Prospective study examining the probability of cerebral fat embolism based on magnetic resonance imaging.

Purpose: Cerebral fat embolism (CFE) is a rare syndrome caused by the embolization of fat particles into the brain circulation. This prospective single-center observational study investigated the incidence of CFE in long-bone or pelvic fractures based on magnetic resonance imaging (MRI) findings. The purpose of this study was to investigate the incidence of CFE by MRI findings with or without symptoms suggestive of CFE. Methods: Eligible patients were consecutive, aged 15 years or older, with high-energy traumas, including pelvic or femur fractures. Excluded patients were those who died, could not undergo MRI resulting from medical conditions, or had insufficient mental capacity and no consultee to provide consent. The MRI was scheduled within 4 weeks of the injury, and the images were reviewed by one of the three neuroradiologists who were unaware of the patient's clinical information. Patient data regarding demographics, preceding trauma, injury severity score (ISS), presentation and examination timing of MRI, management including surgery, and outcome were collected. Results: Sixty-two patients were recruited, and three patients were excluded. All patients were injured by blunt trauma. The median patient age was 44 years. The median ISS was 13, and 53 patients needed surgical fixation. There were 22 patients with long-bone fractures, all of whom received external fixation or intramedullary nailing on admission day. MRI was performed after a median hospital day of 18 days. Using MRI imaging, three (5.0%) patients were diagnosed with CFE, and three patients were suspected of CFE. Conclusions: This is the first study to prospectively examine the probability of CFE based on MRI. Since fat embolism syndrome (FES) is confirmed in patients without clinical symptoms, CFE may be more common in patients with trauma than currently believed. Therefore, studies to determine the diagnostic criteria combined with symptoms, MRI, or other objective findings are required in the future.

A pediatric case of anaplastic astrocytoma with a gliomatosis cerebri; the growth pattern and changes in serum VEGF-121 levels after bevacizumab treatment.

Gliomatosis cerebri (GC) is a rare diffusely infiltrating glial neoplasm that carries a poor prognosis. Because tumors are undetectable in most patients at early-stage of the onset, a useful diagnostic method is expected. We compared serum vascular endothelial growth factor (VEGF)-121 levels in patients with GC or glioblastoma and controls. VEGF-121 levels were significantly higher in one patient with GC and patients with glioblastoma than in controls. VEGF-121 levels decreased in a patient with GC after bevacizumab-based therapy. Thus, VEGF-121 may be useful for diagnosing GC, its disease-monitoring and understanding its etiology.

The importance of FDG-PET/CT parameters for the assessment of the immune status in advanced HNSCC.

OBJECTIVE: Cancer cells secrete large amounts of lactic acid via aerobic glycolysis. We have shown that lactic acid plays an important role as a proinflammatory and immunosuppressive mediator and promotes tumor progression. Fluorine-18 fluorodeoxyglucose (FDG) uptake detected by positron emission tomography/computed tomography (PET/CT) is considered as a good indicator of aerobic glycolysis in cancer. In this study, we examined the relationships between systemic inflammatory parameters and FDG-PET/CT parameters in advanced head and neck squamous cell carcinoma (HNSCC). Furthermore, we investigated the relationships between FDG-PET/CT parameters and M2-macrophage polarization in HNSCC by assessing the ratio of CD163, a M2-macrophage marker, to CD68, a pan-macrophage marker. METHODS: This study included 73 advanced HNSCC patients. We assessed the C-reactive protein (CRP) level, white blood cell (WBC) count, neutrophil count, lymphocyte count, and monocyte count as systemic inflammatory markers. Additionally, we assessed the maximum standardized uptake value (SUVmax), mean SUV (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) as FDG-PET/CT parameters. RESULTS: The CRP level, WBC count, and neutrophil count were correlated with whole-body FDG-PET/CT parameters. The CD163/CD68 ratio was correlated with SUVmax and SUVmean. Our results suggest that systemic inflammation, which is associated with neutrophils, develops in patients with HNSCC having tumors with a larger volume and increased glucose uptake and that M2-macrophage polarization is promoted in HNSCC with increased glucose uptake, SUVmax, and SUVmean. FDG-PET/CT has the potential to reflect cancer-related chronic inflammation and immunosuppressive conditions in cancer patients. CONCLUSIONS: FDG-PET/CT parameters appear to be useful in assessing the immune status in HNSCC.

