J P Jenkins

The University of Manchester, Manchester, ENG, United Kingdom

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Publications (23)35.22 Total impact

  • Clinical Oncology 02/1992; 4(1):11-7. · 2.86 Impact Factor
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    ABSTRACT: Findings on Magnetic Resonance Imaging (MRI) of 52 children with suspected spinal dysraphism have been reviewed. In 24, no significant spinal abnormality was demonstrated. Seven patients had scoliosis or vertebral segmentation anomalies without demonstrable abnormality of the underlying soft tissues and one had an isolated subcutaneous haemangioma. In 20 children with spinal dysraphism, a low tethered cord was the most frequent finding, occurring in 80%. Other manifestations included myelo- or meningocoele (60%), syringomyelia (30%), lipoma (25%), congenital tumour (20%), diastematomyelia (15%) and thickened filum terminale (5%). The relationship between the clinical reason for requesting MRI and the scan results are discussed.
    European Journal of Pediatric Surgery 01/1992; 1 Suppl 1:18-9. · 0.84 Impact Factor
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    ABSTRACT: Thirty-four patients with a presumptive diagnosis of carcinoma of the bladder diagnosed at EUA and cystoscopy have been staged by MRI and the findings correlated with pathology in 15 patients and clinical follow-up, including repeat cystoscopy, in the remainder. MRI is accurate in identifying tumours confined to the bladder wall or extending beyond the wall to involve perivesical fat or adjacent organs. Whilst it is not possible to distinguish between T1, T2 or early T3a tumours they can be distinguished from advanced T3a lesions and this may affect management. MRI is superior to clinical staging, particularly in detecting lymphadenopathy and provides information for optimal radiotherapy planning. The problem of distinguishing between the effects of radiotherapy and suspected recurrent tumour is discussed.
    Clinical Radiology 05/1990; 41(4):258-63. · 1.66 Impact Factor
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    ABSTRACT: MRI and CT findings were reviewed from 11 patients with musculoskeletal haemangiomas. With MRI, morphological characteristics and extent of haemangiomas were optimally demonstrated on T2-weighted spin echo scans. High-resolution contrast-enhanced CT provided equivalent information regarding lesional characteristics and extent for small, localized haemangiomas. In CT evaluation of the extent of large haemangiomas, the radiation dose, transaxial scan plane, amount of intravenous contrast medium required and the necessity for correct timing of post-contrast scans became limiting factors. For such lesions, particularly those extending into the trunk, MRI supplemented by a plain radiograph is the optimum method of evaluation.
    Skeletal Radiology 02/1990; 19(4):251-8. · 1.74 Impact Factor
  • J M Hawnaur, J P Jenkins, I Isherwood
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    ABSTRACT: Musculoaponeurotic fibromatosis can be mistaken for soft-tissue sarcoma both clinically and on X-ray computed tomography. Magnetic resonance imaging (MRI) in three patients with this condition enabled the correct diagnosis to be made prospectively in two. The appearance on MRI of a heterogeneous mass with well-defined, predominantly peripheral areas of very low signal intensity due to dense fibrous tissue and areas of medium to high signal intensity corresponding to a more cellular stroma should raise the the suspicion of musculoaponeurotic fibromatosis. Cellular areas within the tumour showed moderate enhancement after gadolinium diethylene triamine pentaacetic acid administration.
    Skeletal Radiology 02/1990; 19(7):509-14. · 1.74 Impact Factor
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    ABSTRACT: Seventy-six aortic and mitral valves, in 44 patients and 5 normal volunteers, were studied by Cine-Flow MRI (on a 0.26-T superconducting magnet system), utilizing compound oblique imaging planes and a Field Echo Even Rephasing sequence. All patients had had cardiac catheterization and echocardiography. All patients with valvular stenosis and aortic sclerosis (n = 45) showed complete signal loss distal to the respective valve. Length of signal loss distal to the aortic valve in those in whom it was measured (n = 15) allowed differentiation of aortic stenosis (n = 9) from sclerosis (n = 6). This also permitted grading of stenosis with highly significant correlation (T = 0.86; P less than 0.002) with pressure gradient measurement. In mitral stenosis (n = 12) calculation of the area of signal loss distal to the mitral valve as a percentage of left ventricular cross-sectional area showed a highly significant correlation (T = 0.77; P = 0.001) with pressure gradient measurement. Clinically significant valvular regurgitation was graded by size and duration of signal loss proximal to the value with concordance with angiocardiography. It is concluded that Cine-Flow MRI has a clinical role in the diagnosis and assessment of valvular heart disease.
    Magnetic Resonance in Medicine 12/1989; 12(2):181-97. · 3.27 Impact Factor
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    ABSTRACT: Multiple point T1 and T2 values of 424 vertebral bodies were measured and analysed. The influence of several factors including age, sex, location in the spine and status of neighbouring discs on the measured relaxation times were evaluated. The results indicate limitations in the region of interest approach. Vertebral bodies of different age, sex and location in the spine could not be distinguished. For heterogeneous tissues a more advanced form of image analysis appears to be essential. Diurnal factors resulting from the stress of normal ambulatory activity caused increased variation in vertebral body relaxation time values.
