Quality and safety of Telemedicine in acute ischemic stroke: Early experience in Taiwan.

BACKGROUND: Telemedicine helps to provide the safe management of stroke patients in the emergency department (ED) and has been used worldwide. However, we had limited experience of telestroke in Taiwan. We aimed to identify the quality of telestroke and compare it with the original face-to-face consultation model. METHODS: Among 178 consecutive acute ischemic stroke patients treated with intravenous tissue plasminogen activator (IVtPA) from January 1, 2018, to December 31, 2019, we compared two different consultation methods: face-to-face consultation and telestroke consultation. We collected data on demographics, the National Institutes of Health Stroke Scale (NIHSS) scores, Modified Rankin Scale (mRS) scores, time measurements (onset-to-arrival time, onset-to-telestroke activation time, and time of IVtPA administration (Door-to-Needle; DTN)). RESULTS: The mean age to receive a telestroke consultation was 66.6 years, 36% were female, and the median NIHSS score was 9. The median time from patient arrival to telestroke consult activation was 40 min, and the median DTN time was 11 min longer than for face-to-face consults (62 min versus 51 min, p = .01). Telestroke consultation, similar to a face-to-face consultation, resulted in safe IVtPA eligibility assessments and administration with post-thrombolysis ICH in 4% overall (4% telestroke, 3% face-to-face consultation; p = .851). The 90-day outcomes were not different for mRS score, dichotomized 0-2 (60% telestroke 59% face-to-face consultation; p = .961), or for mortality (16% telestroke, 9% face-to-face consultation; p = .292). CONCLUSION: In the ED, consultation via the telestroke program provides equal quality to the original face-to-face consultation model to manage ischemic stroke.

Images Diagnosis and Emergent Endovascular Treatment of Acute Hemorrhagic Basilar Artery Dissection: A Case Report.

PURPOSE: Basilar artery dissection (BAD) is a rare but possibly fatal disease with specific neuroimage findings. The management of BAD varies. This report describes a case with hemorrhagic BAD treated by endovascular stent-assisted coil embolization. CASE REPORT: We report an 82-year-old case of acute mid basilar artery dissection complicated with acute subarachnoid hemorrhage (SAH), intraventricular hemorrhage (IVH) and hydrocephalus, which was diagnosed by complete neuroimage surveys including computed tomography angiography (CTA), magnetic resonance angiography (MRA), and digital subtraction angiography (DSA). She was then successfully treated by endovascular stent-assisted coil embolization. CONCLUSION: By modern sophisticated neuroimages, BAD could be diagnosed. Endovascular treatment with stent-assisted coil embolization can be a safe and efficacious choice for relatively poor surgical indicated patients with hemorrhagic BAD.

Fuzzy C-means clustering of magnetic resonance imaging on apparent diffusion coefficient maps for predicting nodal metastasis in head and neck cancer.

OBJECTIVE: The present study evaluated and analyzed apparent diffusion coefficients (ADCs) from partitions through a fuzzy C-means (FCM) technique for distinguishing nodal metastasis in head and neck cancer. METHODS: MRI studies of 169 lymph node lesions, dissected from 22 patients with a histopathologically confirmed lymph node status, were analyzed using in-house software developed using MATLAB(®) (The MathWorks(®) Inc., Natick, MA). A radiologist manually contoured the lesions, and ADCs for each lesion were divided into two (low and high) and three (low, intermediate and high) partitions by using the FCM clustering algorithm. RESULTS: The results showed that the low-value ADC clusters were more sensitive (95.7%) in distinguishing malignant from benign lesions than the whole-lesion mean ADC values (78.3%), while retaining a high specificity (approximately 90%). Moreover, receiver-operating characteristic curves demonstrated that the low-value ADC clusters used as a predictor of malignancy for lymph nodes could achieve a higher area under the curve (0.949 and 0.944 for two and three partitions, respectively). CONCLUSION: The segmentation by ADC values of lesions through the FCM technique enables the efficient characterization of the lymph node pathology and can help distinguish malignant from benign lymph nodes. ADVANCES IN KNOWLEDGE: Tumour heterogeneity may degrade the prediction of metastatic lymph nodes that involves using mean region-of-interest ADC values. The clustering of ADC values in lesions by using FCM can improve the diagnostic accuracy of nodal metastasis and reduce interreader variance.

