosis without the need for contrast-enhanced examinations in children.

This research was conducted to study x-ray and gamma radiation shielding parameters such as mass attenuation coefficient, mean free path, half value layer, tenth value layer, effective atomic numbers, effective electron density for the xBi2O3-(95-x)B2O3-5BaO (where x = 20 mol%, 35 mol%, 50 mol%, and 70 mol%) glass systems with different molar composition. The studied ceramic specimens were denoted by BB20, BB35, BB50 and BB70 and their density values were 4.438 g/cm3 , 5.973 g/cm3 , 7.156 g/cm3 , and 8.005 g/cm3 , respectively. Radiation shielding parameters of the samples were investigated by using web based XCOM programme. The obtained results revealed that the highest mass attenuation coefficients were reported for BB70 sample, which has the highest Bi2O3 additive in its chemical structure. At 7 MeV photon energy, half value layer (HVL) values were reported as 5.7812 cm, 3.8065 cm, 2.8533 cm, and 2.2457 cm for BB20, BB35, BB50 and BB70, respectively. Therefore, It can be concluded that the present bismuth sesquioxide based glasses in the Bi2O3-B2O3-BaO glass system have a good quality in radiation protection purposes. Therefore, this glass system can be used as an alternative to conventional materials with the right molar compositon in its chemical formation.

Background: Alzheimer???s disease (AD) is a major cognitive disorder classified as a common type of dementia. Magnetic resonance imaging (MRI) is the most practical method for diagnostic purposes in AD. The aim of the study was to determine the volume of the hippocampus and intracranial structures in AD using MRI. Methods: A total of 102 patients with AD were classified based on the mini mental test scores as early, moderate, and advanced stage. The control group included 35 healthy subjects. MRI were compared between the patients and control groups based on the calculations made utilizing volBrain software. Intracranial volumetric parameters were also compared between the three stages of AD. Results: The white matter volumes, total hippocampus, total cerebrum, right cerebrum, left cerebrum, truncus encephalic, total nucleus caudatus and total corpus amygdaloideum were significantly increased in the AD. The white matter volumes, right hippocampus, left hippocampus, total cerebrum, left cerebrum, and right cerebellum were significantly increased in the patients in the early stage compared to the patients in the advanced stage AD. Conclusion: The most efficient volumetric study in AD could be performed by obtaining long-term periodic morphometric data of an early diagnosed and regularly followed-up patient population.

OBJECTIVE:The aim of this study is to evaluate the myocardium structure in patients with chest pain who were determined to have moderate and/or high risk for cardiac ischemic heart disease (IHD) but who had normal findings on conventional coronary angiography by using native cardiac magnetic resonance imaging (CMRI) T1 mapping and comparing with healthy volunteers.METHODS:A total of 50 patients and 30 healthy volunteers who underwent CMRI were included in our prospective study. Patients whose clinical findings were compatible with stable angina pectoris, with moderate and/or high risk for IHD, but whose conventional coronary angiography was normal, were our patient group. Native T1 values were measured for 17 myocardial segments (segmented based on American Heart Association recommendations) by two radiologists independently. The data obtained were statistically compared with the sample t-test.RESULTS:Myocardial native T1 values were found to be significantly prolonged in the patient group compared with the control group (p<0.05). Inter-observer reliability for native T1 value measurements of groups was high for both patient and control groups (α = 0.92 for the patient group and 0.96 for the control group).CONCLUSION:Findings suggestive of ischemia were detected by T1 mapping in the myocardium of our patients. For this reason, it is recommended that this patient group should be included in early diagnosis and close follow-up assessments for IHD.

Objective: COVID-19 has been detected in Turkey since March 11, 2020. Istanbul has become an important center of the pandemic in Turkey. Various risk factors for COVID-19 infection, mortality, and morbidity are under investigation. Recent studies have suggested that certain blood groups are risk factors for the disease. The aim of this study is the evaluation the relationship between blood groups and the risk of contracting COVID-19 disease, clinical severity of the disease, and CT (computed tomography) imaging findings. Material and Methods: Age, gender, blood group data, clinical severity and CT images of 300 patients who were positive with RT PCR (Reverse transcription-polymerase chain reaction) and were followed up in the clinic were retrospectively scanned and recorded. The clinical severity of the disease and CT imaging findings were scored, and the data were evaluated statistically. Results: While the incidence of COVID-19 was high in the A blood group, it was low in the 0 blood group. Although there was no significant difference between blood types and clinical severity, the involvement in the B blood group was more severe on CT imaging. Conclusion: People with A blood group should pay more attention to protection and isolation. Investigating this difference and underlying pathogenic mechanisms can guide science with advanced studies.

