Effect of intravenous gadolinium-DTPA on diffusion-weighted imaging of brain tumors: a short temporal interval assessment.

PURPOSE: To determine the effect of intravenous administration of gadolinium (Gd) contrast medium (Gd-DTPA) on diffusion-weighted imaging (DWI) for the evaluation of normal brain parenchyma vs. brain tumor following a short temporal interval. MATERIALS AND METHODS: Forty-four DWI studies using b values of 0 and 1000 s/mm(2) were performed before, immediately after, 1 min after, 3 min after, and 5 min after the administration of Gd-DTPA on 62 separate lesions including 15 meningioma, 17 glioma and 30 metastatic lesions. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and apparent diffusion coefficient (ADC) values of the brain tumor lesions and normal brain tissues were measured on pre- and postcontrast images. Statistical analysis using paired t-test between precontrast and postcontrast data were obtained on three brain tumors and normal brain tissue. RESULTS: The SNR and CNR of brain tumors and the SNR of normal brain tissue showed no statistical differences between pre- and postcontrast (P > 0.05). The ADC values on the three cases of brain tumors demonstrated significant initial increase on the immediate time point (P < 0.01) and decrease on following the 1 min time point (P < 0.01) after contrast. Significant decrease of ADC value was still found at 3min and 5min time point in the meningioma group (P < 0.01) with gradual normalization over time. The ADC values of normal brain tissues demonstrated significant initial elevation on the immediately postcontrast DWI sequence (P < 0.01). CONCLUSION: Contrast medium can cause a slight but statistically significant change on the ADC value within a short temporal interval after the contrast administration. The effect is both time and lesion-type dependent.

Sensory neuronopathy involves the spinal cord and brachial plexus: a quantitative study employing multiple-echo data image combination (MEDIC) and turbo inversion recovery magnitude (TIRM).

INTRODUCTION: Sensory neuronopathy (SNN) is a distinctive subtype of peripheral neuropathies, specifically targeting dorsal root ganglion (DRG). We utilized MRI to demonstrate the imaging characteristics of DRG, spinal cord (SC), and brachial plexus at C7 level in SNN. METHODS: We attempted multiple-echo data image combination (MEDIC) and turbo inversion recovery magnitude (TIRM) methods in nine patients with sensory neuronopathy and compared with those in 16 disease controls and 20 healthy volunteers. All participants underwent MRI for the measurement of DRG, posterior column (PC), lateral column, and spinal cord area (SCA) at C7 level. DRG diameters were obtained through its largest cross section, standardized by dividing sagittal diameter of mid-C7 vertebral canal. We also made comparisons of standardized anteroposterior diameter (APD) and left-right diameters of SC and PC in these groups. Signal intensity and diameter of C7 spinal nerve were assessed on TIRM. RESULTS: Compared to control groups, signal intensities of DRG and PC were higher in SNN patients when using MEDIC, but the standardized diameters were shorter in either DRG or PC. Abnormal PC signal intensities were identified in eight out of nine SNN patients (89 %) with MEDIC and five out of nine (56 %) with T2-weighted images. SCA, assessed with MEDIC, was smaller in SNN patients than in the other groups, with significant reduction of its standardized APD. C7 nerve root diameters, assessed with TIRM, were decreased in SNN patients. CONCLUSION: MEDIC and TIRM sequences demonstrate increased signal intensities and decreased area of DRG and PC, and decreased diameter of nerve roots in patients with SNN, which can play a significant role in early diagnosis.

Gadobenate dimeglumine-enhanced liver magnetic resonance imaging: value of hepatobiliary phase for the detection of focal liver lesions.

