Weight Image Research Articles

Role of Diffusion-Weighted MRI in Colorectal Cancer

AbstractBackground: To reveal the adding value of diffusion-weighted Magnetic Resonance Imaging (MRI) in the detection and differential diagnosis of the colorectal cancer, comparing the results of Apparent Diffusion Coefficient (ADC) value with histopathological studies.Aim of Study: The aim of the study was to determine the effectiveness of MRI in the diagnosis of colorectal cancers and to reveal the adding value of DWI in the detection and differential diagnosis of the colorectal cancer, comparing the results of ADC value with histopathological studies.Material and Methods: Fifteen patients with suspected colorectal cancers clinically, endoscopically or by CT and US images were included in this study. All cases have been evaluated with 1.5 MR scanner. In addition to the conventional sequences (T2-axial, sagittal and coronal weighted images (WI), axial T2 STIR, T1 WI and a Diffusion-Weighted Images (DWI) with 4 different b-values (0, 400, 600 and 1000s/mm2 and ADC maps were obtained then the results have been compared to histopathological diagnosis.Results: All cases of malignant colorectal cancer showed high signal (restricted diffusion) on DWI. Receiver Operating Curve (ROC) analysis of ADC values yielded an Area Under Curve (AUC) of 0.912, setting a threshold ADC value of Conclusion: DWI with high b-values and ADC value is a feasible method and has the potential to be effective in detection of colorectal cancer.

Pre-operative MRI predictors of hormonal remission status post pituitary adenoma resection

IntroductionContrast-enhanced (CE) Constructive Interference in Steady State (CISS) and Volumetric Interpolated Breath-hold Examination (VIBE) are MRI sequences used to improve the detection of pituitary adenomas and adjacent cranial nerves. The purpose of this study was to assess image quality and identify imaging predictors of postoperative hormonal remission of functioning pituitary adenomas using CE-T1 weighted image (WI), T2WI, CE-CISS, and CE-VIBE MRI sequences. Materials and methodsPatients with pre-operative CE-T1WI, T2WI, CE-CISS, and CE-VIBE pituitary MRI sequences were included in this institutional retrospective review. Three raters independently reviewed randomized sequences in a blinded fashion for adenoma characteristics and parasellar invasion. Subgroup analysis of hormonal remission was performed. ResultsA total of 34 functioning pituitary adenoma patients were included (average age 39.3 ± 12.2; female n = 27), 30 of which had post-operative hormonal remission (n = 34; 88.2%). Compared to CE-T1WI, CE-CISS has significantly higher number of sequences rated “good” image quality (p = 0.02). Hormone remission was associated with decreased degrees of pre-operative internal carotid artery (ICA) contact and Knosp score (p ≤ 0.02) on all sequences except for Knosp score on T2WI. On receiver operating characteristic analysis, the area under curve for differentiating endocrine remission ranged from 0.88 to 0.92 for Knosp score and 0.85–0.93 for ICA contact, depending on sequence. ConclusionExtent of pituitary adenoma cavernous sinus invasion as measured by degrees of ICA contact and Knosp score is associated with postoperative endocrine outcomes. Given improved image quality, inclusion of CE-CISS may be helpful for pre-surgical planning.

Imaging findings of metallic implants associated lymphoma

Purpose Chronic inflammatory condition such as metallic implants insertion state has relevance to develop diffuse large B-cell lymphoma (DLBCL). The purpose of this study is to introduce the imaging features of the metallic implants associated lymphoma. Materials and Methods In 2016 September, a 58 years-old male underwent high tibial osteotomy at right leg after took a knee magnetic resonance image (MRI). After 15 months later, he underwent hardware removal operation. 2 weeks later after operation, he complained right leg pain and swelling. He was hospitalized and radiologic studies including ultrasound (US) and MRI were performed. Soft tissue mass in right popliteal fossa was seen and US-guided biopsy was done to confirm the mass. Results MRI which was taken after hardware removal, showed iso to slightly low signal intensity on T1 weighted image(WI), high signal intensity on T2WI with diffuse marrow involvement and heterogeneous patchy enhancement in right proximal tibia. Also extensive extraosseous soft tissue component was seen, with relatively preserved trabecular pattern in proximal tibia. This intraosseous and extraosseous lesions were not seen in previous MRI which taken before high tibial osteotomy. On US image, it was showed heterogeneous hypoechoic and hypervascular lesion in popliteal fossa of left lower leg. US guided biopsy was done on extraosseous soft tissue mass in left popliteal fossa. It was histologically confirmed as DLBCL. Conclusion Hypoechoic and hypervascular disproportionally large extraosseous soft tissue mass without prominent bone destruction is preferential finding of bone lymphoma. Lymphoma should be considered above all, when these findings were seen in patient who has metallic implant.