Non-Invasive Evaluation of Hepatic Fibrosis: The Diagnostic Performance of Magnetic Resonance Elastography in Patients with Viral Hepatitis B or C.

PURPOSE: To compare the accuracy of magnetic resonance elastography (MRE) with that of aspartate aminotransferase-to-platelet ratio index (APRI) for estimating the stage of hepatic fibrosis in patients with chronic hepatitis B virus (HBV) or chronic hepatitis C virus (HCV) infection. MATERIALS AND METHODS: We retrospectively enrolled 160 patients with chronic hepatitis and 25 healthy living liver donors. Fibrosis stage (METAVIR, F0 to F4) was determined histopathologically for all patients. APRI was recorded at the time of histopathologic examination and liver stiffness values were measured on MRE quantitative stiffness maps. The cutoff values, sensitivity, and specificity of MRE and APRI for each fibrosis stage were determined using receiver operating characteristic (ROC) analysis. RESULTS: MRE had a significantly greater area under the ROC curve than APRI score for discriminating among METAVIR stages F2-F4. Using a cutoff value of 2.80 kPa, MRE had a sensitivity of 94.4% and a specificity of 97.8% for detecting significant fibrosis (≥F2). There were no significant differences in fibrosis stage between patients with HBV and those with HCV infection. For ≥F2, the cutoffs were 2.47 kPa (100% sensitivity), 2.80 kP (maximum sum of sensitivity and specificity), and 3.70 kPa (100% specificity). CONCLUSIONS: MRE is a more accurate modality than APRI for detecting significant fibrosis in patients with chronic HBV or HCV infection. Antiviral treatment should be considered in patients with liver stiffness values ≥ 2.8 kPa.

Efficacy of gadoxetic acid-enhanced magnetic resonance cholangiography compared with T2-weighted magnetic resonance cholangiography in patients with liver cirrhosis.

BACKGROUND: Gadoxetic acid is one of the hepatobiliary-specific agents and so can be used for contrast-enhanced magnetic resonance cholangiography (CE-MRC). The aim of our study was to compare the performance of CE-MRC with that of T2-weighted magnetic resonance cholangiography (T2W-MRC), and also to ascertain the effectiveness of both modalities combined for visualizing anatomic structures of the biliary tree in patients with liver cirrhosis. METHODS: Fifty-six patients underwent CE-MRC and T2W-MRC imaging. In the CE-MRC studies, hepatobiliary phase images were acquired 20 minutes after contrast injection. Two radiologists first evaluated the T2W-MRC and CE-MRC images separately in random order, and then they reviewed both images together 8 weeks later. The readers graded the quality of visualization of each biliary duct and the entire biliary tree (overall rating) using a five-point scale. Images with a grade of 3 or 4 were considered to provide sufficient visualization for clinical application, and those with a grade of 2 or less were considered to provide insufficient visualization. Laboratory data, Child-Pugh classification, and model for end-stage liver disease score were also recorded. RESULTS: The overall rating of T2W-MRC was significantly higher than that of CE-MRC (p < 0.001), although combined T2W/CE-MRC provided better visualization of biliary segments than T2W-MRC alone (p = 0.025). There were no significant differences between liver function and the overall rating of CE-MRC. CONCLUSION: CE-MRC is not superior to conventional T2W-MRC with respect to biliary visualization in patients with liver cirrhosis. However, a combination of T2W-MRC and CE-MRC provides significantly better visualization of biliary structures than T2W-MRC alone.

Cyclophilin A in Ruptured Intracranial Aneurysm: A Prognostic Biomarker.