OBJECTIVE: The objective of the study was to determine the value of addition of hepatobiliary phase to dynamic gadobenate dimeglumine (Gd-BOPTA)-enhanced imaging for the detection of focal liver lesions (nodules with diameter ≤3.0 cm). METHODS: Routine nonenhanced magnetic resonance images were obtained in 25 patients with focal liver lesions suggested by ultrasonography and/or computed tomography.T1-weighted dynamic gradient-echo images were acquired immediately and 100 minutes after bolus injection of Gd-BOPTA. The number of the lesions detected by T1-weighted imaging, T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced, and delayed hepatobiliary-phase imaging was counted, respectively. Contrast-to-noise ratios were measured for all the sequences including delayed hepatobiliary-phase imaging. The signal intensity and morphologic features of liver parenchyma and lesions were recorded and analyzed. RESULTS: There were 7 patients with hepatocellular carcinomas, 6 with hemangiomas, 7 with metastases, and 5 with cholangiocarcinomas. The delayed hepatobiliary-phase imaging showed a homogeneous enhancement of liver parenchyma and distinctive enhancement features of focal liver lesions. The delayed hepatobiliary-phase imaging was better than diffusion-weighted imaging for the detection of focal liver lesions (P < 0.05). CONCLUSION: The addition of hepatobiliary-phase imaging to Gd-BOPTA-enhanced dynamic imaging increased the sensitivity and accuracy for the detection of focal hepatic lesions.

Imaging findings of vertebral osteomyelitis caused by nontuberculous mycobacterial organisms: Three case reports and literature review.

RATIONALE: Prompt diagnosis of nontuberculous Mycobacterial (NTM) vertebral osteomyelitis is challenging, yet necessary to prevent serious morbidity and mortality. Here, we report 3 cases of vertebral osteomyelitis caused by NTM with imaging findings. PATIENT CONCERNS: Case 1, a 58-year-old male patient, was admitted to our hospital because of the presence of a pulmonary mass for 6 months with cough and chest pain.Case 2, a 50-year-old male patient, had fever and cough for 3 years and was diagnosed with tuberculosis. Antituberculosis treatment was ineffective, accompanied by lymph node enlargement and osteosclerotic changes involving vertebral bodies.Case 3, a 66-year-old female patient, was admitted to our hospital with a mass on the top of her head for 1 month, which ruptured in the last 2 weeks. DIAGNOSES: Case 1: Sputum culture revealed Mycobacterium (M.) avium.Case 2: The final culture results of the lymph node biopsy samples were M. intracellulare.Case 3: Culture results of the sputum and pus from the abscess were M. gordon.We found sclerosing lesions in the spine in all 3 NTM patients, which were easily misdiagnosed as metastatic tumors. In 2 cases, there was bone destruction in the ilium with limbic sclerosis, and there were abscesses near the ilium and in front of the sacrum in 1 case. INTERVENTIONS: Case 1 was transferred to other specialist hospital.Case 3 received surgical treatment for cranial lesions and abscess drainage.Case 2 and case 3 received targeted treatment for nontuberculous mycobacteria in our hospital. OUTCOME: The condition of case 1 was unknown.Recovery of case 2 was uneventful because of prolonged illness; however, inflammation gradually improved overall.Case 3 had no recurrence following surgical treatment. LESSONS: In our 3 cases of NTM vertebral osteomyelitis, bone lesions were often misdiagnosed as bony metastases because of the presence of multiple sclerotic lesions. Diagnoses were challenging and delayed. It is important to consider osteomyelitis by NTM when disseminated osteosclerosis with or without osteolytic bone lesions is present in conjunction with continuous inflammatory symptoms and signs. Moreover, an open biopsy of the lesion should be performed for a definitive diagnosis.

CT-guided sclerotherapy with ethanol concentration monitoring for treatment of renal cysts.

OBJECTIVE: The purpose of our study was to investigate the value of ethanol concentration monitoring for efficacy of CT-guided sclerotherapy of simple renal cysts. MATERIALS AND METHODS: For the experimental study, ethanol solutions with various concentrations (from 10% to 100% at 10% increments) were scanned with CT; the correlation between the CT density values and different ethanol concentrations in the ethanol solution were analyzed. For the clinical study, a total of 66 consecutive patients with simple renal cysts treated with sclerotherapy were retrospectively studied. Of the 66 patients, 45 (group A) did not have ethanol concentration monitoring, whereas 21 (group B) had ethanol concentration monitoring during the procedure. Treatment results between the two groups were compared 6 months later with follow-up ultrasound. RESULTS: In the experimental study, there was a linear correlation (r =-0.981) between the CT density values and the ethanol concentration (p < 0.05). In the clinical study, for group A, 25 of 45 patients (55.5%) showed complete regression of the cysts and nine of 45 cases (20%) showed partial regression of the cysts. There was a 24.5% recurrence rate (11/45) in Group A. In group B, 17 of 21 patients (81%) exhibited complete regression of the cyst and four of 21 (19%) showed a partial regression of the cyst. There was no recurrence in Group B. CONCLUSION: Our in vitro experiment showed a linear correlation between ethanol concentration and CT density values. CT density values can be used to measure ethanol concentration. Ethanol concentration monitoring during the procedure can improve the success rate in CT-guided sclerotherapy for simple renal cysts.