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).

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. 1875 patients (male, aged; 18-40years) 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. 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. 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 technique of magnetic resonance fingerprinting and its latest development

Magnetic resonance fingerprinting (MRF) is a brand new MRI technology that features fast, quantitative, and simultaneous mapping of multiple MR and tissue properties, such as proton density, relaxation times and diffusion coefficients. In data acquisition, MRF employs a series of pseudo-randomized RF flip angles and repetition times to excite the spin system for a series of undersampled spatial images, forming a temporal MR signal evolution curves (named measured fingerprints) for each image voxel; on the other hand, a set of signal evolution curves are acquired theoretically by computer simulation and Bloch equation, with all foreseeable combination of tissue parameters (such as T 1, T 2, Proton density, etc) and using the same RF and TR series as in the real MR scan. All the calculated signals and their corresponding parameters constitute a database of fingerprints termed a dictionary. In image reconstruction, the measured fingerprints (i.e., the temporal evolutions of individual voxels of the undersampled images) are compared with the entries in the dictionary (i.e., the simulated theoretical signal evolutions with all possible tissue parameters), using pattern recognition and/or data mining, for the best matches; the tissue parameters corresponding to the best matched dictionary entry are determined for the corresponding voxels. Finally, the collection of these parameters are presented as parametric images, such as T 1-map, T 2-map, and PD-map, instead of T 1-weighted, T 2-weighted, or PD-weighted images. MRF technology breaks the limitation of the conventional, qualitative, motion-sensitive, and time-consuming MRI techniques. It also makes possible the sub-voxel parametric mapping. The multiparametric and quantitative features of MRF are in conformity with and will have great impact on modern model of precision and personalized medicine. This paper introduces the basic principles of MRF, provides detailed description and analysis for RF/TR series optimization, dictionary design, and signal reconstruction, and presents latest development in both the MRF technique and its application in biomedical research. We also discuss the challenges and future directions for MRF research and applications.

Evaluation of magnetic resonance imaging in autoimmune pancreatitis before and after treatment

Objective To evaluate the imaging features of MRI in autoimmune pancreatitis (AIP) and analyze the diagnostic value before and after treatment. Methods MRI data of 20 AIP patients (14 males, 6 females; average age: (54.0±10.3) years) from January 2013 to December 2015 were retrospectively analyzed. The sequences of MRI included T1 weighted imaging (WI), T2WI, MR cholangiopancreatography (MRCP), diffusion weighted imaging (DWI) and dynamic enhancement images. Fifteen of the patients received DWI again after hormone therapy. The location and extent of lesions, signal, patterns of dynamic enhancement, pseudocapsule sign and other accompanying signs, the apparent diffusion coefficient (ADC) of the lesion and the DWI manifestations before and after treatment were observed, calculated and compared. χ2 test and paired t test were used to analyze the data. Results Five patients were confirmed by pathology and 15 by clinical follow-up. In MRI, 16 patients appeared diffusive swollen pancreases, and 4 patients were with focal enlargement. Lesions of pancreas showed low signal on T1WI and high signal on T2WI. Twelve patients presented pseudocapsule around the lesions and progressive enhance was shown in the delayed phase on dynamic contrast enhanced MRI. Ten patients showed stenotic choledoch in the head of pancreas and segmented stenotic pancreatic duct in MRCP. All pancreatic lesions in the 10 patients presented high signals on DWI. The pancreatic morphology, the signal of the lesion, the pseudocapsule sign and the enhancement degree on MRI were significantly improved compared with those before treatment in 15 patients (χ2 values: 5.000-22.941, all P<0.05). After hormone therapy, the signals on DWI were markedly weakened in pancreatic parenchyma, and ADC was significantly higher than that before treatment ((1.27±0.14)×10-3vs (1.05±0.16)×10-3 mm2/s; t=4.15, P<0.01). Conclusion DWI could reflect the pathological and biological characteristics of AIP and be used to evaluate the therapeutic efficacy of hormone treatment in AIP. Key words: Pancreatitis, chronic; Autoimmune disease; Magnetic resonance imaging; Treatment outcome

Examination of the use of needle biopsy to perform laparoscopic surgery safely on uterine smooth muscle tumors.

