Posterior cingulate cortex hyperactivity in conversion disorder: a PET/MRI study.

Introduction: Several neuroimaging studies have been conducted to demonstrate the specific structural and functional brain correlations of conversion disorder. Although the findings of neuroimaging studies are not consistent, when evaluated as a whole, they suggest the presence of significant brain abnormalities. The aim of this study is to investigate brain metabolic activity through F-18 fluorodeoxyglucose PET/MRI in order to shed light on the neural correlates of conversion disorder. Methods: 20 patients diagnosed with conversion disorder were included in the study. Hamilton Depression and Anxiety Rating Scales, Somatosensory Amplification Scale and Somatoform Dissociation Scale were administered. Then, brain F-18 FDG-PET/MRI was performed.. Results: Hypermetabolism was found in posterior cingulate R, while glucose metabolisms of other brain regions were observed to be within the normal limits. When compared with the control group, statistically significant differences in z-scores were observed among all brain regions except for parietal superior R and cerebellum. No correlation was observed between the metabolisms of the left ACC and left medial PFC; left ACC and left temporal lateral cortex; cerebellum and left parietal inferior cortex despite the presence of positive correlations between these regions in the opposite hemisphere. Discussion: Results of the study suggest a potential involvement of the DMN which is associated with arousal and self-referential processing as well as regions associated with motor intention and self-agency.

Discrimination of leptomeningeal carcinomatosis and meningeal inflammation/infection with internal acoustic canal enhancement.

PURPOSE: The purpose of this study is to investigate whether the presence and pattern of enhancement at the internal acoustic canal (IAC) could help in discriminating between leptomeningeal carcinomatosis (LCa) and meningeal inflammation/infection (MMI). METHODS: Magnetic resonance (MR) images of patients with leptomeningeal enhancement were retrospectively evaluated. MR images of the LCa group (n = 33), MMI group (n = 19) and control group (n = 33) were evaluated for the presence, type (moderate/prominent), and localization (unilateral/bilateral) of the IAC enhancement. RESULTS: The presence of IAC enhancement was significantly more common in patients with LCa (p < 0.001). In 73.7 % of patients with MMI, no contrast enhancement was observed in the IAC. In patients with contrast enhancement in the IAC, the risk of LCa in the etiology is 20 times greater than the risk of having MMI. Seventy-five percent of the IAC enhancement seen in LCa patients and 20 % of the IAC enhancements seen in MMI patients was bilateral. This difference was statistically significant (p = 0.029). CONCLUSION: Intense contrast enhancement of the IAC can be a marker for LCa.

Thermal necrosis-aided dental implant removal: A rabbit model pilot study

Background: The significant advances in the materials and biological aspects of dental implants haven't completely eradicated the implant failures. The removal of osseointegrated but otherwise failed implants present several challenges including adjacent tissues damage and necessity of bone augmentation for reimplantation. Controlled thermal necrosis has emerged as an alternative technique to aid removal of osseointegrated dental implants with minimal to no defect to healthy bone or surrounding tissues. This study aimed to evaluate the thermal necrosis-aided implant removal method in a rabbit osseointegration model. Material and methods: A total of 8 male New Zealand rabbits were used in the study. Two dental implants were placed on each femur of the rabbits. Heating of the implants was performed after 7 weeks following the implantation. Heating was done by contacting the tip of an electrosurgey tool in monopolar mode at different power settings and contact durations (5W - 2 seconds, 5W - 10 seconds, and 10 W - 10 seconds). No heating was done on the control group. Implant stability right after implantation, before heat application and after heat application was determined using an Osstell™ Mentor Device. Following the removal of implants histological analyses were performed to determine the effects of heat application at cellular level. Results: ISQ values of the 10W-10s group was significantly lower compared to the other groups (p<0.001). No indication of progressive necrosis or irreversible damage was observed in any of the groups. However, the percent of empty-apoptotic lacunae were statistically higher in the 5W-10s and the 10W-10s groups compared the control and the 5W-2s groups. Conclusions: Within the conditions of this study, we conclude that heat application with an electrosurgery tool using monopolar mode at 10W power for 10 seconds is optimal for reversing osseointegration with no extensive or progressive damage to the bone. (AU)

Determining Subclinical Cardiovascular and Cardiac Diseases in Patients with Non-Alcoholic Fatty Liver Disease.

