Search PubMed⌕ Search

Biomedical subjects

V Goh

Publications and source records attributed to V Goh.

18 recordsLinked to original sources
PubMed2006

Quantitative colorectal cancer perfusion measurement by multidetector-row CT: does greater tumour coverage improve measurement reproducibility?

The purpose of this study was to determine if greater z-axis tumour coverage improves the reproducibility of quantitative colorectal cancer perfusion measurements using CT. A 65 s perfusion study was acquired following intravenous contrast administration in 10 patients with proven colorectal cancer using a four-detector row scanner. This was repeated within 48 h using identical technical parameters to allow reproducibility assessment. Quantitative tumour blood volume, blood flow, mean transit time and permeability measurements were determined using commercially available software (Perfusion 3.0; GE Healthcare, Waukesha, WI) for data obtained from a 5 mm z-axis tumour coverage, and from a 20 mm z-axis tumour coverage. Measurement reproducibility was assessed using Bland-Altman statistics, for a 5 mm z-axis tumour coverage, and 20 mm z-axis tumour coverage, respectively. The mean difference (95% limits of agreement) for blood volume, blood flow, mean transit time and permeability were 0.04 (-2.50 to +2.43) ml/100 g tissue; +8.80 (-50.5 to +68.0) ml/100 g tissue/min; -0.99 (-8.19 to +6.20) seconds; and +1.20 (-5.42 to +7.83) ml/100 g tissue/min, respectively, for a 5 mm coverage, and -0.04 (-2.61 to +2.53) ml/100 g tissue; +7.40 (-50.3 to +65.0) ml/100 g tissue/min; -2.46 (-12.61 to +7.69) seconds; and -0.23 (-8.31 to +7.85) ml/100 g tissue/min, respectively, for a 20 mm coverage, indicating similar levels of agreement. In conclusion, increasing z-axis coverage does not improve reproducibility of quantitative colorectal cancer perfusion measurements.

Adenocarcinoma↗
PubMed2005

Is direct radiologist supervision of abdominal computed tomography (CT) scans necessary?

AIM: To determine the effect of direct radiological supervision of patients attending for abdominal CT by assessing the frequency of protocol alteration subsequent to radiologist review of the images obtained. MATERIALS AND METHODS: A prospective questionnaire-based observational study was performed of 187 consecutive patients undergoing abdominal CT. The CT protocol was determined by a radiologist in advance, with reference to the request form. Any subsequent change in the prescribed study that was contingent on radiologist review of the images obtained was documented on the questionnaire. Comparison was made with a second (control) group of 100 patients undergoing cranial CT. RESULTS: A protocol change was undertaken following radiologist review of the CT images of 17 (9%) of the group undergoing abdominal CT, compared with 14 (14%) of the group undergoing cranial CT. In the abdominal CT group, further scanning was performed for lesion characterization, to guide a subsequent interventional procedure, because of inadequate anatomical coverage or to evaluate an unexpected lung tumour. There was no significant difference in proportions between the two groups (p=0.23). CONCLUSION: When abdominal and cranial CT studies were compared, there was no significant difference in the proportion of studies requiring a change in the prescribed protocol following radiologist review of the images obtained. There was no evidence to suggest that abdominal CT was any less suited to protocol.

Adolescent↗
PubMed2004

Local radiological staging of rectal cancer.

Rectal cancer is a common malignancy with a highly variable outcome. Local recurrence is dependent upon tumour stage and surgical technique. The role of pre-operative imaging is to determine which patients may be safely managed by surgery alone and which need additional therapy in order to facilitate surgery and improve outcome. This decision depends on the distinction between those with early and advanced disease. While trans-rectal ultrasound has traditionally been used to answer this question, a role for magnetic resonance imaging (MRI) is increasingly argued. This review will focus on the treatment options for rectal cancer and the clinical questions that subsequently arise for the radiologist to answer.

Chemotherapy, Adjuvant↗
PubMed2004

Therapeutic impact of abdominopelvic computed tomography in patients with acute abdominal symptoms.