Incidental findings on whole-body computed tomography in trauma patients: the current state of incidental findings and the effect of implementation of a feedback system.

AIM: Whole-body computed tomography (CT) for trauma occasionally reveals significant incidental findings not related to trauma, which require an adequate response. In this study, we examined the current state of incidental findings in trauma patients on whole-body CT and the effects of the feedback system. METHODS: The subject sample included trauma patients who underwent whole-body CT while being examined for trauma during the 2-year period, with the interpretation of the CT reported by a radiologist. The frequency and recognition of incidental findings and the involved body region were investigated. The state of incidental findings before and after implementation of a radiography report feedback system was also examined. RESULTS: During the study period, whole-body CT revealed incidental findings in 79 of 199 trauma patients (40.1%). The mean age of the 79 patients with incidental findings was 62.8 ± 19.5 years, and the mean injury severity score was 16.6 ± 10.0. No difference was observed in the severity of trauma, age, or length of hospital stay. The incidental findings were related to the liver/gallbladder in 22 patients, kidneys in 17, lungs in 14, and the intracranial area in 13. The recognition rate of incidental findings after the implementation of the feedback system increased from 23.3% to 32.6%. CONCLUSIONS: Considering that not all incidental findings are accurately recognized, a proper feedback system is required. A feedback system is beneficial and a need to ensure improvement in the recognition of incidental findings.

Effect of metal artifact reduction software on image quality of C-arm cone-beam computed tomography during intracranial aneurysm treatment.

Background and purpose C-arm cone-beam computed tomography (CBCT) has the drawback that image quality is degraded by artifacts caused by implanted metal objects. We evaluated whether metal artifact reduction (MAR) prototype software can improve the subjective image quality of CBCT images of patients with intracranial aneurysms treated with coils or clips. Materials and methods Forty-four patients with intracranial aneurysms implanted with coils (40 patients) or clips (four patients) underwent one CBCT scan from which uncorrected and MAR-corrected CBCT image datasets were reconstructed. Three blinded readers evaluated the image quality of the image sets using a four-point scale (1: Excellent, 2: Good, 3: Poor, 4: Bad). The median scores of the three readers of uncorrected and MAR-corrected images were compared with the paired Wilcoxon signed-rank and inter-reader agreement of change scores was assessed by weighted kappa statistics. The readers also recorded new clinical findings, such as intracranial hemorrhage, air, or surrounding anatomical structures on MAR-corrected images. Results The image quality of MAR-corrected CBCT images was significantly improved compared with the uncorrected CBCT image ( p < 0.001). Additional clinical findings were seen on CBCT images of 70.4% of patients after MAR correction. Conclusion MAR software improved image quality of CBCT images degraded by metal artifacts.

Clinical findings of a probable case of MM2-cortical-type sporadic Creutzfeldt-Jakob disease with antibodies to anti-N-terminus of α-enolase.

