Publications
1024 results found
Wiesmann F, Taylor AM, Neubauer S, et al., 1997, Current role of magnetic resonance imaging (MRI) in the assessment of coronary artery disease (CAD), ZEITSCHRIFT FUR KARDIOLOGIE, Vol: 86, Pages: 657-668, ISSN: 0300-5860
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- Citations: 1
Gunning MG, Chua TP, Harrington D, et al., 1997, Hibernating myocardium: Clinical and functional response to revascularisation, EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY, Vol: 11, Pages: 1105-1112, ISSN: 1010-7940
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- Citations: 37
Wiesmann F, Gatehouse PD, Jhooti P, et al., 1997, Accuracy of ultrafast magnetic resonance imaging for assessment of right and left ventricular volume and mass, Heart, Vol: 77, ISSN: 1355-6037
In this study we investigated the accuracy and feasibility of 3 ultrafast imaging breath-hold cine sequences in the assessment of right (RV) and left ventricular (LV) volumes and LV mass in comparison with conventional cine gradient echo imaging at the lower field strength of 0.5T. We investigated 15 healthy volunteers (8male, 7female) with mean age 33 yrs (range 21 to 59 yrs). Imaging was performed at 0.5T using echo planar imaging (EPI), fast spiral imaging (SPI), fast gradient echo imaging (FLASH), all with k-space segmentation, and conventional gradient echo imaging (GRE). For all imaging methods, cine images were obtained in contiguous ventricular short axis slices to cover the entire RV and LV. Acquisition of EPI, SPI and FLASH cines took 16 cardiac cycles per slice and was performed during breath-holds. Scan time of the conventional gradient echo sequence (single average) was 128 cardiac cycles per slice. Comparison of LV stroke volume of GRE versus FLASH, EPI and SPI showed good agreement of methods and revealed a mean difference (±sd) of 1.7±13.8, 0.7±13.2 and 0.3±13.8 [ml]. RV stroke volume comparison showed a mean difference (±sd) of 0.1±13.9, 3.3±13.1 and 3.0±13.9 respectively. There was also good agreement of LV enddiastolic (LVEDV) and endsystolic volume (LVESV). RVEDV showed slightly higher variation of values than LVEDV, which represents the fact that clear identification of RV anterior wall is often more difficult than LV wall delineation. The level of agreement in assessing ejection fraction (EF) was high in all three ultrarast imaging sequences for both LV and RV. LV mass was in general underestimated by all three ultrafast breath-hold sequences and showed to comparison with GRE mean differences (±sd) of 11.6±23.7, 14.5±21.8 and 15.5±26.6 [g]for FLASH, EPI and SPI. The degree of agreement with GRE results showed no significant differences between the three ultrafas
Mohiaddin RH, Gatehouse PD, Henien M, et al., 1997, Cinemagnetic resonance Fourier velocimetry of blood flow through cardiac valves: Comparison with Doppler echocardiography, Heart, Vol: 77, ISSN: 1355-6037
Non-invasive measurement of blood flow velocity through the cardiac valves has important clinical applications. A wide variety of magnetic resonance (MR) methods are available for flow measurement. The aim of this study was to investigate the ability of cine MR Fourier velocimetry to measure flow through healthy cardiac valves and to compare MR and Doppler peak velocity measurements. Ten healthy volunteers (age mean ± SD, 24 ± 4 years) without history of valvular disease were studied. Four of the subjects were females. In each subject, aortic, pulmonary, mitral and tricuspid valves were evaluated with MR and Doppler. The heart rate during magnetic resonance and Doppler studies was not significantly different. The mean difference between the two studies was 2 beats / minute, with a 95% confidence interval of (- 22 beats /minute, + 25 beats / minute). Peak systolic flow velocity in the aortic and pulmonary valves, and peak diastolic flow velocity in the mitral and tricuspid valves measured with MRI and Doppler echocardiography correlated well. The mean difference between the two measurements (MR - Doppler) was 63 mm/sec, with a 95% confidence interval of (-180 mm/sec, + 310 mm /sec). The agreement between two observers interpreting the same magnetic resonance velocity maps was close. The mean difference between their two measurements was 23 mm/sec, with a 95% confidence interval of (- 20 mm/sec, + 60 mm /sec). There was no significant difference between MR and Doppler, or between the two MR observers. Magnetic resonance Fourier velocimetry has the necessary ease, reliability and speed to measure blood flow through the cardiac valves. Measurement of peak blood velocity through the cardiac valves by this method showed satisfactory agreement with Doppler but its clinical application for assessing diseased cardiac valves needs to be established.