Multiple sclerosis: hyperintense lesions in the brain on T1-weighted MR images assessed by diffusion tensor imaging.

PURPOSE: To evaluate retrospectively quantitative diffusion tensor imaging (DTI) values of hyperintense lesions on nonenhanced T1-weighted magnetic resonance (MR) images in patients with multiple sclerosis (MS) to elucidate the degree of demyelination or remyelination associated with T1 hyperintense lesions and study their relationship to MR markers of tissue damage (brain atrophy). MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was waived for this HIPAA-compliant study, including 76 patients with MS and 20 healthy control subjects without evidence of MS clinically or on imaging. T1 lesions were compared with normal white matter on nonenhanced images and judged to be hyperintense. Quantitative DTI metrics of T1 hyperintense lesions were examined, and the relationship between DTI parameters and brain atrophy were investigated in this study. RESULTS: At least one T1 hyperintense lesion was found in 16 patients (total, 28 lesions). Hyperintense lesions on T1-weighted imaging (T1WI) had lower mean diffusion (MD) than others signal intensity lesions on T1WI but higher MD than normal white matter (F = 3.931; P < 0.001); Fractional anisotropy (FA; F = 3.24; P < 0.001) and volume ratio (VR; F = 1.664; P < 0.001) were higher in hyperintense lesions on T1WI than hypointense/isointense lesions on T1WI, but were lower than normal-appearing white matter (NAWM) and normal white matter in controls. There was correlation between FA and VR (r = 0.678; P < 0.001) and inverse correlation between FA and MD (r = -0.437; P = 0.02), MD and VR (r = -0.423; P 0.025) for T1 hyperintense lesion. The MD values of T1 hyperintense lesions (r = -0.304; P < 0.001) and the VR values of T1 hyperintense lesions (r = 0.096; P = 0.042) were significantly (negative) correlated with Brain parenchymal fraction (BPF; higher BPF score); the FA values of T1 hyperintense lesions (r = -0.111; P = 0.018), the MD values of T1 hyperintense lesions (r = 0.379; P < 0.001) and the VR values of T1 hyperintense lesions (r = -0.142; P = 0.003) were significantly correlated with third ventricular width (lower width). However, the FA value of T1 hyperintense lesions was not significantly associated with BPF(r = 0.083; P = 0.08). CONCLUSION: The quantitative DTI values of T1 hyperintense MS plaques were between hypo-/isointense lesions and NAWM or normal white matter, and correlated with BPF and third ventricular width. Our results supports the notion that axonal remyelination may be the reason for T1 hyperintense lesions.

Differential changes in deep and cortical gray matters of patients with multiple sclerosis: a quantitative magnetic resonance imaging study.

OBJECTIVE: The objective of our study was to evaluate the changes in quantitative diffusion tensor (DT) metrics and normalized T2-signal intensity (nT2-SI) values of normal-appearing cortical gray matter (CGM) and deep gray matter (DGM) in patients with multiple sclerosis (MS). METHODS: Fifty patients with MS and 25 patients with no MS matched on sex/age were selected as controls. Conventional magnetic resonance imaging and DT imaging were performed. Fractional anisotropy (FA)/mean diffusivity (MD) and nT2-SI values of CGM and DGM were measured. Analyses of variance between the 2 groups were analyzed; Pearson correlations between DT metrics and nT2-SI values and brain parenchymal fraction (BPF) and T2 lesion volumes (LVs) were used. RESULTS: Patients with MS showed larger MD/smaller FA values in the CGM region compared with controls (P < 0.05). However, MD/FA values were not statistically significant in the DGM between MS and healthy control group. In DGM of MS patients, a significant decrease of nT2-SI values were observed when compared with controls (P < 0.05), but nT2-SI values in the CGM of MS patients showed no significant decrease. In CGM, only MD values of frontal lobes in MS patients were significantly (negatively) correlated with BPF(right: P = 0.009, left: P = 0.036) or T2 LVs (right: P = 0.002, left: P = 0.047). Normalized T2-SI values in all DGM regions of MS patients were significantly correlated with BPF (r = 0.282-0.504, P < 0.05) except for the left thalamus and bilateral red nucleus. There was no correlation between nT2-SI in all DGM regions and T2 LVs of MS patients. CONCLUSION: In CGM, the change in quantitative DT metrics of MS patients and the association with BPF and T2 LVs suggest the existence of microstructural destruction corresponding to inflammation, demyelination, or wallerian degeneration, but the changes in CGM were independent of the concomitant changes in BPF and T2 lesion. In DGM, a decrease of nT2-SI in MS patients and the correlation of nT2-SI values with BPF (brain atrophy) suggest excessive iron deposition related to chronic destruction. Our investigation indicates the possibility of different mechanism of pathological change in CGM and DGM.

