Comparison of ASL and DSC perfusion methods in the evaluation of response to treatment in patients with a history of treatment for malignant brain tumor.

OBJECTIVE: Perfusion MRI is of great benefit in the post-treatment evaluation of brain tumors. Interestingly, dynamic susceptibility contrast-enhanced (DSC) perfusion has taken its place in routine examination for this purpose. The use of arterial spin labeling (ASL), a perfusion technique that does not require exogenous contrast material injection, has gained popularity in recent years. The aim of the study was to compare two different perfusion techniques, ASL and DSC, using qualitative and quantitative measurements and to investigate the diagnostic effectiveness of both. The fact that the number of patients is higher than in studies conducted with 3D pseudo-continious ASL (pCASL), the study group is heterogeneous as it consists of patients with both metastases and glial tumors, the use of 3D Turbo Gradient Spin Echo (TGSE), and the inclusion of visual (qualitative) assessment make our study unique. METHODS: Ninety patients, who were treated for malignant brain tumor, were enrolled in the retrospective study. DSC Cerebral Blood Volume (CBV), Cerebral Blood Flow (CBF) and ASL CBF maps of each case were obtained. In qualitative analysis, the lesions of the cases were visually classified as treatment-related changes (TRC) and relapse/residual mass (RRT). In the quantitative analysis, three regions of interest (ROI) measurements were taken from each case. The average of these measurements was compared with the ROI taken from the contralateral white matter and normalized values (n) were obtained. These normalized values were compared across events. RESULTS: Uncorrected DSC normalized CBV (nCBV), DSC normalized CBF (nCBF) and ASL nCBF values of RRT cases were higher than those of TRC cases (p < 0.001). DSC nCBV values were correlated with DSC nCBF (r: 0.94, p < 0.001) and correlated with ASL nCBF (r: 0.75, p < 0.001). Similarly, ASL nCBF was positively correlated with DSC nCBF (r: 0.79 p < 0.01). When the ROC curve parameters were evaluated, the cut-off values were determined as 1.211 for DSC nCBV (AUC: 0.95, 93% sensitivity, 82% specificity), 0.896 for DSC nCBF (AUC; 0.95, 93% sensitivity, 82% specificity), and 0.829 for ASL nCBF (AUC: 0.84, 78% sensitivity, 75% specificity). For qualitative evaluation (visual evaluation), inter-observer agreement was found to be good for ASL CBF (0.714), good for DSC CBF (0.790), and excellent for DSC CBV (0.822). Intra-observer agreement was also evaluated. For the first observer, good agreement was found in ASL CBF (0.626, 70% sensitive, 93% specific), in DSC CBF (0.713, 76% sensitive, 95% specific), and in DSC CBV (0.755, 87% sensitive - 88% specific). In the second observer, moderate agreement was found in ASL CBF (0.584, 61% sensitive, 97% specific) and DSC CBF (0.649, 65% sensitive, 100% specific), and excellent agreement in DSC CBV (0.800, 89% sensitive, 90% specific). CONCLUSION: It was observed that uncorrected DSC nCBV, DSC nCBF and ASL nCBF values were well correlated with each other. In qualitative evaluation, inter-observer and intra-observer agreement was higher in DSC CBV than DSC CBF and ASL CBF. In addition, DSC CBV is found more sensitive, ASL CBF and DSC CBF are found more specific for both observers. From a diagnostic perspective, all three parameters DSC CBV, DSC CBF and ASL CBF can be used, but it was observed that the highest rate belonged to DSC CBV.

Evaluation of toxicity of gadolinium-based contrast agents on neuronal cells.