Panting JR, Gatehouse PD, Yang GZ, et al., 1997, Adenosine stress myocardial perfusion imaging using echo-planar MRI with a 0.5T scanner, Heart, Vol: 77, ISSN: 1355-6037
Myocardial perfusion imaging assesses the physiological significance of coronary stenosis. Current techniques involve the use of ionising radiation and have relatively poor resolution. We compared magnetic resonance imaging (MRI) perfusion studies with radionuclide SPECT scans. In 22 patients with abnormal SPECT (18 males, 4 females, mean age 65, range 46-77) single shot echo-planar imaging with an acquisition time of between 50-100 ms, was performed on a mobile 0.5T scanner. End systolic gating was used with a pixel size of 3.9 x 3.9 mm giving several pixels across the myocardium. Fat suppression reduced the signal from surrounding tissues, and a preparatory inversion pulse was used to null the myocardial signal. For the perfusion study, a bolus of 0.05mmol/kg Gadolinium DTPA was given through a right atrial catheter placed using intravascular electrocardiography via the right antecubital fossa. Two scans were performed, the first at rest and another during the infusion of adenosine at a dose of 140 μg/kg/min to induce maximal coronary hyperaemia. Images were interpreted by visual analysis of the contrast wash-in, and by drawing signal intensity curves obtained from 16 regions of interest around the myocardium. Of the 22 patients, 20 (91%) had interpretable results, the other 2 being hindered by gating problems during acquisition. Of 320 segments, 112 were abnormal by SPECT, of which 94 were reversible and 18 fixed. By MRI, 96 segments were abnormal with 80% concordance with SPECT studies. MRI is fast in comparison to nuclear imaging (1 hour vs typically 4-6 hours) and the use of multislice imaging, which has now been implemented, will enable complete coverage of the myocardium.
Pennell D, 1997, Myocardial perfusion imaging - Techniques for the modern cardiologist, SOUTH AFRICAN MEDICAL JOURNAL, Vol: 87, Pages: C69-C72, ISSN: 0038-2469
Panting JR, Pennell DJ, 1997, Magnetic resonance imaging., Br J Hosp Med, Vol: 57, Pages: 27-30, ISSN: 0007-1064
Yang GZ, Gatehouse PD, Panting J, et al., 1997, Motion analysis for Magnetic Resonance myocardial perfusion imaging, IEE Conference Publication, Pages: 838-842, ISSN: 0537-9989
The assessment of regional myocardial perfusion using Magnetic Resonance (MR) imaging during the first-pass of a contrast agent bolus requires tracking of the signal time course for each myocardial segment so that a detailed perfusion map can be derived. To obtain such a map in practice, however, is not trivial because deformation of the shape of the myocardium and respiratory induced motion render a major difficulty in this process. This study describes a practical implementation of a real-time interactive MR Echo-Planar (EPI) myocardial perfusion imaging system and demonstrates an automated approach for motion and deformation tracking of functional myocardial perfusion images.
Sheppard MN, Kaprielian RR, Gunning M, et al., 1997, Histological, ultrastructural and immunoconfocal microscopical analysis of hibernating ventricular myocardium, JOURNAL OF PATHOLOGY, Vol: 182, Pages: A13-A13, ISSN: 0022-3417
Taylor AM, Wiesmann FW, Pennell DJ, 1996, Assessment of coronary artery anatomy and function by MRI., G Ital Cardiol, Vol: 26, Pages: 1451-1465, ISSN: 0046-5968
Warner OJ, Ohri SK, Pennell DJ, et al., 1996, Magnetic resonance coronary artery imaging for redo coronary operations, ANNALS OF THORACIC SURGERY, Vol: 62, Pages: 1513-1516, ISSN: 0003-4975
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- Citations: 6
Taylor AM, Pennell DJ, 1996, Recent advances in cardiac magnetic resonance imaging, CURRENT OPINION IN CARDIOLOGY, Vol: 11, Pages: 635-642, ISSN: 0268-4705
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- Citations: 5
Kaprielian RR, Dupont E, Gunning M, et al., 1996, Cell structure and connexin43 distribution in hibernating ventricular myocardium, CIRCULATION, Vol: 94, Pages: 1082-1082, ISSN: 0009-7322
Anagnostopoulos C, Gunning MG, Pennell DJ, et al., 1996, Regional myocardial motion and thickening assessed at rest by ECG-gated Tc-99m-MIBI emission tomography and by magnetic resonance imaging, EUROPEAN JOURNAL OF NUCLEAR MEDICINE, Vol: 23, Pages: 909-916, ISSN: 0340-6997
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- Citations: 59
Gunning MG, Knight CJ, Anagnostopoulos C, et al., 1996, Identification of hibernating myocardium: A comparison of TI-201, Tc-99m tetrofosmin, and dobutamine cine magnetic resonance imaging, HEART, Vol: 75, Pages: 242-242, ISSN: 1355-6037
Pennell DJ, Gatehouse PD, Burman ED, et al., 1996, Myocardial perfusion imaging performed using echo-planar single shot magnetic resonance imaging with a mobile 0.5 tesla scanner, HEART, Vol: 75, Pages: 225-225, ISSN: 1355-6037