BACKGROUND: The aims of the present study were to determine the subclinical coronary atherosclerosis and myocardial dysfunction in patients with non-alcoholic fatty liver disease, who were asymptomatic for cardiac disease. METHODS: A total of 61 non-alcoholic fatty liver disease patients were enrolled in the study. The 10-year probability of cardiovascular events was evaluated according to the pooled cohort equation risk score (atherosclerotic cardiovascular disease). The coronary artery calcium score was measured. Conventional echocardiographic examination was followed by 2- and 3-dimensional speckle tracking echocardiography. RESULTS: Patients with non-alcoholic steatohepatitis had significantly higher insulin resistance (P = .018), serum alanine aminotransferase (P = .002) and aspartate aminotransferase levels (P = .021), hepatic steatosis (P = .023), and fibrosis (P = .001) than non-alcoholic fatty liver disease patients. The mean Atherosclerotic Cardiovascular Disease score was 7.5% ± 6.9% and 37% of the patients had medium and high cardiovascular disease risk. Cardiovascular disease (>1) was found in 30% of the patients. Interestingly, 56% had significant and extended atherosclerotic plaques. Among the patients with moderate-to-high atherosclerotic cardiovascular disease scores, 63% had significant atherosclerotic plaques and 21% had extensive plaque burden. The presence of non-alcoholic steatohepatitis did not significantly affect cardiovascular risk. Non-alcoholic steatohepatitis was deleterious on left ventricle diastolic functions. Mean A velocity in non-alcoholic steatohepatitis patients was significantly increased compared to non-alcoholic fatty liver disease patients (87.0 ± 17.5 cm/s vs. 72.3 ± 13.6 cm/s, P = .002). Mean E/e' ratio was 8.1 ± 2.0. Submyocardial fibrosis detected had a slightly higher occurrence in non-alcoholic steatohepatitis patients than in non-alcoholic fatty liver disease patients (P = .530). CONCLUSION: The presence of non-alcoholic steatohepatitis did not significantly increase the risk of cardiovascular disease and subclinical myocardial dysfunction in asymptomatic patients for cardiac disease compared to non-alcoholic fatty liver disease patients.

Botulinum toxin injections in jaw-opening dystonia. The lateral pterygoid - maxillary artery problem.

It has been suggested that the variations in the trajectory of the maxillary artery (MA) near the lateral pterygoid muscle (LPM) play a critical role in Botulinum neurotoxin (BoNT) injections in patients with jaw-opening/deviation dystonia (JOD). In the case of a lateral course to the LPM, an extraoral injection entails risks of MA injury, pain, and hematoma. Previous reports suggest geographical differences in variations of the MA-LPM relationship. We aimed to determine these variations in Turkish individuals and highlight the need to establish a consensus on approach to LPM injections. In 284 individuals, contrast-enhanced magnetic resonance angiography (MRA) images were evaluated by two radiologists on both sides for the variations in the course of the MA in the infratemporal fossa. Images of 44 were excluded due to trauma, arteriovenous malformation, mass, surgery, and imaging artifacts. Of the included, 62.1% were female. In 480 evaluations of 240 individuals, the MA passed lateral to the LPM in 65.6% (n = 315). No sex difference was noted. In 51 individuals (21.3%), the MA course differed on the right and left sides (medial-lateral asymmetry). These results confirm that the lateral course of the MA is more frequent. In patients with JOD, the trajectory of the MA should be determined with imaging prior to extraoral BoNT injections. In the case of a lateral course, an intraoral approach seems to be safer to avoid a potential MA injury.

Agreement between visually estimated left ventricular ejection fraction on echocardiography and quantitative measurements using cardiac magnetic resonance.