BACKGROUND: Gadolinium-based contrast agents (GBCAs) are widely used in magnetic resonance imaging (MRI). Recently, increased signal intensity has been reported in specific brain areas after repeated administrations of GBCAs. PURPOSE: To investigate the toxic effects of GBCAs on neuronal cells by using SH-SY5Y neuroblastoma cell cultures. MATERIAL AND METHODS: For toxicity assays, SH-SY5Y cells were incubated with different doses (0-1000 µM) of several macrocyclic (gadoterate meglumine and gadobutrol) and linear GBCAs (gadoversetamide, gadopentetate dimeglumine, gadodiamide, and gadoxetate disodium) for 48 h. Cell viability and proliferation capacity were evaluated by using MTS assay, LDH assay, and colony-forming assay. In addition, Western blotting of Bcl-2 and Bax proteins and nuclear Hoechst 33258 staining were performed to evaluate apoptotic cell death. The results were expressed as mean ± SEM. The data were analyzed using Student's t-test. A P value < 0.05 was accepted as statistically significant. RESULTS: Both macrocyclic and linear GBCAs significantly and dose-dependently reduced cell viability in neuronal cells compared to control. Cell viability was measured between 89.5% ± 4% and 61% ± 0.7% in GBCA-treated groups. In addition, neurotoxicity was more prominent in linear GBCA-treated cultures (P < 0.0005). Bax protein levels were increased in GBCA-treated cells particularly with linear agents whereas Bcl-2 expression was decreased concomitantly. CONCLUSION: The results of the present study indicated that exposure to specific GBCAs, even at low micro-molar concentrations, may have detrimental effects on neuronal survival. Further investigations are required to clarify the molecular mechanism underlying GBCA-induced cell death.

The role of rare breast cancers in the false negative strain elastography results.

PURPOSE: Elastography was primarily used as an adjunctive method along with ultrasonography in differentiation between benign from malignant lesions. Occasionally, overlaps can occur which are caused by some rare invasive breast cancers. Our aim is to analyze the role of rare breast cancers in false negative strain elastography results and to assess the relation among false negative results and tumor size, lesion distance to skin, and tumor grade. METHODS: Patients with BI-RADS 5 category underwent strain elastography and core biopsy. All those with confirmed invasive breast cancer were included. For each rare breast cancer, four usual invasive breast cancer cases were taken as a control group. The cut-off value of strain ratio was considered as 2.3. The true positive and the false negative groups were compared in terms of histological type (rare carcinomas and the others) and the other parameters. Pearson Chi-square and Fisher's exact test were used for statistical analyses. P values < 0.05 were considered statistically significant. RESULTS: One hundred-thirteen patients were defined as true positive (70.6%), and 47 patients were defined as false negative (29.4%). Strain ratio values of the rare breast cancers were significantly lower than those of the other breast cancers (p = 0.012). There was no statistically significant difference between the groups with respect to tumor size, distance to skin, and tumor grade (p > 0.05). CONCLUSION: The rare breast cancers are an important cause of false negativity in elastographic evaluation of invasive breast cancers. The results should be interpreted in combination with grayscale US findings.

Carotid angle in young stroke.

PURPOSE: To investigate whether the carotid bifurcation angle as assessed by computed tomographic angiography (CTA) is associated with anterior circulation ischemic stroke (ACIS) in young patients. MATERIAL AND METHODS: Thirty patients (mean age 41.5 ± 6 years) with known acute ACIS (group 1) were compared to 30 control patients (mean age/ 41.2 ± 6 years) (group 2) with similar demographic variables in this retrospective study. Geometrical characteristics of bilateral carotid bifurcation were obtained by CTA. The ICA bifurcation (ICAB) angle, the carotid central bifurcation (CCB), and the carotid bifurcation wall (CBW) angle among the ICA, CCA, and ECA were measured. Carotid artery angle measurements were compared between group 1 and group 2. The comparison of pathological (ACIS) and non-pathological (non-ACIS) carotid sides in group 1 was performed as well. RESULTS: All the measured angles (AMA) of group 1 were higher than group 2 (p˂0.05). In patients with left-sided ACIS, AMA on the left side were higher than the right side (p˂0.05), this was more prominent in males (p˂0.05). All angles measured were found to be higher in ipsilateral ACIS (p˂0.05). The left CCB angle values had a significant effect on ischemic stroke (p˂0.05). Male patients had more left-sided ACIS (p˂0.05). Plaque development in ICA was found statistically significant in group 1 compared to group 2 (p˂0.05). CONCLUSION: Carotid artery geometry may play an important role in the development of ischemic events in young patients, especially in men and, also in patients with left-sided stroke. The left CCB angle had a significant effect on ACIS.

Interacting Factors of Strain Ratio Values in Fibroadenomas and the Contribution of Color Scale.

