Imaging features of retinal hemangioblastoma: A case report.

BACKGROUND: Hemangioblastoma typically occurs in the cerebellum, spinal cord, and central nervous system. However, in rare cases, it could occur in the retina or optic nerve. The prevalence of retinal hemangioblastoma is 1 in 73080, and it occurs either alone or as the manifestation of von Hippel Lindau (VHL) disease. Here, we reported a rare case with the imaging features of retinal hemangioblastoma without VHL syndrome, along with the relevant literature review. CASE SUMMARY: A 53-year-old man had progressive swelling, pain and blurred vision in the left eye without obvious inducement for 15 d. Ultrasonography revealed a possible optic nerve head melanoma. Computed tomography (CT) showed punctate calcification on the posterior wall of the left eye ring and small patchy soft tissue density in the posterior part of the eyeball. Magnetic resonance imaging showed slightly hyperintense signal on T1-weighted images and slightly hypointense-to-isointense signal on T2-weighted images at the medial and posterior edges of the left eyeball, a significant enhancement was observed in the contrast-enhanced scans. Positron emission tomography/CT fusion images showed that the glucose metabolism of the lesion was normal. Pathology was consistent with hemangioblastoma. CONCLUSION: Early identification of retinal hemangioblastoma based on imaging features is of great value for its personalized treatment.

Total removal of a large esophageal schwannoma by submucosal tunneling endoscopic resection: A case report and review of literature.

BACKGROUND: Primary schwannoma is a rare submucosal tumor of the esophagus, which is most often benign, and surgery is the only effective treatment. So far, only a few cases have been reported. Herein, we reported a single case diagnosed with primary esophageal schwannoma that was totally removed by submucosal tunneling endoscopic resection (STER). CASE SUMMARY: A 62-year-old man presented to the hospital with a history of resection of a malignant gastric tumor and mild dysphagia. Endoscopic examination revealed a large submucosal elevated lesion in the esophagus 25-30 cm from the incisors. Endoscopic ultrasonography detected a 45 mm × 35 mm × 31 mm hypoechoic lesion; chest computed tomography showed a mass of approximately 55 mm × 35 mm × 29 mm. A preliminary examination showed features suggestive of a stromal tumor. Pathological findings indicated esophageal schwannoma. Next, STER alone was performed to completely resect the mass, and the patient recovered well post-surgery. Afterward, the patient was discharged and showed no tumor recurrence at 33 mo of follow-up. CONCLUSION: Endoscopic resection is still an effective treatment for large esophageal schwannomas (> 30 mm) under meticulous morphological evaluation.

Altered intrinsic brain activity and connectivity in unaffected parents of individuals with autism spectrum disorder: a resting-state fMRI study.

Objectives: Autism spectrum disorder (ASD) is a juvenile onset neurodevelopmental disorder with social impairment and stereotyped behavior as the main symptoms. Unaffected relatives may also exhibit similar ASD features due to genetic factors. Although previous studies have demonstrated atypical brain morphological features as well as task-state brain function abnormalities in unaffected parents with ASD children, it remains unclear the pattern of brain function in the resting state. Methods: A total of 42 unaffected parents of ASD children (pASD) and 39 age-, sex-, and handedness-matched controls were enrolled. Multiple resting-state fMRI (rsfMRI) analyzing methods were applied, including amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), degree centrality (DC), and functional connectivity (FC), to reveal the functional abnormalities of unaffected parents in ASD-related brain regions. Spearman Rho correlation analysis between imaging metric values and the severity of ASD traits were evaluated as well. Results: ALFF, ReHo, and DC methods all revealed abnormal brain regions in the pASD group, such as the left medial orbitofrontal cortex (mOFC) and rectal gyrus (ROI-1), bilateral supplementary motor area (ROI-2), right caudate nucleus head and right amygdala/para-hippocampal gyrus (ROI-3). FC decreasing was observed between ROI-1 and right anterior cingulate cortex (ACC), ROI-2, and bilateral precuneus. FC enhancing was observed between ROI-3 and right anterior cerebellar lobe, left medial temporal gyrus, left superior temporal gyrus, left medial frontal gyrus, left precentral gyrus, right postcentral gyrus in pASD. In addition, ALFF values in ROI-1, DC values in ROI-3 were positively correlated with AQ scores in pASD (ρ 1 = 0.298, P 1 = 0.007; ρ 2 = 0.220, P 2 = 0.040), while FC values between ROI-1 and right ACC were negatively correlated with AQ scores (ρ3 = -0.334, P 3 = 0.002). Conclusion: rsfMRI metrics could be used as biomarkers to reveal the underlying neurobiological feature of ASD for unaffected parents.