OBJECTIVE: Visual estimation of left ventricular ejection fraction (LVEF) is still used in routine clinical practice. However, most of the studies evaluating the agreement between the visually estimated LVEF (ve-LVEF) and quantitatively measured LVEF (qm-LVEF) either have not used appropriate statistical methods or gold standard imaging modality. In this study, we aimed to assess the agreement between the ve-LVEF and qm-LVEF using contemporary statistical methods and cardiac magnetic resonance imaging (CMRI). METHODS: In 54 subjects who underwent 1.5-T CMRI, echocardiographic images were recorded after the CMRI procedure on the same day. Two independent observers estimated ve-LVEFs on echocardiographic records in a random and blinded fashion, and qm-LVEF was obtained by CMRI. Agreement between the ve-LVEF and qm-LVEF values and intra/interobserver ve-LVEF estimations were assessed using intraclass correlation coefficient (ICC), Bland-Altman analysis, and kappa statistics. RESULTS: There was a high agreement between the ve-LVEF and qm-LVEF (ICC 0.93, 95% confidence interval 0.88-0.96). Bland-Altman analysis also demonstrated a good agreement between ve-LVEF and qm-LVEF with ve-LVEF, on average, being 0.6% lower than that obtained by CMRI (mean -0.6, limits of agreement -10.5 and +9.3). A good agreement was also observed for LVEF categories ≤35%, 36%-54%, and ≥55% (unweighted kappa 0.71, linearly weighted kappa 0.76); and LVEF of <55% and ≥55% (kappa 0.80). Intra/inter observer agreement was good for ve-LVEFs (ICC value 0.96 and 0.91, respectively). CONCLUSION: Visual approach for LVEF assessment may be used for rapid assessment of left ventricular systolic function in clinical practice, particularly in patients with good image quality.

Detectability of 18F-choline PET/MR in primary hyperparathyroidism.

PURPOSE: We aimed to evaluate the power of 18F-fluorocholine (FCH) positron emission tomography/magnetic resonance (PET/MR) imaging in unlocalized primary hyperparathyroidism. METHODS: Thirty-four patients were included. In 17/34 patients, PET/MR was performed immediately after a negative 18F-FCH PET/CT. Sensitivity, specificity, positive and negative predictive values were calculated for MR only (blinded to PET data) and PET only (blinded to MR data) findings. RESULTS: 18F-FCH PET/MR was positive in 26/34 (76%) patients. PET/MR was also positive in 12/17 (71%) patients with a negative PET/CT. Among 11/34 (32%) patients where 18F-FCH PET-only and MR-only results were discordant, MR was false positive in 7/11 patients (3/7 of the lesions were not 18F-FCH avid and in 4/7 of them PET and MRI pointed different locations. Postoperative histopathology revealed that 18F-FCH-positive ones were true positives). Sensitivity, specificity, PPV, NPV and accuracy of neck MR evaluated blinded to PET data were 80%, 50%, 70%, 64% and 68%, respectively, and all were calculated as 100% for PET/MR. CONCLUSION: 18F-FCH PET/MR is very effective in preoperative localization of parathyroid adenomas even if 18F-FCH PET/CT is negative. Neck MR alone is insufficient in detecting parathyroid adenomas but PET/MR combination helps in precise localisation.

The Relationship Between Renal Function and Imaging Markers and Total Burden of Cerebral Small Vessel Disease.

BACKGROUND: Previous studies demonstrating the association between renal functions and cerebral small vessel diseases have usually focused on white matter hyperintensity in the general population or lacunar stroke patients. This study aimed to investigate the effects of renal function on imaging markers of cerebral small vessel disease and etiologic subtypes of stroke in patients with acute ischemic stroke or transient ischemic attack. MATERIALS AND METHODS: A total of 356 consecutive patients with acute ischemic stroke or transient ischemic attack who were admitted to the Stroke Unit and underwent brain magnetic resonance imaging were evaluated. Demographic data, vascular risk factors, stroke etiology, estimated glomerular filtration rate and severity of cerebral small vessel disease markers, and total cerebral small vessel disease burden were evaluated. RESULTS: There was a significant inverse correlation between estimated glomerular filtration rate and total number of lacunes, periventricular and deep subcortical Fazekas scores, grade of enlarged perivascular spaces in the centrum semiovale, lobar and total cerebral microbleeds, and total cerebral small vessel disease burden. Impaired renal function was an independent risk factor for the presence of lacunes, deep cerebral microbleeds, and increased total burden. Renal function impairment and periventricular white matter hyperintensities were significantly associated with the etiologic subgroup of small vessel occlusion. The results were still significant after the exclusion of patients below 50 years of age. CONCLUSION: Our results indicate that there is a relationship between renal function impairment and increased total burden, as well as acute ischemic stroke/transient ischemic attack due to small vessel occlusion.

The Correlation of Epidural Fibrosis with Epiduroscopic and Radiologic Imaging for Chronic Pain after Back Surgery.