PURPOSE: To determine the diagnostic and therapeutic impact of abdominopelvic computed tomography (CT) in patients with acute abdominopelvic pain. MATERIAL AND METHODS: Referring clinicians completed pre-CT and post-CT questionnaires for 50 patients in whom CT had been requested because of acute abdominopelvic pain. Clinicians recorded their leading diagnosis, confidence in this, and intended management. Following CT, clinicians again recorded these responses in the light of CT findings. Responses pre-CT and post-CT were compared in order to determine diagnostic and therapeutic impact. RESULTS: Diagnostic confidence rose significantly following CT (mean score 6.8 pre-CT versus 8.3 post-CT; P<0.0001). Intended management changed because of CT findings in 29 (58%) patients: 14 (28%) subjects whose intended management was surgical were treated medically and an additional 2 were transferred to gynecological care; 4 patients whose intended management was medical were treated surgically; 2 patients whose intended management was medical were treated by percutaneous drainage; a patient whose intended management was percutaneous drainage was treated by surgery. Of 6 patients with uncertain management pre-CT, 2 were treated surgically and 4 medically. The leading diagnosis also changed as a consequence of CT in 7 (33%) of 21 patients in whom intended management did not alter. CONCLUSION: CT in patients with acute abdominopelvic pain has considerable diagnostic and therapeutic impact, altering management in 58% of patients studied. The major effect is to avert intended laparotomy.

Abdomen, Acute↗
PubMed2003

Optimizing bowel preparation for multidetector row CT colonography: effect of Citramag and Picolax.

AIM: To compare the adequacy and acceptability of Picolax and Citramag bowel cleansing agents for CT colonography. MATERIALS AND METHODS: Multidetector row CT colonography was performed in 124 subjects; 43 had been prepared with Picolax and 81 with Citramag. Datasets were assessed for retained fluid and solid residue, and overall adequacy of segmental visualization. Preparation acceptability was also assessed. RESULTS: There was significantly less retained fluid with Picolax. The odds of being in the next higher category for retained fluid when using Picolax were 0.33 (CI: 0.22-0.50, p<0.0001) when compared with Citramag, for all segments combined. However there was significantly more retained solid residue with Picolax. The odds of being in the next higher category for retained residue when using Picolax were 2.44 (CI: 1.41-4.24, p=0.002) when compared with Citramag, for all segments combined. There was no significant difference with respect to overall segmental visualization: the odds of a segment being adequately visualized when using Picolax were 1.52 (CI: 0.88-2.65, p=0.14) when compared with Citramag. There was no significant difference with respect to acceptability. CONCLUSION: Picolax results in a significantly drier colon than Citramag and associated with more retained residue. We found Picolax the more suitable preparation for CT colonography.

Adenoma↗
PubMed2002

The therapeutic impact of abdominal ultrasound in patients with acute abdominal symptoms.

AIM: The technical performance of abdominal ultrasound in the investigation of acute abdominal pain has been thoroughly investigated but its therapeutic effects are less well understood. We aimed to determine the therapeutic effect of abdominal ultrasound in the investigation of acute abdominal pain. MATERIAL AND METHODS: A pre- and post-intervention observational study design was used to determine the diagnostic and therapeutic effects of abdominal ultrasound for acute abdominal pain. Referring clinicians completed a pre-ultrasound questionnaire that detailed their leading diagnosis, confidence in this and intended management in 100 consecutive adult patients. Following ultrasound a second questionnaire was completed. This again detailed the leading diagnosis, confidence in this and their intended management. Clinicians quantified the management contribution of ultrasound both for the individual case in question and in their clinical experience generally. RESULTS: The leading diagnosis was either confirmed or rejected in 72 patients and a new diagnosis provided where no prior differential diagnosis existed in 10. Diagnostic confidence increased significantly following ultrasound (mean score 6.5 pre-ultrasound vs 7.6 post-ultrasound, P < 0.001). Intended management changed following ultrasound in 22 patients; 15 intended laparotomies were halted and a further seven patients underwent surgery where this was not originally intended. Ultrasound was rated either 'very' or 'moderately' helpful in 87% of patients, with 99% of clinicians finding it either 'very' or 'moderately' helpful generally. CONCLUSION: Abdominal ultrasound has considerable diagnostic and therapeutic effect in the setting of acute abdominal pain.

