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Mahon MM, Williams AD, Soutter WP, Cox IJ, McIndoe GA, Coutts GA, Dina R, deSouza NM. 1H magnetic resonance spectroscopy of invasive cervical cancer: an in vivo study with ex vivo corroboration. NMR IN BIOMEDICINE 2004; 17:1-9. [PMID: 15011245 DOI: 10.1002/nbm.830] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The objective of this study was to establish in vivo (1)H-magnetic resonance (MR) spectroscopic appearances of cervical cancer using an endovaginal receiver coil and corroborate findings with magic angle spinning (MAS) MR spectroscopy of tissue samples. Fifty-three women (14 controls and 39 with cervical cancer) underwent endovaginal coil MR imaging at 1.5 T with T(1)- and T(2)-weighted scans sagittal and transverse to the cervix. Localized (1)H MR spectra (PRESS technique, TR 1600 ms, TE 135 ms) were accumulated in all controls and 29 cancer patients whose tumour filled > 50% of a single 3.4 cm(3) voxel. Peaks from triglyceride-CH(2) and -CH(3) were defined as present and in-phase (with the choline resonance), present but out-of-phase, or not present. Peak areas of choline-containing compounds were standardized to the area of unsuppressed tissue water resonance. Comparisons in observed resonances between groups were made using Fisher's exact test (qualitative data) and a t-test (quantitative data). Biopsies from these women analysed using MAS-MR spectroscopy and normalized to the intensity of an external standard of silicone rubber were similarly compared. Adequate water suppression permitted spectral analysis in 11 controls and 27 cancer patients. In-phase triglyceride-CH(2) resonances (1.3 ppm) were observed in 74% of tumours but in no control women (p < 0.001). No differences were observed in the presence of a 2 ppm resonance, choline-containing compounds or creatine in cancer compared with control women. However, ex vivo analysis showed significant differences not only in -CH(2), but also in -CH(3), a 2 ppm resonance, choline-containing compounds and creatine between tissues from control women and cancer tissue (p < 0.001, = 0.001, = 0.036, < 0.001 and = 0.004 respectively). On in vivo (1)H-MR spectroscopy, the presence of positive triglyceride-CH(2) resonances can be used to detect and confirm the presence of cervical cancer. However, technical improvements are required before routine clinical use.
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Mahon MM, Cox IJ, Dina R, Soutter WP, McIndoe GA, Williams AD, deSouza NM. 1H magnetic resonance spectroscopy of preinvasive and invasive cervical cancer: In vivo-ex vivo profiles and effect of tumor load. J Magn Reson Imaging 2004; 19:356-64. [PMID: 14994305 DOI: 10.1002/jmri.20012] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To compare in vivo (1)H magnetic resonance (MR) spectra of preinvasive and invasive cervical lesions with ex vivo magic angle spinning (MAS) spectra of intact biopsies from the same subjects and to establish the effects of tumor load in the tissue sampled on the findings. MATERIALS AND METHODS A total of 51 subjects (nine with normal cervix, 10 with cervical intraepithelial neoplasia [CIN], and 32 with cervical cancer) underwent endovaginal MR at 1.5 T. Single-voxel (3.4 cm(3)) (1)H MR spectra were acquired and voxel tumor load was calculated (tumor volume within voxel as a percentage of voxel volume). Resonances from triglycerides -CH(2) and -CH(3) and choline-containing compounds (Cho) were correlated with voxel tumor load. Biopsies analyzed by (1)H MAS-MR spectroscopy (MRS) had metabolite levels correlated with tumor load in the sample at histology. RESULTS In vivo studies detected Cho in normal, CIN, and cancer patients with no significant differences in levels (P = 0.93); levels were independent of voxel tumor load. Triglyceride -CH(2) and -CH(3) signals in-phase with Cho were present in 77% and 29%, respectively, of cancer subjects (but not in normal women or those with CIN), but did not correlate with voxel tumor load. Ex vivo cancer biopsies showed levels of triglycerides -CH(2) and -CH(3) and of Cho that were significantly greater than in normal or CIN biopsies (P < 0.05); levels were independent of the tumor load in the sample. The presence of -CH(2) in vivo predicted the presence of cancer with a sensitivity and specificity of 77.4% and 93.8% respectively, positive (PPV) and negative (NPV) predictive values were 96% and 68.2%; for -CH(2) ex vivo, sensitivity was 100%; specificity, 69%; PPV, 82%; and NPV, 100%. CONCLUSION Elevated lipid levels are detected by MRS in vivo and ex vivo in cervical cancer and are independent of tumor load in the volume of tissue sampled.
