Dual-Layer Detector Cone-Beam CT Angiography for Stroke Assessment: First-in-Human Results (the Next Generation X-ray Imaging System Trial).

BACKGROUND AND PURPOSE: In patients with stroke, IV cone-beam CTA in the angiography suite could be an alternative to CTA to shorten the door-to-thrombectomy time. However, image quality in cone-beam CTA is typically limited by artifacts. This study evaluated a prototype dual-layer detector cone-beam CT angiography versus CTA in patients with stroke. MATERIALS AND METHODS: A prospective, single-center trial enrolled consecutive patients with ischemic or hemorrhagic stroke on initial CT. Intracranial arterial segment vessel conspicuity and artifact presence were evaluated on dual-layer cone-beam CTA 70-keV virtual monoenergetic images and CTA. Eleven predetermined vessel segments were matched for every patient. Twelve patients were necessary to show noninferiority to CTA. Noninferiority was determined by the exact binomial test; the 1-sided lower performance boundary was prospectively set to 80% (98.75% CI). RESULTS: Twenty-one patients had matched image sets (mean age, 72 years). After excluding examinations with movement or contrast media injection issues, all readers individually considered dual-layer cone-beam CT angiography noninferior to CTA (CI boundary, 93%, 84%, 80%, respectively) when evaluating arteries relevant in candidates for intracranial thrombectomy. Artifacts were more prevalent compared with CTA. The majority assessment rated each individual segment except M1 as having noninferior conspicuity compared with CTA. CONCLUSIONS: In a single-center stroke setting, dual-layer detector cone-beam CTA virtual monoenergetic images are noninferior to CTA under certain conditions. Notably, the prototype is hampered by a long scan time and is not capable of contrast media bolus tracking. After excluding examinations with such scan issues, readers considered dual-layer detector cone-beam CTA noninferior to CTA, despite more artifacts.

Randomized assessment of imatinib in patients with acute ischaemic stroke treated with intravenous thrombolysis.

BACKGROUND: Imatinib, a tyrosine kinase inhibitor, has been shown to restore blood-brain barrier integrity and reduce infarct size, haemorrhagic transformation and cerebral oedema in stroke models treated with tissue plasminogen activator. We evaluated the safety of imatinib, based on clinical and neuroradiological data, and its potential influence on neurological and functional outcomes. METHODS: A phase II randomized trial was performed in patients with acute ischaemic stroke treated with intravenous thrombolysis. A total of 60 patients were randomly assigned to four groups [3 (active): 1 (control)]; the active treatment groups received oral imatinib for 6 days at three dose levels (400, 600 and 800 mg). Primary outcome was any adverse event; secondary outcomes were haemorrhagic transformation, cerebral oedema, neurological severity on the National Institutes of Health Stroke Scale (NIHSS) at 7 days and at 3 months and functional outcomes on the modified Rankin scale (mRS). RESULTS: Four serious adverse events were reported, which resulted in three deaths (one in the control group and two in the 400-mg dose group; one patient in the latter group did not receive active treatment and the other received two doses). Nonserious adverse events were mostly mild, resulting in full recovery. Imatinib ameliorated neurological outcomes with an improvement of 0.6 NIHSS points per 100 mg imatinib (P = 0.02). For the 800-mg group, the mean unadjusted and adjusted NIHSS improvements were 4 (P = 0.037) and 5 points (P = 0.012), respectively, versus controls. Functional independence (mRS 0-2) increased by 18% versus controls (61 vs. 79; P = 0.296). CONCLUSION: This phase II study showed that imatinib is safe and tolerable and may reduce neurological disability in patients treated with intravenous thrombolysis after ischaemic stroke. A confirmatory randomized trial is currently underway.

Negative CT angiography findings in patients with spontaneous subarachnoid hemorrhage: When is digital subtraction angiography still needed?