Cyclophilin A (CyPA), an oxidative stress-induced factor, was found to play an important role in the aneurysm formation. Our working hypothesis was that the plasma level of CyPA in ruptured intracranial aneurysm could predict the neurological outcome. From 2011 to 2013, a total of 36 patients with ruptured saccular intracranial aneurysm were recruited in our study. Before coil embolization, we draw blood samples at the orifice of a culprit aneurysm and in the remote peripheral vein for measurements of the CyPA levels. We utilized the modified Rankin scale 30 days after aneurysm rupture as the outcome measure. Generalized linear models were used to estimate the adjusted odds ratios of the poor neurological outcome given the presence of high plasma level of CyPA. The aneurysmal and venous CyPA levels were significantly associated with the initial clinical severity (P = 0.004 and 0.03, respectively) and 30-day outcome (P = 0.01 and 0.02, respectively). The aneurysmal CyPA levels modestly correlated with age and high Fisher grade (ρ = 0.39 and 0.41; P = 0.02 and 0.01, respectively). The aneurysmal CyPA levels strongly correlated with the venous counterpart (ρ = 0.89; P < 0.001). Patients with high levels of aneurysmal CyPA were 15.66 times (95% CI, 1.48-166.24; P = 0.02) more likely to have worse neurological outcome than those with the low levels after adjustment of the age, gender, and the documented confounding factors. High plasma level of CyPA is a significant prognostic biomarker for poor neurological outcome in patients with ruptured intracranial aneurysm.

Interleukin-6 as a Prognostic Biomarker in Ruptured Intracranial Aneurysms.

BACKGROUND: Interleukin-6 (IL-6), a proinflammatory cytokine, was found to surge in the cerebral spinal fluid after aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that the plasma level of IL-6 could be an independent biomarker in predicting clinical outcome of patients with ruptured intracranial aneurysm. METHODS: We prospectively included 53 consecutive patients treated with platinum coil embolization of the ruptured intracranial aneurysm. Plasma IL-6 levels were measured in the blood samples at the orifices of the aneurysms and from peripheral veins. The outcome measure was the modified Rankin Scale one month after SAH. Multiple logistic regression analyses were used to evaluate the associations between the plasma IL-6 levels and the neurological outcome. RESULTS: Significant risk factors for the poor outcome were old age, low Glasgow Coma Scale (GCS) on day 0, high Fisher grades, and high aneurysmal and venous IL-6 levels in univariate analyses. Aneurysmal IL-6 levels showed modest to moderate correlations with GCS on day 0, vasospasm grade and Fisher grade. A strong correlation was found between the aneurysmal and the corresponding venous IL-6 levels (ρ = 0.721; P<0.001). In the multiple logistic regression models, the poor 30-day mRS was significantly associated with high aneurysmal IL-6 level (OR, 17.97; 95% CI, 1.51-214.33; P = 0.022) and marginally associated with high venous IL-6 level (OR, 12.71; 95% CI, 0.90-180.35; P = 0.022) after adjusting for dichotomized age, GCS on day 0, and vasospasm and Fisher grades. CONCLUSIONS: The plasma level of IL-6 is an independent prognostic biomarker that could be used to aid in the identification of patients at high-risk of poor neurological outcome after rupture of the intracranial aneurysm.

Efficiency of three-dimensional Doppler ultrasonography in assessing nodal metastasis of head and neck cancer.

The aim of this study was to assess the clinical usefulness of three-dimensional (3D) color Doppler ultrasonography with a novel predictive model in the detection of cervical metastasis of untreated head and neck squamous cell carcinoma patients. We assessed cervical lymph node metastasis in 52 head and neck squamous cell carcinoma patients by 3D color Doppler ultrasonography, magnetic resonance imaging, and [(18)F] fluorodeoxyglucose positron emission tomography with computed tomography. Pathologic analysis was used as the gold standard for evaluation of these imaging modalities. The rate of correct N staging was 84.6% on ultrasonography, 55.8% on magnetic resonance imaging, and 71.2% on positron emission tomography/computed tomography. On a level-by-level basis, the ultrasonography had 78.9% sensitivity, 99.0% specificity, 93.8% positive predictive value, 96.0% negative predictive value, and 95.7% accuracy. It also showed the highest agreement to histology results as compared with magnetic resonance imaging and positron emission tomography/computed tomography (kappa value = 0.832, 0.506, and 0.537, respectively). 3D Doppler ultrasonography with our prediction model provides a rapid, low-cost, noninvasive, and reliable method with low inter-observation variations for detecting neck metastasis of head and neck squamous cell carcinoma patients.