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Dave UR, Williams AD, Wilson JA, Amin Z, Gilderdale DJ, Larkman DJ, Thursz MR, Taylor-Robinson SD, deSouza NM. Esophageal cancer staging with endoscopic MR imaging: pilot study. Radiology 2003; 230:281-6. [PMID: 14645876 DOI: 10.1148/radiol.2301021047] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The authors defined esophageal anatomy and evaluated esophageal cancer staging in a pilot group by comparing endoscopic magnetic resonance (MR) imaging results with pathologic and endoscopic ultrasonographic (US) results when available. A porcine esophagus, one volunteer, and 23 patients suspected of having esophageal cancer were imaged at 0.5 T. MR imaging was successful in 21 patients. Eight of these patients underwent esophagectomy (one after chemotherapy, which invalidated comparison with MR imaging; another did not undergo lymphadenectomy) and one underwent laparoscopy and nodal staging only; eight underwent US. When verified with pathologic staging, endoscopic MR imaging was accurate in six of seven patients (T stage) and five of six patients (N stage; nodal areas too obscured by artifact for comparison in one case). MR imaging and US results concurred in seven of eight (T stage) and five of eight (N stage) patients. No complications were observed. Endoscopic MR imaging is safe and probably comparable to endoscopic US, but with a tendency to overstage the disease.
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Gilderdale DJ, Williams AD, Dave U, deSouza NM. An inductively-coupled, detachable receiver coil system for use with magnetic resonance compatible endoscopes. J Magn Reson Imaging 2003; 18:131-5. [PMID: 12815649 DOI: 10.1002/jmri.10321] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To construct an inductively-coupled receiver coil system for use with a magnetic resonance (MR) compatible endoscope, and to evaluate its use in a pilot group of patients with esophageal cancer. MATERIALS AND METHODS An inductively-coupled coil system, comprising a saddle geometry cylindrical receiver coil fitted as a sleeve around the endoscope tip and a pick-up coil housed within a channel of an MR-compatible endoscope, was designed and developed for use at 0.5 T. Twenty-three patients with esophageal cancer were recruited for MR endoscopy. In 17 cases, the endoscopic coil system was used in conjunction with an external surface coil in order to obtain information from the surrounding mediastinum. The examination took 40-50 minutes. RESULTS MR imaging using the inductively-coupled endoscopic coil was successful in 21 cases (one failed intubation and one artifact from unrelated external source). Image artifact was largely due to respiration and global patient motion in sedated individuals undergoing endoscopy. CONCLUSION Inductively-coupled coil systems may be used with endoscopes to allow improved safety through increased patient-system isolation and detachability of coils and electronics for repair or replacement with coils tuned for different frequencies.
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Connors AM, deSouza NM, McIndoe GA. Adenomyoma mimicking an aggressive uterine neoplasm on MRI. Br J Radiol 2003; 76:66-8. [PMID: 12595328 DOI: 10.1259/bjr/19147576] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
This case report concerns a nulliparous female with prolonged vaginal bleeding, where MRI demonstrated a mass with an aggressive, tumour like appearance involving the posterior aspect of the uterus. Histological examination confirmed that this was an adenomyoma. The unusual imaging appearance of this lesion and its differential diagnosis are discussed. Adenomyoma should be considered in the differential diagnosis of aggressive-appearing uterine masses.