BACKGROUND AND PURPOSE: CTA is becoming the frontline modality to reveal aneurysms in patients with SAH. However, in about 20% of SAH patients no aneurysm is found. In these cases, intra-arterial DSA is still performed. Our aim was to evaluate whether negative findings on CTA can reliably exclude aneurysms in patients with acute SAH. MATERIALS AND METHODS: We conducted a retrospective analysis of all negative findings on CTAs performed from 2005 to 2009 in patients with spontaneous SAH. Findings were compared with DSA. CTAs were performed with a 64-section multidetector row CT scanner. RESULTS: One hundred ninety-three patients with SAH and negative findings on CTA who underwent subsequent DSA were identified. The distribution of blood on unenhanced CT was the following: PMH in 93 patients, diffuse aneurysmal pattern in 50, no blood on CT (xanthochromic LP) in 32, and peripheral sulcal distribution in 18. All patients with PMH had negative findings on DSA. One patient with no blood on CT had vasculitis on DSA. Six of 18 (33%) patients with peripheral blood had vasculitis on DSA. Three of these were also diagnosed by CTA. All except 1 patient with diffuse aneurysmal blood had negative findings on DSA. One patient was diagnosed with an aneurysm on DSA (1/50, 0.5%). Repeat delayed DSA performed in 28 of these patients revealed a small aneurysm in 4 (14%). Five patients had a complication of DSA (2.6%); 1 was a clinical stroke (0.5%). CONCLUSIONS: In patients with SAH, negative CTA findings are reliable in ruling out aneurysms in the PMH pattern or no blood on CT. DSA is indicated in the diffuse aneurysmal pattern of SAH, and repeat delayed DSA is required if the initial DSA findings are negative. When the blood is peripheral, CTA should be scrutinized for vasculitis and DSA is recommended for confirmation.

Non-invasive management of superficial root caries lesions in disabled and infirm patients.

UNLABELLED: In disabled and infirm patients with limited, if any, capacity for independent oral self-care, it is difficult to control progression of root caries lesions. OBJECTIVE: To evaluate the effect of non-restorative cariostatic treatment on progression of active superficial root caries lesions (n = 56). DESIGN: Pilot study. SETTING: Department of Cariology, Institute of Odontology, Karolinska Institutet, Huddinge. SUBJECTS: 15 physically-dependent patients. INTERVENTION: The patients were allotted to one of the following groups. Group 1, professional tooth cleaning and application of tap water flavoured with eucalyptus oil; Group 2, professional tooth cleaning and application of Cervitec, (1% chlorhexidine in thymol-containing varnish), Group 3, professional tooth cleaning and application of Cervitec and Fluor Protector (varnish containing 0.1% fluoride). Every three months for 18 months, each subject received the treatment twice within a 10-day interval. MEASUREMENTS: The status of the 56 root caries lesions was evaluated every six months using a root caries index based on visual and tactile criteria. The examiners were blind to which treatment group the patients belonged. RESULTS: In most subjects (14 out of 15), progression of root caries lesions was arrested. No statistically significant differences could be demonstrated between the three treatment groups. However, regardless of treatment regimen, there was a statistically significant difference between the greater number of subjects exhibiting no progression of root caries lesions and those with lesion progression, at 6 (p = 0.022), 12 (p = 0.006) and 18 months (p < 0.001). CONCLUSION: This pilot study suggests that in disabled and infirm patients regular professional tooth cleaning with a fluoride containing paste, with or without supplementary varnishing with chlorhexidine-thymol and/or fluoride can prevent further progression of existing superficial root caries lesions.

Effect of eyelid botulinum toxin injection on lacrimal drainage.