Abdomen, Acute↗
PubMed2000

A new presentation of angiopathy in neurofibromatosis type 1.

Neurofibromatosis is a genetic condition characterized by localized over-growth of mesodermal and ectodermal tissues. Neurofibromatosis type 1 is characterized by cutaneous and skeletal abnormalities. Angiopathy is rare. We describe a new presentation of angiopathy in neurofibromatosis type 1. The patient presented with extensive bruising of the right side of her neck together with intra-oral and pharyngeal submucosal haemorrhage. Radiological investigation confirmed that an aneurysm of the right ascending pharyngeal artery had ruptured. This was successfully embolized without complication.

Aneurysm, Ruptured↗
PubMed2000

Dynamic MR imaging of the pelvic floor in asymptomatic subjects.

OBJECTIVE: Dynamic MR imaging may be used as an alternative to dynamic cystoproctography for the evaluation of pelvic floor prolapse and configuration. MR criteria for normality are derived from proctographic studies because no large MR study of asymptomatic individuals has been performed. Our study aimed to define the normal range of dynamic pelvic MR appearances in a large group of asymptomatic individuals. SUBJECTS AND METHODS: Fifty healthy adult volunteers (25 men and 25 women; age range, 20-66 years; mean age, 34 years) were prospectively recruited and examined using dynamic MR imaging. All subjects were interviewed and established as healthy using a validated questionnaire. Axial, coronal, and sagittal MR imaging was performed at rest and during maximum pelvic strain using a static 1.0-T unit and a fast-field-echo sequence, providing 10 slices in 31 sec. Standardized measurements of pelvic configuration were taken, and rest and strain imaging were compared to determine the range of normal appearances. RESULTS: Three women developed a cystocele during maximum pelvic strain, two of whom also showed grade 1 uterocervical prolapse, which was also seen in another woman. Three men showed posterior pelvic floor descent in excess of 3 cm during straining. No rectocele, enterocele, rectal prolapse, or perineal hernia was seen in any subject. CONCLUSION: The normal range of pelvic organ descent in asymptomatic subjects seen on dynamic MR imaging included cystocele, uterocervical prolapse, and excessive anorectal junction descent. Although we encountered pelvic prolapse in seven volunteers, it was infrequent and low grade, suggesting that criteria for abnormality derived from proctography are generally applicable to MR imaging.

Adult↗
PubMed1998

The frequency of an inactivating point mutation (566C-->T) of the human follicle-stimulating hormone receptor gene in four populations using allele-specific hybridization and time-resolved fluorometry.

We have described previously in the Finnish population an inactivating point mutation (566C-->T) in the human FSH receptor (FSHR) gene. In women, this mutation causes hypergonadotropic ovarian failure with arrest of follicular maturation and infertility, whereas in men, there is variable suppression of spermatogenesis, but no absolute infertility. To determine whether the same FSHR mutation occurs in other populations, its frequency was determined in Finland, Switzerland, Denmark, and the Chinese population of Singapore. The mutation was screened for using genomic DNA extracted from whole blood or dried blood spots. Exon 7 of the FSHR gene was first amplified using a pair of biotinylated primers. The PCR products were then immobilized on streptavidin-coated microtitration wells and hybridized using short allele-specific oligonucleotide probes labeled with europium. Time-resolved fluorometry was used for europium signal detection. To test the reliability of this method, 40 isolated DNA samples and 35 dried blood spot samples were blindly tested for the 566C-->T FSHR mutation. The analyses yielded identical results with denaturing gradient gel electrophoresis and allele-specific restriction enzyme digestion of the same samples, thus demonstrating the reliability of the tested method. Automation of this procedure allows the screening of large numbers of samples, which was subsequently carried out to investigate the frequency of the 566C-->T mutation in the study populations. A total of 4981 samples from the above-mentioned 4 countries were analyzed. The frequency of the 566C-->T mutation was 0.96% for all Finnish samples (n=1976), with a strong enrichment of the mutant allele in the northeastern part of the country. Only 1 mutation carrier was identified in the samples from Switzerland (n=1162), whereas none was found in samples from Denmark (n=1094) and the Singapore Chinese (n=540). These results suggest that the 566C-->T mutation of the FSHR gene is enriched in Finland, but is uncommon in other populations.