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deSouza NM, Daniels OJ, Williams AD, Gilderdale DJ, Abel PD. Female urinary genuine stress incontinence: anatomic considerations at MR imaging of the paravaginal fascia and urethra initial observations. Radiology 2002; 225:433-9. [PMID: 12409577 DOI: 10.1148/radiol.2252011347] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE To compare, on high-spatial-resolution magnetic resonance (MR) images, the presence and distribution of the paravaginal fascia in continent women and in those with genuine stress incontinence (GSI) to establish its role in the pathophysiology of GSI. MATERIALS AND METHODS Eleven continent reference subjects and 10 GSI patients underwent MR imaging with a specifically designed endovaginal receiver coil. A urinary continence questionnaire and urogynecologic clinical examination had been completed. GSI was diagnosed with urodynamic tests. Paravaginal fascial tissue distribution was determined, and the paravaginal fascial volume (PFV) anteriorly associated with the urethra was measured. Retropubic urethral length (UL) in the supine position at rest was compared with its total length and expressed as a percentage ratio. Comparisons of urethral PFV and retropubic UL between reference subjects and the GSI patients were performed by means of two-sample t tests with unequal variances because data were parametric by means of the Shapiro-Francia W' test for normal data. RESULTS The paravaginal fascia (connective tissue that contained venous plexus) was a consistent MR imaging feature in all women. Mean urethral PFV was 5.3 cm(3) +/- 0.6 (SD) in reference subjects compared with 3.5 cm(3) +/- 2.0 in GSI patients (P =.017). The ratio of the retropubic UL to its total length was 82.6% +/- 7.4 in reference subjects compared with 57.4% +/- 9.8 in GSI patients (P <.001). There was a weak correlation between urethral PFV and retropubic UL (r = 0.46). CONCLUSION There is a significant association between urethral PFV and continence status. GSI patients have a reduced urethral PFV, and greater than 40% of their urethral length lies below the pubis in the supine position at rest. However, the effects of age and hormonal status on urethral PFV remain to be evaluated.
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Hettiarachchi M, Garcea G, deSouza NM, Williams AD, Clayden GS, Ward HC. Evaluation of dysfunction following reconstruction of an anorectal anomaly. Pediatr Surg Int 2002; 18:405-9. [PMID: 12415366 DOI: 10.1007/s00383-002-0808-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/16/2001] [Indexed: 10/27/2022]
Abstract
To evaluate the utility of anorectal manometry (ARM) and magnetic resonance imaging (MRI) with an endocoil in the assessment of dysfunction in children with repaired anorectal anomalies (ARA), 15 patients aged 1 to 15 years with repaired ARAs and chronic faecal incontinence or constipation were prospectively recruited. They underwent clinical assessment using a modified Wingfield score (MWS). ARM and MRI with an endocoil and conventional external coil were carried out. The results of ARM alone, MRI alone, and a combination of ARM and MRI were correlated with the MWS. Manometric internal anal sphincter (IAS) scores determined from sphincter length and activity correlated with MWS (r = 0.56, P = 0.02); manometric scores of rectal peristaltic activity did not. Overall manometric score (IAS and rectal scores combined) showed a correlation with MWS (r = 0.55, P = 0.02). Endoanal MRI sphincter scores did not correlate with MWS, but the presence of a megarectum on MRI did (r = 0.44, P = 0.05). Overall MRI score did not correlate with MWS. Minor neurosacral anomalies were shown on MRI in 3 children who had poor functional scores. Combined manometric and MRI scores showed a correlation with MWS (r = 0.58, P = 0.01). ARM and MRI are potentially useful in the assessment of dysfunction of children with repaired ARAs. Both modalities require refinement and further assessment in the context of directing management.
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Eckersley RJ, Sedelaar JPM, Blomley MJK, Wijkstra H, deSouza NM, Cosgrove DO, de la Rosette JJMCH. Quantitative microbubble enhanced transrectal ultrasound as a tool for monitoring hormonal treatment of prostate carcinoma. Prostate 2002; 51:256-67. [PMID: 11987154 DOI: 10.1002/pros.10065] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND We quantified changes in prostate carcinoma vascularity treated with anti-androgens using color Doppler and power transrectal ultrasound in combination with microbubble contrast agent Levovist. METHODS Thirty-six men with prostate carcinoma were studied at baseline and at intervals during treatment. At each attendance, Levovist((R)) (10 ml, 300 mg/ml) was given as an iv bolus. Using quantitative analysis, we calculated the pre-enhancement scores, arrival time, time to peak, peak value, and area under the time-enhancement curve (AUC). These were compared to pre-treatment values and serial PSA measurements. RESULTS The pre-enhancement, peak value, and AUC each showed a marked response with reductions within one week. The average AUC declined to 68% +/- 9% (mean +/- standard error) by week 1, 56% +/- 9% by week 3, and 20% +/- 4% by week 6. A strong correlation with changes in the mean PSA (r = 0.95, P < 0.001) was also measured. In four patients, Doppler indices did not fall with PSA: two patients with the most marked discrepancy relapsed at 6 months. CONCLUSION The vascular enhancement declined with therapy, similar to PSA. Microbubble enhanced ultrasound can show early response to treatment.