Delayed toxicity from gamma knife radiosurgery to lesions in and adjacent to the brainstem.

The aims of this study were to assess the incidence of, and risk factors for, delayed toxicity following gamma knife stereotactic radiosurgery (GKRS) to lesions in and adjacent to the brainstem. We retrospectively evaluated the delayed toxicity of GKRS following the treatment of 114 lesions in and adjacent to the brainstem in 107 patients. The median tumor volume was 6.2 cm(3) and the median dose to the tumor margin was 16Gy. The mean follow-up was 40 months. Thirteen patients (12%) demonstrated clinical evidence of delayed toxicity, with a median latency to the development of toxicity of 6 months. The actuarial incidence of toxicity at 1 year and 5 years was 10.2% and 13.8%. Larger tumor volume (p=0.02) and larger treatment volume (p=0.04) were associated with an increased incidence of delayed toxicity. Large lesions adjacent to the brainstem have a higher than previously suspected rate of delayed toxicity.

Using Real-Time Fusion Imaging Constructed from Contrast-Enhanced Ultrasonography and Magnetic Resonance Imaging for High-Grade Glioma in Neurosurgery.

OBJECTIVE: To compare the observation of high-grade glioma (HGG) based on intraoperative multiplane ultrasonography (US) images and preoperative reconstructive coplanar T1-weighted enhanced magnetic resonance imaging (MRI) using volume navigation (V Nav) fusion image technology. METHODS: We retrospectively evaluated intraoperative data obtained from 16 patients diagnosed with HGG (grade III and IV). Overall, 18 nodules observed in 15 patients were examined. HGG images from US and contrast-enhanced US (CEUS) were compared with those from preoperative reconstructive coplanar enhanced T1-weighted MRI using automatic V Nav fusion image technology. RESULTS: All HGG tumors were detected. Images of 13 of 18 tumors (72.2%) with obscure margins using B-mode US were improved with clear tumor boundaries using CEUS imaging. The relative difference in tumor area between CEUS and enhanced MRI modalities in 14 mainly solid component lesions was considered statistically significant (P value < 0.05). There was a perfect correlation of the enhanced area between coplanar CEUS and enhanced MRI. CONCLUSIONS: The V Nav fusion image system combining intraoperative real-time US imaging with reconstructive preoperative coplanar MRI is valuable for image-guided HGG resection. It is suitable for neurosurgeons who lack the expertise in US technology to discern the brain structure and allows better recognition of tumor and edema tissues compared with reconstructive preoperative coplanar-enhanced MRI in real time and in multiplane from different angles. In addition, CEUS combined with B-mode US could improve tumor detection and resection control in neurosurgery, even in single US-guided operations.

The real-time ultrasonography for fusion image in glioma neurosugery.

