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C Metreweli

Publications and source records attributed to C Metreweli.

At least 91 records · Page 5Linked to original sources
PubMed1999

MR imaging of thyroglossal duct cysts in adults.

AIM: To describe the magnetic resonance (MR) features of thyroglossal duct cysts (TDC) in adults. PATIENTS AND METHODS: Sixteen patients with TDC underwent MR imaging to obtain T1- and T2-weighted images and T2-weighted fat saturation images. In addition, contrast enhanced images were obtained in five patients. RESULTS: The signal intensity of TDC was of that of a simple cyst in seven (44%) patients, yielding high signal intensity on T2- and low signal intensity on T1-weighted images. In nine (56%), the signal intensity was either intermediate or high on T1-weighted images, the T2 signal intensity in these cases being high (7), intermediate (1) or low (1). Enhancement of the wall of the cyst was present in three of five (60%) patients. All 16 TDC were located at or just to one side of the midline and 12 were embedded in the strap muscles. All TDC were infrahyoid in location but 11 also extended superiorly to be directly related to the hyoid. At the hyoid the cystic component was immediately posterior (6) anterior (3) or anterior and posterior (2) to the bone. Intralaryngeal extension was present in eight (50%) patients. A suprahyoid tract was identified in three patients. The thyroid gland was in a normal location in all patients. CONCLUSION: Thyroglossal duct cysts are most commonly of high T1 signal intensity consistent with high protein content. The tract leading to the base of the tongue is infrequently seen, the diagnosis being determined by the intimate relationship to the hyoid and strap muscles. Intralaryngeal extension in adult patients with TDC is more frequent than reported previously.

Adult↗
PubMed1999

Percutaneous vertebral biopsy through intact bone: a coaxial bone transgressing technique with 18 gauge needle.

Advancement of radiologic technologies allows the detection of vertebral lesions at an earlier stage, thereby increasing the proportion of vertebral lesions that are surrounded by intact bone when they are detected. While biopsy guns are effective in obtaining good-quality tissue samples of osteolytic bone lesions, lesions that are covered by intact bone are not accessible with a biopsy gun. For percutaneous biopsy of osteolytic vertebral lesions, an intact-bone transgressing technique is described in which a simple, inexpensive and small-calibre (18-gauge) instrument is used to allow multiple passage of 20-gauge biopsy guns for effective tissue sampling. In this series consisting of metastatic and myeloproliferative lesions, the effectiveness and safety of this well-tolerated technique are demonstrated in thoracic and lumbar vertebrae.

Biopsy, Needle↗
PubMed1999

Imaging of iliopsoas metastasis.

The imaging features of four patients with metastasis to the iliopsoas are presented with emphasis on the ultrasound, CT and MRI appearances. In patients with a known primary tumour, the possibility of iliopsoas metastasis, although uncommon should be considered.

Adult↗
PubMed1999

Submental metastases from nasopharyngeal carcinoma.

The primary treatment for nasopharyngeal carcinoma is radiotherapy. Despite optimal treatment the incidence of recurrent persistent or recurrent regional disease is significant. It is believed that recurrent regional disease is usually associated with local disease. Recurrent nodal disease commonly involves the subdigastric and upper jugular region and submental involvement is less common. This study includes 25 patients who had palpable submental nodes 2 years or more after radiotherapy. Five of the seven patients with proven malignant submental nodal recurrence of nasopharyngeal carcinoma had no other evidence of disease. Ultrasound accurately identified enlarged nodes and correctly predicted involvement. The ultrasound appearances of these nodes and their impact on management and prognosis is discussed.

Adult↗
PubMed1999

A new management algorithm for impalpable undescended testis with gadolinium enhanced magnetic resonance angiography.

PURPOSE: We evaluated the diagnostic accuracy of preoperative localization of impalpable undescended testis using ultrasound and gadolinium (Gd) enhanced magnetic resonance angiography (MRA). MATERIALS AND METHODS: Ultrasound and Gd-MRA were performed prospectively in 21 boys (23 impalpable testes) with cryptorchidism before laparoscopy and surgical exploration. Gd-MRA was done using a 1.5 Tesla magnetic resonance scanner with a turbo field echo technique after bolus intravenous injection of 0.4 mmol./kg. body weight of Gd diethylenetriaminepentaacetic acid. A total of 10 dynamic scans were acquired during 15 minutes after Gd injection to cover the early arterial and delayed venous phases. All patients subsequently underwent diagnostic laparoscopy and definitive surgery. RESULTS: Ultrasound correctly localized 9 of 10 intracanalicular testes but failed to reveal any intra-abdominal or vanishing testes. In contrast, Gd-MRA correctly localized 4 intra-abdominal, all 10 intracanalicular and 8 canalicular vanishing testes. In 1 patient with an intra-abdominal vanishing testis ultrasound and Gd-MRA failed to make the diagnosis. When correlated with the findings of subsequent laparoscopy and surgical exploration, Gd-MRA had a diagnostic sensitivity of 96% and a specificity of 100% for localizing impalpable undescended testes. Based on Gd-MRA and ultrasound findings laparoscopy could have been avoided in 18 of 23 cases (78%). No adverse effect was associated with Gd use in this study. CONCLUSIONS: Gd-MRA accurately diagnoses vanishing testes and reliably differentiates intraabdominal from intracanalicular impalpable testes, allowing definite preoperative planning of the surgical approach and avoiding unnecessary laparoscopy. A new management algorithm for impalpable testis in patients with cryptorchidism is proposed based on ultrasound and Gd-MRA findings.

