Elevated glutamate impedes anti-HIV-1 CD8 + T cell responses in HIV-1-infected individuals on antiretroviral therapy.

CD8 + T cells are essential for long-lasting HIV-1 control and have been harnessed to develop therapeutic and preventive approaches for people living with HIV-1 (PLWH). HIV-1 infection induces marked metabolic alterations. However, it is unclear whether these changes affect the anti-HIV function of CD8 + T cells. Here, we show that PLWH exhibit higher levels of plasma glutamate than healthy controls. In PLWH, glutamate levels positively correlate with HIV-1 reservoir and negatively correlate with the anti-HIV function of CD8 + T cells. Single-cell metabolic modeling reveals glutamate metabolism is surprisingly robust in virtual memory CD8 + T cells (TVM). We further confirmed that glutamate inhibits TVM cells function via the mTORC1 pathway in vitro. Our findings reveal an association between metabolic plasticity and CD8 + T cell-mediated HIV control, suggesting that glutamate metabolism can be exploited as a therapeutic target for the reversion of anti-HIV CD8 + T cell function in PLWH.

CCL5-Secreting Virtual Memory CD8+ T Cells Inversely Associate With Viral Reservoir Size in HIV-1-Infected Individuals on Antiretroviral Therapy.

Recent studies highlighted that CD8+ T cells are necessary for restraining reservoir in HIV-1-infected individuals who undergo antiretroviral therapy (ART), whereas the underlying cellular and molecular mechanisms remain largely unknown. Here, we enrolled 60 virologically suppressed HIV-1-infected individuals, to assess the correlations of the effector molecules and phenotypic subsets of CD8+ T cells with HIV-1 DNA and cell-associated unspliced RNA (CA usRNA). We found that the levels of HIV-1 DNA and usRNA correlated positively with the percentage of CCL4+CCL5- CD8+ central memory cells (TCM) while negatively with CCL4-CCL5+ CD8+ terminally differentiated effector memory cells (TEMRA). Moreover, a virtual memory CD8+ T cell (TVM) subset was enriched in CCL4-CCL5+ TEMRA cells and phenotypically distinctive from CCL4+ TCM subset, supported by single-cell RNA-Seq data. Specifically, TVM cells showed superior cytotoxicity potentially driven by T-bet and RUNX3, while CCL4+ TCM subset displayed a suppressive phenotype dominated by JUNB and CREM. In viral inhibition assays, TVM cells inhibited HIV-1 reactivation more effectively than non-TVM CD8+ T cells, which was dependent on CCL5 secretion. Our study highlights CCL5-secreting TVM cells subset as a potential determinant of HIV-1 reservoir size. This might be helpful to design CD8+ T cell-based therapeutic strategies for cure of the disease.

The Detection of Invisible Abnormal Metabolism in the FDG-PET Images of Patients With Anti-LGI1 Encephalitis by Machine Learning.

Objective: This study aims to detect the invisible metabolic abnormality in PET images of patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis using a multivariate cross-classification method. Methods: Participants were divided into two groups, namely, the training cohort and the testing cohort. The training cohort included 17 healthy participants and 17 patients with anti-LGI1 encephalitis whose metabolic abnormality was able to be visibly detected in both the medial temporal lobe and the basal ganglia in their PET images [completely detectable (CD) patients]. The testing cohort included another 16 healthy participants and 16 patients with anti-LGI1 encephalitis whose metabolic abnormality was not able to be visibly detected in the medial temporal lobe and the basal ganglia in their PET images [non-completely detectable (non-CD) patients]. Independent component analysis (ICA) was used to extract features and reduce dimensions. A logistic regression model was constructed to identify the non-CD patients. Results: For the testing cohort, the accuracy of classification was 90.63% with 13 out of 16 non-CD patients identified and all healthy participants distinguished from non-CD patients. The patterns of PET signal changes resulting from metabolic abnormalities related to anti-LGI1 encephalitis were similar for CD patients and non-CD patients. Conclusion: This study demonstrated that multivariate cross-classification combined with ICA could improve, to some degree, the detection of invisible abnormal metabolism in the PET images of patients with anti-LGI1 encephalitis. More importantly, the invisible metabolic abnormality in the PET images of non-CD patients showed patterns that were similar to those seen in CD patients.