We report the case of a 76-year-old woman presenting with 47-month history of progressive dementia and cortical blindness with no family history. Antibodies against thyroid glands and the N-terminus of α-enolase (NAE) were detected in her serum. Neurological examination revealed progressive dementia, frontal signs, visual disturbance, and exaggerated bilateral tendon reflexes in both legs. Diffusion MRI showed cortical hyper-intensities in the bilateral occipital and parietal, and the left frontal and temporal cortices. 99mTc-ethyl cysteinate dimer-single photon emission computed tomography indicated decreased regional cerebral blood flow throughout the bilateral parietal lobes and partially in the left frontal and temporal lobes. PRNP gene analysis showed no mutations with methionine homozygosity at codon 129 in peripheral blood. Cerebrospinal fluid examination, including 14-3-3 and total tau protein detection, revealed normal levels; however, prion proteins were amplified by the real-time quaking-induced conversion method. Hashimoto's encephalopathy was excluded on the basis of unresponsiveness to corticosteroids. The symptoms progressed slowly. Periodic sharp-wave complexes were observed on electroencephalogram 36 months after the onset of symptoms; the patient reached a state of akinetic mutism at 47 months. This was a probable case of MM2-cortical-type sCJD with anti-NAE antibodies based on the World Health Organization (WHO) diagnostic criteria for sCJD, genetic information, and the slowly progressive course. However, this case did not meet with the probable WHO diagnostic criteria until 3 years after symptom onset, highlighting the difficulty of diagnosing a living case of the MM2-type of sCJD. Therefore, establishment of clinical diagnostic criteria for MM2-type of sCJD is required.

An autopsy-verified case of steroid-responsive encephalopathy with convulsion and a false-positive result from the real-time quaking-induced conversion assay.

We report an autopsy-verified case of steroid-responsive encephalopathy with convulsion and a false-positive result from the real-time quaking-induced conversion (RT-QUIC) assay. A 61-year-old Japanese man presented with acute onset of consciousness disturbance, and convulsions, but without a past medical or family history of progressive dementia, epilepsy, or prion disease. Brain diffusion and fluid-attenuated inverted recovery MR images revealed edematous cortical hyper-intensity, which diminished after the acute phase. Steroid pulse therapy was partially effective, although he continued to have dementia with myoclonus and psychiatric symptoms, despite resolution of the consciousness disturbance. Cerebrospinal fluid (CSF) analysis revealed a normal cell count, with significantly elevated levels of 14-3-3 protein and total tau protein. In addition, prion protein in the CSF was slowly amplified by the RT-QUIC assay. PRNP gene analysis revealed methionine homozygosity at codon 129 without mutation. The patient died of sudden cardiac arrest at 3 months after the onset of symptoms. The positive result from the RT-QUIC assay led us to suspect involvement of prion disease, although a postmortem assessment revealed that he had pathological changes after convulsion, and no prion disease. This case indicates that convulsion may cause false-positive RT-QUIC results, and that a postmortem evaluation remains the gold standard for diagnosing similar cases.

An autopsy-verified case of FTLD-TDP type A with upper motor neuron-predominant motor neuron disease mimicking MM2-thalamic-type sporadic Creutzfeldt-Jakob disease.

Here we report an autopsy-verified case of frontotemporal lobar degeneration (FTLD)-transactivation responsive region (TAR) DNA binding protein (TDP) type A with upper motor neuron-predominant motor neuron disease mimicking MM2-thalamic-type sporadic Creutzfeldt-Jakob disease (sCJD). A 69-year-old woman presented with an 11-month history of progressive dementia, irritability, insomnia, and gait disturbance without a family history of dementia or prion disease. Neurological examination revealed severe dementia, frontal signs, and exaggerated bilateral tendon reflexes. Periodic sharp-wave complexes were not observed on the electroencephalogram. Brain diffusion MRI did not reveal abnormal changes. An easy Z score (eZIS) analysis for 99mTc-ECD-single photon emission computed tomography (99mTc-ECD-SPECT) revealed a bilateral decrease in thalamic regional cerebral blood flow (rCBF). PRNP gene analysis demonstrated methionine homozygosity at codon 129 without mutation. Cerebrospinal fluid (CSF) analysis showed normal levels of both 14-3-3 and total tau proteins. Conversely, prion protein was slowly amplified in the CSF by a real-time quaking-induced conversion assay. Her symptoms deteriorated to a state of akinetic mutism, and she died of sudden cardiac arrest, one year after symptom onset. Despite the SPECT results supporting a clinical diagnosis of MM2-thalamic-type sCJD, a postmortem assessment revealed that this was a case of FTLD-TDP type A, and excluded prion disease. Thus, this case indicates that whereas a bilateral decreasing thalamic rCBF detected by 99mTc-ECD-SPECT can be useful for diagnosing MM2-thalamic-type sCJD, it is not sufficiently specific. Postmortem diagnosis remains the gold standard for the diagnosis of this condition.