BACKGROUND: Chronic low back pain is observed frequently after lumbar spinal surgery. Epidural fibrosis has been implicated in the etiology of persistent pain after back surgery. The incidence of epidural fibrosis increases as the number and extent of spinal surgery increases. Epidural fibrosis can be detected by conventional radiologic methods [e.g., lumbosacral magnetic resonance imaging (MRI) with gadolinium], but these methods are insufficient to reveal the presence of epidural adhesions. Imaging of the epidural cavity using an epiduroscope is one of the best methods for visualizing the spinal cavity without damaging anatomic structures. OBJECTIVES: To evaluate the correlation between the type and number of surgery and the degree of epidural fibrosis and to compare epidural fibrosis in epiduroscopic and MRI findings in patients with failed back surgery syndrome (FBSS). STUDY DESIGN: A prospective trial. SETTING: A university hospital. METHODS: This study included 61 patients with persistent low back pain and/or radicular pain for at least 6 months, despite lumbar surgery and conservative treatment, and who accepted epiduroscopic imaging. All patients were evaluated in a physical examination using a visual analog scale (VAS) per the elapsed time after surgery. The patients were divided into 3 groups according to the number and type of surgeries. Epidural fibrosis was rated using MRI with gadolinium and epiduroscopy. RESULTS: When the relationship between admission symptoms and epidural fibrosis was evaluated, MRI findings of fibrosis were found to be significantly higher in all patients with both lumbar and radicular pain symptoms at the confidence level of 95% (P = 0.001). The degree of fibrosis detected using epiduroscopy was grade 1 and 2 in almost all patients who presented with low back pain only, only radicular pain, or only distal paresthesia (P = 0.001). In the correlation analysis between the duration of the postoperative period (4.13 ± 2.97 years) and the degree of fibrosis detected using MRI and epiduroscopy, a statistically significant relationship was found at the confidence level of 95% (P < 0.05). As the number and extent of spinal surgeries increased, the incidence of MRI fibrosis increased, which is compatible with the literature (P = 0.001) There was a statistically significant relationship between the degree of fibrosis as detected using MRI and epiduroscopy at the confidence level of 95% (P < 0.05). Differently, we observed that 6 patients had grade 1 fibrosis as diagnosed using epiduroscopy, whereas none had fibrosis on MRI. LIMITATIONS: We did not have a control group. Further studies are required to demonstrate the relevance of these 2 imaging techniques (epiduroscopy and MRI) in terms of detecting epidural fibrosis in patients with FBSS.  CONCLUSIONS: Epiduroscopic imaging seems to be more sensitive than MRI in detecting grade I epidural fibrosis in patients with FBSS. Thus, the possibility of low-grade epidural fibrosis as a source of pain after back surgery, should be kept in mind in normally reported MRIs. Treatment should be planned accordingly.

Comparison of Frontal Sinuses for Personal Identification in 3 Populations Using Cameriere's Code Number.

ABSTRACT: The identification of unknown individuals is of crucial importance to society, especially in the context of mass disasters involving individuals of different nationalities. The comparison of frontal sinus patterns is an important tool for personal identification. In Cameriere's method, a new personal code number (codC) containing 8 digits was elaborated, based on the measurements of frontal sinus patterns. The present study is an update of this previous work. Digital radiographic images of the skulls of 299 individuals of different nationalities (100 Italians, 99 Kosovars, and 100 Turks) were analyzed, adopting the same maximum-weight dependence tree used in the original work. For comparisons between groups, Fisher exact test and the χ2 test were carried out. The method, applied to different population groups, significantly increases the likelihood of identifying a person by comparison of antemortem and postmortem frontal sinus radiographs. Results demonstrated that the model is more discriminative in identifying individuals of different nationalities.

MRI quantification techniques in fatty liver: the diagnostic performance of hepatic T1, T2, and stiffness measurements in relation to the proton density fat fraction.