The warning statement issued by the United States Food and Drug Administration against the use of laparoscopic power morcellators prompted a discussion about the methods of preoperative diagnosis of uterine myometrial lesions. Since 1994, transcervical needle biopsies have been performed to differentiate between uterine leiomyomas and leiomyosarcomas. Needle biopsies are also useful for performing laparoscopic surgery on uterine smooth muscle tumors with histopathological safety. In the present study, data from hematoxylin and eosin (HE)-stained specimens obtained by transcervical needle biopsies from 331 patients with smooth muscle tumors and high intensity regions on T1 weighted images (WI) and/or T2WI from magnetic resonance imaging (MRI) scans were retrospectively examined. From a total of 10 patients with moderate or severe cytological atypia, 4 exhibited smooth muscle tumors of uncertain malignant potential and 6 exhibited leiomyosarcomas. The final diagnosis in 3 patients with ≥10 mitotic figures/high-power field was leiomyosarcoma. A total of 5 patients with coagulative tumor cell necrosis exhibited final diagnoses of leiomyosarcoma. Patients without cytological atypia, mitotic figures or coagulative tumor cell necrosis were not diagnosed with either leiomyosarcomas or smooth muscle tumors of uncertain malignant potential. The present study revealed that laparoscopic surgery is safe when HE-stained specimens obtained by transcervical needle biopsy from areas of high intensity on an MRI scan are negative for all three criteria assessed-cytological atypia, mitotic figures and coagulative tumor cell necrosis.

Hemodynamic and Metabolic Assessment of Neonates With Punctate White Matter Lesions Using Phase-Contrast MRI and T2-Relaxation-Under-Spin-Tagging (TRUST) MRI.

The brain's hemodynamic and metabolism of punctate white matter lesions (PWML) is poorly understood due to a scarcity of non-invasive imaging techniques. The aim of this study was to apply new MRI techniques to quantify cerebral metabolic rate of oxygen (CMRO2), global cerebral blood flow (CBF), oxygen saturation fractions in venous blood (Yv) and oxygen extraction fraction (OEF) in neonates with PWML, for better understanding of the pathophysiology of PWML. Fifty-one newborns were recruited continuously, including 23 neonatal patients with PWML and 28 normal control neonates. Phase-contrast (PC) MRI and T2-Relaxation-Under-Spin-Tagging (TRUST) MRI were performed for the measurement of CBF and Yv. OEF and CMRO2 were calculated from the CBF and Yv values. The total maturation score (TMS) was assessed for each neonate on standard T1, 2-weighted images to evaluate cerebral maturation. The CMRO2, CBF, Yv, and OEF values were compared between groups, and their associations with age and TMS were evaluated. Significant differences between PWML group and control group were found in CMRO2 (P = 0.020), CBF (P = 0.027), Yv (P = 0.012), OEF (P = 0.018). After age/maturation is accounted for, Yv and OEF showed significant dependence on the groups (P < 0.05). Newborns with PWML had lower OEF and higher Yv. CMRO2, CBF and brain volume were correlated with age (P < 0.001) and TMS (P < 0.05). It is feasible to use non-invasive MRI methods to measure cerebral oxygen supply and consumption in neonates with PWML. Newborns with PWML have lower oxygen consumption. Yv and OEF may be helpful for the diagnosis of PWML. The positive correlation between CBF and TMS, and between CMRO2 and TMS suggested that as myelination progresses, the blood supply and oxygen metabolism in the brain increase to meet the escalating energy demand.

Hepatic Mass in a Patient With Bladder Cancer History

82-year-old asymptomatic man with an incidental finding of liver lesion on CT angiogram performed for infrarenal abdominal aortic aneurysm repair surveillance. He had a history of bladder cancer 7 years prior, with no evidence of disease since the end of the treatment. He did not have history of liver disease or immunosuppression. At presentation his laboratory exams were normal. He underwent abdominal MRI which showed a 3.5 × 3.0 cm liver mass in segment II/IVA; the mass was T2 weighted images (WI) mildly hyperintense and T1 WI hypointense to the background liver, and demonstrated hyperenhancement in the arterial phase, and heterogeneous enhancement and capsule on the delayed phase). The central portion of the mass was hyperintense on T2WI (Figures A and D, dashed arrow) and demonstrated enhancement in the delayed phase.