PURPOSE: To determine the effect of eyelid botulinum toxin injection on the lacrimal drainage and to assess the use of botulinum toxin in dry eye conditions. METHODS: Prospectively, three test groups were examined and one lacrimal system investigated in each person in each group. Botulinum toxin A (3.75 IU) was injected into the medial part of 13 lower eyelids of 13 normal test subjects and the medial part of nine lower eyelids in nine patients with dry eyes. A dose of 2.5 IU was injected into the medial part of 10 lower eyelids and the medial part of 10 upper eyelids of 10 patients with dry eyes. The drop test was used to determine the lacrimal drainage capacity and the blink output, before and after the injection. The subjective effect of the botulinum toxin injection on eye comfort was investigated. RESULTS: Three weeks after lower eyelid botulinum toxin injection, the mean blink output was reduced to 64% (1.19 of 1.87; P <.001) and 70% (0.94 of 1.35; P <.001) of the baseline values in the groups of normal subjects and patients, respectively. After injection in both the upper and lower eyelid, the mean blink output was reduced to 38% (0.54 of 1.41; P <.001) of the baseline value. The patients with dry eyes reported an improved eye comfort in six of nine cases after injection in the lower eyelid and in seven of 10 cases after injection in both the upper and lower eyelid. Adverse effects included one case of increased discomfort for 3 weeks after injection. CONCLUSION: Injection of botulinum toxin into the medial part of the eyelids decreased the lacrimal drainage, suggesting a new way to treat dry eye conditions. Further studies are required to assess the clinical value of this treatment.

Effect of intermittent delivery of fluoride to solution on root hard-tissue de- and remineralization measured by 125I absorptiometry.

The effect of intermittent fluoride levels on root hard-tissue de- and remineralization was studied once daily for 21 days in a pH-cycling caries model with simulated fluoride clearance curves. Four root hard-tissue blocks, from each of 12 human teeth, were cut out parallel to the cementum surface. During a daily 15-hour period, the blocks were subjected 12 times to pH changes similar to those which occur in plaque after a carbohydrate intake. The fluoride was delivered immediately before a daily nine-hour remineralization period. Four experiments were independently carried out: One block from each tooth was subjected to pH-cycling without and with fluoride delivery, simulating a rinse with 0.025, 0.2, and 1.0% sodium fluoride (NaF), respectively. The mineral change in the blocks was monitored by 125I absorptiometry and expressed as the change in transmission (delta T). The surface between the data points (delta T values) and the x axis (time points) was used as a summary measure, i.e., the area under the curve (AUC). When no fluoride was delivered, the delta T increased over 21 days, indicating loss of mineral. The AUC was, on average, 5.85 +/- 0.68 (mean +/- S.E.) %.day. In the 0.025% NaF-rinse experiment, there was a marked reduction in mineral loss, indicated by an average AUC of 1.66 +/- 0.59%.day. In both the 0.2 and 1.0% NaF-rinse experiments, a decrease in delta T, indicating gain of mineral, was observed from day 2. Negative delta T values occurred after 7 and 3 days, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of constant fluoride levels in solution on root hard tissue de- and remineralization measured by 125I absorptiometry.

To study the effect of fluoride on de- and remineralization of root hard tissue, an automatic pH-cycling caries model, simulating Stephan curves, was used for 21 days. From each of 13 unexposed human roots, four cementum/dentin blocks were prepared. Four experiments were carried out: one block from each tooth as subjected to pH cycling without and with fluoride at the concentrations of 0.02 ppm (1.0 mumol/l), 0.20 ppm (10.5 mumol/l) and 2.00 ppm (105.3 mumol/l) in the de- and remineralizing solutions, respectively. Mineral change in the specimens was monitored by 125I absorptiometry. When no fluoride was added to the solutions the change in transmission (delta T) increased continuously over 21 days, indicating loss of mineral. In the 0.02-ppm F experiment, there was a marked decrease in delta T, but almost no change in the 0.20-ppm F experiment. pH cycling with 2.00 ppm F in the solutions resulted in a gain of mineral in or most likely on the surface of the cementum/dentin blocks, indicated by a continuously decreasing delta T. The fluoride level in the solution significantly influenced the change in the mineral content of the specimens. Microradiographs of the sectioned blocks showed radiodense surface zones, varying degrees of subsurface demineralization and signs of remineralization or mineral deposition.

Root hard-tissue demineralization rate measured by 125I absorptiometry: comparison with lesion-depth measurements.