OBJECTIVES: The aim of study is to evaluate the general performance and efficiency of the using real time intraoperative ultrasound system with Volume Navigation system technology in glioma. Compare glioma intraoperative ultrasound and contrast agent ultrasound images to obtained preoperative MRI with fusion image in a real-time. PATIENTS AND METHODS: Fifteen patients had been performed fusion imaging involved intraoperative real-time ultrasound and contrast agent ultrasound with preoperative MR imaging including preoperative gadolinium-enhanced MRI from March 2017 to December 2017. The number of tumor was counted online fusion imaging in real time ultrasound with and without preoperative MR. We analyzed ultrasound coplanar MR modalities in real time including tumor location, margin (obscure or defined). In addition, intraoperative ultrasound enhancement pattern was analyzed compare it to preoperative reconstruction gadolinium-enhanced T1-weighted MRI. Two radiologists who made planning ultrasound assessment for the focus lesion based on a 4 scoring system according to the degree of confidence. RESULTS: Thirteen of fifteen patients whose automatically registration successful intraoperative neurosurgery accepted preoperative MR examination. Seven of fifteen fine-tuning registration phase were performed and satisfactory with fusion image substantially. Intraoperatively, 73.3% (11/15) glioma nodules were definite on conventional B-mode US by a radiologist who doesn't know the MR result before fusion US with MRI. However, 100% tumors were detected on fusion B-mode ultrasound imaging with MRI. Two radiologists evaluated the score between fusion B-mode ultrasound and CEUS with coplanar MRI and had a result that score was upgraded in 69.2% (9/13) and 84.6% (11/13) patients. Inter-observer agreement was significant (kappa value = 1.0, p < 0.001) in B-mode ultrasound fusion image with MRI. Inter-observer agreement was moderate (kappa value = 0. 0.618, p < 0.001) in CEUS fusion image with MRI. CONCLUSION: Fusion imaging is very useful to detect poor sonographic visibility tumor on fusion B-mode US imaging with MR images. Fusion image may demonstrate multiplane images including same standard and nonstandard MRI and US images to help localize tumor. The additional real time fusion CEUS mode image with MR is a safe method for neurosurgery and the use of CEUS should be considered when fusion B-mode ultrasound imaging alone is not satisfactory for margin.

Primary intraosseous meningioma.

Primary intraosseous meningiomas are a subtype of primary extradural meningiomas and constitute fewer than 2% of meningiomas overall, but they represent approximately two thirds of all extradural meningiomas. These types of meningiomas originate within the bones of the skull and thus can have a clinical presentation and radiographic differential diagnosis that is different from those for intradural meningiomas. Primary intraosseous meningiomas are classified based on their location and histopathological characteristics. Treatment primarily involves resection with wide margins if possible. Very little literature exists regarding the use of adjuvant therapies such as radiation and chemotherapy for these tumors. In fact, the literature regarding primary intra-osseous meningiomas consists mostly of clinical case reports and case series. This literature is reviewed and summarized in this article.

Abnormal brain function in neuromyelitis optica: A fMRI investigation of mPASAT.

PURPOSE: Cognitive impairment with the Neuromyelitis Optica (NMO) patients is debated. The present study is to study patterns of brain activation in NMO patients during a pair of task-related fMRI. MATERIALS AND METHODS: We studied 20 patients with NMO and 20 control subjects matched for age, gender, education and handedness. All patients with NMO met the 2006 Wingerchuk diagnostic criteria. The fMRI paradigm included an auditory attention monitoring task and a modified version of the Paced Auditory Serial Addition Task (mPASAT). Both tasks were temporally and spatially balanced, with the exception of task difficulty. RESULTS: In mPASAT, Activation regions in control subjects included bilateral superior temporal gyri (BA22), left inferior frontal gyrus (BA45), bilateral inferior parietal lobule (BA7), left cingulate gyrus (BA32), left insula (BA13), and cerebellum. Activation regions in NMO patients included bilateral superior temporal gyri (BA22), left inferior frontal gyrus (BA9), right cingulate gyrus (BA32), right inferior parietal gyrus (BA40), left insula (BA13) and cerebellum. Some dispersed cognition related regions are greater in the patients. CONCLUSIONS: The present study showed altered cerebral activation during mPASAT in patients with NMO relative to healthy controls. These results are speculated to provide further evidence for brain plasticity in patients with NMO.

The capability of inflow inversion recovery magnetic resonance compared to contrast-enhanced magnetic resonance in renal artery angiography.