    Magnetic Resonance Imaging 01/1989; 7(1):17-23. · 2.06 Impact Factor
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    ABSTRACT: Magnetic resonance imaging (MRI) was performed in 20 patients with evidence on computed tomography (CT) of 21 acoustic neuromas before and after intravenous administration (0.1-0.2 mmol/kg body weight) of gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA). Multi-section spin-echo (SE) sequences of varying repetition (TR) and echo (TE) times were performed in the transverse and coronal planes with a section thickness of 10 mm. All acoustic neuromas displayed marked enhancement on the T1-weighted (short TR/TE) SE sequence post-Gd-DTPA. The intrameatal component was particularly well demonstrated compared with non-enhanced magnetic resonance (MR) images and contrast-enhanced CT. Identification of intrameatal tumour was difficult on T2-weighted SE images and one tumour was not identified on the T1-weighted SE sequence prior to Gd-DTPA. Four of five intrameatal tumours measuring less than 8 mm could only be demonstrated on CT by using CT air meatography. Extrameatal tumour extension was demonstrated on contrast-enhanced CT, although the assessment of brain-stem involvement and displacement was not as clearly seen as on coronal MR images. In two patients with large acoustic neuromas and a cyst, the true relationship of the cyst to the tumour could only be identified on the post-Gd-DTPA scan. Magnetic resonance imaging with gadolinium-DTPA is a relatively quick, safe, well tolerated and effective method for the diagnosis of acoustic neuroma.
    British Journal of Radiology 10/1988; 61(729):800-5. · 1.22 Impact Factor
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    ABSTRACT: Clivus meningioma is an uncommon tumour arising from the region of the synchrondrosis between the basal portions of the sphenoid and occipital bones. We report a case of a patient with a large meningioma of the clivus whose presenting symptom was auditory change. Alteration of hearing is a rare mode of presentation for such a tumour although it may present at a later stage in about 50 per cent of cases. The discrepancy between the size of the tumour and the paucity of physical findings, the value of a multiple test auditory screening strategy, and the surgical approach in this case are discussed.
    The Journal of Laryngology & Otology 09/1988; 102(8):720-3. · 0.68 Impact Factor
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    ABSTRACT: A case of chronic aortic dissection is presented, in which computed tomography and magnetic resonance imaging both demonstrated the abnormality non-invasively. Velocity flow patterns within the true and false lumens obtained by magnetic resonance imaging, using a flow-mapping technique, gave a more thorough analysis.
    Clinical Radiology 08/1988; 39(4):458-61. · 1.66 Impact Factor
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    ABSTRACT: One hundred patients with CT-proven intracranial disease have been studied by magnetic resonance imaging (MRI) before and after intravenous injection with Gadolinium-DTPA (Gd-DTPA), in order to assess the role and clinical efficacy of Gd-DTPA. T2-weighted spin echo sequences, although sensitive to the detection of intracranial disease, in general fail to differentiate macroscopic tumor from oedema. Following Gd-DTPA, T1-weighted spin echo sequences in primary tumours demonstrated a variable degree of contrast enhancement unrelated to histological type. Small tumours, especially acoustic neuromas and meningiomas in the posterior fossa, were rendered more conspicuous. Optimum time for scanning was between five and 25 min following injection for all lesions except those adjacent to normal enhancing structures such as nasal/sinus mucosa and pituitary gland when delayed scans up to 45 min were necessary. No differences were observed between the 0.1 and 0.2 mmol/kg Gd-DTPA concentrations used and no complications attributable to Gd-DTPA were detected. Clinical advantages of Gd-DTPA include shorter scan times, macroscopic tumour/oedema separation and improved detection of certain tumours, particularly acoustic neuromas.
    Neuroradiology 02/1988; 30(2):145-54. · 2.70 Impact Factor
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    ABSTRACT: In a study of 22 patients with 60 coronary artery bypass grafts, magnetic resonance imaging (MRI) correctly assessed graft patency or occlusion in 90% of cases when compared with selective coronary graft angiography and computed tomography. It is concluded that MRI can detect a normally functioning coronary artery bypass graft and could be used as a non-invasive technique to assess graft patency in patients presenting with post-operative angina.
    British Journal of Radiology 02/1988; 61(721):2-4. · 1.22 Impact Factor
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    British Journal of Radiology 12/1987; 60(719):1142-3. · 1.22 Impact Factor
  • J P Jenkins, D S Hickey, I Isherwood
    British Journal of Radiology 11/1987; 60(718):1041-2. · 1.22 Impact Factor
  • J P Jenkins, I Isherwood
    American Journal of Roentgenology 10/1987; 149(4):859. · 2.90 Impact Factor
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    ABSTRACT: T1 and T2 relaxation times have been calculated in 30 patients with rectal carcinoma and seven patients with a fibrotic pelvic mass. The relaxation times were calculated using a multipoint iterative method with data from seven total saturation recovery and six spin-echo sequences. The results show that the calculated T1 relaxation value is a useful discriminant between carcinoma and pelvic fibrosis and should improve the detection of early tumour recurrence.