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deSouza NM, Williams AD. Uterine arterial embolization for leiomyomas: perfusion and volume changes at MR imaging and relation to clinical outcome. Radiology 2002; 222:367-74. [PMID: 11818601 DOI: 10.1148/radiol.2222010584] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To monitor changes in perfusion and volume of uterus and leiomyomas after bilateral uterine artery embolization (UAE) and to correlate immediate perfusion changes with subsequent reduction in leiomyoma volume and clinical outcome. MATERIALS AND METHODS Eleven consecutive women underwent magnetic resonance (MR) imaging before UAE, immediately after, and at 1 and 4 months. Reduction in maximal enhancement above baseline at 90 seconds (ME(90)) after injection of the dominant leiomyoma immediately after embolization was correlated with its volume reduction at 4 months and with clinical response at 12 months. RESULTS Forty-five leiomyomas were noted (mean, four per patient). Myometrium enhanced briskly (ME(90) of 110%), with a reduction in ME(90) to 26% immediately after embolization. Initial leiomyoma ME(90) was lower (P <.001), but it suppressed to baseline levels immediately after embolization. At 1 and 4 months, myometrial perfusion returned to normal, but leiomyoma perfusion remained suppressed (P <.001). Immediate reduction in leiomyoma ME(90) correlated with clinical response (Spearman rho = 0.64). Leiomyomas initially high in SI on T2-weighted images showed significantly greater volume reduction than those low in SI (P =.006). Well-perfused leiomyomas did not show greater volume reduction than those that were poorly perfused. Volume reduction did not correlate with improvement in clinical symptom score. CONCLUSION Immediate reduction in leiomyoma perfusion after bilateral UAE correlates with clinical response, whereas leiomyomas initially high in SI on T2-weighted images indicate a likely greater volume reduction.
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Gornall RJ, Standfield N, deSouza NM, Aachi VR, McIndoe GA. Resection of recurrent bulky gynaecological side wall malignancy with iliac vessel reconstruction. BJOG 2001; 108:1305-8. [PMID: 11843398 DOI: 10.1111/j.1471-0528.2001.00271.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Larkman DJ, deSouza NM, Bydder M, Hajnal JV. An investigation into the use of sensitivity-encoded techniques to increase temporal resolution in dynamic contrast-enhanced breast imaging. J Magn Reson Imaging 2001; 14:329-35. [PMID: 11536411 DOI: 10.1002/jmri.1190] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Gadolinium-enhanced dynamic magnetic resonance (MR) imaging is playing an increasingly important diagnostic role in patients with breast cancer. Because of the multi-focal nature of the disease, it is mandatory to cover all of both breasts, not only in the initial scan, but also at subsequent follow-up. This requires volume acquisitions with a temporal resolution limited to 60-80 seconds, which is insufficient to clearly discriminate malignant from benign rates of contrast uptake. In this work, we performed sensitivity-encoded imaging using a commercially available four-channel breast coil (MRI Devices Corporation) on a commercial 0.5-T scanner with moderate gradient performance to give increased temporal resolution in these dynamic contrast-enhanced scans. A two-fold increase in temporal resolution was readily achievable with this coil. Image reconstruction was robust and image quality was assessed qualitatively to be good. We also investigated higher speed-up factors using two directions of sensitivity-encoded reduction and discussed some of the potential artifacts associated with such imaging.
