Pyoung Jeon

Analysis of the layering pattern of the apparent diffusion coefficient (ADC) for differentiation of radiation necrosis from tumour progression

ObjectivesTo evaluate the added value of diffusion-weighted imaging (DWI) to perfusion-weighted imaging (PWI) for differentiating tumour progression from radiation necrosis.MethodsSixteen consecutive patients who underwent removal of a metastatic brain tumour that increased in size after stereotactic radiosurgery were retrospectively reviewed. The layering of the ADC was categorised into three patterns. ADC values were measured on each layer, and the maximum rCBV was measured. rCBV and the layering pattern of the ADC of radiation necrosis and tumour progression were compared.ResultsNine cases of radiation necrosis and seven cases of tumour progression were pathologically confirmed. Radiation necrosis (88.9xa0% vs. 14.3xa0%) showed a three-layer pattern of ADC with a middle layer of minimum ADC more frequently. If rCBV larger than 2.6 was used to differentiate radiation necrosis and tumour progression, the sensitivity was 100xa0% but specificity was 56xa0%. If the lesions with the three-layer pattern of ADC with moderately increased rCBV (2.6–4.1) were excluded from tumour progression, the sensitivity and specificity increased to 100xa0%.ConclusionsThe three-layer pattern of ADC shows high specificity in diagnosing radiation necrosis; therefore, combined analysis of the ADC pattern with rCBV may have added value in the correct differentiation of tumour progression from radiation necrosis.Key Points•MRI follow-up often reveals increasing size of enhancing lesions after stereotactic radiosurgery•Inflammation around tumour necrosis increases regional cerebral blood volume (rCBV), mimicking progression•A three-layer apparent diffusion coefficient (ADC) pattern on diffusion-weighted MRI suggests radiation necrosis.•The combined use of rCBV and DW MRI enables accurate differentiation.

18F-FDG PET/CT findings of sinonasal inverted papilloma with or without coexistent malignancy : comparison with MR imaging findings in eight patients

IntroductionSinonasal inverted papilloma (IP) is known for high rate of associated malignancy. The purpose of this study was to identify 18F-FDG PET/CT findings of sinonasal IPs. We also tried to compare the PET/CT findings with the MR imaging findings.MethodsWe retrospectively reviewed PET/CT and MR images of eight patients with sinonasal IP with (nu2009=u20096) or without (nu2009=u20092) coexistent squamous cell carcinoma (SCC). Particular attention was paid to correlate the PET/CT findings with the MR imaging findings in terms of area distribution of standard uptake values (SUVs) and a convoluted cerebriform pattern (CCP).ResultsIn two benign IPs, the maximum SUVs measured 8.2 and 7.8, respectively (mean, 8.0). In both tumors, MR images demonstrated a diffuse CCP. In six IPs with coexistent SCC, the maximum SUVs ranged from 13.3 to 31.9 (meanu2009±u2009SD, 20.2u2009±u20096.6). In these tumors, MR images demonstrated a diffuse CCP in two, a partial CCP in three, and no CCP in one. A wide discrepancy was noted between MR imaging and PET/CT in terms of area distribution of a CCP and SUVs.ConclusionIn sinonasal lesions with MR imaging features of IP, 18F-FDG PET/CT demonstrating avid FDG uptake does not necessarily imply the presence of coexistent malignancy. In our small series, although IPs containing foci of SCC had consistently higher SUVs than IPs without SCC, the limited literature on this subject suggests that PET cannot be used reliably to make the distinction.

Signal intensity change of the labyrinth in patients with surgically confirmed or radiologically diagnosed vestibular schwannoma on isotropic 3D fluid-attenuated inversion recovery MR imaging at 3 T

ObjectiveThe purpose of this study was to evaluate the signal intensity (SI) change of the labyrinth in patients with vestibular schwannoma on isotropic 3D fluid-attenuated inversion recovery (FLAIR) imaging at 3xa0T.MethodsThirty-four patients with surgically confirmed or radiologically diagnosed vestibular schwannoma were included in this study. Retrospectively, we visually and quantitatively compared the SIs of the cochlea and vestibule on the affected side with those on the unaffected side. We also investigated whether there was correlation between the SI ratios (SIRs) of the labyrinth and the audiometric findings.ResultsOn 3D FLAIR images, the SI of the cochlea and vestibule on the affected side was significantly increased in 97% (33/34) and 91% (31/34), respectively. While the SI of the cochlea was diffusely increased, that of the vestibule was only partially increased. Quantitative study also revealed statistically significantly higher SIRs of the cochlea (0.99u2009±u20090.29) and vestibule (0.73u2009±u20090.31) on the affected side, compared with the cochlea (0.47u2009±u20090.20) and vestibule (0.19u2009±u20090.10) on the unaffected side. There was no significant correlation of the SIRs of the labyrinth with the degree of hearing loss.ConclusionIn patients with vestibular schwannoma, isotropic 3D FLAIR imaging is a useful method for the evaluation of the SI changes of the labyrinth.