BACKGROUND: The purpose of this retrospective study is to investigate the association of qualitative and semiquantitative strain elastography (SE) features with factors such as lesion size, skin-to-lesion distance, and patient's age in fibroadenomas and to discuss false-positive results. METHODS: A total of 120 lesions that were performed SE with histopathologically confirmed fibroadenoma were included in the study. All images were reviewed from the archiving system with a consensus of two radiologists. Tsukuba elasticity score was used for color scoring (from 1 to 5). Lesions with strain ratio (SR) ≥2.27 and color scale score of 4 or 5 were considered as false positive. The patients were divided into two groups according to the age: <50 and ≥50 years old. Regard of the size, lesions were divided into two groups: <15 mm and ≥15 mm. The distances of the lesions to the skin were also divided into two groups: <5 mm and ≥5 mm. Statistical analysis to identify associations between these groups and SR was carried out with Pearson Chi-square test and Fisher's exact test. The false-positive rates were calculated. RESULTS: There was no statistically significant difference between patients' age, lesion size, skin-to-lesion distance, and SR values. The false-positive rate was 21.66% for SR, while it was 3.33% for color scale. CONCLUSION: SR values of the fibroadenomas were not affected by factors such as age, lesion size, and depth. In addition, false-positive rates significantly decrease when color scale scores are evaluated for fibroadenomas.

Tumor size estimation of the breast cancer molecular subtypes using imaging techniques.

BACKGROUND AND AIM: In medical practice the classification of breast cancer is most commonly based on the molecular subtypes, in order to predict the disease prognosis, avoid over-treatment, and provide individualized cancer management. Tumor size is a major determiner of treatment planning, acting on the decision-making process, whether to perform breast surgery or administer neoadjuvant chemotherapy. Imaging methods play a key role in determining the tumor size in breast cancers at the time of the diagnosis.We aimed to compare the radiologically determined tumor sizes with the corresponding pathologically determined tumor sizes of breast cancer at the time of the diagnosis, in correlation with the molecular subtypes. METHODS: Ninety-one patients with primary invasive breast cancer were evaluated. The main molecular subtypes were luminal A, luminal B, HER-2 positive, and triple-negative. The Bland-Altman plot was used for presenting the limits of agreement between the radiologically and the pathologically determined tumor sizes by the molecular subtypes. RESULTS: A significantly proportional underestimation was found for the luminal A subtype, especially for large tumors. The p-values for the magnetic resonance imaging, mammography, and ultrasonography were 0.020, 0.030, and <0.001, respectively. No statistically significant differences were observed among the radiologic modalities in determining the tumor size in the remaining molecular subtypes (p>0.05). CONCLUSION: The radiologically determined tumor size was significantly smaller than the pathologically determined tumor size in the luminal A subtype of breast cancers when measured with all three imaging modalities. The differences were more prominent with ultrasonography and mammography. The underestimation rate increases as the tumor gets larger.

Migraine or idiopathic intracranial hypertension: Magnetic resonance venography and magnetic resonance imaging findings.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a disease characterised by increased cerebral pressure without a mass or hydrocephalus. We aimed to differentiate migraine and IIH patients based on imaging findings. RESULTS: Patients with IIH (n = 32), migraine patients (n = 34) and control subjects (n = 33) were evaluated. Routine magnetic resonance imaging, contrast-enhanced 3D magnetic resonance venography and/or T1-weighted 3D gradient-recalled echo were taken with a 1.5 T magnetic resonance scanner. Optic-nerve sheath distention, flattened posterior globe and the height of the pituitary gland were evaluated in the three groups. Transverse sinuses (TS) were evaluated with respect to score of attenuation/stenosis and distribution. Pearson chi-square, Fisher's exact test and chi-square trend statistical analyses were used for comparisons between the groups. A p-value of <0.05 was considered statistically significant. Decreased pituitary gland height, optic-nerve sheath distention and flattened posterior globe were found to be statistically significant (p < 0.001) in IIH patients. Bilateral TS stenosis was also more common in IIH patients than in the control group and migraine group (p = 0.02). CONCLUSION: Decreased pituitary gland height, optic-nerve sheath distention, flattened posterior globe, bilateral stenosis and discontinuity in TS are significant findings in differentiating IIH cases from healthy individuals and migraine patients. Bilateral TS stenosis may be the cause rather than the result of increased intracranial pressure. The increase in intracranial pressure, which is considered to be responsible for the pathophysiology of IIH, is not involved in the pathophysiology of migraine.

Tethered cord syndrome and transitional vertebrae.