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Williams AD, Cousins C, Soutter WP, Mubashar M, Peters AM, Dina R, Fuchsel F, McIndoe GA, deSouza NM. Detection of pelvic lymph node metastases in gynecologic malignancy: a comparison of CT, MR imaging, and positron emission tomography. AJR Am J Roentgenol 2001; 177:343-8. [PMID: 11461859 DOI: 10.2214/ajr.177.2.1770343] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Accurate assessment of lymph node status before treatment is critical in the treatment of gynecologic cancers because the 5-year survival and treatment of women is influenced by lymph node involvement. The aims of this study were to investigate the ability of X-ray CT, MR imaging, and (18)F-FDG positron emission tomography (PET) to detect pelvic lymph node metastases by comparing imaging with histopathologic findings after lymph node dissection. MATERIALS AND METHODS Eighteen patients with gynecologic cancers were studied by all three imaging methods before surgery. The images were initially reviewed with routine diagnostic conditions and then, subsequently, by two observers who were unaware of the clinical and histopathologic findings of the patients. The nodal sites were split into upper (aortic to common iliac bifurcations) and lower (common iliac bifurcations to inguinal ligament) iliac chains. All observers' results were statistically analyzed with specificity, sensitivity, positive and negative predictive values, Fisher's exact test (individual observers) or chi-square test (combined observers), and Cohen's kappa test. RESULTS Eight of 18 patients had lymph node metastases at histology. Findings of all three modalities agreed in full in only one patient. CT correctly revealed 10 node-negative patients, whereas MR imaging was correct in eight of these patients. (18)F-FDG PET correctly depicted one patient with lymph nodes negative for tumor. CT was the most specific imaging modality (97.0%), with MR imaging and PET rendering values of 90.7% and 77.3%, respectively, but sensitivity of all modalities was low (CT, 48.1%; MR imaging, 53.7%; PET, 24.5%). Observer agreement for each modality was good; kappa values among all observers were 0.88 for CT, 0.85 for MR imaging, and 0.72 for PET. CONCLUSION CT is the most specific modality for detecting lymph nodes positive for tumor in gynecologic cancers, whereas MR imaging is the most sensitive. The poor results of PET in the pelvis are attributed to urinary (18)F-FDG in the ureters or bladder, which may mask or imitate lymph node metastases.
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Herlihy DJ, Larkman DJ, deSouza NM, Williams AD, Young IR. Catheter tracking for MR fluoroscopy: design of a transmit/receive coil for use with a nasogastric tube. J Magn Reson Imaging 2001; 13:127-30. [PMID: 11169814 DOI: 10.1002/1522-2586(200101)13:1<127::aid-jmri1019>3.0.co;2-k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A coil tuned to 21.3 MHz was incorporated into a nasogastric tube and used as a marker of tube position during magnetic resonance (MR) imaging in a 0.5-T scanner. Catheter tracking was investigated with the coil used in both transmit/receive and in receive-only modes. Data acquired from this coil were overlaid on images obtained using the body coil of the scanner. Visualization of the full length of the catheter with local high signal at the tip was achieved with a temporal resolution of approximately 1 second. J. Magn. Reson. Imaging 2001;13:127-130.
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deSouza NM, Whittle M, Williams AD, Sohail M, Krausz T, Gilderdale DJ, McIndoe GA, Soutter WP. Magnetic resonance imaging of the primary site in stage I cervical carcinoma: A comparison of endovaginal coil with external phased array coil techniques at 0.5T. J Magn Reson Imaging 2000; 12:1020-6. [PMID: 11105045 DOI: 10.1002/1522-2586(200012)12:6<1020::aid-jmri30>3.0.co;2-t] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
OBJECTIVE To compare endovaginal with pelvic phased array coil magnetic resonance imaging (MRI) in detection of Stage I cervical carcinoma by correlating the findings with histopathology. PATIENTS AND METHODS Forty consecutive patients with Stage I cervical carcinoma confirmed histologically were studied using an endovaginal coil alone immediately followed by a pelvic phased array coil. T1-W transverse and T2-W FSE sagittal images made with each coil were analyzed independently by two radiologists noting the presence and size of a mass within the cervix and any parametrial extension or involvement of adjacent organs. Tumor volumes were measured using the electronic calliper to compute tumor area on each slice and multiplying by the slice thickness. Thirty patients underwent radical hysterectomy, one a trachylectomy, one simple hysterectomy and four extended cone biopsies. Four patients had radiotherapy to the primary tumor. Following surgery, histopathologic findings were recorded and tumor volumes measured. RESULTS Tumor volumes ranged from 0-106 cm(3)(median 1.4 cm(3), mean 9 +/- 19.4 cm(3)). Thirty-six patients had correlation of the primary site with the surgical specimen. Agreement between observers was excellent for both endovaginal (k = 0.90) and pelvic phased array (k = 0.96) techniques. Combined sensitivity and specificity for both observers of endovaginal MR imaging for detection of tumor was 96% and 70%, respectively; for pelvic phased array imaging sensitivity was substantially less at 54%. Specificity was higher at 83.7%, probably because small abnormalities were seldom visible. In patients treated surgically, early parametrial involvement in four women on endovaginal MRI was confirmed histologically in two. Pelvic phased array imaging showed early parametrial involvement in four women and was confirmed in one. CONCLUSION Endovaginal MRI adds substantially to information from pelvic phased array images in the preoperative assessment of patients with early cervical cancer. J. Magn. Reson. Imaging 2000;12:1020-1026.