PURPOSE: To assess the capability of inflow inversion recovery (IFIR) magnetic resonance angiography (MRA), compared with contrast-enhanced MRA (CE-MRA) as reference standard, in evaluating renal artery stenosis (RAS). METHODS: Seventy-two subjects were examined by IFIR MRA with respiratory-gated, prior to CE-MRA with a 1.5-T scanner. Two readers evaluated the quality of IFIR MRA images and renal artery depiction on artery-by-artery basis. The agreement of two methods to assess RAS was analyzed using the Kappa test. The relationship between image quality of IFIR MRA and respiratory rate was analyzed by ANOVA test. RESULTS: The visibility of renal artery branch vessels was significantly higher using IFIR MRA than CE-MRA (p < 0.05). A good agreement of two methods in evaluating stenosis grade, and a near-perfect inter-observer agreement for IFIR MRA (Kappa value 0.98) and CE-MRA (Kappa value 0.93), were demonstrated. As RAS ≥50%, the sensitivity and specificity of IFIR MRA were 92 and 98% in reader 1, 93 and 98% in reader 2, respectively. The image quality was significantly better in patients with stable respiration (p < 0.01). CONCLUSIONS: IFIR MRA in patients with stable respiration has higher visibility of renal artery branch vessels than CE-MRA, and a good agreement with CE-MRA in evaluating stenosis grade. It could be used to evaluate RAS for screening, and monitoring treatment.

Leukoencephalopathy with cerebral calcifications and cysts: clinical and pathological features in two adults.

Two adult patients diagnosed with Leukoencephalopathy with cerebral calcifications and cysts (LCC) were presented. Both patients had a long-term (8-10 years) following-up. Radiological findings of both patients revealed the characteristic signs of LCC: cerebral white matter abnormalities, calcifications, and cysts. In case 1, the initial CT scan showed a low-density area in the right frontal lobe and it had developed into a large cystic lesion after 8 years. Histopathological determination revealed that the cyst wall was associated with hemorrhage, angiomatous formation, and some Rosenthal fibers. In case 2, a major cystic lesion was located at the left parietal lobe which was resected and an old hematoma was found inside the cyst. Nine years later, the follow-up neuroimaging of case 2 showed a remarkable improvement of white matter abnormalities and cystic lesions. Hemorrhagic fluid was observed inside the cysts. Additionally, follow-up CT and MR scans showed a rapid enlargement of cystic lesions accompanied with hemorrhagic fluid levels after a year. Then, a major cyst was surgically removed to relieve pressure symptoms. Pathology of the resected cyst exhibited an organized hemorrhage inside the cyst and a large amount of hemosiderin surrounding the cyst wall. In conclusion, our two cases demonstrated that angiomatous changes subsequent with hemorrhage may be the major mechanism of cyst formation and development.

Intrinsic Functional Plasticity of the Thalamocortical System in Minimally Disabled Patients with Relapsing-Remitting Multiple Sclerosis.

The thalamus plays a crucial role in sensorimotor, cognitive, and attentional circuit functions. Disruptions in thalamic connectivity are believed to underlie the symptoms of multiple sclerosis (MS). Therefore, assessing thalamocortical structural connectivity (SC) and functional connectivity (FC) may provide new insights into the mechanism of intrinsic functional plasticity in a large-scale neural network. We used resting-state FC measurement and diffusion tensor imaging probabilistic tractography to study the functional and structural integrity of the thalamocortical system in patients with relapsing-remitting MS (RRMS) and matched healthy controls. In the thalamocortical connections of RRMS patients, we found lesion load-related regional FC in the right temporal pole, which reflected compensatory hyperconnectivity related to lesion-related demyelination. We also found significant correlations between increased diffusivity and slowed cognitive processing (PASAT) or the impact of fatigue (MFIS-5), as well as between connective fiber loss and disease duration. Taken together, the evidence from SC and FC analysis of the thalamocortical system suggests that minimally disabled RRMS patients exhibit a dissociated SC-FC pattern and limited regional functional plasticity to compensate for the chronic demyelination-related loss of long-distance SC. These results also provide further evidence supporting the notion that MS is a disorder of anatomical disconnection.

Atypical central neurocytoma with metastatic craniospinal dissemination: a case report.

Central neurocytomas comprise nearly half of adult intraventricular neoplasms. The median age of onset is 34 years. It is typically a low-grade neoplasm (World Health Organization grade II), although some cases of malignant neurocytomas have been described. We present a rare case of an atypical central neurocytoma with craniospinal dissemination, including both imaging and pathologic findings.

The imaging features of neurologic complications of left atrial myxomas.