OBJECTIVE:Computed tomography of the thorax (Thorax CT) is frequently used to diagnose viral pneumonia in moderate to severe COVID-19 patients, but its diagnostic performance in mildly symptomatic COVID-19 patients is still unclear. Assessing the diagnostic performance of thorax CT in mildly symptomatic COVID-19 patients was the purpose of our study.METHODS:Mildly symptomatic and clinically stable, suspected COVID-19 patients scanned with Thorax CTs between March 11, 2020, and April 13, 2020, were included in this study. The sensitivity, specificity, positive and negative likelihood ratios, positive and negative predictive values, and the respective accuracies were calculated for diagnostic purposes.RESULTS:Among the 1119 patients enrolled in our study, abnormal thorax CT scans were 527 out of which 363/527 (68.9%) had typical CT features for COVID-19. According to analysis of typical COVID findings, sensitivity, specificity, positive predictive values, negative predictive value, and the accuracy of Thorax CTs with were 51.45%, 86.07%, 78.24%, 64.55%, and 68.99%, respectively. When typical CT findings and atypical CT findings were combined for the statistical analysis, the sensitivity, specificity, and accuracy observed 68.84%, 74%, and 71.49%.CONCLUSION:Diagnosing pneumonia can be challenging in mildly symptomatic COVID-19 patients since the Reverse Transcription Polymerase Chain Reaction test results, when compared with symptoms are not always evident. According to our study, thorax CT sensitivity was higher when atypical COVID-19 CT findings were included compared to those with typical COVID-19 CT findings alone. Our study which included the largest number of patients among all other similar studies indicates that not only typical but also atypical CT findings should be considered for an accured diagnosis of COVID-19 pneumonia.

This study was aimed to investigate the relationship between pineal cyst and headache in children. MR imaging was performed in 65 pediatric patients with headache and in a control group of 65 children with a 1.5 T Siemens MR device. The presence of pineal cysts and cyst sizes were noted. True pineal cysts and cystic transformations were evaluated separately. True pineal cysts were detected in 15 (23%) patients in the headache group and in 1 (1.5%) patient in the control group. True pineal cysts were detected in 5 (15.6%) migraine patients and in 10 (30.3%) patients with non-migraine headaches. A significant correlation was found between non-migraine headaches and pineal cysts (p <0.05) on the chi-square testing. However, no significant relationship was found between migraine and pineal cyst on the Fisher?s exact chi-square test. Pineal cystic transformations were detected in 13 (20%) patients in the headache group, in 13 (20%) patients in the control group. Pineal cystic transformations were detected in 5 (15.6%) migraine patients and in 8 (24.2%) non-migraine headache patients. There was no significant relationship between non-migraine headache and pineal cystic transformation and between migraine and pineal cystic transformation on chi-square testing. In conclusion, disruption of the circadian release of melatonin may be causally related to headaches. The knowledge of clinicians that pineal cysts may play a role in headache development, may be of therapeutic relevance.

Background : Covid-19 diagnosis may be difficult in patients with pleural effusion and pneumonia symptoms with heart failure and having atypical clinical course with consecutive negative RT-PCR tests. Case Report : An 80-year-old woman, with the history of chronic dyspnea, previous coronary bypass surgery, heart failure, and obesity was diagnosed as Covid-19 with chest tomography findings. Conclusion : It is observed that despite the improvement of symptoms in the first week, it is possible for a second phase to develop in such patients, which may result in mortality so clinicians should keep in mind that negative consecutive RT-PCR tests do not necessarily rule out Covid-19 pneumonia with bilaterally pleural effusion.