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Nelson SR, deSouza NM, Allison DJ. Endovascular stents and stent-grafts: is heparin coating desirable? Cardiovasc Intervent Radiol 2000; 23:252-5. [PMID: 10960536 DOI: 10.1007/s002700010064] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Heparins are glycosaminoglycans that, in addition to their anticoagulant activity, have interactions with growth factors and other glycoproteins. These interactions may stimulate neointimal hyperplasia when heparin is delivered locally on stents and stent-grafts. Modifying the structure of heparin to retain anticoagulant activity while minimizing these stimulatory effects on the vascular endothelium is desirable and may be achieved by understanding the relationships between the structure and function of the various parts of the heparin molecule.
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Gilderdale DJ, deSouza NM, Coutts GA, Chui MK, Larkman DJ, Williams AD, Young IR. Design and use of internal receiver coils for magnetic resonance imaging. Br J Radiol 1999; 72:1141-51. [PMID: 10703469 DOI: 10.1259/bjr.72.864.10703469] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
This review describes coils for MRI that are inserted into the body through natural orifices. It covers the design and implementation of small internal receiver coils for use in the pelvis and gastrointestinal tract. Normal anatomy delineated by the high resolution obtained by using these coils and the appearances in a number of disease states for each clinical application are described.
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Young IR, deSouza NM, Hall AS, Williams AD, Hajnal JV, Coutts GA. Pre-polarized saline: an in vivo feasibility study of a potential contrast agent. NMR IN BIOMEDICINE 1999; 12:381-386. [PMID: 10516620 DOI: 10.1002/(sici)1099-1492(199910)12:6<381::aid-nbm574>3.0.co;2-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The potential for using pre-polarized liquids as contrast agents in vivo is investigated and the feasibility of the method demonstrated. In this study we show the enhancement obtained following intravenous delivery of pre-polarized saline into the antecubital vein of a volunteer. This form of contrast agent provides signal gain on time scales commensurate with its T(1) and allows repeated doses to be administered, thus making alternate acquisitions of data with and without enhancement practicable.
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deSouza NM, Ward HC, Williams AD, Battin M, Harris DN, McIver DK. Transanal MR imaging after repair of anorectal anomalies in children: appearances in pull-through versus posterior sagittal reconstructions. AJR Am J Roentgenol 1999; 173:723-8. [PMID: 10470912 DOI: 10.2214/ajr.173.3.10470912] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Our objective was to use transanal MR imaging to compare the anatomic appearance of the components of the anal sphincter and the pattern of scarring after a pull-through perineoplasty versus a posterior sagittal anorectoplasty. SUBJECTS AND METHODS Sixteen children ranging in age from 10 months to 15 years (mean, 10 years) were imaged using transanal receiver coils appropriate to the size of the child. Five had low, four intermediate, and seven high anomalies. Seven had undergone a transanal pull-through procedure, and nine had undergone posterior sagittal reconstruction. The integrity of the muscles was assessed on T1-weighted and short inversion time inversion recovery transverse and coronal images using a qualitative MR imaging score. The pattern of scarring was also assessed. RESULTS In the transanal pull-through group, four of seven patients showed external sphincter deficiency. A circumferential low-signal-intensity band was seen inferior to the sphincter in six patients. All posterior sagittal reconstructions had a long posterior midline scar. Five of nine patients showed external sphincter deficiency, whereas a further two had internal sphincter deficiency. No differences were seen in MR imaging scores for each operative procedure for all grades of severity of anorectal anomaly. However, a comparison between high and intermediate anomalies showed a small improvement in MR imaging score using the transanal pull-through procedure (Mann-Whitney U test = 3, p < .03). Manometric pressures obtained in 13 patients were poor. CONCLUSION Transanal MR imaging identifies focal defects and patterns of scarring of the anal sphincter complex in infants and children and provides valuable information about individual muscle components.