Alleles↗
PubMed1992

The first oocyte donation pregnancy home-bred and delivered in Singapore to illustrate a simplified oocyte donation programme--no more embryo freezing, synchronisation or disruption of social life.

The wait for an oocyte donor is highly unpredictable and stressful. The recipients may have to remain contactable at all times. Even when a donor is present, their reproductive cycles may not be in synchrony to enable gamete or embryo replacement, and embryo freezing is required for the transfer of embryos in the subsequent cycle. After the release of the Guidelines for Assisted Reproductive Technique by the Ministry of Health we have established a simplified oocyte donation programme with which the need for synchronisation, embryo freezing and the disruption to the recipient couple's social life are eliminated. To illustrate, we report the first report of oocyte donation pregnancy home bred and delivered in Singapore.

Adult↗
PubMed1988

Gamete intrafallopian transfer (GIFT): an alternate method of conception in couples with unexplained infertility, endometriosis and oligo-asthenospermia.

138 treatment cycles of GIFT were carried out in couples with mainly unexplained infertility, endometriosis and male factor. The overall pregnancy rate was 24.6%, abortion 29.2%, multiple pregnancy 20.6% and ectopic pregnancy 0%. Four oocytes seem to be the optimal number of oocytes to be transferred. Patients with male factor infertility fared the worse in comparison with the other groups. Successful in-vitro fertilization of excess eggs did not correlate with a positive outcome of the GIFT procedure.

Endometriosis↗
PubMed1976

Cardiomyopathy.

Explore the source record for details and available documents.

Cardiomyopathies↗
PubMedDate not supplied

Imaging tumor angiogenesis: functional assessment using MDCT or MRI?

Functional imaging using multidetector row computed tomography and dynamic contrast-enhanced magnetic resonance imaging are increasingly advocated for assessment of tumor vascularity because these techniques provide excellent anatomic imaging and reliable quantitative perfusion data and are easily incorporated into routine examinations. However, differences in acquisition techniques, mathematical analysis, measurement parameters, and propensity to artifacts influence the choice of imaging modality, which is explored in this review.

Contrast Media↗
PubMedDate not supplied

Horse-related injuries in children.

OBJECTIVES: To identify the frequency, spectrum and outcome of horse-related injuries in children. DESIGN AND SETTING: Retrospective case series of horse-related injuries in children admitted to the Children's Hospital at Westmead (CHW) from January 1988 to December 1999, the John Hunter Children's Hospital (JHCH) from January 1991 to December 1997 and deaths reported to the New South Wales Paediatric Trauma Death (NPTD) Registry from January 1988 to December 1999. MAIN OUTCOME MEASURES: Circumstances of injury; helmet use; adult supervision; type and number of injuries identified. RESULTS: 232 children were admitted with horse-related trauma, 97 to the CHW over 12 years and 135 to JHCH over seven years, with one death at each hospital. There were six deaths reported to the NPTD Registry over 12 years. The median age was 11 years (range, 1-17). Girls accounted for 65% of those injured and 75% of children were injured while riding. Falls caused the injury in 76.3% of cases. Head and upper-limb trauma accounted for 216 of the injuries (73%). Five out of six children with severe head injuries died. In the CHW group, helmet use was documented in only 24 riders (38%) and adult supervision in 22 (22.9%). CONCLUSIONS: Horse-related trauma accounts for a considerable number of deaths and injuries in children in NSW. The use of a Standards-approved helmet for riding or horse-related activities might have decreased the severity of head injuries.

Adolescent↗