Usefulness of the dynamic gadolinium-enhanced magnetic resonance imaging with simultaneous acquisition of coronal and sagittal planes for detection of pituitary microadenomas

AbstractObjectiveDoes dynamic gadolinium-enhanced imaging with simultaneous acquisition of coronal and sagittal planes improve diagnostic accuracy of pituitary microadenomas compared with coronal images alone?MethodsFifty-six patients underwent 3-T sella MRI including dynamic simultaneous acquisition of coronal and sagittal planes after gadolinium injection. According to conspicuity, lesions were divided into four scores (0, no; 1, possible; 2, probable; 3, definite delayed enhancing lesion). Additional information on supplementary sagittal images compared with coronal ones was evaluated with a 4-point score (0, no; 1, possible; 2, probable; 3, definite additional information). Accuracy of tumour detection was calculated.ResultsAverage scores for lesion detection of a combination of two planes, coronal, and sagittal images were 2.59, 2.32, and 2.18. 6/10 lesions negative on coronal images were detected on sagittal ones. Accuracy of a combination of two planes, of coronal and of sagittal images was 92.86%, 82.14% and 75%. Six patients had probable or definite additional information on supplementary sagittal images compared with coronal ones alone (10.71%).ConclusionDynamic MRI with combined coronal and sagittal planes was more accurate for detection of pituitary microadenomas than routinely used coronal images. Simultaneous dynamic enhanced acquisition can make study time fast and costs low.Key Points• We present a new dynamic MRI technique for evaluating pituitary microadenomasn • This technique provides simultaneous acquisition of contrast enhanced coronal and sagittal images.• This technique makes the diagnosis more accurate and reduces the examination time.• Such MR imaging only requires one single bolus of contrast agent.

Y-configuration double-stent-assisted coiling using two closed-cell stents for wide-neck basilar tip aneurysms

AbstractsBackgroundThis study aimed to evaluate clinical and angiographic outcomes of Y-configuration double-stent-assisted (Y-stent) coiling using two closed-cell stents for wide-necked basilar tip aneurysm (BTA).MaterialsA total of 25 patients underwent Y-stent coiling using two closed-cell stents as a first-time treatment in 18 (3 ruptured) BTAs, retreatment in 2 BTAs and as a third treatment in 5 wide-necked BTAs. Clinical and angiographic outcomes were evaluated retrospectively.ResultsTreatment-related complications were three (12.0xa0%) thromboembolic infarctions due to two acute in-stent thromboses and one embolism. Twenty-two (88xa0%) patients had favorable outcomes (modified Rankin scale score [mRS], 0–2) during the follow-up period (mean, 30xa0months; range, 6–54xa0months). Two patients died: one from initial subarachnoid hemorrhage and the other from intracerebral hemorrhage due to underlying Moyamoya disease. Post-treatment angiograms showed complete occlusion in nine aneurysms, residual neck in 11 aneurysms and residual sac in five aneurysms. Follow-up angiograms were available at least once between 5 to 34xa0months (mean, 16xa0months) in 21 patients. Nineteen patients showed improved or stable states (complete occlusion, nu2009=u200917; residual neck, nu2009=u20092). Major recurrences occurred in two BTAs (9.5xa0%). Those two major recurrent aneurysms had been large-sized aneurysms at the initial coiling procedure. Both showed not only coil compaction but also progressive growth to giant-sized aneurysms and intra-aneurysmal thrombus formation at the Y-stent coiling as a third-time treatment.ConclusionsY-stent coiling using two closed-cell stents is a safe and durable treatment option for wide-necked BTA, but may have limited efficacy for large/giant sized and thrombosed aneurysms.