The Impacts of Obstructive Sleep Apnea Severity on Brain White Matter Integrity and Cognitive Functions in Children: A Diffusion Tensor Imaging Study.

OBJECTIVE: To investigate the impacts of obstructive sleep apnea (OSA) on white matter (WM) integrity and cognitive functions of pediatric patients with different levels of OSA severity. METHODS: Fifty-eight children with OSA and thirty-four healthy controls (HC) were recruited. All participants underwent diffusion tensor imaging (DTI) examination, polysomnography (PSG), and neurocognitive assessments. Patients were divided into mild OSA (MG) and moderate-severe OSA (SG) groups. WM integrity, PSG data, and neurocognitive assessment scores were compared among those groups. RESULTS: For apnea hypopnea index (AHI), obstructive apnea hypopnea index (OAHI), arousal index, SpO2 nadir, and attention, SG was worse than both MG and HC with MG worse than HC. For baseline SpO2 and intelligence, SG was worse than both MG and HC with no significant difference between MG and HC. Impaired WM integrity was observed in bilateral anterior thalamic radiation, bilateral inferior fronto-occipital fasciculus, bilateral inferior longitudinal fasciculus, right superior longitudinal fasciculus, right hippocampus, left cingulate gyrus, right uncinate fasciculus, callosum forceps major, and callosum forceps minor only for SG than for HC. WM integrity was significantly correlated with OSA severity and neurocognitive assessment scores only for SG, but not for MG. CONCLUSION: Decreased baseline SpO2, WM impairment, and intelligence decline were all observed only for SG, but not for MG, implying an associated relationship among decreased SpO2, WM impairment and WM impairment. Thus, for SG, additional assessments of brain damage and cognitive function decline are needed for prognostic evaluation of OSA.

Identification of a Transcriptionally Forward α Gene and Two υ Genes within the Pigeon (Columba livia) IgH Gene Locus.

Compared with mammals, the bird Ig genetic system relies on gene conversion to create an Ab repertoire, with inversion of the IgA-encoding gene and very few cases of Ig subclass diversification. Although gene conversion has been studied intensively, class-switch recombination, a mechanism by which the IgH C region is exchanged, has rarely been investigated in birds. In this study, based on the published genome of pigeon (Columba livia) and high-throughput transcriptome sequencing of immune-related tissues, we identified a transcriptionally forward α gene and found that the pigeon IgH gene locus is arranged as µ-α-υ1-υ2. In this article, we show that both DNA deletion and inversion may result from IgA and IgY class switching, and similar junction patterns were observed for both types of class-switch recombination. We also identified two subclasses of υ genes in pigeon, which share low sequence identity. Phylogenetic analysis suggests that divergence of the two pigeon υ genes occurred during the early stage of bird evolution. The data obtained in this study provide new insight into class-switch recombination and Ig gene evolution in birds.

Two-dimensional frameworks formed by pentagonal bipyramidal cobalt(ii) ions and hexacyanometallates: antiferromagnetic ordering, metamagnetism and slow magnetic relaxation.