PURPOSE: Tethered cord syndrome (TCS) usually presents with low-lying conus medullaris and thickened filum terminale. Spinal cord anomalies usually accompany congenital malformations and variations of the vertebral column. Transitional vertebrae (TV) are common variant, especially in the lumbosacral region. Accurate definition of the spine level is essential for proper radiological diagnosis and treatment. In this study, congenital spinal cord and vertebral anomalies and the relation with TV groups and types were evaluated in TCS patients. METHODS: The study was performed in 97 patients. Radiological imaging findings [computed tomography (CT), magnetic resonance imaging (MRI), and radiography] and medical records were evaluated. Spine bony malformation, spinal cord malformation, and spinal level of malformation were compared with TV and non-TV groups in TCS patients. In addition, TV groups and types were compared with each other for these anomalies. RESULTS: There was no statistically significant difference between TV and non-TV group in terms of the presence of vertebral bone and spinal cord anomalies. There were some significant differences in some of the spine bone and spinal cord anomalies among the groups and types of TV. CONCLUSION: Sixty-two point nine percent TCS patients had TV. Although these findings indicate that TV is common in patients with TCS, no significant difference is observed in most of the studied anomalies. However, there were some differences among the TV groups and TV types in relation to congenital malformations. It can be concluded that TV anomaly could be a distinct malformation apart from all the other anomalies that were studied. Transitional vertebrae may cause pain due to biomechanical changes in addition to progressive neurological symptoms which are usually seen with TCS.

Lumbosacral transitional vertebra in the young men population with low back pain: anatomical considerations and degenerations (transitional vertebra types in the young men population with low back pain).

INTRODUCTION: To evaluate the prevalence of subtypes of congenital lumbosacral transition vertebra (LSTV) in young male populations with low back pain (LBP) and their relationship to lumbar disc and facet degeneration. MATERIALS AND METHODS: 1875 patients (male, aged; 18-40 years) with LBP were investigated retrospectively. Standard lumbar MRI protocol of sagittal, and axial T1 weighted images (WI) and T2 WI and coronal short tau inversion recovery (STIR) T2 WI were obtained. Castellvi classification of LSTV were used for subtyping. The level and above the level of LSTV were evaluated for the lumbar disc space and facet degeneration based on grading methods which compares subtype groups with each other. RESULTS: Prevalence of LSTV was 32% (600 of 1875). The most frequent LSTV types were type I (dysplastic enlarged transverse process; 66.5%) and type II (pseudoarticulation; 21.8%). Eight percent of the patients were type III (fusion) and 3.6% patients type IV (one transverse process fused and one with pseudoarticulation). The most commonly detected LSTV types were type I + II (88%) and all bilateral LSTV types were seen much more than unilateral types (bilateral versus unilateral 63.2%, 33.2%). The LSTV type I highly correlated with the disc degeneration and facet arthrosis. But the groups with higher grade of disc degeneration were type IV and III. CONCLUSION: In young male patients with LBP, LSTV was found to be high in frequency and mostly occurred to be subtype I. LSTV type I and associated disk and facet degeneration were found to be remarkable in this group. Coronal T2 STIR images are useful in showing lumbosacral region anomalies and variants, and should be included in the routine lumbar MRI protocol.

The incidence and most common levels of thoracic degenerative disc pathologies.

OBJECTIVES: In this study, we aimed to describe and characterize the incidence of thoracic degenerative disc pathologies, bulging/herniation, and the most common affected levels. PATIENTS AND METHODS: Between January 2008 and May 2012, a total of 195 patients (109 females, 86 males; mean age 43.5 years; range, 15 to 74 years) who were admitted with the complaint of dorsalgia and underwent magnetic resonance imaging (MRI) of the thoracic vertebral column were included in the study. Data including MRI findings, endplate and disc degeneration, disc height loss, bulging, and disc herniation were retrospectively analyzed. RESULTS: Of 3,348 patients, 195 patients had disc bulging/herniation. When 12 levels in 195 cases were taken into consideration, disc pathologies were found in 412 (18%) levels among the total of 2,340 intervertebral disc levels. Bulging was present in 11% (244/2,340) of the levels. Disc herniation was present in 7% (168/2,340) of the levels. The most commonly affected site was T7-8, followed by T8-9 and T11-12. CONCLUSION: Thoracic disc pathologies are still a significant diagnostic challenge. Our study results show that the incidence of these pathologies is higher than expected.