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Zbar AP, deSouza NM. Prospective comparison of endosonography, magnetic resonance imaging and surgical findings in anorectal fistula and abscess complicating Crohn's disease. Br J Surg 1999; 86:1093-4. [PMID: 10498422 DOI: 10.1046/j.1365-2168.1999.01197-3.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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deSouza NM, Williams AD, Gilderdale DJ. High-resolution magnetic resonance imaging of the anal sphincter using a dedicated endoanal receiver coil. Eur Radiol 1999; 9:436-43. [PMID: 10087112 DOI: 10.1007/s003300050688] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The use of a surface coil in MR imaging improves signal-to-noise ratio of adjacent tissues of interest. We therefore devised an endoanal receiver coil for imaging the anal sphincter. The probe is solid and re-usable: it comprises a saddle geometry receiver with integral tuning, matching and decoupling. It is placed in the anal canal and immobilised externally. Both in vitro and in vivo normal anatomy is identified. The mucosa is high signal intensity, the submucosa low signal intensity, the internal sphincter uniformly high signal intensity and the external sphincter low signal intensity on T1- and T2-weighted images. In females, the transverse perineal muscle bridges the inferior part of the external sphincter anteriorly. In perianal sepsis, collections and the site of the endoanal opening are identified. In early-onset fecal incontinence following obstetric trauma/surgery, focal sphincter defects are demonstrated; in late-onset fecal incontinence external sphincter atrophy is seen. In fecally incontinent patients with scleroderma, forward deviation of the anterior sphincter musculature with descent of rectal air and feces into the anal canal is noted. The extent of sphincter invasion is assessed in low rectal tumours. In children with congenital anorectal anomalies, abnormalities of the muscle components are defined using smaller-diameter coils. Such information is invaluable in the assessment and surgical planning of patients with a variety of anorectal pathologies.
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deSouza NM, Williams AD, Wilson HJ, Gilderdale DJ, Coutts GA, Black CM. Fecal incontinence in scleroderma: assessment of the anal sphincter with thin-section endoanal MR imaging. Radiology 1998; 208:529-35. [PMID: 9680588 DOI: 10.1148/radiology.208.2.9680588] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To compare the magnetic resonance (MR) imaging appearance of the anal sphincter in patients with fecal incontinence and scleroderma with that in patients with fecal incontinence alone, scleroderma alone, or neither. MATERIALS AND METHODS The study population comprised 14 patients with fecal incontinence and scleroderma, four with scleroderma alone, 13 with incontinence alone, and six with neither. T1- and T2-weighted spin-echo, magnetization transfer contrast-weighted, and dynamic gadolinium-enhanced images were obtained and analyzed for the integrity, thickness, and length of sphincter components. Magnetization transfer contrast ratios and T2 were calculated to assess fibrosis of the internal sphincter. The percentage enhancement above baseline was calculated at 30-second intervals for the internal and the external sphincter. RESULTS Eleven patients with incontinence and scleroderma showed descent of rectal air and feces into the anterior anal canal, with forward deviation of the significantly (P < .05) atrophied internal sphincter, which showed a slower gadolinium-enhancement pattern compared with that in other groups. Patients with incontinence alone showed no evidence of internal sphincter deviation or altered vascularity but had a significant reduction (P < .05) in deep external sphincter bulk. CONCLUSION In patients with fecal incontinence and scleroderma, endoanal MR imaging helps delineate the anterior sphincter deformity and shows the slower gadolinium-enhancement pattern on dynamic studies of the internal sphincter.
