Abnormal Regional Spontaneous Neural Activity in Nonarteritic Anterior Ischemic Optic Neuropathy: A Resting-State Functional MRI Study.

Objective: To explore altered regional neuronal activity in patients with nonarteritic anterior ischemic optic neuropathy (NAION) and its correlation with clinical performances using the regional homogeneity (ReHo) method, which is based on resting-state functional magnetic resonance imaging (fMRI). Method: Thirty-one patients with NAION (20 males, 11 females) and 31 age- and sex-matched normal controls (NCs) (20 males, 11 females) were enrolled in the study. All patients underwent ophthalmic examination, including eyesight, intraocular pressure measurement, optimal coherence tomography (OCT), visual field analysis, and fMRI scans. After ReHo was calculated, we investigated group differences in results between the patients and NCs. We analyzed the relationship between ReHo values for different brain regions in patients with NAION and intraocular pressure, visual field analysis, and OCT. A receiver operating characteristic (ROC) curve was used to assess the diagnostic ability of the ReHo method. Results: Compared with NCs, patients with NAION exhibited higher ReHo values in the left middle frontal gyrus, left middle cingulate gyrus, left superior temporal gyrus, and left inferior parietal lobule. Additionally, they exhibited lower ReHo values in the right lingual gyrus, left putamen/lentiform nucleus, and left superior parietal lobule. ReHo values in the left superior parietal lobule were negatively correlated with right retinal nerve fiber layer values (r = -0.462, P = 0.01). The area under the ROC curve for each brain region indicated that the ReHo method is a credible means of diagnosing patient with NAION. Conclusion: NAION was primarily associated with dysfunction in the default mode network, which may reflect its underlying neural mechanisms.

Prediction of the response of ocular adnexal lymphoma to chemotherapy using combined pretreatment dynamic contrast-enhanced and diffusion-weighted MRI.

Background There are no established biomarkers predictive of the efficacy of treatment for ocular adnexal lymphoma (OAL). Purpose To evaluate the effectiveness of pretreatment dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) in predicting the response of OAL to chemotherapy. Material and Methods Twenty-one patients, who were pathologically diagnosed with OAL, were retrospectively analyzed. According to the National Comprehensive Cancer Network (NCCN) response evaluation criteria for non-Hodgkin's lymphoma, patients were divided into responders (n = 14) and non-responders (n = 7). The volume transfer constant (Ktrans), rate constant (Kep), extracellular extravascular volume fraction (Ve), and apparent diffusion coefficient (ADC) were computed. Two independent-sample tests were applied for statistical analysis. For significantly different parameters, receiver-operator characteristics curve analysis was performed. Results The Ktrans value (min-1), Kep value (min-1), and ADC value (10-3 mm2/s) were 0.76 ± 0.36 vs. 0.47 ± 0.18 (mean ± SD), 4.43 ± 1.29 vs. 3.14 ± 1.37, and 0.51 ± 0.12 vs. 0.66 ± 0.15, respectively, in the responders and non-responders groups. Significant differences were found between the two groups regarding these parameters ( P < 0.05). However, no significant difference was observed in Ve (min-1) between the groups ( P > 0.05). Ktrans, Kep, and ADC had a moderately predictive sensitivity or specificity. When Ktrans and ADC or the three parameters were combined, a considerably higher sensitivity (85.7%) and specificity (85.7%) with a significant discriminative accuracy (area under the curve = 0.929; P = 0.002) was found. Conclusion Ktrans, Kep, and ADC could potentially predict OAL response to chemotherapy. A combination of these DWI and DCE-MRI quantitative parameters might increase sensitivity and specificity.

[Clinical application of internal carotid artery occlusion].

OBJECTIVE: To evaluate the efficiency of the internal carotid artery (ICA) occlusion in treatment of head and neck diseases. METHODS: To retrospectively analyze 28 cases related with the ICA. According to the result of balloon test occlusion (BTO) and cerebral angiogram, the balloon, spring coil or glue were used to block the fistula or haemorrhage, sometimes even to embolism the related ICA. RESULTS: Twenty-six cases and 2 cases presented negative and positive in total 28 cases in BTO. Of the 26 patients, 22 were succeed in ICA occlusion. The clinical symptoms disappeared in some patients, and the others had the related tumor or foreign body being resected. Two cases (glomus jugulare tumors and intractable epistaxis after Juvenile nasopharyngeal angiofibroma surgery in 1 case respectively) presented delayed cerebral infarction. With the thrombolysis anticoagulant therapy, the clinical symptoms in the former disappeared and in the later reduced. The balloon was let out in 1 case with the embolism the distal middle cerebral artery branches. However, the patient did not show any symptoms during the operation and observation period. One case with intractable epistaxis in nasopharygeal cancer after radiotherapy was dead. In emergency, the left ICA was blocked, then bleeding reduced with the left hemisphere presented extensive cerebral embolism. However, he died in nasal bleeding in three days. CONCLUSIONS: ICA occlusion was an efficient method to save the life. Moreover, the patient's tolerance and collateral circulation should be evaluated in detail before the operation.