[Initial experience of 640-slice CT coronary angiography in pacemaker patients].

OBJECTIVE: To investigate the feasibility and image quality of coronary artery angiography with 640-slice CT system in the pacemaker patients. METHODS: ECG-triggered 640-slice CT coronary angiography was performed in 16 pacemaker patients. Image quality of the fifteen coronary segments and metal-related artifact originating from pacemaker were assessed by two experienced radiologists in consensus. Image quality was assessed using a 4-point grading scale. ECG trigger information was recorded. RESULTS: The rate of available diagnostic images was 99.07% (Grade 1 in 83.64%, Grade 2 in 15.42%, Grade 3 in 0.47% and Grade 4 in 0.47% of patients, respectively). Image quality and the effect of streak artifact were similar between the high heart rate group and low heart rate group (P > 0.05) and between normal pacing group and arrhythmia group (P > 0.05). In coronary MSCT angiography, streak artifact of the pacemaker can render segments of the coronary artery uninterpretable, especially on S1, S2, S3, S4 and S8 segments of the coronary artery. Small shifts in the reconstruction window resulted in significance reduction of streak artifact (χ(2) = 151.818, P < 0.01). CONCLUSIONS: 640-slice gated CT coronary angiography could provide excellent image quality for patients with pacemaker. The streak artifact induced by pacemaker on some segments of the coronary artery could be improved by small shifts in the reconstruction window.

Asymptomatic traumatic rupture of an intracranial dermoid cyst: A case report.

BACKGROUND: Previous studies reported that most of the intracranial dermoid cyst ruptures were spontaneous, and only a few were traumatic, with asymptomatic much rarer than the symptomatic ruptures. Hence, how to deal with the asymptomatic traumatic rupture of intracranial dermoid cyst remains a challenge in the clinic. CASE SUMMARY: A 59-year-old man was accidentally diagnosed with intracranial dermoid cyst through a cranial computed tomography (CT) scan due to a car accident. A mixed-density lesion with fat and a calcified margin was observed in the midline of the posterior fossa, accompanied with lipid droplet drifts in brain sulci, fissures, cisterns, and ventricles. After 1 wk of conservative observation, no change was observed on the updated cranial CT scan. After 2 wk of conservative observation, magnetic resonance imaging examination confirmed that the lesion was a traumatic rupture of a posterior fossa dermoid cyst with lipid droplet drifts. As the patient exhibited no adverse symptoms throughout the 2 wk, a 6-mo follow-up visit was arranged for him instead of aggressive treatment. Nonetheless, the patient did not show any abnormal neurological symptoms in the 6 mo of follow-up visits. CONCLUSION: Asymptomatic traumatic rupture of intracranial dermoid cyst could be just followed or treated conservatively rather than treated aggressively.

Abnormal amplitude of spontaneous low-frequency fluctuation in children with growth hormone deficiency: A resting-state functional magnetic resonance imaging study.

Growth hormone deficiency (GHD) is a developmental disorder caused by the partial or complete deficiency of growth hormone secreted by the pituitary gland, or its receptor. Patients with GHD are characterized by short stature, slow growth, and certain cognitive and behavioral abnormalities. Previous behavioral and neuroimaging studies indicate that GHD might affect the brain functional activity associated with cognitive and behavioral abilities. We thus investigated the spontaneous neural activity in children with GHD using amplitude of low-frequency fluctuation (ALFF) analysis. ALFF was calculated based on resting-state functional magnetic resonance imaging (rs-fMRI) data in 26 children with GHD and 15 age- and sex-matched healthy controls (HCs). Comparative analysis revealed that the ALFF of the right lingual gyrus and angular gyrus were significantly increased, while the ALFF of the right dorsolateral superior frontal gyrus, the left postcentral gyrus, superior parietal gyrus and middle temporal gyrus were significantly decreased in children with GHD relative to HCs. These findings support the presence of abnormal brain functional activity in children with GHD, which may account for the abnormal cognition and behavior, such as aggression, somatic complaints, attention deficits, and language withdrawal. This study provides imaging evidence for future studies on the pathophysiological mechanisms of abnormal behavior and cognition in children with GHD.