MRI appearance of ovarian serous borderline tumors of the micropapillary type compared to that of typical ovarian serous borderline tumors: radiologic-pathologic correlation

BackgroundSerous borderline tumor (SBT) of the micropapillary type (SBT-MP) became one of the major pathological SBT diagnoses in addition to typical SBT, and was also defined as “non-invasive” low-gradeserous carcinoma according to the World Health Organization (WHO) classification in 2014. In this study, we investigated the MRI appearance of SBT-MP compared to that of typical SBT in order to identify specific imaging features of SBT-MP that correspond to pathological findings.MethodsMR images of 6 histologically proven ovarian SBT-MP in four patients and 14 typical SBT in ten patients were reviewed retrospectively. Images were evaluated for laterality, size and morphology of the lesion and the solid component (SC) and signal intensity (SI) of the SC. MRI findings were correlated with pathological findings.ResultsThe patients with SBT-MP (mean 26.3 years) were younger than those with typical SBT (mean 44.5 years). Postoperative staging in patients with SBT-MP was II in two and III in two cases, while staging for typical SBT was I in seven, II in one and III in two cases. The morphologic patterns of SBT-MP were a unilateral cystic mass with intracystic mural nodules (CwMN) (n = 2), bilateral solid papillary masses (SM), and bilateral SM with CwMN. The pattern of typical SBT was CwMN (n = 13) in all but one lesion (SM with CwMN). All SCs showed inhomogeneous slight hyperintensity on T2 weighted images (WI) and high SI on diffusion-WI (DWI) except for in one typical SBT. Although diffuse proliferation of the tumor cells in micropapillary projections with little stroma seemed to correspond to inhomogeneous slightly hyperintense foci in SC on T2WI and high SI on DWI, similar MR findings were observed in typical SBT in all lesions on T2WI and 11 of 12 lesions on DWI. In typical SBT, inhomogeneous slightly hyperintense foci in SC on T2WI and high SI on DWI corresponded to highly cellular foci with densely branched papillae.ConclusionPathological findings and clinical behavior of SBT-MP differed from those of typical SBT, but morphology and SI of SC on MRI were similar, with papillary projections demonstrating inhomogeneous slight hyperintensity on T2WI and high SI on DWI.

Differentiation between vasogenic edema and infiltrative tumor in patients with high-grade gliomas using texture patch-based analysis.

High-grade gliomas (HGGs) induce both vasogenic edema and extensive infiltration of tumor cells, both of which present with similar appearance on conventional MRI. Using current radiological criteria, differentiation between these tumoral and nontumoral areas within the nonenhancing lesion area remains challenging. To use radiomics patch-based analysis, based on conventional MRI, for the classification of the nonenhancing lesion area in patients with HGG into tumoral and nontumoral components. Prospective. In all, 179 MRI scans were obtained from 102 patients: 67 patients with HGG and 35 patients with brain metastases. A subgroup of 15 patients with HGG were scanned before and following administration of bevacizumab. Pre and postcontrast agent T1 -weighted-imaging (WI), T2 WI, FLAIR, diffusion-tensor-imaging (DTI), and dynamic-contrast-enhanced (DCE)-MRI at 3T. A total of 225 histograms and gray-level-co-occurrence matrix-based features were extracted from the nonenhancing lesion area. Tumoral volumes of interest (VOIs) were defined at the peritumoral area in patients with HGG; nontumoral VOIs were defined in patients with brain metastasis. Twenty machine-learning algorithms including support-vector-machine (SVM), k-nearest neighbor, decision-trees, and ensemble classifiers were tested. The best classifier was trained on the entire labeled data, and was used to classify the entire data. Dimensional reduction was performed on the 225 features using principal component analysis. Classification results were evaluated based on the sensitivity, specificity, and accuracy of each of the 20 classifiers, first based on a training and testing dataset (80% of the labeled data) in a 5-fold manner, and next by applying the best classifier to the validation data (the remaining 20% of the labeled data). Results were additionally evaluated by assessing differences in dynamic-contrast-enhanced plasma-volume (vp ) and volume-transfer-constant (ktrans ) values between the two components using Mann-Whitney U-test/t-test. The best classification into tumoral and nontumoral lesion components was obtained using a linear SVM classifier, with average accuracy of 87%, sensitivity 86%, and specificity of 89% (for the training and testing data). Significantly higher vp and ktrans values (P < 0.0001) were detected in the tumoral compared to the nontumoral component. Preliminary classification results in a subgroup of patients treated with bevacizumab demonstrated a reduction mainly in the nontumoral component following administration of bevacizumab, enabling early assessment of disease progression in some patients. A radiomics patch-based analysis enables classification of the nonenhancing lesion area in patients with HGG. Preliminary results were promising and the proposed method has the potential to assist in clinical decision-making and to improve therapy response assessment in patients with HGG. 1 Technical Efficacy Stage 4 J. Magn. Reson. Imaging 2018.