Pennell DJ, Bogren HG, Keegan J, et al., 1996, Assessment of coronary artery stenosis by magnetic resonance imaging, HEART, Vol: 75, Pages: 127-133, ISSN: 1355-6037
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- Citations: 128
ANAGNOSTOPOULOS C, LANEY R, PENNELL D, et al., 1995, A COMPARISON OF RESTING IMAGES FROM 2 MYOCARDIAL PERFUSION TRACERS, EUROPEAN JOURNAL OF NUCLEAR MEDICINE, Vol: 22, Pages: 1029-1034, ISSN: 0340-6997
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- Citations: 5
ANAGNOSTOPOULOS C, PENNELL D, LANEY R, et al., 1995, AVOIDANCE OF UPWARD CREEP ARTIFACT DURING TI-201 MYOCARDIAL PERFUSION TOMOGRAPHY USING ADENOSINE INFUSION - A CASE-REPORT, CLINICAL NUCLEAR MEDICINE, Vol: 20, Pages: 685-687, ISSN: 0363-9762
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- Citations: 2
PENNELL DJ, MAVROGENI SI, FORBAT SM, et al., 1995, ADENOSINE COMBINED WITH DYNAMIC EXERCISE FOR MYOCARDIAL PERFUSION IMAGING, JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY, Vol: 25, Pages: 1300-1309, ISSN: 0735-1097
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- Citations: 84
Pennell D, Prvulovic E, 1995, nuclear cardiology, Publisher: British Nuclear Medicine Society
Pennell D, Firmin D, Burger P, et al., 1995, Assessment by magnetic resonance velocity mapping of global ventricular function during dobutamine infusion in coronary artery disease, British Heart Journal, Vol: 74, Pages: 163-170
PENNELL DJ, BOGREN HG, KEEGAN J, et al., 1994, Magnetic resonance imaging of coronary arteries and coronary stenosis, 1st Nottingham Symposium on Magnetic Resonance Imaging, Publisher: CHAPMAN HALL LTD, Pages: 393-395, ISSN: 1352-8661
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- Citations: 1
PENNELL DJ, 1994, PHARMACOLOGICAL CARDIAC STRESS - WHEN AND HOW, NUCLEAR MEDICINE COMMUNICATIONS, Vol: 15, Pages: 578-585, ISSN: 0143-3636
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- Citations: 23
PENNELL DJ, ELL PJ, 1994, WHOLE-BODY IMAGING OF TL-201 AFTER 6 DIFFERENT STRESS REGIMENS, JOURNAL OF NUCLEAR MEDICINE, Vol: 35, Pages: 425-428, ISSN: 0161-5505
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- Citations: 16
PENNELL DJ, 1994, THALLIUM MYOCARDIAL PERFUSION TOMOGRAPHY USING INTRAVENOUS DIPYRIDAMOLE COMBINED WITH MAXIMAL DYNAMIC EXERCISE, (VOL 14, PG 939, 1993), NUCLEAR MEDICINE COMMUNICATIONS, Vol: 15, Pages: 123-123, ISSN: 0143-3636
PENNELL DJ, MAHMOOD S, ELL PJ, et al., 1994, BRADYCARDIA PROGRESSING TO CARDIAC-ARREST DURING ADENOSINE THALLIUM MYOCARDIAL PERFUSION IMAGING IN OCCULT SINOATRIAL DISEASE, EUROPEAN JOURNAL OF NUCLEAR MEDICINE, Vol: 21, Pages: 170-172, ISSN: 0340-6997
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- Citations: 13
Pennell DJ, 1994, Review pharmacological cardiac stress: When and how?, Nuclear Medicine Communications, Vol: 15, Pages: 578-585, ISSN: 0143-3636
Pharmacological stress is vital to the modern nuclear cardiological laboratory. In clinical practice only adenosine, dipyridamole and dobutamine are used. Both adenosine (directly) and dipyridamole (indirectly) work via activation of a2 receptors, which causes vasodilatation. Adenosine has a very short half-life and any adverse effects can be rapidly controlled. It is however more expensive and not yet commercially available in the UK when compared with dipyridamole, which has a prolonged 30-min half-life. Dobutamine is a (i-agonist which mimics exercise by raising the rate pressure product, and it also has a short half-life. Adenosine and dipyridamole share some contraindications which include asthma. Dobutamine has been shown to be safe in these patients. Exaggerated responses to adenosine are seen in sinoatrial disease and in patients taking maintenance dipyridamole treatment orally. The adenosine receptor antagonists must be avoided prior to the use of the vasodilators (caffeine 12 h, aminophylline/theophylline 24 h). There is no evidence to suggest any significant difference between pharmacological stress and maximal exercise for myocardial perfusion imaging, but pharmacological stress is necessary for patients who have no exercise capability. Studies which show that submaximal exercise reduces sensitivity suggest that pharmacological stress should also be used in patients whose exercise capacity is suboptimal. The addition of exercise to the vasodilator infusion has been shown to reduce non-cardiac side effects and improve imaging. © 1994 Chapman and Hall Ltd.
JOLOBE OMP, 1994, MANAGEMENT OF ACUTE MYOCARDIAL-INFARCTION, JOURNAL OF THE ROYAL COLLEGE OF PHYSICIANS OF LONDON, Vol: 28, Pages: 485-486, ISSN: 0035-8819
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- Citations: 2
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