Interhemispheric functional connectivity for Alzheimer's disease and amnestic mild cognitive impairment based on the triple network model.

The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) based on a triple network model consisting of the default mode network (DMN), salience network (SN), and executive control network (ECN). The technique of voxel-mirrored homotopic connectivity (VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that: (1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions (i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions (i.e. frontoinsular cortex), and ECN-related brain regions (i.e. frontal middle gyrus and frontal inferior); (2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control (HC) groups, but no significant difference was observed between the aMCI and HC groups; and (3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination (MMSE) and Montreal Cognitive Scale (MOCA) scores and their factor scores in the AD, aMCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the aMCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD.

[Value of Radiation Therapy Oncology Group guidelines based on MR imaging in diagnosing lymph node metastasis of nasopharyngeal carcinoma].

BACKGROUND AND OBJECTIVE: Radiation Therapy Oncology Group (RTOG) and other major cooperative groups endorse the consensus guidelines for the delineation of the node levels in stage N0 cases. But it is unclear if these guidelines can be extrapolated to N+ cases. This study was to explore the value of RTOG guidelines in delineating cervical target volumes for nasopharyngeal carcinoma (NPC) patients with lymph node metastasis. METHODS: Conventional magnetic resonance imaging (MRI) of the nasopharynx, including plain and contrast enhanced sequences, was performed on 254 naive NPC patients. The lymph nodes were divided into six cervical levels plus retropharyngeal nodes (RN) according to RTOG guidelines proposed in 2003. RESULTS: Anatomic boundaries of node levels were observed clearly on MRI. Of the 254 patients, 107 (42.1%) had obvious lymph node necrosis, 78 (30.7%) had extracapsular nodal spread, four (1.6%) had skipped metastasis. The levels of lymph node metastases in 51 (20.1%) patients were beyond RTOG guidelines, 42 of which were above cranial level IIb, six were behind the anterior edge of the trapezius muscle, and 23 were below the caudal of level IV; 20 patients had two regions of lymph node metastases beyond RTOG guidelines. No patient only with lymph node metastasis beyond RTOG guidelines was found. CONCLUSIONS: MRI is feasible to diagnose cervical node metastasis with RTOG guidelines. The boundaries of node levels should be enlarged rationally when delineating target volumes for the N+ NPC patients according to RTOG guidelines.

[Significance of dynamic enhanced MRI in differential diagnosis of radiofibrosis and recurrent nasopharyngeal carcinoma at the basilar clivus].

BACKGROUND & OBJECTIVE: Basilar clivus is a common site of recurrent nasopharyngeal carcinoma (RNPC). Biopsy of the basilar clivus is seldom done because of its deep location and complex anatomic structure, therefore, early differential diagnosis of radiofibrosis (RF) and RNPC at the basilar clivus is very difficult. This study was designed to investigate the characteristics of radiofibrosis and RNPC at the basilar clivus on dynamic enhanced magnetic resonance imaging (DMRI) for differential diagnosis. METHODS: A total of 38 NPC patients, treated in Cancer Center and the Second Affiliated Hospital of Sun Yat-sen University with follow-up of 1-5 years, were divided into 2 groups: 22 in RF group and 16 in RNPC (RNPC at the basilar clivus) group. After conventional plain MRI scan of nasopharynx, DMRI and conventional contrast enhanced T(1)-weighted imaging (T1WI) were performed. Maximal contrast enhancement ratio (MCER), time to MCER (Tmax), and contrast enhancement ratio at the 40th second of DMRI (CER(40s)) of basilar clivus, condylar process, and nasal concha were measured. RESULTS: The MCER and CER(40s) of RF at the basilar clivus were lower, and the Tmax was longer than those of RNPC at the basilar clivus. When CER40s > or =150%, CER40s of basilar clivus > or = CER(40s) of nasal concha, and the combination of these 2 indexes were respectively set as the DMRI diagnostic criteria of RNPC at the basilar clivus, the diagnostic sensitivity of the second criterion was the highest (81.3%), and the diagnostic specificity of the third criterion was also the highest (86.4%). CONCLUSIONS: DMRI is helpful for differential diagnosis of radiofibrosis and RNPC at the basilar clivus. RNPC at the basilar clivus is highly suggested when it meet the criteria of both CER(40s) > or =150% and CER(40s) of basilar clivus > or = CER(40s) of nasal concha. When the 2 criteria are conflictive, the latter is more accurate, MCER and Tmax of the basilar clivus should be took into consideration.