Predictors of thromboembolism during coil embolization in patients with unruptured intracranial aneurysm

ObjectivesTo identify the incidence of thromboembolic complications based on magnetic resonance imaging (MRI) and to explore the potential risk factors for thromboembolism (TE) during the periprocedural period of elective coil embolization for unruptured intracranial aneurysms.MethodsWe retrospectively reviewed all aneurysm cases treated with coil insertion between January 2008 and March 2011. Two hundred eighty-two coiling procedures for unruptured aneurysms were included in this study. The patients’ demographic characteristics were documented and records reviewed for abnormalities in diffusion-weighted imaging (DWI) seen on post-procedure MRI, intraoperative thrombus formation, and clinical signs of stroke.ResultsOverall, there were 87 (30.9xa0%) procedure-related complications in 282 aneurysms treated: 2 (0.7xa0%) procedural ruptures, 5 (1.8xa0%) symptomatic infarctions, and 80 (28.3xa0%) asymptomatic infarctions. Thromboembolic events during the procedure were observed more often in the the hyperlipidemia group (32/71 aneurysms, 45.1xa0%) than in the normal lipid profile group (39/196 aneurysms, 25.6xa0%; pu2009=u20090.002; chi-squre test). The coiling technique and size of the aneurysm were also associated with TE (pu2009<u20090.001 and pu2009=u20090.004).ConclusionHyperlipidemia seems to be associated with a significant increase in the rate of thromboembolic events. In preventive procedures, modifiable risk factors should be managed to reduce complications. Although permanent deficits are rare, the high rate of thromboembolic events suggests that improvements in the technique, such as the addition of antiplatelet agents and the development of new embolic materials, are necessary.

Multiparametric MR imaging of tumor response to intraarterial chemotherapy in orthotopic xenograft models of human metastatic brain tumor

The purpose of our study was to investigate the therapeutic efficacy of intraarterial (IA) chemotherapy via multiparametric magnetic resonance imaging (MRI) analysis in orthotopic mouse brain tumor models. Stereotactic-guided intracranial inoculation of MDA-MB-231 cells was performed in nude mice. Thirty tumor bearing mice were randomized into three groups, and each group received either IA docetaxel administration (nxa0=xa010), intravenous (IV) docetaxel administration (nxa0=xa010), or IA solvent injection (nxa0=xa010) as control. Treatment response was monitored by diffusion-weighted imaging and dynamic contrast enhanced-MRI obtained 1xa0day before and 8xa0days after therapy initiation. Imaging results were correlated with histopathology. In the results, IA chemotherapy showed a significant decrease in tumor volume (86.5xa0±xa015.6xa0%) compared to the IV chemotherapy (121.1xa0±xa039.6xa0%) and control (126.2xa0±xa022.0xa0%) 8xa0days after therapy (pxa0<xa00.05). Furthermore, IA chemotherapy resulted in a significant increase in mean tumor apparent diffusion coefficient (ADC) values (116.8xa0±xa044.9xa0%); in contrary IV chemotherapy (66.6xa0±xa026.9xa0%) and control (69.1xa0±xa029.5xa0%) showed a significant decrease in ADC values corresponding to further tumor growth (pxa0<xa00.05). However, there was no significant difference in perfusion parameters including initial area under the curve, Ktrans, Kep, and Ve between the groups (pxa0>xa00.05). Histopathology confirmed necrosis and necroptosis in the tumors after IA chemotherapy. In conclusion, IA chemotherapy may lead to effective inhibition of tumor cell proliferation and offer potential benefit of inducing higher degree of treatment response than IV chemotherapy.

Jostent covered stent placement for emergency reconstruction of a ruptured internal carotid artery during or after transsphenoidal surgery