We herein report the syntheses, structures, and magnetic properties of two isostructural two-dimensional (2D) coordination polymers based on a pentagonal bipyramidal CoII unit [Co(TODA)]2+ and two hexacyanometallates, namely [MIII(CN)6]2[CoII(TODA)]3·9H2O (M = Cr (1), Co (2), TODA = 1,4,10-trioxa-7,13-diazacyclopentadecane). Structure analyses show that both complexes have 2D honeycomb structures where the [Co(TODA)]2+ units are bridged by the [MIII(CN)6]3- groups through three cyano groups in the facial positions. Magnetic investigation reveals ferromagnetic coupling between the CrIII and CoII centres through cyanides in 1. Due to the antiferromagnetic interaction between the layers, compound 1 exhibits an antiferromagnetic ordering below 11.4 K, and shows a metamagnetic phase transition under an external dc field. Due to the disorder of the TODA ligands, compound 1 shows a spin glass behavior, which leads to slow magnetic relaxation in 1. A butterfly-shaped hysteresis loop at 1.8 K can be observed with a coercive field of 720 Oe, which is quite large for cyano-bridged Cr-Co molecular magnets. For compound 2 containing the diamagnetic [CoIII(CN)6]3- unit, field-induced slow magnetic relaxation was also verified, which makes compound 2 a rare example of an SIM assembled in a 2D network. An easy-plane magnetic anisotropy with a positive D value (29.9 cm-1 by PHI and 26.5 cm-1 by Anisofit2.0) was deduced for hepta-coordinated CoII centers. These results show the efficiency of the strategy of combining cyanometallates and pentagonal bipyramidal precursors for novel molecular magnetic materials.

[Correlation between Fractional Anisotropy and Amyotrophic Lateral Sclerosis, and Effect of Inte- grative Medical Treatment on ALS].

OBJECTIVE: To explore whether fractional anisotropy (FA) value could be taken as a quantitative indicator for tracing and reexamining amyotrophic lateral sclerosis (ALS), and to analyze the correlation between FA value and integrative medical treatment. METHODS: Totally 18 ALS patients were recruited in this study. All patients received diffusion tensor imaging (DTI) using 3. OT (Propeller HD) MRI twice. Six regions of interest (ROI) were selected to measure FA values. Survival analyses were performed in 11 cases of end point events. RESULTS: (1) Three ROI (cerebral peduncle, posterior limb of internal capsule, and corona radiata) all indicated that FA value was the highest in patients with mild health status scale of amyotrophic lateral sclerosis (ALS/HSS). (2) There was statistical difference in the means of FA values in cerebral peduncle, posterior limb of internal capsule, and corona radiata of 18 cases between initial examination and reexamination (P < 0.01). (3) Kaplan-Meier survival curve showed the survival rate of ALS patients decreased as time went by, with the median survival time of 48 months. CONCLUSIONS: FA value was inversely proportional to the severity of ALS, the more severe, the lower FA values. FA value was an objective indicator for assessing the severity of ALS. ALS is an incurable disease till now. Integrative medical treatment might become one direction for ALS patients.

Diffusion Weighted Imaging, Diffusion Tensor Imaging, and T2* Mapping of Lumbar Intervertebral Disc in Young Healthy Adults.

BACKGROUND: Although conventional magnetic resonance imaging (MRI) could provide excellent detection of morphological changes in the diagnosis of lumbar disc degeneration (LDD), it has some difficulties in discriminating minimal changes associated with early LDD before morphological or clinical alterations. Therefore, newer MRI techniques have emerged for investigation of early LDD. OBJECTIVES: The aim of this study was to use diffusion weighted imaging (DWI), diffusion Tensor Imaging (DTI) and T2* mapping to detect lumbar discs in healthy young adults, to evaluate if they could depict the microstructural changes of early LDD. PATIENTS AND METHODS: Apparent diffusion coefficient (ADC), fractional anisotropy (FA), and T2* images of the lumbar discs were obtained for 40 asymptomatic young subjects (19 males and 21 females; mean age of 24.3 years), using DWI, DTI and T2* mapping with a 1.5-T MRI scanner. ADC, FA, and T2* values were measured to compare five regions of interest (ROI) selected in each nucleus pulposus (NP) of the images. RESULTS: The ADC, FA, and T2* values were different (P < 0.05) among different ROIs within the same disc or among corresponding ROIs in different level discs. While the average values of ADC increased regularly with the lowering of the anatomical location (P < 0.05), the average FA and T2* values also associated with the anatomic locations, showed an increase in L4-L5 and L5-S1 discs (P < 0.05). CONCLUSION: ADC, FA, and T2* values may quantitatively reflect the microstructural characteristics of NP, therefore they could be used to detect the minimal changes of early LDD.