Idiopathic Granulomatous Mastitis Associated with Erythema Nodosum.

BACKGROUND: Idiopathic granulomatous mastitis (IGM) is an uncommon benign chronic inflammatory breast disease, and erythema nodosum (EN) is an extremely rare systemic manifestation of IGM. Here, we report a rare case of IGM accompanied by EN. CASE REPORT: A 32-year-old patient was admitted to our clinic with a history of a tender mass in the right breast. On physical examination, the right breast contained a hard, tender mass in the lower half with indrawing of the nipple. She had florid EN affecting both legs. She was evaluated with mammography, ultrasound, power Doppler ultrasound, non-enhancing magnetic resonance imaging (MRI), dynamic contrast-enhanced MRI, fine needle aspiration biopsy (FNAB) and excisional biopsy. Time-intensity curves showed a type II pattern on dynamic contrast-enhanced MRI, which has an intermediate probability for malignancy. The FNAB reported a benign cytology suggestive of a granulomatous inflammation, which was also supported by the histopathological findings. A partial mastectomy was performed following medical treatment. There was no recurrence at 1-year follow-up. CONCLUSION: IGM should be considered in the differential diagnosis of EN. Although histopathological examination remains the only method for the definite diagnosis of IGM, MRI can be helpful in the diagnosis or differentiation of benign lesions from malignant ones.

Protection by Edaravone, a Radical Scavenger, against Manganese-Induced Neurotoxicity in Rats.

Manganese (Mn) is a required element for biological systems; however, its excessive exposure may lead to a neurological syndrome known as manganism. The aim of the present study was to assess the toxic effects of subacute exposure of Mn by measuring weight gain, motor performance, and biochemical parameters (complex I activity, lipid peroxides, and protein carbonyls) in brain mitochondria in rats. We also examined whether edaravone (EDA), a radical scavenger, exerts protective effects against Mn-induced neurotoxicity. In addition, we evaluated the accumulation of Mn in brain regions using magnetic resonance imaging. Mn-exposed rats revealed significantly impaired motor performance, weight loss, and Mn accumulation in particular brain area. Lipid peroxides and protein carbonyls were significantly increased in Mn-exposed rats, whereas complex I activity was found to be decreased. EDA treatment significantly prevented mitochondrial oxidative damage and improved motor performance. These findings suggested that EDA might serve as a clinically effective agent against Mn-induced neurotoxicity.

Venous flow volume measured by duplex ultrasound can be used as an indicator of impaired tissue perfusion in patients with peripheral arterial disease.

AIM: In this study, we aimed to investigate the arterial and venous flow volume rate (FV) in order to determine the tissue perfusion using duplex ultrasonography (DU). We hypothesized that FV provides reliable information regarding tissue perfusion in patients with peripheral arterial disease (PAD). MATERIAL AND METHODS: The study comprised 38 patients (72 legs) with PAD. In all patients, common femoral, popliteal, anterior tibial, posterior tibial arteries and veins were examined with DU. Measurements were obtained in the supine position with 15 cm elevation of the foot to neutralise central venous pressure. The diameter, blood flow velocity, and FV of arteries and veins were measured for each patient. RESULTS: The FV of the common femoral artery and vein (p = 0.001), popliteal artery and vein (p=0.003), and posterior tibial artery and vein (p = 0.008) had statistically significant differences. However, there was no statistically significant difference between the FV of the anterior tibial vein and artery (p = 0.408). The mean FV values of all veins were significantly lower than those of homonymous arteries in patients with PAD. CONCLUSIONS: Our study showed that venous FV measured by DU can be used as an indicator of impaired tissue perfusion in patients with PAD.

Protective effect of edaravone against manganese-induced toxicity in cultured rat astrocytes.