[Magnetic resonance imaging diagnosis of cervical lymph node metastasis from lingual squamous cell carcinoma].

BACKGROUND & OBJECTIVE: The identification of cervical lymph node metastasis is very important for the treatment and prognosis prediction of lingual squamous cell carcinoma. Simple palpation is unsatisfactory for the accurate diagnosis of cervical lymph node metastasis. Magnetic resonance imaging (MRI) has been increasingly used to evaluate cervical lymph node status. This study was to explore MRI features of cervical lymph nodes metastasis from lingual squamous cell carcinoma, and to investigate the role of MRI in diagnosing this kind of metastasis. METHODS: The MR images of 448 nodal levels in 92 patients with lingual squamous cell carcinoma were analyzed, and compared with their pathologic diagnoses. RESULTS: Of the 488 nodal levels, 166 (37.1%) were proved pathologically as metastases, level II was the most commonly involved. False-positive and false-negative rates of MRI diagnoses were higher in levels I, and II than in levels III, IV, and V. There is no statistical difference in the incidence of cervical lymph nodes metastases of different nodal levels between squamous cell carcinoma of corpus linguae and that of radix linguae. Obvious central nodal necrosis was seen in 76 nodal levels at MR images,which were proved pathologically as metastatic nodes. Extracapsular nodal invasions in 34 nodal levels had irregular contour, and infiltration of adjacent fat tissues around lymph nodes, among which carotid artery walls were encased in 2 cases. With the diagnostic criteria of metastasis as the minimal nodal diameter of >/= 8 mm or central nodal necrosis, the diagnostic sensitivity, specificity, and accuracy of MRI were 79.5%, 90.4%, and 86.4%, respectively. CONCLUSIONS: The incidence of cervical lymph nodes metastasis from lingual squamous cell carcinoma is highest in level II. MRI diagnostic criteria of cervical lymph nodes metastasis are nodal size, central nodal necrosis, and irregular contour of lymph nodes. MRI may diagnose lymph node metastasis in levels III-V with high accuracy, While its diagnosis accuracy on levels I-II is affected by the sites, which weakens its clinical value.

[Magnetic resonance imaging manifestations of radiation injury in brain stem and cervical spinal cord of nasopharyngeal carcinoma patients after radiotherapy].

BACKGROUND & OBJECTIVE: It is very important to diagnose the radiation injury in brain stem and cervical spinal cord of patients with nasopharyngeal carcinoma (NPC) after radiotherapy. Magnetic resonance imaging (MRI) manifestations of radiation encephalopathy have been widely reported, while those of radiation injury in brain stem and cervical spinal cord have been seldom reported. This study was to analyze the MRI characteristics of radiation injury in brain stem and cervical spinal cord of patients with NPC after radiotherapy. METHODS: MRI was performed in 60 NPC patients 6 months to 5 years after radiotherapy. The imaging sequences included T(1)-weighted image (T(1)WI), T2-weighted image (T(2)WI), fluid attenuated inversion recovery (FLAIR). All patients received T(1)WI contrast-enhanced scanning. RESULTS: Of the 60 patients, 6 had lesions in cervical spinal cord, 54 had lesions in brain stem. Of the 54 cases of radiation injury in brain stem, most lesions located in pons (20 cases), basis pons and medulla oblongata (26 cases), others located in mesencephalon (3 cases), medulla oblongata (5 cases). All lesions showed hypo- or iso-intense signal on T(1)WI, and hyper-intense signal on T(2)WI. After contrast-enhanced scanning, 11 cases (18.3%) had no enhancement; 49 (81.7%) markedly enhanced with 21 cases (42.9%) of homogenous patchy enhancement, and 28 cases (57.1%) of hetergenerous ringed and patchy enhancement. CONCLUSION: MRI shows clearly the radiation injury in brain stem and cervical spinal cord of NPC patients after radiotherapy.