Role of quantitative intravoxel incoherent motion parameters in the preoperative diagnosis of nodal metastasis in patients with rectal carcinoma.

PURPOSE: To evaluate the diagnostic value of intravoxel incoherent motion imaging (IVIM) in differentiating metastatic and nonmetastatic lymph nodes in patients with rectal carcinoma. MATERIALS AND METHODS: In all, 68 patients with histologically proven rectal carcinoma underwent an IVIM sequence (b = 0, 25, 50, 75, 100, 150, 200, 400, 600, 800, 1000, 1200, 1500, and 2000 s/mm(2) ) on a 3.0T MRI scanner. The IVIM parameters (D, D*, f, and apparent diffusion coefficient [ADC] values) in metastatic and nonmetastatic lymph nodes were measured and calculated. Receiver-operating characteristic (ROC) analyses were conducted to determine the optimal thresholds, the sensitivities, and specificities for differentiation. RESULTS: Mean D, f, and ADC values of metastatic lymph nodes were significantly greater than those of the normal lymph nodes (P < 0.01), whereas the mean D* value of metastatic lymph node was statistically lower (P = 0.03). The AUC, sensitivity, specificity, and the cutoff value, respectively, for differentiating metastatic from nonmetastatic lymph nodes for D, D*, f, and ADC were as follows: D, 0.9460, 89.25%, 91.04%, and 1.14 × 10(-3) mm(2) /s; D*, 0.6930, 64.18%, 82.80%, and 7.02 × 10(-3) mm(2) /s; f, 0.7810, 92.47%, 55.22%, and 0.27%; ADC, 0.8970, 87.10%, 88.06%, and 0.80 × 10(-3) mm(2) /s. The ROC curves demonstrated that the area under the ROC (AUC) of the D, ADC, f, and D* values successively decreased, and D had the highest AUC, with D* values being lowest. CONCLUSION: An IVIM sequence may be helpful in diagnosing metastatic lymph nodes of rectal carcinoma. Average D and ADC values are more sensitive than f and D* values in this differentiation. J. MAGN. RESON. IMAGING 2016;44:1031-1039.

Correlation between Fractional Anisotropy and Amyotrophic Lateral Sclerosis, and Effect of Inte- grative Medical Treatment on ALS / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore whether fractional anisotropy (FA) value could be taken as a quantitative indicator for tracing and reexamining amyotrophic lateral sclerosis (ALS), and to analyze the correlation between FA value and integrative medical treatment.</p><p><b>METHODS</b>Totally 18 ALS patients were recruited in this study. All patients received diffusion tensor imaging (DTI) using 3. OT (Propeller HD) MRI twice. Six regions of interest (ROI) were selected to measure FA values. Survival analyses were performed in 11 cases of end point events.</p><p><b>RESULTS</b>(1) Three ROI (cerebral peduncle, posterior limb of internal capsule, and corona radiata) all indicated that FA value was the highest in patients with mild health status scale of amyotrophic lateral sclerosis (ALS/HSS). (2) There was statistical difference in the means of FA values in cerebral peduncle, posterior limb of internal capsule, and corona radiata of 18 cases between initial examination and reexamination (P < 0.01). (3) Kaplan-Meier survival curve showed the survival rate of ALS patients decreased as time went by, with the median survival time of 48 months.</p><p><b>CONCLUSIONS</b>FA value was inversely proportional to the severity of ALS, the more severe, the lower FA values. FA value was an objective indicator for assessing the severity of ALS. ALS is an incurable disease till now. Integrative medical treatment might become one direction for ALS patients.</p>

Assessment of levator ani morphology and function in asymptomatic nulliparous women via static and dynamic magnetic resonance imaging.