Intracranial venous hemodynamics and rupture of cerebral aneurysm.

Many uncertain and inconsistent etiologies of cerebral aneurysmal rupture including a wide spectrum of factors have been reported. Our recent observation discloses the potential new factor of cerebral aneurysm rupture with cerebral venous pressure gradient. We retrospectively reviewed 52 cases treated with coil embolization with or without cerebral aneurysmal rupture. Seventeen males and 30 females were recruited in this study. Quantitative color-coded cerebral angiography was performed during coil therapeutic procedures to measure cerebral venous circulation. Ruptured cases had shorter and symmetrical cerebral venous circulation time (P <0.05). In addition, an asymmetrical venous outflow pattern was critical for aneurysmal rupture. Non-ruptured cases tended to have slower and asymmetrical cerebral venous circulation compared with rupture cases. Symmetrical and shorter cerebral venous circulation in the dysplasia venous outlet may be a potential new factor for cerebral aneurysm rupture.

Time sensitivity factor of single pulmonary nodule: a new cancer characteristic metabolic parameter by (18) F-FDG PET.

OBJECTIVE: To calculate the time sensitivity factor (S) for discriminating the solitary pulmonary nodule (SPN) by FDG PET at different time points. METHODS: The multiple time-point FDG PET images from 41 patients for evaluating SPN seen on chest X-ray or CT were prospectively analyzed to calculate and evaluate S against the gold standard of tissue histology (n = 38) or long term clinicoradiographic follow-up (n = 3). The maximal standardized uptake values (SUV) at the 3 hourly time points were measured. The S was calculated using S = d{ln⁡(SUV)}/d{ln⁡(t)} at 3 different time intervals. ROC analysis of the S parameters was performed to evaluate the optimal cut-off value and their accuracy in classifying the SPN. RESULTS: The SUV in malignant SPN was higher than the corresponding value in benign lesions at all 3 hourly time points (P < 0.003). The S parameters using 3 different time intervals all significantly separated the two groups (P < 0.0005) with an optimal cut-off point near the theoretical value of zero with a high sensitivity of 100% and specificity of 86%. CONCLUSION. The S can be calculated for SPNs using multiple time-point FDG PET, providing a tumor characteristic metabolic parameter with high discrimination power using a simple positive value representing malignancy.

Full-endoscopic interlaminar removal of chronic lumbar epidural hematoma after spinal manipulation.

BACKGROUND: Spinal manipulation is widely used for low back pain treatments. Complications associated with spinal manipulation are seen. Lumbar epidural hematoma (EDH) is one of the complications reported in the literature. If lumbar chronic EDH symptoms are present, which are similar to those of a herniated nucleus pulposus, surgery may be considered if medical treatment fails. Percutaneous endoscopic discectomy utilizing an interlaminar approach can be successfully applied to those with herniated nucleus pulposus. We use the same technique to remove the lumbar chronic EDH, which is the first documented report in the related literature. METHODS: We present a case with chronic lumbar EDH associated with spinal manipulation. Neurologic deficits were noted on physical examination. We arranged for a full-endoscopic interlaminar approach to remove the hematoma for the patient with the rigid endoscopy (Vertebris system; Richard Wolf, Knittlingen, Germany). RESULTS: After surgery, the patient's radiculopathy immediately began to disappear. Magnetic resonance imaging (MRI) follow-up 10 days after the surgery revealed no residual hematoma. No complications were noted during the outpatient department follow up. CONCLUSIONS: Lumbar EDH is a possible complication of spinal manipulation. Patient experiencing rapidly progressive neurologic deficit require early surgical evacuation, while conservative treatment may only be applied to those with mild symptoms. A percutaneous full-endoscopic interlaminar approach may be a viable alternative for the treatment of those with chronic EDH with progressive neurologic deficits.