[Features of clinical presentation, pathology and magnetic resonance or computed tomography imaging for ocular lymphoma].

OBJECTIVE: To explore the distribution and magnetic resonance imaging or computed tomography (MRI/CT) of lymphoma in orbit. METHODS: Retrospective analyses were conducted for 73 cases with ocular complaints at Beijing Tong'ren Hospital from June 2006 to September 2012. They were confirmed pathologically as lymphoma with complete MRI/CT records. RESULTS: Ocular adnexal lymphoma occurred predominantly in adults. There were 47 males and 26 females with a median age of (60 ± 12.0) years. The lesions were bilateral (n = 24), right side (n = 23) and left side (n = 26) respectively. The pathological types included mucosa-associated lymphoid tissue (MALT) lymphoma (n = 59), diffuse large B-cell lymphoma (DLBCL, n = 7), mantle cell lymphoma (MCL, n = 3), lymphoplasmacytic lymphoma (LPL, n = 2) and follicular lymphoma and natural killer/T-cell lymphoma (FL and NKT, n = 1) respectively. They had well-defined margins in 64 sides, less well-defined margins in 17 sides and ill-defined margins in 16 sides. And 29 sides of lesions presented as a regional mass within conjunctiva in 16/97 sides (16.5%), lacrimal gland in 5/97 sides (5.2%), eyelids in 3/97 sides (3.1%), ocular muscle in 2/97 sides (2.1%) and lacrimal sac in 3/97 sides (3.1%). Moreover, 68 sides of lesion were diffusely distributed. The invaded sites included preseptal region in 38/97 sides (39.2%), extraconal compartment in 69/97 sides (71.1%), intraconal compartment in 54/97 sides (55.7%), eyeball region in 45/97 sides (46.4%), subperiosteum in 14/97 sides (14.4%), cone compartment in 73/97 sides (75.3%), lacrimal gland in 38/97 sides (39.2%) and sheath of optic nerve in 33/97 sides (34.0%). And, on MRI scan, 70 cases (94 sides) had isointensity in 88/94 sides, hypointensity in 6/94 sides on T1WI and isointensity in 52/94 sides, mild hypointensity in 40/94 sides or mixed signal in 2/94 sides on T2WI. In addition, the signals were homogeneous in 67/94 sides and heterogeneous in 27/94 sides. After contrasting, these lesions showed mild contrast-enhancement (CE) in 27/94 sides, moderate CE in 67/94 sides with homogeneous CE in 52/94 sides and heterogeneous CE in 42/94 sides. On CT scan, 21 cases (24 sides) had isodensity in 18/24 sides and mild hyperdensity in 6/24 sides with homogeneous in 7/24 sides and heterogeneous in 17/24 sides. Moreover, most adjacent bone show no change (16/24 sides). Only 16/24 sides and 2/24 sides showed reformation or destruction respectively. At the same time, the lesions also involved other para-orbit structures, such as orbital apex (27/97 sides, 27.8%), fissure orbitalis inferior (14/97 sides, 14.4%), fossa pterygopalatina (10/97 sides, 10.3%), supraorbital nerve (8/97 sides, 8.2%), cavernous sinus (8/97 sides, 8.2%) and facial soft tissue (6/97 sides, 6.2%), et al. CONCLUSION: Ocular adnexal lymphoma occurs predominantly in male adults. And multiple strictures and sites are often involved. There is iso-/mild hyperintensity with mild-to-moderate homo-/heterogeneous CE and little change of adjacent bone on T1WI and T2WI.

Altered small-world and disrupted topological properties of functional connectivity networks in patients with nonarteritic anterior ischemic optic neuropathy.

BACKGROUND: Nonarteritic anterior ischemic optic neuropathy (NAION) is a disease of the optic nerve, but its effect on brain network topology is still unclear.This study aimed to investigate brain network alterations in NAION patients and to explore their relationship with functional impairment. METHODS: Resting-state functional MRI data were collected from 23 NAION patients and 23 matched healthy control subjects.We used graph theory analysis to investigate the global and nodal network topological properties,and network-based statistical (NBS) methods were used to explore intergroup differences in functional connectivity (FC) strength. RESULTS: Compared to the control group, NAION patients had lower global efficiency, normalized clustering coefficient and small-world values and higher characteristic path length (P < 0.05). In the hub distributions of functional networks, the NAION group had one hub region disappearing and four hub regions appearing in nodal degree centrality (Dc), and two hubs disappearing and one hub region appearing in nodal betweenness centrality (Bc). The NAION group also had enhanced brain FC primarily associated with the frontal, prefrontal, parietal lobes and cerebellum. Furthermore, the right temporal pole, superior temporal gyrus (r = -0.424), the right inferior temporal gyrus (r = -0.414), the right cerebellar lobule Ⅵ (r = 0.450), and the left cerebellar lobule crus Ⅰ (r = 0.584) were significantly correlated with clinical severity. CONCLUSION: NAION patients show disruption and redistribution of FC in specific regions of the brain network, which may be associated with visual impairment.