MRI radiomics analysis of molecular alterations in low-grade gliomas.

Low-grade gliomas (LGG) are classified into three distinct groups based on their IDH1 mutation and 1p/19q codeletion status, each of which is associated with a different clinical expression. The genomic sub-classification of LGG requires tumor sampling via neurosurgical procedures. The aim of this study was to evaluate the radiomics approach for noninvasive classification of patients with LGG and IDH mutation, based on their 1p/19q codeletion status, by testing different classifiers and assessing the contribution of the different MR contrasts. Preoperative MRI scans of 47 patients diagnosed with LGG with IDH1-mutated tumors and a genetic analysis for 1p/19q deletion status were included in this study. A total of 152 features, including size, location and texture, were extracted from fluid-attenuated inversion recovery images, [Formula: see text]-weighted images (WI) and post-contrast [Formula: see text]. Classification was performed using 17 machine learning classifiers. Results were evaluated by a fivefold cross-validation analysis. Radiomic analysis differentiated tumors with 1p/19q intact ([Formula: see text]; astrocytomas) from those with 1p/19q codeleted ([Formula: see text]; oligodendrogliomas). Best classification was obtained using the Ensemble Bagged Trees classifier, with sensitivity [Formula: see text] 92%, specificity [Formula: see text] 83% and accuracy [Formula: see text] 87%, and with area under the curve [Formula: see text] 0.87. Tumors with 1p/19q intact were larger than those with 1p/19q codeleted ([Formula: see text] vs. [Formula: see text]cc, respectively; [Formula: see text]) and predominantly located to the left insula ([Formula: see text]). The proposed method yielded good discrimination between LGG with and without 1p/19q codeletion. Results from this study demonstrate the great potential of this method to aid decision-making in the clinical management of patients with LGG.

EP03.03: Fetal neurosonography: experience and correlation with magnetic resonance images (MRI) in T2 weighted images (WI) at Hospital Italiano of Buenos Aires

The aim is to describe our experience in fetal neurosonography, correlating them with the RMI T2WI and with the early evolution of the newborns. Retrospective evaluation of a series of cases evaluated with neurosonography between September 2014 and March 2017. In a total of 54 patients 61 evaluations were performed. The neurosonography was indicated: in 87% (47/54) of the cases due to CNS anomalies in routine obstetric ultrasound, in 3.7% (2/54) had previous child with CNS malformation, 3.7% (2/54) was indicated by the death of a twin monochorial pregnancy, 1.85% (1/54) had IUGR and 1.85% (1/54) for cardiac tumours. The mean gestational age (GA) at neurosonography was 29.4 weeks (range 21-37 weeks). The findings were: 15 normal ultrasound,10 corpus callosum alterations, 9 ventriculomegaly; 8 megacisterna Magna; 7 Blake's pouch cyst; 1 brain tumour; 1 Arachnoid cyst; 1 intracranial hemorrhage; 3 ventricular asymmetry; 1 posterior fossa hemorrhage; 4 holoprosencephaly; 1 microcephaly. MRI was performed in 57.4% (31/54) of the patients. In 96% (30/31) the findings visualised in T2WI were correlated with those of neurosonography. An evolutionary control was performed in 70.3% (38/54) of the newborns, of whom the 92.1 (35/38) presented evolution as expected for age, and 7.89% (3/38) neonatal died. Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

An Efficient Reconstruction Algorithm Based on the Alternating Direction Method of Multipliers for Joint Estimation of ${R}_{{2}}^{*}$ and Off-Resonance in fMRI.