OBJECTIVE: To evaluate levator ani morphology and function in healthy nulliparous women using static and dynamic magnetic resonance imaging. METHODS: Eighty asymptomatic, healthy nulliparous Chinese women (mean age, 25.3±3.5years) volunteered for the present study. Static T2-weighted fast spin-echo images were employed to evaluate levator ani morphology; dynamic T2-weighted fast imaging employing steady-state acquisition was used to evaluate its function. A 2 samples t test was employed to compare groups. RESULTS: No morphologic abnormality was detected in the 80 healthy nulliparous women. However, 15% (12/80) of women had various degrees of pelvic organ descent below the pubococcygeal line. In these women, the width of the pubic portion of the levator ani was significantly reduced during straining, whereas the levator plate angle, the levator hiatus area, and the H and M line lengths were enlarged. These changes were associated with weakened levator ani function and pelvic floor laxity. CONCLUSION: Functional abnormality of the levator ani muscle was noted in nulliparous women at static and dynamic magnetic resonance imaging. Further follow-up investigation is needed to confirm whether women with functional abnormality are more likely to develop a prolapse after vaginal birth.

Dissociated brain organization for two-digit addition and subtraction: an fMRI investigation.

The present study compared the patterns of brain activation elicited by two-digit addition and subtraction problems. Thirty-two Chinese undergraduates of the same educational background and of similar age were asked to assess whether arithmetic operations were true or false during functional magnetic resonance imaging. Results showed that both complex addition and subtraction were supported by the broad neural system that involved regions within the inferior parietal lobule, the precuneus, and the inferior occipital gyrus, as well as some subcortical structures. Nevertheless, complex problems involving addition elicited more activation mainly in the bilateral medial frontal gyrus, whereas problems involving subtraction had more activation in the precentral gyrus and the thalamus in the right hemisphere, as well as the inferior parietal lobule in the left hemisphere. This pattern of dissociated activation suggests that partially separate neuronal networks might support these different operations. It also suggests that complex addition has a greater reliance on the fronto-parietal cortical circuit and subtraction on the parieto-subcortical circuit.

Emergency response and medical rescue in the worst hit Mianyang areas after the Wenchuan earthquake.

The 12 May 2008 earthquake caused damage to 88% of the health systems in the worst hit areas of Mianyang with 326 casualties and the direct economic loss of RMB 3124 billion. Within 30 minutes of the earthquake, the Mianyang headquarters for earthquake disaster relief and the Mianyang public health headquarters for medical rescue and treatment were organized. Five medical teams were sent to Beichuang County, the worst hit Mianyang area, four hours after the earthquake. A total of 22,947 wounded and sick people were delivered to local hospitals after simple triage and rapid treatment through three stations. By 30 June, the Mianyang medical organization had received 379,600 people and admitted 21,628 inpatients. These 2772 severely wounded (including 146 with limbs amputated and 846 who died in hospital). Since 17 May, 3381 wounded had been transferred to 14 provincial and city-level hospitals across China. On 20 June, the Mianyang Rehabilitation Center for wounded and sick people was established and received 156 rehabilitation inpatients. Together with the medical team for psychological intervention, they provided psychological support for over 70,000 people. Within two hours of the earthquake, the Mianyang Organization for Health and Epidemic Control and Prevention launched the emergency response plan for major natural disasters. The organization sent emergency teams for disease prevention and control and completed disinfection and burial of corpses and disposal of carcasses, monitoring of water quality and epidemics, disinfection of environmental ruins, epidemic control in resettled areas, precautions against secondary disasters caused by the earthquake, and large-scale health education. The emergency command system for medical rescue and disease control and prevention in the Mianyang areas integrated resources, carried out unified command, and responded rapidly. Furthermore, the headquarters of medical relief co-ordinated and united the governmental and nongovernmental organizations, achieving good performance for both medical relief and epidemic control. This experience of earthquake medical relief will benefit post-disaster reconstruction, as well as the establishment of national and regional emergency response systems.

[Effects of acupuncture on the cortical functional areas activated by index finger motion in the patient with ischemic stroke].