The aim of the present study was to compare demineralization of root hard tissue, monitored by 125I absorptiometry, with lesion-depth measurements under polarized light microscopy. The intact roots of ten human molars, which had not been exposed to the oral environment, were divided into 39 cementum/dentin blocks and exposed to a buffer solution of pH 4.5 containing 2.2 mmol/L calcium and inorganic phosphate. After demineralization for 3.5, 7, 14, and 21 days, transmission measurements by 125I absorptiometry were performed, and one block from each tooth was taken out of the solution for lesion-depth measurement. The results showed a high degree of correlation (r = 0.952) between lesion depth and change in transmission, with a more rapid increase initially in both variables. A linear relationship with the square root of time was found. Conversion of transmission data to lesion-depth data was possible when this caries model system was used on cementum dentin blocks.

Automatic pH-cycling caries model applied on root hard tissue.

The development of a caries lesion is a dynamic process that includes frequently alternating periods of de- and remineralization, a process for which no in vitro models currently exists. The aim of this study was to develop a model which could repeatedly generate identical pH versus time curves over extended periods of time. To test the model demineralization studies on cementum/dentin were performed. Cementum/dentin blocks were repeatedly subjected to de- and remineralizing solutions delivered by a computerized pump system connected to a pH-meter and a recorder. pH versus time curves similar to those produced in plaque after carbohydrate intake were generated 18 times during 15 h followed by a remineralizing period of 9 h every day for 16 days. The intra-day and inter-day variation of the pH-cycling model were found to be low. The mineral change of the blocks was followed by 125I absorptiometry and the transmission through the blocks during the experimental period increased in average by 1.4 +/- (SE) 0.18%. Microradiographic analysis of the transversal sections of the blocks confirmed the development of lesions resembling root caries.

Gingival and mucosal reactions after intensive chlorhexidine gel treatment with or without oral hygiene measures.

The aim of this study was to elucidate whether soft tissue reactions during chlorhexidine (CHX) treatment might be associated with meticulous oral hygiene measures. A commercially available 1% chlorhexidine digluconate gel (Hibitane Dental Gel) was applied in a custom tray for the mandibular arch, 10 min daily, for 14 days. A split mouth approach was used to allow evaluation of the effect of oral hygiene measures with toothbrush, toothpaste, and dental floss on one side of the arch. During the treatment period, 8 out of 12 subjects developed gingival and/or mucosal reactions appearing as white patches or ulcerations. Both the gingival reactions on the buccal marginal gingiva and the mucosal reactions near the margin of the custom tray occurred only when the gel treatment was combined with meticulous oral hygiene measures. The white patches, which could easily be detached, leaving ulcerated areas, consisted entirely of stratified squamous epithelium. The findings suggest that intensive treatment with chlorhexidine gel, in individually fitted custom trays, combined with meticulous oral hygiene measures may induce toxic effects on the surface layers of the gingiva and mucosa.

In vitro root caries progression measured by 125I absorptiometry: comparison with chemical analysis.

Radiation from a 125I source and a non-image-forming detector was used for non-destructive measurements of root caries progression. Blocks were cut parallel to the cementum surface of unexposed human roots. These blocks were then individually demineralized in under-saturated calcium phosphate solutions over an 84-hour period. In order for the in vitro root surface demineralization to be followed, the changes in transmission (delta T) through the blocks were measured, by 125I absorptiometry, eight times during the course of the experiment. Chemical analyses of the calcium output (delta Ca) from the blocks into the demineralizing solutions were also performed, and the rate of demineralization (Vdem) was calculated from these values. The precision of 125I absorptiometry was calculated from 176 duplicate transmission measurements, and the coefficient of variation was found to be 0.20%. The correlation coefficient between delta T and total delta Ca for each of 22 cementum/dentin blocks ranged between r = 0.934 and r = 0.998. The progression of root hard-tissue lesions observed by these two methods and by the calculated Vdem was found to be proportional to the square and cubic roots of time. The study shows that 125I absorptiometry can be used for continuous non-destructive measurements of root hard-tissue demineralization in vitro.