Altered functional connectivity of the default mode network in non-arteritic anterior ischaemic optic neuropathy.

The functional connectivity of the default mode network is important in understanding the neuro-pathophysiological abnormalities in patients with non-arteritic anterior ischaemic optic neuropathy. Independent component analysis can effectively determine within and between network connectivity of different brain components. Therefore, in order to explore the association between the default mode network and other brain regions, we utilized independent component analysis to investigate the alteration of functional connectivity of the default mode network. Thirty-one patients with non-arteritic anterior ischaemic optic neuropathy and 31 healthy controls, matched for age, sex and years of education, were recruited. For patients and healthy controls, functional connectivity within and between the default mode network and other brain regions were evaluated by independent component analysis. Compared with healthy controls, patients with non-arteritic anterior ischaemic optic neuropathy showed reduced functional connectivity within the default mode network in the right cerebellar tonsil and left cerebellum posterior lobe and increased functional connectivity in the left inferior temporal and right middle frontal gyri. Furthermore, patients with non-arteritic anterior ischaemic optic neuropathy showed reduced functional connectivity between the default mode network and other brain regions in the left cerebellar tonsil and increased functional connectivity in the right putamen, left thalamus, right middle temporal and left middle frontal gyri. In conclusion, negative correlations between several clinical parameters and functional connectivity of the default mode network were observed. The study contributes to understanding the mechanism of functional reorganization in non-arteritic anterior ischaemic optic neuropathy.

Altered Brain Functional Connectivity at Resting-State in Patients With Non-arteritic Anterior Ischemic Optic Neuropathy.

Purpose: To investigate the possible changes in functional connectivity (FC) in patients with non-arteritic anterior ischemic optic neuropathy (NAION) using resting-state functional MRI (fMRI). Methods: Thirty-one NAION patients and 31 healthy controls were recruited and underwent resting-state fMRI scans. Regions of interest (ROIs) were defined as bilateral Brodmann's area 17 (BA17). FC analysis was performed between the ROIs and the rest of the brain regions, and the between group comparisons of FC were performed. We conducted correlation analysis between the FC changes and the clinical variables in NAION patients. Results: Compared with healthy controls, patients with NAION showed significantly decreased FC between the left BA17 and the right inferior frontal gyrus, left caudate nucleus. As for the right BA17, patients exhibited significantly increased FC with the left olfactory gyrus and decreased FC with the right superior frontal gyrus (SFG), right insula. Moreover, FC values between the right insula and the right BA17 were positively correlated with the right side of mean sensitivity in the central visual field (r = 0.52, P < 0.01) and negatively correlated with the right side of mean defect in the central visual field (r = -0.55, P < 0.01). Conclusion: Our study indicated that patients with NAION showed significantly abnormal functional reorganization between the primary visual cortex and several other brain regions not directly related to visual function, which supports that NAION may not only be an ophthalmic disease but also a neuro-ophthalmological disease.

Imaging and histopathological findings of lacrimal sac lymphoma.

BACKGROUND: Lymphoma of the lacrimal sac is rare, often misdiagnosed clinically. This study aimed to investigate the imaging features of these tumors and provide suggestions to aid the diagnosis. METHODS: In this retrospective study, five cases were assessed according to magnetic resonance imaging (MRI), computed tomography (CT), and pathological findings. All five patients underwent MRI and contrast-enhanced T1-weighted imaging (CE-T1WI), of which four patients underwent dynamic contrast-enhanced (DCE) MRI and three patients underwent CT. RESULTS: Four cases and one case had a lymphoma in left and right medial canthus, respectively. Soft tissue surrounding the eyelids, subcutaneous tissue in the nasal dorsum, and involvement of the entire nasolacrimal canal were demonstrated in all five lesions. In two cases, the mass invaded the extraconal space. In one case, the mass invaded the adjacent medial rectus muscle and nasal area. Well-defined margins were observed in three cases and ill-defined margins in two cases. All cases showed homogeneous isointense lesions on T1WI. Four cases showed homogeneous isointensity and one case demonstrated heterogeneous isointensity on T2WI. After contrast injection, the lesion showed slight homogeneous isointensity and moderate enhancement in four cases and heterogeneous isointensity and moderate enhancement in one case. In the four patients who underwent DCE-MRI, a plateau pattern was revealed in three cases and washout pattern in one case. In the three cases who underwent CT, two cases had isointense and one case had hyperintense lesions. The lacrimal duct was remodeled and the surrounding bone compressed. CONCLUSIONS: Tumors of the lacrimal sac showed homogeneous and isointense patterns on T1WI and T2WI with mildto- moderate enhancement and a plateau pattern on DCE-MRI. CT showed remodeling of the lacrimal duct with bone compression.