R*2 mapping is a useful tool in blood-oxygen-level dependent fMRI due to its quantitative-nature. However, like T*2-weighted imaging, standard R*2 mapping based on multi-echo EPI suffers from geometric distortion, due to strong off-resonance near the air-tissue interface. Joint mapping of R*2 and off-resonance can correct the geometric distortion and is less susceptible to motion artifacts. Single-shot joint mapping of R*2 and off-resonance is possible with a rosette trajectory due to its frequent sampling of the k-space center. However, the corresponding reconstruction is nonlinear, ill-conditioned, large-scale, and computationally inefficient with current algorithms. In this paper, we propose a novel algorithm for joint mapping of R*2 and off-resonance, using rosette k-space trajectories. The new algorithm, based on the alternating direction method of multipliers, improves the reconstruction efficiency by simplifying the original complicated cost function into a composition of simpler optimization steps. Compared with a recently developed trust region algorithm, the new algorithm achieves the same accuracy and an acceleration of threefold to sixfold in reconstruction time. Based on the new algorithm, we present simulation and in vivo data from single-shot, double-shot, and quadruple-shot rosettes and demonstrate the improved image quality and reduction of distortions in the reconstructed R*2 map.

The use of low-field MRI for visualization of epileptogenic brain lesions in children

To analyze MR-images of patients with focal epilepsy using a method close to the protocol of epileptic scanning on a MRI-device with the magnetic field tension of 0.4 Tesla. MRI data of 50 children who underwent examination due to difficult-to-treat or drug-resistant forms of focal epilepsy were analyzed. MRI study was conducted using open-ended device of static magnetic field HITACHI 'APERTO' with the magnetic field tension of 0.4 Tesla. The thickness of the slices and the scan step was performed at 3.0 and 3.5 mm with the use of special positioning of slices in the coronal and axial projections, T2, T1, STIR, FLAIR weighted images (WI) perpendicular and parallel to the long axis of the hippocampus. Potentially epileptogenic structural changes were identified in 37 patients. Abnormalities of brain development of different severity were identified in 16 patients. In 21 cases, the changes were due to the consequences of cerebral vascular catastrophes, neuroinfections, brain traumas affecting the cortical plate. A method close to the epileptic scanning protocol allowed the identification of signs of acute cerebral catastrophes in two patients. In 8 patients, potentially epileptogenic changes after false-negative descriptions of the results of previous MRI studies were newly identified. The most difficult for the diagnosis was the visualization of small structural changes in mediobasal regions of the temporal lobes. Confirmation of this supposition according to the recommended thorough investigation was obtained only in 5 out of 12 patients with suspected small-bore pathological changes in mediobasal temporal regions. Low-tension technique approximated to the epileptic scanning protocol does not allow the reliable diagnosis of small and similar in signal characteristics changes in the visualization of mediobasal temporal lobes regions. It was not possible to reliably differentiate some cortical-subcortical neoplastic formations from various forms of focal cortical dysplasia.

Internal Structures of the Globus Pallidus in Patients with Parkinson's Disease: Evaluation with Phase Difference-enhanced Imaging.

Purpose:The medial medullary lamina (MML) separates the medial globus pallidus (GPm) from the lateral. The aim of this study was to assess the changes in appearance of MML related to age using the phase difference-enhanced (PADRE) imaging and to determine whether PADRE can depict the MML in the patients with Parkinson’s disease (PD).Materials and Methods:We enrolled 20 patients with PD and 50 normal control subjects (NC). First, for the visualization of the MML in the NC, we compared the PADRE, susceptibility-weighted imaging (SWI)-like images and T2weighted imaging (WI) by using multiple comparison. The grading methods are as follows: grade 1; MML was not delineated, grade 2; less than half of MML was delineated, grade 3; more than half of MML was delineated and grade 4; whole MML was clearly delineated. We determined grade 3 and 4 as good depiction, delineating the GPm. Then, we evaluated patients with PD using the same method.Results:In NC, the delineation of MML was good in 84% of cases on PADRE, but only 34% of cases showed a good depiction on SWI-like images (average grading score 3.31 vs 2.11, P < 0.05). No MML was delineated in all cases on T2WI. Although younger subjects tended to show whole MML clearly, a part of MML tends to be obscured with age on PADRE. In patients with PD the depiction of MML on PADRE was also good in 90% of cases.Conclusion:The PADRE technique facilitates the depiction of the MML within globus pallidus (GP) on a broad range of age NC and patients with PD and it is superior to SWI-like images and T2WI.

Imaging features of surgical complications of Crohn′s disease

Imaging features of surgical complications of Crohn′s disease

Early identification of hypoxic-ischemic encephalopathy by combination of magnetic resonance (MR) imaging and proton MR spectroscopy.