Manganese (Mn), a trace metal, is essential for maintaining the normal regulation of many biochemical and cellular processes. However, accumulation of Mn due to excessive environmental exposure leads to neurological impairment, referred to as manganism. Edaravone (EDA) is a potent free radical scavenger that has been clinically shown to reduce the neuronal injury after cerebral ischemia. In the present study, we aimed to examine the protective effects of EDA against Mn toxicity in astrocyte cultures. Astrocyte cultures were prepared from cerebral cortices of newborn Sprague-Dawley rats. The experiments were performed between 16 and 18 days of cultures. Astrocytes were treated in DMEM medium containing Mn (1-1000µM) for 24h to test Mn toxicity. In order to assess the effect of EDA, cells were pre-treated with different doses of EDA (10, 100 and 1000µM) 6h before Mn treatment. Cell viability (MTT), apoptotic cell death (Hoechst test) and lipid peroxide levels were evaluated in cultures. Our results showed that Mn significantly and dose-dependently reduced cell viability in astrocyte cultures. The apoptotic cell death and lipid peroxides were significantly higher in Mn treated cultures. Treatment of astrocytes with EDA successfully suppressed oxidative stress and cell death due to Mn exposure. The findings of the present study suggest that Mn cytotoxicity is mainly associated with ROS generation and apoptotic cell death. Besides, EDA may have beneficial effects against Mn toxicity. However, further studies are needed to elucidate the molecular mechanisms underlying protective effect of EDA.

Measure the Vascular Flow Volume rather than Vascular Stenosis and Pressure Gradient.

We aimed to investigate the extent to which measurements of flow volume (FV) with colour flow duplex ultrasonography (CDU) could predict tissue perfusion. A 68 year-old male patient was admitted to our clinic complaining of intermittent claudication in the right leg. Digital subtraction angiography showed total occlusion of the right femoral artery. The right popliteal artery (PA) was filling by collaterals. CDU showed that the FV in the right PA was higher than in the left. Arterial-venous FV measurement with CDU should be performed rather than the detection of arterial stenosis to assess whether intervention is necessary.

Diffusion-weighted magnetic resonance imaging findings of kidneys with obstructive uropathy: differentiation between benign and malignant etiology.

PURPOSE: In this study, we aimed to evaluate the capability of diffusion-weighted magnetic resonance imaging (DWI) in differentiation between benign and malignant etiology of obstructive uropathy. MATERIALS AND METHODS: DWI was performed in 41 patients with hydronephrotic kidneys and 26 healthy volunteers. MR imaging was performed using a 1.5 T whole-body superconducting MR scanner. The signal intensities of the renal parenchyma on DWI and apparent diffusion coefficient (ADC) maps were noted. DWI was performed with the following diffusion gradient b values: 100, 600, and 1000 s/mm(2). A large circular region of interest was placed in the corticomedullary junction of the kidneys. For statistical analysis, the independent-samples t test was used. RESULTS: The mean renal ADC values for b100, b600, and b1000 in hydronephrosis patients with benign and malignant etiology and the healthy volunteers of the control group were analysed. ADC measurements of renal parenchyma in all hydronephrotic kidneys with benign and malignant etiology were found to be statistically low compared to those of normal kidneys (P < 0.05). CONCLUSIONS: There were significant differences in the ADC values of obstructed kidneys compared to those of normal kidneys. Obstructed kidneys with malignant etiology had lower ADC values for b1000 compared to obstructed kidneys with benign etiology, but these alterations were statistically insignificant.

Manganese-enhanced MRI to evaluate neurodegenerative changes in a rat model of kainic acid-induced excitotoxicity.

PURPOSE: Manganese-enhanced magnetic resonance imaging (MEMRI) has been used to detect brain activity based on the ability of active neurons to take up manganese ions through calcium channels. Kainic acid (KA), an analog of excitotoxic glutamate, can elicit selective neuronal death in the brains of rodents, of which the pathological changes partially mimic neurodegeneration in the central nervous system. We used in vivo MEMRI to evaluate neurodegenerative changes in an excitotoxicity model induced by KA in rats. MATERIALS AND METHODS: Adult Sprague-Dawley rats (220-250 g) were injected with either KA or saline into the right lateral ventricle. Precontrast and postcontrast MEMRI sessions were obtained. Region of interest (ROI) analyses were performed on both injected (saline and KA) and contralateral (normal) sites in the hippocampal area. All brains were evaluated histologically following MEMRI. RESULTS: Analysis of percentage change in ROI intensities of T1-weighted fluid-attenuated inversion-recovery MR images in the hippocampal area revealed a significant difference between the KA-injected (ipsilateral) and contralateral sites (P = 0.008), whereas no significant difference was observed between the saline-injected and contralateral sites. Furthermore, there was a significant difference between ipsilateral sites of the saline-treated and KA-treated groups (P = 0.026). The histological results supported these findings. CONCLUSION: MEMRI is a simple and useful in vivo method for detecting neurodegenerative changes due to excitotoxicity in the rat brain. The development of a manganese-based contrast agent that can be safely used in humans is warranted to investigate neurological disorders.