OBJECTIVE: To observe the effect of acupuncture on cortical functional areas of the patient with ischemic stroke activated by the index finger motion. METHODS: The cortical magnetic resonance imaging (fMRI) were carried out in 15 cases of ischemic stroke during the index finger motion at acupuncture or non-acupuncture. The distribution of the cortical functional areas activated and the size of the activated region and the intension of signals were measured. RESULTS: The finger motion with no acupuncture could activate the contralateral primary somatomotor area (M1), contralateral premotor area (PMA) and contralateral first somatosensory area (S1). The finger motion with acupuncture could activate the same areas and also activate ipsilateral M1, focus area contralateral superior parietal lobule, contralateral superior temporal gyrus, and contralateral insular lobe, etc.. Both the area of the activated region and the minimum signal in the finger motion with acupuncture were statistically significantly larger than those in finger motion with no acupuncture. CONCLUSION: Rehabilitation of motor functions of the patient with ischemic stroke by acupuncture is related with improvement of blood circulation functional area in the cortex.

Effects of acupuncture on the cortical functional areas activated by index finger motion in the patient with ischemic stroke / 中国针灸

<p><b>OBJECTIVE</b>To observe the effect of acupuncture on cortical functional areas of the patient with ischemic stroke activated by the index finger motion.</p><p><b>METHODS</b>The cortical magnetic resonance imaging (fMRI) were carried out in 15 cases of ischemic stroke during the index finger motion at acupuncture or non-acupuncture. The distribution of the cortical functional areas activated and the size of the activated region and the intension of signals were measured.</p><p><b>RESULTS</b>The finger motion with no acupuncture could activate the contralateral primary somatomotor area (M1), contralateral premotor area (PMA) and contralateral first somatosensory area (S1). The finger motion with acupuncture could activate the same areas and also activate ipsilateral M1, focus area contralateral superior parietal lobule, contralateral superior temporal gyrus, and contralateral insular lobe, etc.. Both the area of the activated region and the minimum signal in the finger motion with acupuncture were statistically significantly larger than those in finger motion with no acupuncture.</p><p><b>CONCLUSION</b>Rehabilitation of motor functions of the patient with ischemic stroke by acupuncture is related with improvement of blood circulation functional area in the cortex.</p>

[Comparative study of barium enema, computed tomography and magnetic resonance imaging in preoperative diagnosis of colorectal carcinoma].

OBJECTIVE: To compare the diagnostic value of barium enema (BE), computed tomography (CT) and magnetic resonance imaging(MRI) in primary colorectal carcinoma. METHODS: A total of 64 patients with suspected colorectal carcinoma received BE (n=39), spiral CT (n=31) and MRI (n=42). The detective results were compared with the surgical results. RESULTS: Among 64 patients, 54 cases were pathologically proved as colorectal carcinoma. The diagnostic sensitivity of BE,CT and MRI was 96.9% ,96.2% and 97.1% ,and the overall accuracy was 92.3% 83.9 % and 90.5% respectively. The overall accuracy of CT and MRI for tumor T staging was 73.1% and 82.9% respectively. CONCLUSION: BE can be considered as a primary approach for diagnosing colorectal carcinoma, CT and MRI be necessary diagnostic approaches. Combined BE with MRI is the best choice for diagnosing of colorectal carcinoma.

A sequence investigation on Wallerian degeneration after pontine infarction with diffusion tensor imaging / 中华神经科杂志

Objective To investigate the Wallerian degeneration of neural fiber tract in medulla and bilateral middle cerebellar peduncle following pontine infarction and to explore its impacts on neurological recovery.Methods Fourteen patients with a recent unilateral pontine infarct underwent the diffusion tensor imaging(DTI)and evaluations with the NIH stroke scale(NIHSS),the Fugl-Meyer motor scale(FM), ataxia rating scale(ARS)and the Barthel index(BI)at the first week(W1),the fourth(W4)and twelfth week(W12)respectively.Mean diffusivity(MD)and fractional anisotropy(FA)were measured at pons, medulla and middle cerebellar peduncle.Fourteenth age and gender matched volunteers underwent a DTI were studied as controls.Results Compared with the matched regions in controls,the FA values of infarct side medulla and bilateral middle cerebellar peduncle in patients significantly decreased at W1,W4 and W12(on the infarct side of medulla:W1:0.43?0.01;W4:0.37?0.02;W12:0.30?0.02;on the infarct side of middle cerebellar peduncle:W1:0.50?0.01;W4:0.43?0.02;W12:0.35?0.04;on the opposite side of middle cerebellar peduncle infarction:W1:0.54?0.02;W4:0.52?0.03;W12:0.47?0.04,t values are 1.92 to 28.56,P0.05 respectively).The absolute value of percent reduction of FA in infarct side medulla and bilateral middle cerebellar peduncle was correlated negatively to the absolute value of percent change of NIHSS and BI score(P