Cyclophilin-A: a novel biomarker for untreated male essential hypertension.

Vascular cytokines, total nitrite, and cyclophilin-A (CyP-A) may be related to the pathogenesis of untreated hypertension. Forty males with normotensive and untreated essential hypertension were recruited in this cytokines survey. Body mass index (BMI), hyperlipidemia, and plasma CyP-A were increased in the hypertensive group (p < 0.05). However, only BMI (p = 0.022) and plasma CyP-A (p = 0.020) were found to be significant contributors to hypertension by multiple regression analysis. CyP-A was also positively correlated with systolic blood pressure (p = 0.029) and diastolic blood pressure (p = 0.047). These findings indicated that plasma CyP-A is a critical molecular biomarker in the early pathogenesis of essential hypertension.

Bath-related thunderclap headache associated with subarachnoid and intracerebral hemorrhage.

PURPOSE: Bath-related thunderclap headache (BRTH) is a rare and usually benign condition. We report a case of episodic explosive thunderclap headache (TH) provoked by showering water, with the complications of cortical subarachnoid hemorrhages (SAH) and delayed intracerebral hemorrhage (ICH). CASE REPORT: A 56-year-old premenopausal woman, without chronic illness or headache history, suffered from 4 episodes of severe explosive TH within 11 days. Two of these attacks were provoked by hot water and 1 by cold water. A small acute SAH was found in the left high frontal cortex on brain computed tomography (CT) performed 7 days after the first attack (day 7). Brain magnetic resonance imaging (MRI) and angiography (MRA) on day 9 disclosed a new acute SAH in the right frontal cortex but with no apparent vasoconstriction. CT angiography (CTA) on day 12 first revealed vasoconstriction in the M2 segment of right middle cerebral artery (MCA), and found a new ICH in the right anterior frontal lobe. Conventional angiography on day 14 revealed partial remission of vasoconstriction with only mild short segmental narrowing at the proximal M1 segment of right MCA. The patient had no clinical neurological deficit. She was free of headache at day 11 when she started taking nimodipine. CONCLUSION: Reversible cerebral vasoconstriction syndrome (RCVS) presented with BRTH is rare and is not always that benign as was once thought. The delayed ICH and the short-period of vasoconstriction in this patient extended our knowledge that the time course of the complications and the duration of vasospasm in RCVS could vary widely among patients. Nimodipine is probably effective in both relieving symptoms and reversing vasoconstriction.

Hepatic inflammatory pseudotumor mimicking hepatocellular carcinoma.

Inflammatory pseudotumor of the liver is a rare tumor. It has variable clinical presentations and image findings. It can mimic benign or malignant hepatic tumors, and may be difficult to diagnose. We present a case in which a hepatic inflammatory pseudotumor was misdiagnosed as hepatocellular carcinoma because the tumor presented a typical enhancing profile and morphology of hepatocellular carcinoma on computed tomography, and the patient had liver cirrhosis. However, a thicker tumor capsule than that of typical hepatocellular carcinoma was noted while reviewing the computed tomography images. A capsule of inflammatory pseudotumor thicker than that of hepatocellular carcinoma has never been reported in the literature before, and could be an important diagnostic clue to differentiate inflammatory pseudotumor from hepatocellular carcinoma.

Dual energy computed tomography angiography for the rapid diagnosis of reversible cerebral vasoconstriction syndromes: report of a case.