Brain damage following a perinatal hypoxic-ischemic encephalopathy (HIE) can be diagnosed by different techniques. The aim of the present study was to combine magnetic resonance (MR) imaging with proton MR spectroscopy in HIE diagnosis and to evaluate their correlation with outcome. A prospective observational cohort study was performed between February 2012 and February 2013. Consecutive newborns, 24 full-term neonates with HIE (mild to moderate and severe group) and 5 normal neonates, were included. Two sequential MR studies were performed; a conventional MR imaging for observation in T1 weighted image (WI) and T2WI, and proton MR spectroscopy for observation in the left or right basal ganglia and thalamus. MR images were assessed and scored by two neuroradiologists who were blinded to the clinical condition of the infants. The mild to moderate group (n=13) and severe group (n=11) were similar in the visualization of punctate hyperintensity lesions on T1WI and brain edema on T2WI. The differences of N-acetylaspartate/creatine (Cr), choline/Cr and lactate/Cr in the basal ganglia and thalamus in the HIE group were significantly different (P<0.05) compared with the control group, while no significant difference was identified between the mild to moderate and severe group (P>0.05). In conclusion, MR spectroscopy is a complementary tool for the diagnosis of HIE.

Neuroimaging of full term newborn´s brain with hypoxic-ischemic encephalopathy

Introduction. Hypoxic-ischemic encephalopathy (HIE) in full term newborn is the most frequent courses of neonatal mortality and development of neurology handicap. Magnetic resonance imaging (MRI) is common noninvasive method for detect of post hypoxic brain lesions in newborn. Method of research. We assessed MR-pattern of hypoxic brain injury using Philips Ingenia 1.5 Tl for examination newborn on 14-16 days after delivery. Protocol of MRI scans included axial and coronal plan T1, T2, Flair weighted imaging (WI) and diffusion tensor imaging (DTI) with program Fiber tracking and detected fractional anisotropy (FA). FA was measuring within cortico-spinal tract besides. 3D reconstruction allowed to visualized white matter along the axon direction of cortico-spinal tract. Studies. Four full term newborn (after 37 weeks gestation) have been examined and separated in two groups. First group included newborns with HIE (evidence of fetal distress, low Apgar Scores, low umbilical cord pH ˂ 7.1, necessity for resuscitation and neurological signs, second group consisted term newborn without any medical and problems of health. Results of research. We detected MR-patterns of basal ganglia and thalamus lesions in newborn with HIE (abnormal high signal intensity on T1 and Flair WI). We didn’t detect any abnormal MR scans in healthy newborns (control group). FA within cortico-spinal tracts besides (total and ROI-1) were lower in newborns with HI then in healthy ones. Conclusion. This investigation showed common MR patterns of brain lesions in full term newborns with HIE which included changes of signal intensity T1 and Flair from basal ganglia and thalamus as well as reduction of FA within cortico-spinal tract.

A novel alternative to classify tissues from T 1 and T 2 relaxation times for prostate MRI

To segment and classify the different attenuation regions from MRI at the pelvis level using the T 1 and T 2 relaxation times and anatomical knowledge as a first step towards the creation of PET/MR attenuation maps. Relaxation times were calculated by fitting the pixel-wise intensities of acquired T 1- and T 2-weighted images from eight men with inversion-recovery and multi-echo multi-slice spin-echo sequences. A decision binary tree based on relaxation times was implemented to segment and classify fat, muscle, prostate, and air (within the body). Connected component analysis and an anatomical knowledge-based procedure were implemented to localize the background and bone. Relaxation times at 3T are reported for fat (T 1=385ms, T 2=121ms), muscle (T 1=1295ms, T 2=40ms), and prostate (T 1=1700ms, T 2=80ms). The relaxation times allowed the segmentation-classification of fat, prostate, muscle, and air, and combined with anatomical knowledge, they allowed classification of bone. The good segmentation-classification of prostate [mean Dice similarity score (mDSC)=0.70] suggests a viable implementation in oncology and that of fat (mDSC=0.99), muscle (mDSC=0.99), and bone (mDSCs=0.78) advocates for its implementation in PET/MR attenuation correction. Our method allows the segmentation and classification of the attenuation-relevant structures required for the generation of the attenuation map of PET/MR systems in prostate imaging: air, background, bone, fat, muscle, and prostate.