OBJECTIVEThe objectives of this study were to describe lung computed tomography findings of patients with COVID-19 diagnosed by real-time reverse transcription polymerase chain reaction test, investigate whether the findings differ regarding age and gender, and evaluate the diagnostic performance of chest computed tomography based on the duration of symptoms at the time of presentation to the hospital.METHODSFrom March 11 to May 11, 2020, 1271 consecutive patients (733 males and 538 females) were included in this retrospective, cross-sectional study. Based on age, patients were divided into five separate subgroups. Then based on the duration of symptoms, patients were divided into five separate phases. The presence of lung lesion(s) and their characteristics, distribution patterns, and the presence of concomitant pleural thickening/effusion and other findings (malignancy, metastasis, chronic obstructive pulmonary disease, interstitial lung disease, bronchiectasis, bronchiectasis, cardiomegaly, pericardial effusion) were evaluated by five radiologists independently.RESULTSThe "normal lung computed tomography finding" was the most common chest CT finding (37%), followed by ground-glass opacity (31%). Regardless of the shape of the lesion, the distribution features were significant (peripheral, subpleural, and lower lobe distribution) (p<0.05). The presence of pleural thickening posteriorly and adjacent to the lesion was statistically different in groups 1-3 (p<0.05). Other concomitant pathologies, except pulmonary congestion, did not suppress the typical findings of COVID-19.CONCLUSIONChest computed tomography findings were mostly normal in the early phase (P1). Therefore, it may be appropriate to perform the first computed tomography screening of COVID-19 after 6 days to decrease the radiation exposure.

OBJECTIVE:The objective of the study was to describe the findings of pediatric patients diagnosed with COVID-19 in computed tomography (CT) and chest X-ray (CXR) images. Therefore, the aim of this study is to show protecting the children from radiation as much as possible while guiding the diagnosis. METHODS:Between March and June 2020, 148 pediatric patients examined who underwent CT due to suspicion of COVID-19. Fifty patients of 148 with normal thorax CT and negative reverse transcription polymerase chain reaction (RT-PCR) were excluded from the study. Of the remaining 98 patients were evaluated retrospectively by two pediatric radiologists with 15 years of experience. RESULTS:The demographic, clinical, and laboratory data were evaluated for 52 RT-PCR-positive patients. CT finding of 23 RT-PCR positive and 12 negative patients was classified. According to our study, unilateral (61-67%), multifocal (50-52%), and peripheral (83-91%) involvement were higher in all groups. Lower lobe involvement was frequently detected (58-65%). The most frequently detected parenchymal lesion was ground-glass opacity followed by consolidated areas accompanying ground-grass opacities. Halo sign and vascular enlargement signs were the common signs of lung lesions (35%). In addition, some rare findings not previously described in this disease in children were mentioned in this study. The clinical course of all our patients was mild and control radiological imaging checked by CXR. CONCLUSION:Most pediatric patients have a mild course. Hence, a balance between the risk of radiation and necessity for chest CT is very important. Low-dose CT scan is more suitable for pediatric patients but still it should be used cautiously.

Objective: We aimed to evaluate the diagnostic value and comparison of sonoelastography and diffusion-weighted magnetic resonance imaging in differentiation of benign and malignant breast masses. Method: Forty-five patients who were referred to our Radiology Department for the biopsy of a known breast mass following a breast MRI were evaluated by sonoelastography using a 5-scaled Tsukuba scoring system and measurements of ADC values on diffusion weighted MRIs. Contribution of the Tsukuba scores and ADC values of the masses to the conventional methods were evaluated. Results: Histopathological results of all masses with Tsukuba scores 1 and 2 were evaluated as benign. Histopathological results of 37.5% of patients with a Tsukuba score of 3 were found to be benign and 62.5% of the patients were found to be malignant. Histopathologically 80% of the patients with a Tsukuba score of 4 were evaluated to have malignant, while all (100 %) of the patients with a Tsukuba score of 5 were considered to have malignant disease. Statistically significant correlation was found between the histopathological results and Tsukuba scoring system (p<0.05). Sonoelastographic sensitivity, specificity, positive, and negative predictive values were 83.3%, 96.3%, 93.7% and 89.6%, respectively in the patients with Tsukuba scores of 4 and 5. The mean ADC values of histopathologically proven malignant, and benign masses were 0.95 +/- 0.17x10(-3) mm(2)/sec and 1.37 +/- 0.16x10(-3) mm(2)/sec, respectively. The mean ADC value of histopathologically proven malignant masses was significantly lower than histopathologically proven benign masses (p<0.01). At sonoelastographic evaluation, one false-positive and 5 false-negative results were found. Three out of 4 false-negative results were diagnosed correctly using ADC values. False-negativity was detected in one lesion diagnosed based on both sonoelastographic results, and ADC values. Conclusion: We think solely sonoelastography or ADC evaluations are inadequate, however, can be used in differentiation of benign and malignant breast masses.