PURPOSE: Nonalcoholic fatty liver disease (NAFLD) can progress to liver cirrhosis and is predicted to become the most frequent indication for liver transplantation in the near future. Noninvasive assessment of NAFLD is important for diagnosis and patient management. This study aims to prospectively determine the liver stiffness and T1 and T2 values in patients with NAFLD and to compare the diagnostic performance of magnetic resonance elastography (MRE) and mapping techniques in relation to the proton density fat fraction (PDFF). METHODS: Eighty-three patients with NAFLD and 26 participants with normal livers were imaged with a 1.5 T scanner. PDFF measurements obtained from the multiecho Dixon technique were used to quantify the liver fat. MRE, native T1 mapping (modified Look-Locker inversion recovery [MOLLI] schemes 5(3)3, 3(3)3(3)5, and 3(2)3(2)5 and the B1-corrected variable flip angle [VFA] method), and T2 mapping values were correlated with PDFF. The diagnostic performance of MRE and the mapping techniques were analyzed and compared. RESULTS: T1 values measured with the MOLLI schemes and the B1-corrected VFA (P < 0.001), and the stiffness values from MRE (P = 0.047) were significantly higher in the NAFLD group. No significant difference was found between the groups in terms of T2 values (P = 0.127). In differentiation of the NAFLD and control groups, the B1-corrected VFA technique had slightly higher accuracy and area under the curve (AUC) than the MOLLI schemes. In the NAFLD group, there was a good correlation between the PDFF, MOLLI 3(3)3(3)5 and 3(2)3(2)5, and VFA T1 measurements (r=0.732; r=0.735; r=0.716, P < 0.001, respectively). CONCLUSION: Liver T1 mapping techniques have the potential to distinguish steatotic from nonsteatotic livers, and T1 values seem to have a strong correlation with the liver fat content.

Diagnostic Accuracy of Mapping Techniques and Postprocessing Methods for Acute Myocarditis.

OBJECTIVE. Many T1 mapping sequences and measurement methods have been reported in the literature. To obtain accurate results, the most appropriate T1 and T2 mapping sequences and postprocessing methods should be used. The aim of the present study is to compare the T1 and T2 mapping sequences and measurement methods used to diagnose acute myocarditis. MATERIALS AND METHODS. Fourteen patients with an interval of 7 days or less between symptom onset and MRI examination were included in the study. The control group consisted of 22 healthy individuals. T1 mapping images acquired using four different methods (modified Look-Locker inversion recovery [MOLLI] 3[3]3[3]5, MOLLI 3[2]3[2]5, MOLLI 5[3]3 heart rate-corrected, and MOLLI 5[3]3 heart rate-uncorrected sequences) and T2 mapping images obtained using two different methods (FLASH and true fast imaging with steady-state precession) in the area from the short axis through the basal slice were retrospectively evaluated. RESULTS. The mean T1 and T2 values were significantly higher in the patient group than in the control group for all sequences in SAX measurements and segmental measurements (segments 1, 4, 5, and 6). Measurements from segments 2 and 3 were not statistically significant between patient and control groups. The segment with the highest AUC value of T1 and T2 mapping values was the inferior segment, followed by the inferolateral segment. The highest diagnostic performance for short-axis measurements was obtained using the MOLLI 3(2)3(2)5 sequence (AUC value = 0.902). CONCLUSION. According to the results of this study and many other studies, pathologic changes in the myocardium can be detected by native T1 and T2 mapping. The accuracy of mapping methods will increase with increased knowledge of the advantages and disadvantages of currently used sequences and measurement methods.

Prediction of degree of carotid stenosis with the transluminal attenuation difference ratio.

PURPOSE: We aimed to assess the diagnostic performance of transluminal attenuation difference (TAD) in predicting the severity of internal carotid artery (ICA) stenosis. METHODS: The study cohort consisted of 48 patients with <50% stenosis, 50%-69% stenosis, 70%-99% stenosis, and 51 controls without plaque development in ICA. A total of 143 measurements were performed through right and left internal and common carotid arteries. The TAD ratio was calculated as the difference between the mean attenuation values of the common carotid artery (CCA) and ICA, divided by the MAV of the CCA, multiplied by 100. RESULTS: TAD ratio was significantly higher in severe (>70%) stenosis compared with control arteries and low-moderate stenosis. A TAD ratio cutoff of 4.5 predicted 70%-99% stenosis with a sensitivity of 100% and specificity of 93%. The inter- and intraobserver agreements in TAD measurements were almost perfect (ICC, 0.89-0.86). CONCLUSION: Assessment of TAD ratio predicts the degree of stenosis in concordance with NASCET system.

Can we differentiate histologic subtypes of neuroendocrine tumour liver metastases at a single phase contrast-enhanced CT-correlation with Ga-68 DOTATATE PET/CT findings.