BACKGROUND: Neurologic complications may be the first symptoms of atrial myxomas. Understanding the imaging features of neurologic complications of atrial myxomas can be helpful for the prompt diagnosis. OBJECTIVE: To identify neuroimaging features for patients with neurologic complications attributed to atrial myxoma. METHODS: We retrospectively reviewed the medical records of 103 patients with pathologically confirmed atrial myxoma at Xiangya Hospital from January 2009 to January 2014. The neuroimaging data for patients with neurologic complications were analyzed. RESULTS: Eight patients with atrial myxomas (7.77%) presented with neurologic manifestations, which constituted the initial symptoms for seven patients (87.5%). Neuroimaging showed five cases of cerebral infarctions and three cases of aneurysms. The main patterns of the infarctions were multiplicity (100.0%) and involvement of the middle cerebral artery territory (80.0%). The aneurysms were fusiform in shape, multiple in number (100.0%) and located in the distal middle cerebral artery (100.0%). More specifically, high-density in the vicinity of the aneurysms was observed on CT for two patients (66.7%), and homogenous enhancement surrounding the aneurysms was detected in the enhanced imaging for two patients (66.7%). CONCLUSION: Neurologic complications secondary to atrial myxoma consist of cerebral infarctions and aneurysms, which show certain characteristic features in neuroimaging. Echocardiography should be performed in patients with multiple cerebral infarctions, and multiple aneurysms, especially when aneurysms are distal in location. More importantly, greater attention should be paid to the imaging changes surrounding the aneurysms when myxomatous aneurysms are suspected and these are going to be the relevant features in our article.

Gamma knife radiosurgery for pituitary adenoma: early results.

OBJECTIVE: In recent years, gamma knife radiosurgery (GKRS) has emerged as an important treatment modality in the management of pituitary adenomas. Treatment results after performing GKRS and the complications of this procedure are reviewed. METHODS: Between 1994 and 2002, a total of 78 patients with pituitary adenomas underwent a total of 84 GKRS procedures in our medical center. This patient group comprised 46 men (59%) and 32 women (41%). All patients were treated for recurrent or residual disease after surgery or radiotherapy, with 83% presenting with extensive tumor involvement. The cavernous sinus was involved in 75 patients (96%), and 22 patients (28%) had hormone-secreting adenomas. This latter subset of patients included 12 prolactinomas (15%), 6 growth-hormone secreting tumors (8%), and 4 adrenocorticotropic hormone-secreting tumors (5%). The median tumor volume was 2.3 cm(3), and the median radiation dose was 15 Gy defined to the 50% isodose line. The mean and median follow-up periods were 41 and 36 months, respectively. RESULTS: GKRS was tolerated well in these patients; acute toxicity was uncommon and of no clinical significance. Late toxicity was noted in three patients (4%) and consisted of VIth cranial nerve palsy. In two patients, there was spontaneous resolution of this palsy, and in one patient, it persisted for the entire 3-year duration of follow-up. Of the 15 patients who presented with cranial nerve dysfunction, 8 (53%) experienced complete recovery and 3 (20%) showed major improvement within 12 months of therapy. Tumor volume reduction was slow, with 30% of patients showing decreased tumor volume more than 3 years after undergoing GKRS. None of the 56 patients with nonfunctioning tumors showed progression in the treated volume, and 4 (18%) of the 22 hormone-secreting tumors relapsed (P = 0.008). Of the four patients with adrenocorticotropic hormone-secreting adenomas, therapy failed in two of them. All six patients with growth hormone-producing tumors responded well to therapy. Of the 12 patients with prolactinomas 10 (83%) had normalization of hormone level and 2 patients experienced increasing prolactin level. Two patients with prolactinomas had three normal pregnancies after undergoing GKRS. CONCLUSION: GKRS is a safe and effective therapy in selected patients with pituitary adenomas. None of the patients in our study experienced injury to the optic apparatus. A radiation dose higher than 15 Gy is probably needed to improve control of hormone-secreting adenomas. Longer follow-up is required for a more complete assessment of late toxicity and treatment efficacy.

Radiographic assessment of cranial gunshot wounds.

Though advances in MRI will undoubtedly increase its use, particularly in the subacute period, CT will likely continue its primary role in the management of these injuries in the foreseeable future. The spectrum of imaging features of cranial gunshot injuries is vast, because they encompass all of the findings encountered in closed head injury in addition to the wide variety of problems associated with penetration. Thus, only a brief summary of the many varied aspects of this complex problem is presented here as a review of the more salient issues.