To investigate the effectiveness of gadoxetic acid-enhanced magnetic resonance cholangiopancreatography (CE-MRCP) and T2-weighted half-Fourier acquisition single-shot turbo spin-echo (T2W HASTE) sequences for diagnosis of cysto-biliary communication in hydatid cysts compared to surgical results. Preoperative abdominal magnetic resonance imaging examinations of patients who underwent surgery for hepatic hydatid cysts were reviewed by two radiologists retrospectively. A total of 45 patients with hydatid cysts were included. Of 45, 27 also had CE-MRCPs. T2W HASTE sequences and CE-MRCPs were investigated separately for cysto-biliary communication. The relationship between radiological and surgical results was analyzed. The interobserver agreement was evaluated. Of 45 hydatid cysts, there were surgically proven 21 cysts without biliary communications and 24 cysts with biliary communications. All cysts with biliary communications were shown on T2W HASTE sequences. There was no leakage of gadoxetic acid into these cysts (n = 24). Sensitivity, specificity, negative predictive value, positive predictive value (PPV), and accuracy of diagnosis of cyst with biliary communication on T2W HASTE sequences was 100%, 63.64%, 100%, 66.67%, and 78.95%, respectively. Specificity (77.78%), PPV (87.50%), and accuracy (91.30%) were increased in ≥ 10 cm cysts. There was almost perfect interobserver agreement (K = 0.81–1.00). Leakage of gadoxetic acid inside the cyst indicates biliary communication. However, the lack of leakage does not rule out cysto-biliary communication. When biliary communication is clearly shown on T2W HASTE sequences, it should be reported as cysto-biliary communication even if there is no leakage of gadoxetic acid into the cyst on CE-MRCP.

Level of Evidence: 5Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2020;52:636–637.

Background Magnetic resonance myelography (MRM) with three-dimensional (3D) T2-weighted (T2W) turbo spin echo (TSE) sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) may be a guide to the etiology of low back pain. Purpose To research the efficiency of a 3D T2W TSE SPACE MRM sequence for visualization of anatomic details of spinal nerve root at the spinal canal and lateral recess levels in the patients with low back pain. Material and Methods Lumbar spinal MRM 3D T2W TSE SPACE was performed in a total of 70 patients (median age 46 years). Patients were imaged while lying in a supine position with straightened legs. According to the degree of facet arthropathy findings, patients were divided into four separate subgroups in our retrospective cross-sectional study. Spinal nerve root angle was measured within the spinal canal and at lateral recess level, and facet joint angle and lumbar lordosis measurements were measured by two radiologists, independently. Results Lumbar level was strongly negatively correlated with facet joint angle (r = −0.95) as well as nerve root angle within the spinal canal (NRASC) (r = –0.857) and at the lateral recess level (NRALR) (r = −0.947). Intracanal decline of the spinal root angle caused by spinal stenosis findings was also observed ( P < 0.05). For the measurements of NRASC and NRALR, inter-observer correlation was 0.85 and 0.82 for the spinal canal and at lateral recess level, respectively. Conclusion 3D T2W SPACE in NRASC and NRALR provided high resolution images for evaluation. Therefore, this method may be a qualitative guide for the clinician and the surgeon in terms of root anatomy before any intervention.

Aim: To investigate the role of non-contrast magnetic resonance imaging (MRI) and findings of quantitative MRI in the evaluation of pancreatic lipomatosis in patients undergoing bariatric surgery. Methods: Pre-operative and post-operative MRI findings and laboratory test results of 44 obese patients, who underwent sleeve gastrectomy, were reviewed retrospectively. Liver craniocaudal length, hepatic and pancreatic region of interest (ROI) ratios at in-phase and out-of phase sequences (in-phase/outof phase), pancreas/spleen ROI ratio on T2-weighted sequence (T2 ratio) and thickness of subcutaneous fat were estimated. The relationship between pre-operative and postoperative findings was analyzed. Results: A total of 44 (41 female, three male) patients with a mean age of 42 were included in the study. Liver length, hepatic and pancreatic in-phase/out-of phase ratios, pancreas/spleen T2 ratio and thickness of subcutaneous fat in the post-operative period were found to be lower than those in the pre-operative period (p<0.05). When pancreas/spleen T2 ratio at was considered abnormal for the diagnosis of pancreatic lipomatosis, high specificity (100%), positive predictive value (100%) and accuracy (75%) were obtained. Conclusion: Non-enhanced MRI with quantitative measurements, including pancreas/spleen T2 ratios, can be performed efficiently for the diagnosis of pancreatic lipomatosis and patient follow-up.