OBJECTIVE: To assess the usefulness of a single-phase contrast-enhanced CT to differentiate subtypes of neuroendocrine tumour (NET) liver metastases and to evaluate the correlation between CT features and Ga-68 DOTATATE positron emission tomography/CT (PET/CT) findings. METHODS: Between December 2017 and April 2019 patients with liver metastases of neuroendocrine tumours who underwent CT and Ga-68 DOTATATE PET/CT were enrolled in the study. All patients involved in the study had undergone a standardised single-phase contrast-enhanced CT. Whole body PET/CT images were obtained with a combined PET/CT scanner. All CT images were retrospectively analysed by two radiologists. Enhancement patterns of lesions were assessed. For quantitative examination; CT attenuation values of metastatic lesions, liver parenchyma and aorta were measured using a freehand ROI and tumour-to-liver ratio [T-L = (Tumour-Liver) / Liver] and tumour-to-aorta ratio [T-A = (Tumour-Aorta) / Aorta] were calculated. The lesion with the highest Ga-68 DOTATATE uptake in the liver was used for calculations. The metabolic tumour volume (MTV), maximum standardised uptake value (SUV max) and SUV mean were calculated for the target liver lesion. RESULTS: A total of 137 NET liver metastases divided into in three groups: 49 (35.7%) pancreatic, 60 (44.5%) gastroenteric and 26 (18.9%) lung NET liver metastases were analysed. Gastroenteric NET metastases often showed heterogeneous enhancement which was significantly higher than in the pancreas and lung NET liver metastases (p < 0.001). 96.72% (n = 59) of the gastroenteric NET liver metastases were hypoattenuating whereas the most frequent presentation for the pancreatic group was hyperattenuation (63.26%,n = 31). The difference in enhancement patterns of the liver metastases was statistically significant (p < 0.001) with respect to the location of the primary tumour. For quantitative analysis; tumour CT values were significantly different between the groups (p < 0.001). The T-L ratio was statistically different between gastroenteric and pancreatic NET liver metastases and pancreatic and lung NET groups (p < 0.001). The T-A ratio was significantly higher in the pancreatic NET metastases (p < 0.001). SUVmax, SUVmean and MTV values, however, were not significantly different between the subgroups. There was a weak positive correlation between T-L ratio and SUV meanvalues. CONCLUSION: We noticed statistically significant differences in both qualitative and quantitative CT features between histologic subgroups of neuroendocrine tumour liver metastases at a single phase contrast-enhanced CT. ADVANCES IN KNOWLEDGE: Our study will be the first in the literature which extensively focus on assessing the CT features of liver metastases of NETs at a single phase CT and Ga-68DOTATATE PET/CT. As the different histological subtypes of NET liver metastases exhibit different clinical outcomes, these features might help to identify the primary tumour to provide optimal treatment.

Is It Possible to Discriminate Active MS Lesions with Diffusion Weighted Imaging?

OBJECTIVE: Patients with multiple sclerosis (MS) are at a risk of gadolinium deposition because of multiple control imaging. Therefore, it is important to determine biomarkers that can differentiate active and chronic lesions without using contrast agent. This study aimed to assess mean apparent diffusion coefficient (ADC) values and signal intensities (SI) on diffusion weighted imaging (DWI) values of active and nonactive lesions. MATERIALS AND METHODS: We included 25 patients in this study. We measured mean ADC values and SI on DWI of the randomly selected active and nonactive lesions and normal appearing white matter (NAWM) for all patients with MS. SI on DWI and ADC values were normalized to the SI of the CSF. We compared all of the measurements between active and nonactive lesions, active lesions and NAWM, and nonactive lesions and NAWM. SI on DWI and mean ADC values of normal healthy white matter (NHWM) of control group were measured. A comparison was made between NHWM and NAWM. RESULTS: For patients with active lesions, the mean nADC value was 0.35±0.06 for active lesions and 0.30±0.07 for nonactive lesions (p>0.050). The mean nDWI-SI value was 3.69±0.68 for active lesions was 3.39±0.68 for nonactive lesions (p<0.050). When patients with and without active lesions were compared, both nDWI values and nADC values for active and nonactive lesions were statistically insignificant (p>0.050). DISCUSSION: In MS lesions, diffusion alternations can be quantitatively evaluated with ADC mapping. Lesions seen in patients with MS have higher mean ADC values than NAWM and NHWM.

Evaluation of Extramural Venous Invasion by Diffusion-Weighted Magnetic Resonance Imaging and Computed Tomography in Rectal Adenocarcinoma.

