A high spatial resolution brain positron tomograph, the ECAT 953B/31, is presented. The machine consists of two 76.5 cm diameter rings (patient port diameter: 36 cm) made of 24 8x8 BGO detector blocks each, each block being coupled to four 1 in(2) Hammamatsu phototubes. The machine has 15 9 cmx1 mm motorized removable septa, which allows reconstruction of 31 slices 3.375 mm apart. The transaxial resolution (FWHM) in the reconstructed image (with wobbling) is 4.5 mm at center, 5.2 mm (tangential) and 5.6 mm at 10 cm from center. With septa out of the field of view (FOV), the axial resolution degrades to 5.5 mm a center and 6.3 mm at 10 cm from center. At 1 muCi/cc with a 250 keV threshold and a 12 ns coincidence window, the sensitivity is 146100 true events, the ratio of randoms to trues is 0.10, the scatter fraction is 17% and the dead-time losses are 30%. With septa out of the FOV, the sensitivity is increased by a factor 3.6, while the scatter fraction reaches 0.9. Images obtained with (18 )F-DG and H(2)(15)O in human brains and (18 )F-DOPA in a baboon brain demonstrate that the ECAT 953B/31 will be suitable for high resolution and for low count rate brain studies.
ObjectiveTo assess quantitative perfusion of intra‐ and extraocular regions of interest (ROIs) in conscious, healthy dogs utilizing contrast‐enhanced ultrasonography (CEUS); to compare varying enhancement with the first and second bolus injection and in the right and left eye; and to determine the most appropriate examination time.ProceduresGray scale ultrasonography and contrast harmonic imaging using sulfur hexafluoride were performed randomly assigned in both eyes in 10 university‐owned beagles. Perfusion parameters including slope time, time to peak (TTP), peak intensity (PI), and area under the curve (AUC) were measured at individually drawn ROIs (retrobulbar cone = ROI 1, choroid‐retina complex = ROI 2, medial = ROI 3, and lateral anterior uvea = ROI 4).ResultsTime‐intensity curve parameters revealed no significant differences in eyes examined by the first or second bolus injection (P > 0.05) or in the right or left eye (P > 0.05). Pooled data from all eyes were analyzed. Peak intensity of ROI 2 was significantly higher compared to all other ROIs (P < 0.001). Area under the curve at ROI 2 was significantly higher compared to all other ROIs (P < 0.05), and AUC at ROI 1 was significantly higher than at ROI 4 (P < 0.05). No significant differences in TTP were observed between different ROIs (P > 0.05). Ratios relative to different ROI sizes showed fastest enhancement in the retrobulbar cone and most intense perfusion in the anterior uveal regions. The first minute after contrast injection provided the highest diagnostic value.ConclusionQuantitative perfusion in nondiseased canine eyes revealed consistent parameters. Application of standardized CEUS protocols may be a promising diagnostic tool to differentiate ocular lesions.
We present a new high spatial resolution brain positron tomograph the ECAT 953B/31. The machine consists of two 76.5 cm diameter rings (patient port diameter : 36 cm) made of 24 8x8 BGO detector blocks each, each block being coupled to four 1 incha Hammamatsu phototubes. The machine has fifteen 9 cm x 1 mm motorized removable septa which allows reconstruction of 31 slices 3.375 mm apart.The transaxial resolution (FWHM) in the reconstructed image (with wobbling) is 4.5 mm at center, 5.2 mm (tangential) and 5.6 mm (radial) at 10 cm. The axial resolution is 4.4 mm and 5.8 mm at 10 cm from center. With septa out of the field of view (FOV), the axial resolution degrades to 5.5 mm at center and 6.3 mm at 10 cm from center. At 1 pCi/cc with a 250 keV threshold and a 12 nsec coincidence window, the sensitivity is 146,100 true events/sec, the ratio of random to trues is .lo, the scatter fraction is 17% and the dead time losses are 30%. With septa out of the FOV, the sensitivity is increased by a factor 3.6, while the scatter fraction reaches 41%.Images obtained with '"F-DG and Hi50 in human brains and '"F-DOPA in a baboon brain demonstrate that the ECAT 953B/31 will be particularly suitable both for high resolution and for low count rate brain studies.
A 13-year-old warmblood gelding presented with a history of lameness, muscle atrophy and weight loss of 3 months. The horse demonstrated extensive hyperaesthesia over the left dorsal trunk, marked effusion of several joints, laryngitis and a dampened mental attitude. Synovial fluid analysis revealed arthritis of the left tarsocrural joint, being PCR-positive for Borreliaafzelii DNA. Subsequently, mild anterior uveitis of the right and severe panuveitis of the left eye with B. afzelii PCR-positive aqueous and vitreous humour, respectively, were diagnosed. Treatment included arthroscopy of the left tarsocrural joint, oral doxycycline administration for 6 weeks, ophthalmic and systemic anti-inflammatory therapy and left intravitreal preservative-free gentamicin (4 mg) injection. After initial improvement, the gelding’s clinical signs deteriorated resulting in peracute recumbency and sudden death 12 months later. Lyme borreliosis should be considered as differential diagnosis in complex cases of equine lameness, particularly when accompanied by hyperaesthesia and bilateral uveitis.
Zusammenfassung: Die Fixierung der Zunge am Unterkiefer mittels sogenannter Zungenbänder (Tongue Ties, TTs) bei Trab-und Galopprennpferden wurde in Deutschland durch die deutschen Rennsportverbände bisher nicht dokumentiert und es ist wenig bekannt zum Tierschutzaspekt ihres Einsatzes. Das Ziel dieser Studie war es, kasuistische Daten zur Nutzung von TTs im Training und bei Rennen in Deutschland zu sammeln. Dazu wurden Daten von 499 Galopprennpferden gesammelt, indem Fragebögen an 153 beim Direktorium für Vollblutzucht und Rennen (DVR) registrierte Trainer versandt wurden. Außerdem wurden Daten von 9 Trainern über 82 Trabrennpferde erhoben. Von diesen insgesamt 581 Pferden nahmen 133 auch an internationalen Rennen teil. Insgesamt wurden 17,2 % der Pferde mit TTs trainiert und 19,3 % mit TT gestartet. Jüngere 3-und 4-jährige Traber wurden dabei häufiger mit TTs trainiert als Galopprennpferde, während mehr ältere Galopper als Traber TTs im Training und beim Rennen trugen (5 Jahre und älter). Die häufigsten positiven Effekte, die von den Trainern berichtet wurden, waren die Verhinderung der Verlagerung der Zunge über das Gebiss (37/41) und die Reduktion eines Atemgeräusches (24/41). Die Mehrheit berichtete außerdem von einer Leistungsverbesserung im Training (63 %) und beim Rennen (76 %). Die Mehrheit (22/41) der Trainer hatten bislang keine negativen Auswirkungen des Einsatzes von TTs bemerkt, während die anderen in bis zu 10 % der Einsätze (14/41) oder sogar mehr (5/41) von negativen Auswirkungen berichteten. Die häufigsten Nebenwirkungen waren eine Verfärbung der Zunge unter Fixation (n = 16), gefolgt von Blutungen (n = 4) und Paralysen (n = 1) der Zunge, wobei Mehrfachnennungen möglich waren. Insgesamt erscheint der Einsatz von TTs trotz des häufigen Gebrauchs und der positiven Effekte, die von Trab-und Galopprenntrainern berichtet wurden, aus Tierschutzgründen mehr als fraglich. Der Einsatz des TT ist mittlerweile, seit Juni 2018, im Galopprennsport in Deutschland vom DVR verboten, im Trabrennsport aber weiterhin erlaubt.
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