PURPOSE: Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by segmental vasoconstriction and dilatation of intracranial arteries, typically affecting bilateral medium-sized intracranial arteries and their branches. The diagnosis usually relies both on clinical presentations and cerebral vascular imaging such as magnetic resonance angiography or conventional angiography. Dual energy computed tomography angiography (CTA) could provide high-quality imaging and is usually immediately available for the diagnosis at the emergency department. CASE REPORT: A 37-year-old previously healthy woman was admitted to the neurology ward for recurrent episodes of headaches within 3 days. She was diagnosed as having RCVS presenting with thunderclap headaches. Dual energy CTA provided high-quality imaging and almost immediately available for diagnosis at the emergency department (ER). CT perfusion showed adequate brain perfusion. Transcranial Doppler disclosed increased arterial velocities at bilateral middle cerebral arteries. We treated the patient with oral diclofenac and nimodipine. After a few days, she had great improvement of headaches. The follow-up CTA 3 months after her initial presentation disclosed complete resolution of the constrictions of these intracranial arteries. CONCLUSION: Brain magnetic resonance imaging (MRI) with magnetic resonance angiography (MRA) and MR venography is the choice for initial investigation; however, CTA is an alternative diagnostic tool when MRI is not readily available. Dual energy CTA has the great advantage in providing high-resolution imaging, high speed scanning with a lower radiation dose.

Intracerebral hemorrhage following endovascular embolization of brain arteriovenous malformation with a combination of Onyx and n-butyl cyanoacrylate: a case report.

We report a 29-year-old female patient who developed intracerebral hemorrhage 16 h after endovascular embolization of a brain arteriovenous malformation with a combination of liquid embolic agents of Onyx and n-butyl cyanoacrylate. After emergent craniectomy with evacuation of the hematoma, the patient recovered consciousness with mild expressive aphasia. The possible etiology of postembolization brain hemorrhage was discussed, and the literature was reviewed.

Efficacy of transarterial chemoembolization for hepatocellular carcinoma in interlobar watershed zone of liver: comparison of unilateral and bilateral chemoembolization.

PURPOSE: To evaluate the treatment efficacy of unilateral versus bilateral transarterial chemoembolization for hepatocellular carcinoma (HCC) based on whether the tumor is located across the Cantlie line within the watershed zone of the liver. MATERIALS AND METHODS: Seventy-seven patients with 87 HCCs located in the watershed zone who underwent complete chemoembolization (unilateral, n = 57 [74%]; bilateral, n = 20 [26%]) were included. Tumors located in the watershed zone were further divided into two groups: tumors across the Cantlie line (type A) and tumors not across the line (type B). Comparison of treatment outcomes of unilateral or bilateral chemoembolization for the two groups was performed. The tumor viability (ie, presence of viable component or tumor progression) and position of the viable component on follow-up computed tomography was recorded. RESULTS: Tumor viability rates for type A tumors in the unilateral and bilateral chemoembolization groups were 52.2% and 11.1%, respectively; for type B tumors, they were 23.7% and 11.8%, respectively. The tumor viability rate of type A tumors was significantly higher in the unilateral chemoembolization group than in the bilateral chemoembolization group (P = .05), but there was no significant difference for type B tumors (P > .05). CONCLUSIONS: The tumor viability rate of HCC tumors across the Cantlie line was higher with unilateral chemoembolization group than with bilateral chemoembolization. In patients with HCC across the Cantlie line, embolization of bilateral hepatic arteries may achieve better treatment efficacy.

Acute cerebral infarction masked by a brain tumor.

We report on an 81-year-old man who presented with left limbs weakness and was brought to the emergency room where a brain computed tomography revealed a tumor at the right parasellar region. The patient was admitted to the neurosurgery department, and the symptoms were thought to be due to the tumor mass effect. The final diagnosis turned out to be acute ischemic infarction with an incidentally found brain tumor following angiography and magnetic resonance imaging.

Local intra-arterial thrombolysis with urokinase for acute ischemic stroke before and after the approval of intravenous tissue plasminogen activator treatment in Taiwan.