Preserved regional cerebral blood flow in the occipital cortices, brainstem, and cerebellum of patients with V180I-129M genetic Creutzfeldt-Jakob disease in serial SPECT studies.

Creutzfeldt-Jakob disease (CJD) with a causative point mutation of valine to isoleucine at codon 180 (V180I) is one of the major types of genetic CJD (gCJD) in Japan. V180I gCJD is rarely accompanied by a family history, and its clinical characteristics include late-onset, long disease duration, and edematous cortical hyperintensity in diffusion, fluid attenuate inversion and T2-weighted MRI. We performed serial imaging with single-photon emission computed tomography (SPECT) and MRI in three V180I gCJD cases over long-term observation. All cases were characterized by progressive dementia, parkinsonism, and the absence of cerebellar signs or cortical visual dysfunction in their clinical courses. Moreover, during the end-stage, SPECT findings showed preserved regional cerebral blood flow (rCBF) in the occipital cortices, brainstem, and cerebellum. Similarly, no apparent atrophy or increased signal intensities were observed in MRI images of the occipital and cerebellar regions. In conclusion, we report a decrease in rCBF predominantly in the frontal and temporal cortices during the early-stage, which became more widespread as the disease progressed. Importantly, rCBF was preserved in the occipital cortices, brainstem, and cerebellar regions until the end-stage, which may be distinct to V180I gCJD cases.

A robust conversion method of radioactivities between plastic and NaI scintillation well counters for long-term quality control and quality assurance.

PURPOSE: The purpose of this study is to specify a simple procedure for a robust data conversion of radioactivity value between plastic scintillator (PL) and NaI scintillator (NaI) devices. MATERIALS AND METHODS: The radioactivity estimate of 100 blood samples was measured by the two devices. The two radioactivities were plotted on the same graph. The least-squares method was applied to obtain the conversion function. The differences between the actual radioradioy (N) from the NaI device and the estimated radioactivity for NaI (N') from the PL device activity (P) were statistically analyzed. RESULTS: N' was determined from P as N' = 4.45 P + 6.28 with high correlation (r = 0.997). The Bland-Altman analysis between N' and N showed no fixed bias and no proportional bias. CONCLUSIONS: A hundred blood samples using a fixed type of sample tubes and a fixed radionuclide may be required to set up the robust conversion function.

Gorham-Stout Disease of the Skull Base With Hearing Loss: Dramatic Recovery and Antiangiogenic Therapy.

Gorham-Stout disease (GSD) is a rare disorder of unknown etiology. We present a 6-year-old male with GSD involving the skull base who presented with recurrent cerebrospinal fluid (CSF) rhinorrhea, severe hearing loss, and facial palsy secondary to cerebellar herniation into the internal auditory canal. After 2 months of treatment with pegylated interferon (IFN) α-2b (50 µg/week), his hearing recovered dramatically. Two years later, new bone formation appeared radiologically and IFN was switched to sirolimus. One year after the switch, CSF rhinorrhea disappeared. Antiangiogenic therapy might inhibit proliferation of vascular endothelial cells in osteolytic lesions and lead to new bone formation.

Successive MRI Findings of Reversible Cerebral White Matter Lesions in a Patient with Cystathionine ß-Synthase Deficiency.