OBJECTnInternal carotid artery (ICA) rupture during transsphenoidal surgery (TSS) is an extremely difficult complication to treat. This study aimed to evaluate the immediate and long-term outcomes of covered stent placement for emergency reconstruction of ruptured ICAs during or after TSS.nnnMETHODSnSeven patients underwent covered stent placement for emergency reconstruction of a ruptured ICA during or after TSS. The safety and effectiveness of covered stent placement for emergency reconstruction of ruptured ICAs were retrospectively analyzed.nnnRESULTSnPretreatment angiography showed active bleeding in 6 patients (5 intraoperative and 1 postoperative) and a pseudoaneurysm in 1 patient. Of the 6 patients with active bleeding, 5 were treated with a successive operation to control active bleeding. The other patient was treated just after cardiopulmonary resuscitation due to massive nasal bleeding 20 days after revision of TSS. All active bleeding was controlled immediately after covered stent insertion in these 6 patients. One patient showed a gap between the covered stent and ICA wall without active bleeding 30 minutes after glycoprotein IIb/IIIa inhibitor administration due to in-stent thrombosis. The gap was occluded with coil embolization after completion of the temporarily suspended TSS. The seventh patient, whose ICA tear was treated with surgical suture, underwent covered stent placement for a pseudoaneurysm detected on postoperative Day 2. During a mean follow-up period of 46 months (range 12-85 months), all patients had excellent outcomes (modified Rankin Scale score of 0). All the stented ICAs were patent on vascular imaging follow-up at a mean of 34 months (range 12-85 months).nnnCONCLUSIONSnCovered stents appear to be a safe and effective option for emergency reconstruction of ruptured ICAs during or after TSS.

Differentiation of Hemangioblastoma from Metastatic Brain Tumor using Dynamic Contrast-enhanced MR Imaging

PurposeThe aim of this study was to differentiate hemangioblastomas from metastatic brain tumors using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and compare the diagnostic performances with diffusion-weighted imaging (DWI) and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI).MethodsWe retrospectively reviewed 7 patients with hemangioblastoma and 15 patients with metastatic adenocarcinoma with magnetic resonance imaging (MRI) including DWI, DSC-MRI, and DCE-MRI. Apparent diffusion coefficient (ADC), relative cerebral blood volume (rCBV), and DCE-MRI parameters (Ktrans, kep, ve, and vp) were compared between the two groups. The diagnostic performance of each parameter was evaluated with receiver operating characteristic (ROC) curve analysis.Resultsvp, kep, and rCBV were significantly different between patients with hemangioblastoma and those with metastatic brain tumor (pu2009<u20090.001, pu2009=u20090.005, and pu2009=u20090.017, respectively). A vp cutoff value of 0.012 and a rCBV cutoff value of 8.0 showed the highest accuracy for differentiating hemangioblastoma from metastasis. The area under the ROC curve for vp and rCBV was 0.99 and 0.89, respectively. A vpu2009>u20090.012 showed 100u2009% sensitivity, 93.3u2009% specificity, and 95.5u2009% accuracy and a rCBVu2009>u20098.0 showed 85.7u2009% sensitivity, 93.3u2009% specificity, and 90.9u2009% accuracy for differentiating hemangioblastoma from metastatic brain tumor.ConclusionDCE-MRI was useful for differentiating hemangioblastoma from metastatic brain tumor.

Safety and efficacy of antiplatelet response assay and drug adjustment in coil embolization: a propensity score analysis

IntroductionThe purpose of this study was to explore the safety and efficacy of an antiplatelet response assay and drug adjustment to prevent delayed thromboembolic events after stent-assisted coil embolization.MethodsA total of 370 patients were enrolled in this study between December 2005 and July 2014. Of these, 124 patients were placed into the drug resistance test (DRT) group with drug adjustment according to response to an antiplatelet agent, and 246 patients comprised the control group with a standard antiplatelet regimen. The response to the antiplatelet agent was evaluated with the VerifyNow Rapid Platelet Function Assay. Propensity score matching analysis was performed with one-to-multiple matching.ResultsAmong 370 patients, delayed thromboembolic events occurred in 28 (7.6xa0%) patients including 25 (10.2xa0%) in the control group and three (2.4xa0%) in the DRT group. Antiplatelet response test (pxa0=xa00.012), diabetes mellitus (DM) (pxa0=xa00.014), and hypertension (HTN) (pxa0<xa00.001) were associated with delayed infarction in multivariate analysis. In propensity score matching analysis, 331 patients were matched (control group (nxa0=xa0229) vs. DRT group (nxa0=xa0103)), and antiplatelet response (hazard ratio 0.247, 95xa0% confidence interval 0.070–0.868, pxa0=xa00.029) was correlated with delayed infarction. Conversely, the two groups were not significantly different with regard to total (pxa0=xa00.368) or major hemorrhagic complications (pxa0=xa00.108).ConclusionAntiplatelet drug adjustment according to the results of an antiplatelet response assay might be associated with a decreased risk of delayed thromboembolic infarction compared with the standard antiplatelet regimen.