BACKGROUND: Local intra-arterial thrombolysis (LIT) has been previously suggested as an effective therapy for acute ischemic stroke. In this study, we describe our experience of using LIT for the treatment of Taiwanese patients with ischemic stroke at different vascular locations, before and after Alteplase was approved as a first-line treatment in Taiwan. The criteria required for the initiation of LIT have become more stringent after the approval of Alteplase (AA). METHODS: A retrospective analysis of medical records was conducted for 20 ischemic stroke patients treated with LIT; including 10 patients treated before and 10 patients treated after AA (we did not treat any of the patients in this study with AA). Urokinase was used for LIT treatment. Outcome measures included patient demographics, clinical characteristics, and clinical outcomes before and after LIT. Clinical outcomes were evaluated using four different stroke scales. RESULTS: The median National Institutes of Health stroke scale score (NIHSS) before treatment was reported to be 19.2 (range: 8-30). After AA, only one patient who had an occluded internal carotid artery (ICA) was treated with LIT. Among the 20 patients, 11 (55%) (five before AA and six after AA) reported having favorable or good clinical outcomes within 3 months of treatment, whereas five reported having poor outcomes (three before AA and two after AA), and the rest four patients died following treatment (two before AA and two after AA). Arterial recanalization was reported as complete in 10 patients (50%; seven middle cerebral artery [MCA] and three basilar artery; six before AA and four after AA), as incomplete in four patients (20%; one MCA and three basilar artery; one before AA and three after AA), and it failed in the remaining six patients (30%; two MCA and four ICA; three before AA and three after AA). Five patients (one MCA and four ICA) in whom recanalization had failed reported having poor outcomes, including one ICA patient who subsequently succumbed to the illness. Intracranial hemorrhagic and intraventricular hemorrhage transformation occurred in three and two patients, respectively. A case of intraventricular hemorrhage transformation after AA was also reported. CONCLUSION: On the basis of our experience, we found that LIT was of limited value in patients with ICA occlusion before AA approval. After AA, the outcomes in acute stroke patients, who were receiving urokinase therapy and who were carefully selected on the basis of the site of occlusion, were improved.

The influence of I-131 therapy on FDG uptake in differentiated thyroid cancer.

OBJECTIVE: 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) [or PET/computed tomography (CT)] is more likely to show false-negative results when it is performed shortly after chemotherapy and/or radiotherapy because of "metabolic stunning". The present study aimed to evaluate the influence of I-131 therapy on FDG uptake and the detection of recurrence or metastasis of differentiated thyroid cancer (DTC). METHODS: We retrospectively enrolled 16 consecutive FDG-PET/CT studies which had been performed in patients with DTC with elevated thyroglobulin (TG) but negative I-131 whole-body scan. All studies were performed under L: -thyroxine suppression. The patients were divided into groups A and B for PET/CT performed within 4 months of I-131 therapy or no such therapy, respectively. Each lesion identified on PET/CT was characterized using a 5-point scale by visual analysis: 0 = definitely benign, 1 = probably benign, 2 = equivocal, 3 = probably malignant, and 4 = definitely malignant. The maximum standardized uptake value (SUV max) in each lesion was also measured for semiquantitative analysis. We compared the visual grading and SUV max of the lesion of highest FDG uptake between groups A and B. RESULTS: For visual analysis, group B had significantly more patients with an uptake score of 3 or 4 than group A (80% vs. 17%, P = 0.01). In addition, there were significantly more equivocal results from group A than from group B (67% vs. 10%, P = 0.02). If the patients with the highest uptake scores of 2, 3, and 4 were considered to be positive for local recurrence or metastasis, there would be no significant difference between the positive rates of groups A and B (83% vs. 90%, P = 0.7). However, the mean SUV max of positive results was significantly lower for group A than for group B (3.1 +/- 0.9 and 6.6 +/- 3.5, respectively, P = 0.02). CONCLUSIONS: The preliminary results suggested that FDG uptake in DTC may be negatively influenced by I-131 therapy within 4 months, resulting in lower FDG uptake and more equivocal results. Further studies are necessary to determine whether it is secondary to "metabolic stunning" caused by I-131 therapy.