Comparative study of barium enema, computed tomography and magnetic resonance imaging in preoperative diagnosis of colorectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To compare the diagnostic value of barium enema (BE), computed tomography (CT) and magnetic resonance imaging(MRI) in primary colorectal carcinoma.</p><p><b>METHODS</b>A total of 64 patients with suspected colorectal carcinoma received BE (n=39), spiral CT (n=31) and MRI (n=42). The detective results were compared with the surgical results.</p><p><b>RESULTS</b>Among 64 patients, 54 cases were pathologically proved as colorectal carcinoma. The diagnostic sensitivity of BE,CT and MRI was 96.9% ,96.2% and 97.1% ,and the overall accuracy was 92.3% 83.9 % and 90.5% respectively. The overall accuracy of CT and MRI for tumor T staging was 73.1% and 82.9% respectively.</p><p><b>CONCLUSION</b>BE can be considered as a primary approach for diagnosing colorectal carcinoma, CT and MRI be necessary diagnostic approaches. Combined BE with MRI is the best choice for diagnosing of colorectal carcinoma.</p>

Appearance of HR-MR imaging of non-Hodgkin lymphomas of the orbits in extraconal compartment / 中华放射学杂志

Objective To investigate HR-MR imaging characteristics of non-Hodgkin lymphomas (NHL) of the orbits in extraconal compartment. Methods The HR-MR images of 16 patients with NHL of the orbits identified pathologically were retrospectively analyzed. MRI of the orbit at a 1.5 T scanner was performed with 4-cm surface coil, thin slice, suitable bandwidth, small FOV, and large matrix. T1-weighted (before and after i.v. bolus injection of contrast medium) and fast spin-echo T2-weighted sequences were acquired in all patients. All cases were performed with fat suppression techniques. The analyzed criteria of imaging appearance included location, number, size, shape, margins, extension, adjacent structures, and signal intensity of the lesions. Results The lesions in 13 of 16 cases located in anterior part of extraconal compartment, posterior to the orbital septum, and with irregular cast shape. The other 3 patients showed diffuse lesions with infiltration in extraconal compartment and with irregular shape. Eleven lesions had the large volume above 3.0 ml, 4 lesions with medium volume ranging from 1.0 to 3.0 ml, and only one with small volume less than 1.0 ml. 13 cases had a poor-defined margin with infiltration of extraocular muscles, but without mechanical shift of the muscles. 7 patients had infiltration of eyeball, but only 3 cases with exophthalmos. Destruction of orbital bone was evident in 2 cases with diffuse lesions but never in isolated orbital lymphoma. On the T_1-weighted images, the signal intensity of the lymphoma was isointense compared with that of the muscle in all patients. The T_2-weighted fast SE images showed a hyperintense signal in 13 cases and intermediate in 3 cases. All lesions enhanced after intravenous Gd-DTPA administration, 15 cases with homogeneous enhancement, and 10 cases with reliably visible enhancement in the T_1-weighted fat-suppressed sequences. Conclusion Most NHL of the orbits in extraconal compartment have the characteristic findings on HR-MR imaging, including anterior part of extraconal compartment location, posterior to the orbital septum, irregular cast shape, large volume, poor-defined margin with infiltration but without mechanical shift of extraocular muscles, uniform signal characteristics and marked enhancement after injection of contrast medium, and without bony destruction in isolated orbital lymphoma. The understanding of HR-MRI features of orbital NHL in extraconal compartment is very useful for making the differential diagnosis with other orbital diseases.