    British Journal of Radiology 09/1987; 60(716):761-4. · 1.22 Impact Factor
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    ABSTRACT: Twenty-nine patients, 27 of whom had either inflammatory disease of the pancreas or pancreatic tumour, were studied by magnetic resonance imaging (MRI) and computed tomography (CT). Six healthy volunteers were studied by MRI alone. The pancreatic T1 and T2 relaxation times were calculated using a multipoint iterative method with data from seven total saturation recovery and six spin echo sequences. Magnetic resonance imaging can demonstrate the normal pancreas and a variety of pathological processes greater than 1-2 cm in size, but with less spatial resolution than CT. The relaxation-time results indicated no significant discrimination between chronic pancreatitis and pancreatic tumour. A significant elevation in the relaxation times was observed, however, in those patients with calcific chronic pancreatitis compared with the non-calcific chronic pancreatitic group and normal controls, suggesting a different pathophysiology for the two subgroups of chronic pancreatitis. The active phase of acute pancreatitis was associated with significantly elevated relaxation times, which returned to normal levels during the resolved phase of the disease. Associated extrapancreatic fluid collections were characterised by their very long relaxation times. The problems associated with spatial resolution, respiratory motion and lack of quantitative tissue characterisation suggest that MRI of the pancreas, using present methods, is unlikely to contribute to the overall management of patients with exocrine pancreatic disease.
    British Journal of Radiology 05/1987; 60(712):333-41. · 1.22 Impact Factor
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    ABSTRACT: Degenerate discs can be identified quantitatively by measurement of magnetic resonance (MR) relaxation times. MR images have been recorded from 16-year-old and 82-year-old cadaveric L3-4 discs at the highest resolution attainable with a Picker International MR Imaging System operating at 0.26 Tesla. By recording images with a series of spin-echo and/or saturation-recovery sequences of differing time intervals, the values for sample magnetization, M infinity, and the T1 and T2 relaxation times, have been calculated from each pixel in the MR image. The distribution of M infinity values shows the relative degrees of hydration in different regions of the disc while the corresponding T1 and T2 values are sensitive to the chemical environment of the water molecules. Images from cadaveric discs allowed the nucleus pulposus and annulus fibrosus to be distinguished clearly, and the laminated structure of the annulus could be seen. Loss of water from the nucleus during aging was demonstrated by a reduction and change in the distribution of the M infinity values for an 82-year-old disc, as compared with a 16-year-old disc. Values of T1 and T2 indicated a difference in the chemical environment of water molecules in the nucleus pulposus and annulus fibrosus; the extent of this difference was much greater for younger than for older discs. High-resolution MR images from discs of living subjects showed almost as much detail as those from experimental specimens, but in the latter, the laminated structure of the annulus was resolved.(ABSTRACT TRUNCATED AT 250 WORDS)
    Spine 10/1986; 11(7):702-8. · 2.16 Impact Factor
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    ABSTRACT: A method for the determination of relaxation times in clinical magnetic resonance images is described. Three components are measured: the spin-lattice (T1) and spin-spin (T2) relaxation times and the proton density (M infinity). These components are separated in the algorithm to give increased tissue discrimination. Multiple data points are used to minimise error and increase reproducibility. Errors that arise in imaging data because of the short sequence repetition periods are considered and a technique for their reduction described. Clinical results obtained using the method are reviewed. These results demonstrate the clinical utility of the technique.
    British Journal of Radiology 07/1986; 59(702):565-76. · 1.22 Impact Factor
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    ABSTRACT: A reduction in signal intensity from the nucleus can be a feature of intervertebral disc disease. It has been established that T1 and T2 relaxation times of the nucleus decrease with age and that evidence of disc degeneration can be determined before classical clinical features are apparent. A robust multiple point algorithm has been developed which now enables proton density and T1 and T2 values to be computed for each pixel, providing images which are effectively spatial maps of these parameters. Such high resolution maps have provided quantitative data from volunteers, patients and cadavers. These studies have been carried out with specially constructed coils and the cadaveric information compared with cut sections. The spatial maps revealed detailed anatomic structures including the laminae of the annulus and relative levels of hydration. These levels, which are known to be related to the ability of the disc to withstand compressive loads, can now be measured in vivo. Analysis of the proton density and relaxation times in vivo has demonstrated that both water content and the chemical environment in the nucleus change during aging. The results are consistent with changes in the glycosaminoglycan content and fixed charged density measured by other chemical and physical techniques. Such detailed methods can be used to investigate the effects of aging and disease on disc structure and have enabled observations to be made of the effects of stress on the normal disc.
    Acta radiologica. Supplementum 02/1986; 369:492-5.