Cystathionine ß-synthase (CBS) deficiency, well known as classical homocystinuria, is a rare autosomal recessive inborn error of homocysteine and sulfur metabolism. CBS converts homocysteine to cystathionine. The clinical features of untreated CBS deficiency include myopia, ectopia lentis, mental retardation, skeletal anomalies resembling Marfan syndrome, and thromboembolic events. Cerebral white matter lesions (CWMLs), identified in magnetic resonance imaging (MRI), are related to various clinical conditions including ischemia, inflammation, demyelination, infection, a tumor, and metabolic disorders such as phenylketonuria. The presence of CWMLs is, however, believed to be a very rare condition in CBS-deficient patients. Herein, we report reversible CWMLs associated with hypermethioninemia caused by poor protein restriction and betaine therapy in a 21-year-old male with pyridoxine-nonresponsive CBS deficiency. T2-weighted images (T2WI) and fluid-attenuated inversion-recovery (FLAIR) images showed diffuse high signal intensity in subcortical areas extending to the deep white matter. Diffusion-weighted images (DWI) showed high signal intensity, while apparent diffusion coefficient (ADC) map demonstrated decreased ADC value in the lesions. The course of improvement after correct methionine restriction was successively followed by brain MRI. The CWMLs had regressed at 1 month after restriction, and disappeared after 5 months. ADC values were very low before proper methionine restriction, but normalized after 2 months. Use of betaine in the presence of elevated plasma methionine may increase the risk of reversible CWMLs in some CBS-deficient patients.

Decreased regional cerebral blood flow in the bilateral thalami and medulla oblongata determined by an easy Z-score (eZIS) analysis of (99m)Tc-ECD-SPECT images in a case of MM2-thalamic-type sporadic Creutzfeldt-Jakob disease.

We report a case of autopsy-verified MM2-thalamic-type sporadic Creutzfeldt-Jakob disease (sCJD) in a 46-year-old patient with a 16-month history of abnormal behavior, progressive dementia, insomnia, and speech disturbances without family history. Neurological examination revealed progressive dementia, frontal signs, insomnia, speech disturbance, gait disturbance and bilaterally exaggerated tendon reflexes. Both brain MRI and cerebrospinal fluid examinations, including 14-3-3 protein, yielded normal results. An easy Z-score (eZIS) analysis for (99m)Tc-ethyl cysteinate dimer-single photon emission computed tomography ((99m)Tc-ECD-SPECT) revealed decreased regional cerebral blood flow in the bilateral thalami and medulla oblongata. PRNP gene analysis revealed methionine homozygosity at codon 129 without mutation. Neuropathological examinations revealed severe neuronal loss, gliosis, and hypertrophic astrocytosis in the medial thalamus and inferior olivary nucleus. A slight depletion of Purkinje cells was observed. PrP immunostaining showed no obvious PrP deposits in the basal ganglia, thalamus, cerebellum, or brainstem; however, mild synaptic-type PrP deposits with some smaller plaque-like structures were only partially observed in the localized region of the frontal lobe with the spongiform change. Western blot analyses of protease-resistant PrP showed a type 2 pattern. In conclusion, eZIS analysis of (99m)Tc-ECD-SPECT images is useful for detecting both thalamic and medullary lesions. This is the first case of medullary lesions detected in a live patient with MM2-thalamic-type sCJD using SPECT.

Prediction of macrometastasis in axillary lymph nodes of patients with invasive breast cancer and the utility of the SUV lymph node/tumor ratio using FDG-PET/CT.