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deSouza NM, Gilderdale DJ, Coutts GA, Puni R, Steiner RE. MRI of fistula-in-ano: a comparison of endoanal coil with external phased array coil techniques. J Comput Assist Tomogr 1998; 22:357-63. [PMID: 9606374 DOI: 10.1097/00004728-199805000-00004] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The objective of our study was to compare MRI of fistulas-in-ano using an endoanal coil with that using a pelvic phased array coil and to assess the value of a combined approach by correlating the findings with those at surgery. METHOD Twenty consecutive patients with clinical suspicion of perianal sepsis were studied using an endoanal coil immediately followed by a phased array coil. T1 weighted and STIR images in transverse and coronal planes were made with each coil and analysed by noting the presence and site of a collection and primary track, the position of any internal opening, and subcutaneous or supralevator extension. Operative findings were similarly recorded. RESULTS Of 20 patients with suspected fistulas, 8 had simple fistulas, 8 had complex fistulas, and 4 had no current evidence of infection. The concordance between MR and surgery for identifying the presence and site of the collection, the primary track, and the internal opening in both simple and complex cases was superior using the endoanal coil as compared with the phased array. Both coils together reflected the findings of the endoanal coil used alone. However, for supralevator/subcutaneous extension, concordance was superior using the phased array compared with the endoanal coil, and a combined approach reflected the values of the phased array coil used alone. CONCLUSION Endoanal MRI is highly sensitive in the delineation of fistulas-in-ano. In combination with phased array techniques, it provides valuable preoperative assessment in both simple and complex cases.
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deSouza NM, McIndoe GA, Soutter WP, Krausz T, Chui KM, Hughes C, Mason WP. Value of magnetic resonance imaging with an endovaginal receiver coil in the pre-operative assessment of Stage I and IIa cervical neoplasia. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1998; 105:500-7. [PMID: 9637118 DOI: 10.1111/j.1471-0528.1998.tb10149.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To assess the value of high resolution endovaginal magnetic resonance images (MRI) of the uterine cervix in planning management of early cervical cancer. DESIGN Prospective cross-sectional study. SETTING Specialist gynaecological oncology unit of a postgraduate teaching hospital. PARTICIPANTS Thirty nine women aged 25-76 years old (mean 42.5 years) with invasive carcinoma Stage I or IIa of the cervix. METHODS A ring coil was positioned endovaginally around the cervix. Imaging was performed on a 1.0 T HPQ Vista or 0.5 T Asset (Picker, Highland Heights, Ohio, USA) using T1 weighted and T2 weighted sequences in transverse and sagittal planes with thin slices (2.5 mm) and small fields of view (12 cm). Tumour volumes were measured and any extension into adjacent organs and parametrium was noted. The patients were followed up after treatment and the outcome related to the MRI findings. RESULTS There was one false positive and one false negative result among five Stage Ia patients being assessed for residual disease after cone biopsy or LLETZ. The MRI assessment of the size and distribution of the tumour was confirmed histologically in all 31 patients with Stage Ib or IIa disease who were treated surgically. One of these patients in whom no endocervical tumour was visible on MRI underwent radical trachelectomy. Three patients had radiotherapy as primary treatment. Patients with Stage Ib or IIa disease who had tumour volumes > 10 cm3 with early parametrial extension on MRI had a substantially worse prognosis at 24 months (disease-free survival 58.3% vs 95.5%, P = 0.003). CONCLUSION High resolution MRI with an endovaginal coil allows precise measurement of tumour volume and identifies patients with small volume disease who might be considered for more conservative therapy. This technique also reveals early parametrial invasion that cannot be identified reliably by any other method. Early parametrial invasion in women with large tumours appears to have a very much worse prognosis.
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deSouza NM, Soutter WP, McIndoe GA, Gilderdale DJ, Krausz T. Stage I cervical cancer: tumor volume by magnetic resonance imaging of screen-detected versus symptomatic lesions. J Natl Cancer Inst 1997; 89:1314-5. [PMID: 9293923 DOI: 10.1093/jnci/89.17.1314] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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deSouza NM, Gilderdale DJ, MacIver DK, Ward HC. High-resolution MR imaging of the anal sphincter in children: a pilot study using endoanal receiver coils. AJR Am J Roentgenol 1997; 169:201-6. [PMID: 9207525 DOI: 10.2214/ajr.169.1.9207525] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The purpose of this study was to obtain high-resolution MR images of the various components of the anal sphincter complex in children who have anorectal disorders. We therefore used dedicated endoanal receiver coils for MR imaging. CONCLUSION Our pilot study suggested that MR imaging that uses a dedicated endoanal coil may have considerable diagnostic potential in children who have anorectal disorders.
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