Carotid intima-media thickness increase in patients with habitual simple snoring and obstructive sleep apnea syndrome is associated with metabolic syndrome.

OBJECTIVES: Sleep disorders are emerging risk factors for atherosclerosis. Increased carotid intima-media thickness (CCA-IMT) is a surrogate marker of cardiovascular risk. The aim of the present study was to investigate the relationship between CCA-IMT and habitual simple snoring or obstructive sleep apnea syndrome (OSAS) and the other cardiovascular risk factors. METHODS: Sleep disorders were diagnosed and staged by polysomnography. Patients were then classified into either habitual simple snoring (n = 20, group 1) or OSAS (n = 67, group 2), which was subclassified as mild-moderate (n = 27) or severe (n = 40). CCA-IMT was measured by B-mode ultrasonography. The other major risk factors were investigated. RESULTS: The mean CCA-IMT was 0.65 ± 0.02 mm (mean ± SD) in group 1 versus 0.75 ± 0.02 mm in group 2 (p = 0.03). Using CCA-IMT ≥ 0. 9 mm as the threshold value also yielded significant results between the two groups (p = 0.03). The mean CCA-IMT did not differ between patients with mild-moderate and severe OSAS, whereas metabolic risk factors and metabolic syndrome (MS) were more prominent in the latter. Age, MS, neck and waist circumference, waist/ hip circumference, and fasting glucose level were higher in patients with CCA-IMT ≥ 0.9 mm. CONCLUSIONS: CCA-IMT increase was associated with OSAS, but did not correlate with its severity, which could be due to the higher incidence of MS in this group.

Puffed-cheek computed tomography: a dynamic maneuver for imaging oral cavity tumors.

We conducted a prospective study to compare the effectiveness of conventional computed tomography (CT) and puffed-cheek CT in detecting the presence and extension of oral cavity malignant tumors. We enrolled 11 patients--5 men and 6 women, aged 32 to 85 years--who had a primary squamous cell carcinoma of the oral cavity. These tumors were located in the floor of the mouth in 4 patients, in the buccal mucosa in 4, in both the buccal mucosa and retromolar trigone in 2, and in the retromolar trigone only in 1. First, conventional contrast-enhanced axial CT was obtained through the oral cavity and neck in each patient. Next, axial imaging was obtained through the oral cavity while patients inflated their cheeks, pursed their lips, and held their breath. We found that the puffed-cheek CTs provided more information regarding the size and extent of the squamous cell carcinomas than did the conventional CTs. For example, in 8 patients, conventional CT could not differentiate the tumor from the normal mucosal surface, but puffed-cheek images clearly showed the surface of the tumor as distinct from the normal mucosa. More disconcerting was the fact that in the other 3 patients, conventional CTs were evaluated as normal, even though puffed-cheek imaging clearly showed the mass in each case. We conclude that puffed-cheek CT is superior to conventional CT for evaluating the mucosal surfaces of the oral cavity. It provides a clearer and more detailed picture with no downside.

Echolucency of carotid plaques and cerebrovascular events.

OBJECTIVES: To assess the relationship between carotid plaque echogenicity and degree of stenosis with acute and chronic stroke. METHODS: A retrospective study of cerebral MRI and carotid B-mode and Doppler ultrasonography in 60 patients with stroke. Plaque echogenicity was graded as echolucent (1), predominantly echolucent (2), predominantly echogenic (3), or echogenic (4). Sonographic findings were compared between patients with acute (group 1) and chronic (group 2) stroke. RESULTS: In group 1 (n = 39 patients), the carotid plaques were grade 1 in 21, grade 2 in 22, grade 3 in 9, and grade 4 in 4 carotid arteries. In group 2 (n = 21), the carotid plaques were grade 1 in 2, grade 2 in 8, grade 3 in 4, and grade 4 in 11 carotid arteries. Plaque echogenicity was lower in group 1 than in group 2 (p < 0.05). Plaque echolucency was associated independently with acute stroke from the degree of stenosis. CONCLUSIONS: Patients with acute infarcts have predominantly echolucent plaques, regardless of the degree of stenosis.