BACKGROUND: Axillary lymph node dissection (ALND) is important for improving the prognosis of patients with node-positive breast cancer. However, ALND can be avoided in select micrometastatic cases, preventing complications such as lymphedema or paresthesia of the upper limb. To appropriately omit ALND from treatment, evaluation of the axillary tumor burden is critical. The present study evaluated a method for preoperative quantification of axillary lymph node metastasis using positron emission tomography/computed tomography (PET/CT). METHODS: The records of breast cancer patients who received radical surgery at the Gifu University Hospital (Gifu, Japan) between 2009 and 2014 were reviewed. The axillary lymph nodes were preoperatively evaluated by PET/CT. Lymph nodes were dissected by sentinel lymph node biopsy (SLNB) or ALND and were histologically diagnosed by experienced pathologists. The maximum standardized uptake value (SUVmax) was measured in both the axillary lymph node (SUV-LN) and primary tumor (SUV-T). The SUV-LN/T ratio (NT ratio) was calculated by dividing the SUV-LN by the SUV-T, and the efficacies of the NT ratio and SUV-LN were compared using receiver operating characteristic (ROC) curve analysis. The diagnostic performance was also compared between the techniques with the McNemar test. RESULTS: A total of 171 operable invasive breast cancer patients were enrolled, comprising 69 node-positive patients (macrometastasis (Mac): n = 55; micrometastasis (Mic): n = 14) and 102 node-negative patients (Neg). The NT ratio for node-positive patients was significantly higher than in node-negative patients (0.5 vs. 0.316, respectively, P = 0.041). The NT ratio for Mac patients (0.571) was significantly higher than in Mic (0.227) and Neg (0.316) patients (P <0.01 and P = 0.021, respectively). The areas under the curves (AUCs) by ROC analysis for the NT ratio and SUV-LN were 0.647 and 0.811, respectively (P <0.01). In patients with an SUV-T ≥2.5, the modified AUCs for the NT ratio and SUV-LV were 0.757 and 0.797 (not significant). CONCLUSION: The NT ratio and SUV-LN are significantly higher in patients with axillary macrometastasis than in those with micrometastasis or no metastasis. The NT ratio and SUV-LN can help quantify axillary lymph node metastasis and may assist in macrometastasis identification, particularly in patients with an SUV-T ≥2.5.

Facial palsy as an unusual presenting symptom associated with acute myeloid leukemia.

Extramedullary infiltration is common in acute myeloid leukemia (AML) patients. Although AML can cause neurological symptoms, especially when associated with extramedullary infiltration, a presenting manifestation of facial palsy is rare. We report on a 1-year-old boy who developed right facial palsy. Detailed examination led to a diagnosis of AML (French-American-British classification M1). Magnetic resonance imaging enhanced with gadolinium-diethylenetriamine penta-acetic acid showed abnormal enhancement of the right facial nerve, which disappeared after chemotherapy. AML should be considered as a differential diagnosis of facial palsy. Enhanced magnetic resonance imaging may be useful for diagnosing facial palsy associated with AML and for evaluating treatment outcome.

High frequency of calcification in basal ganglia on brain computed tomography images in Japanese older adults.

AIM: To investigate the frequency of calcification in the basal ganglia and the dentate nuclei in the cerebellum, and compare the difference in age and area, we examined the brain computed tomography (CT) images of all patients in two representative university hospitals in Japan. METHODS: We examined the brain CT images of 2526 patients in Gifu University Hospital (UH) and 2573 patients in Niigata UH. These patients were examined in these hospitals from October 2009 to September 2010. RESULTS: Punctate calcification of the basal ganglia was observed in 435 of 2526 patients (17.2%) in Gifu UH and 530 of 2573 patients (20.6%) in Niigata UH. The frequency of calcification increased with age. Patchy calcification of the basal ganglia was observed in 32 (1.3%) and 50 patients (1.9%) in Gifu UH and Niigata UH, respectively. Among patients aged over 65 years, 24 (2.1%) and 34 (3.1%) patients showed patchy calcification in Gifu UH and Niigata UH, respectively. Calcification of the cerebellar dentate nuclei was detected in just seven and four patients in Gifu UH and Niigata UH, respectively. CONCLUSION: Compared with previous reports, the frequency of calcification of the basal ganglia in this study markedly increased. This might be because of the increased number of older adults and the increased sensitivity of CT.

Selection of carotid artery stenting or endarterectomy based on magnetic resonance plaque imaging reduced periprocedural adverse events.