PURPOSE: The aim of this study is to evaluate the diagnostic contribution of diffusion-weighted magnetic resonance imaging (MRI) and computed tomography (CT) to distinguish extramural venous invasion (EMVI) in rectal adenocarcinoma. MATERIALS AND METHODS: Fifty-eight patients who had been diagnosed with rectal adenocarcinoma (30 patients with EMVI and 28 patients without EMVI) were enrolled in the study. Apparent diffusion coefficient (ADC) values of the tumour and the EMVI (+) vein, the lengths of the tumours were measured on MRI. The diameters of the superior rectal vein (SRV)-inferior mesenteric vein (IMV) and distant metastatic spread were evaluated on CT. The ability of these findings to detect EMVI was assessed using receiver operating characteristic (ROC) analysis. Pathology was accepted as the reference test for EMVI. RESULTS: Mean diameters of the SRV (4.9 ± 0.9 mm vs 3.7 ± 0.8 mm) and IMV (6.9 ± 0.8 mm vs 5.4 ± 0.9 mm) were significantly larger (P < .001) and tumour ADC values were significantly lower (0.926 ± 0.281 × 10-3 mm2/s vs 1.026 ± 0.246 × 10-3 mm2/s; P = .032) in EMVI (+) patients. Diameters of 3.95 mm for the SRV (area under the curve [AUC] ± standard error [SE]: 0.851 ± 0.051, P < .001, sensitivity: 93.3%, specificity: 67.9%) and 5.95 mm for the IMV (AUC ± SE: 0.893 ± 0.040, P < .001, sensitivity: 93.3%, specificity: 71.4%) and an ADC value of 0.929 × 10-3 mm2/s (AUC ± SE: 0.664 ± 0.072, P = .032 sensitivity: 76.7%, specificity: 57.1%) were found to be cutoff values, determined by ROC analysis, for detection of EMVI. Distant metastases were significantly more prevalent in EMVI (+) patients (P < .001). CONCLUSION: The measurement of ADC values and SRV-IMV diameters seems to have contribution for diagnosis of EMVI in rectal adenocarcinoma. EMVI (+) patients appear to have higher risks of distant metastases at diagnosis.

Neuro-Ophthalmologic MRI Findings in the Detection of Rhinorrhoea Aetiology.

The purpose of this study is to evaluate the importance of neuro-ophthalmological magnetic resonance imaging (MRI) findings in the identification of the aetiology of rhinorrhoea, and the differentiation of spontaneous rhinorrhoea from non-spontaneous rhinorrhoea. MR images of 25 patients with spontaneous and 21 patients with non-spontaneous rhinorrhoea were evaluated for the presence of neuro-ophthalmological findings of intracranial hypertension (IHT). These include optic nerve vertical tortuosity, optic nerve sheath enlargement, flattening of the posterior sclera and optic nerve protrusion, as well as other MRI findings of ICH, such as partial empty sella, dilatation of Meckel's cave and the presence of arachnoid pits. IHT findings were more common in the spontaneous group. Six criteria (optic nerve distention, optic nerve vertical tortuosity, posterior flattening of the sclera, partial empty sella, Meckel's cave dilatation and presence of arachnoid pits) differentiate between patient and control groups. Patients with spontaneous cerebrospinal fluid (CSF) leaks should be evaluated for signs of IHT on MRI, as they are present in the majority of spontaneous CSF leaks and are representative of increased intracranial pressure.

The Significance and Reliability of Imaging Findings in Pseudotumor Cerebri.

The objective of our study was to provide a comparative assessment of previously reported magnetic resonance imaging (MRI) parameters in primary and secondary pseudotumor cerebri (PTC) patients, to examine their diagnostic contribution, and to evaluate their association with symptoms, neuro-ophthalmological findings, laboratory results, and cerebrospinal fluid characteristics. Twenty-eight consecutive patients with PTC were included in the study. Age- and sex-matched 20 individuals with normal neurologic examination served as the control group. Modified Dandy Criteria were used for the diagnosis of PTC. Orbital and cranial MRI and MR venography of all patients and controls were assessed by three radiologists. According to our study, posterior flattening of the globe (64% sensitive, 100% specific), optic nerve sheath distention (46% sensitive, 100% specific), vertical tortuosity of the optic nerve (30% sensitive, 95% specific), and partial empty sella (43% sensitive, 100% specific) emerged as particularly valuable markers for a diagnosis of PTC.