BACKGROUND: The aim of this study was to elucidate the impact of treatment selection, either carotid stenting or endarterectomy, based on preoperative magnetic resonance (MR) plaque imaging on periprocedural events. METHODS: A total of 205 consecutive patients with high-grade carotid artery stenosis scheduled for elective revascularization with stenting or endarterectomy were retrospectively analyzed. In period 1, 95 patients were treated regardless of preoperative plaque imaging. In period 2, 110 patients received time of flight MR angiography, and endarterectomy was selected when a high-intensity signal in the plaque was observed on MR angiography because it indicated an unstable plaque. Periprocedural clinical results and outcome at 30 days were analyzed. RESULTS: In period 1, 5 patients (5.3%) were treated with endarterectomy and the other 90 patients (94.7%) were treated with stenting. In period 2, 35 patients (31.8%) were treated with endarterectomy and the other 75 patients (68.2%) were treated with stenting. Periprocedural adverse events, including any stroke, myocardial infarction, or death, were significantly more frequent in period 1 than in period 2 (9.5% v 1.8%; P = .034). Ischemic stroke was significantly reduced from period 1 to period 2 (7.4% v 0.9%; P = .043). Multivariate logistic regression analysis revealed "treatment selection by plaque imaging" was the only factor identified as an independent predictor of periprocedural events (P = .043). CONCLUSIONS: Treatment selection based on preoperative plaque imaging appears useful for reducing periprocedural events of carotid artery revascularizations.

Ultra-early endovascular embolization of ruptured cerebral aneurysm and the increased risk of hematoma growth unrelated to aneurysmal rebleeding.

OBJECT: Hematoma growth unrelated to aneurysmal rebleeding is recognized as a somewhat common complication following endovascular embolization of ruptured aneurysms, but it is scarcely studied. The aim of this study is to elucidate the possible risk factors for this phenomenon. METHODS: Included in this study were 101 consecutive patients with subarachnoid hemorrhage (SAH) who underwent endovascular embolization for saccular aneurysms at the authors' institution within 72 hours of symptom onset. All endovascular procedures were conducted under intraprocedural systemic anticoagulation. Age, sex, hypertension, type 2 diabetes, preoperative antiplatelet or anticoagulation use, neurological grade, Fisher grade, location and size of the aneurysm, grade of aneurysm occlusion, and timing of the endovascular procedure were retrospectively analyzed to determine the risk factors for hematoma growth unrelated to aneurysmal rebleeding. To determine the clinical significance of this complication, the authors also investigated the risk factors for poor clinical outcome (modified Rankin Scale Scores 3-6 at 30 days after onset). RESULTS: This series included 32 men (31.7%) and 69 women (68.3%) with a mean age ± SD of 65.5 ± 14.0 years. The mean time from onset to endovascular procedure was 12.1 ± 14.0 hours. After the procedure, hematoma growth unrelated to aneurysmal rebleeding occurred in 14 patients (13.9%), 10 of whom required surgical removal of the hematoma and/or ventriculostomy to control intracranial pressure. All 14 patients had an anterior circulation aneurysm and had Fisher Grade 3 or 4 SAH. Ultra-early embolization (conducted within 6 hours after onset), female sex, history of hypertension, and poor neurological grade (World Federation of Neurosurgical Societies Grades IV and V) were significant risk factors for hematoma growth (p < 0.05 for all, univariate logistic analysis). In multivariate analysis, ultra-early embolization (OR 18.0 [95% CI 3.26-338], p < 0.001) and female sex (OR 9.83 [95% CI 1.73-187], p = 0.007) were independent risk factors for this phenomenon. Anterior circulation aneurysms and Fisher Grade 3 or 4 SAH were also revealed to be significant risk factors (p = 0.02 for each, chi-square test). Furthermore, hematoma growth without aneurysmal rebleeding was determined as an independent risk factor for poor clinical outcome by multivariate logistic analysis (OR 11.8 [95% CI 2.31-87.1], p = 0.002). CONCLUSIONS: Ultra-early endovascular embolization for ruptured cerebral aneurysms under systemic anticoagulation increases the risk of growth of hematomas unrelated to aneurysmal rebleeding. It is important to recognize the risk of this complication and to either reduce the amount of heparin or to refer the patient for direct clipping if appropriate.