Algorithms↗
PubMed1999

Relationship of thyroid blood flow to reproductive events in normal Chinese females.

The purpose of this study was to investigate the blood flow characteristics in the superior thyroid artery (STA) in normal females of prepubertal, reproductive, and postmenopausal age. The study was performed in 29 prepubertal girls, 27 females of reproductive age, and 26 postmenopausal women. The peak systolic velocity (PSV) and the pulsatility index (PI) of the STA were measured repeatedly during one menstrual cycle in females of reproductive age, and measured once in each prepubertal and postmenopausal subject. Different waveforms were observed in females of prepubertal, reproductive, and postmenopausal age. The PSV of the STA increased progressively in females from prepubertal to postmenopausal phases. The PI of the STA in all of the prepubertal girls was lower than that of adult females in different phases of the menstrual cycle. In adult females, the PI in the follicular phase was significantly higher than those in the ovulatory and luteal phases. In all of the postmenopausal women, the PI was comparable to that in older prepubertal subjects and in adult females during the ovulatory and luteal phases. The results suggest that oestrogen may affect thyroid blood flow during the normal menstrual cycle. Growth and progressive change of arterial structure are suggested to affect the thyroid blood flow in prepubertal and postmenopausal states.

Adult↗
PubMed1999

Nodal shape (S/L) and its combination with size for assessment of cervical lymphadenopathy: which cut-off should be used?

The short axis to long axis (S/L) ratio is commonly used to assess cervical lymphadenopathy; however, the cut-off value used has been limited to 0.5. The accuracy of the combination of S/L ratio and nodal size has not been documented previously. We evaluated 1143 normal cervical nodes from 95 healthy subjects, and 1441 nodes from 290 patients with proven cervical lymphadenopathy. The optimum cut-off value of the S/L ratio was determined in different regions of the neck: submental (0.5), submandibular (0.7), parotid (0.5), upper cervical (0.4), middle cervical (0.3) and posterior triangle (0.4). In the submandibular and parotid regions, the combination of the S/L ratio and short axis shows substantial improvement in diagnostic accuracy when compared to the S/L ratio alone.

Adolescent↗
PubMed1999

Folic acid improves arterial endothelial function in adults with hyperhomocystinemia.

OBJECTIVES: To evaluate whether oral folic acid supplementation might improve endothelial function in the arteries of asymptomatic adults with hyperhomocystinemia. BACKGROUND: Hyperhomocystinemia is an independent risk factor for endothelial dysfunction and occlusive vascular disease. Folic acid supplementation can lower homocystine levels in subjects with hyperhomocystinemia; however, the effect of this on arterial physiology is not known. METHODS: Adults subjects were recruited from a community-based atherosclerosis study on healthy volunteers aged 40 to 70 years who had no history of hypertension, diabetes mellitus, hyperlipidemia, ischemic heart disease or family history of premature atherosclerosis (n = 89). Seventeen subjects (aged 54 +/- 10 years, 15 male) with fasting total homocystine levels above 75th percentile (mean, 9.8 +/- 2.8 micromol/liter) consented to participate in a double-blind, randomized, placebo-controlled and crossover trial; each subject received oral folic acid (10 mg/day) and placebo for 8 weeks, each separated by a washout period of four weeks. Flow-mediated endothelium-dependent dilation (percent increase in diameter) of the brachial artery was assessed by high resolution ultrasound, before and after folic acid or placebo supplementation. RESULTS: Compared with placebo, folic acid supplementation resulted in higher serum folate levels (66.2 +/- 7.0 vs. 29.7 +/- 14.8 nmol/liter; p < 0.001), lower total plasma homocystine levels (8.1 +/- 3.1 vs. 9.5 +/- 2.5 micromol/liter, p = 0.03) and significant improvement in endothelium-dependent dilation (8.2 +/- 1.6% vs. 6 +/- 1.3%, p < 0.001). Endothelium-independent responses to nitroglycerin were unchanged. No adverse events were observed. CONCLUSION: Folic acid supplementation improves arterial endothelial function in adults with relative hyperhomocystinemia, with potentially beneficial effects on the atherosclerotic process.

Administration, Oral↗
PubMed1999

Echography of metastatic nodes treated by radiotherapy.

The purpose of this study was to evaluate whether the ultrasonographic appearances of nodal metastases in nasopharyngeal carcinoma (NPC) revert to normal after radiotherapy. Serial ultrasonography was performed in 18 patients with palpable nodal metastases in the neck who underwent radiotherapy for NPC. All patients had a pre-radiotherapy baseline and another study at least one year after radiotherapy. The largest node in each patient was evaluated for any change in the ultrasonographic features following radiotherapy. One year after radiotherapy nodes returned to normal size for their respective areas, the shape of the node and the echogenic hilus also reverted to normal. However, the nodes are more echogenic than nodes in normal subjects. This distinguishes these nodes from nodes not affected by radiotherapy. The histological basis for this observation is presumed to be the result of fibrosis. At first glance the post-radiotherapy nodes may resemble normal nodes, however subtle changes within the node and adjacent soft tissues can be recognized on ultrasonography. During long-term follow-up, the appearance of nodes at sites previously uninvolved or any change in the appearance of nodes should alert the sonologist to the possibility of recurrence.

Adult↗
PubMed1999

MR imaging in amyopathic dermatomyositis.

PURPOSE: Amyopathic dermatomyositis is a distinct clinical entity with cutaneous involvement but no myopathy. We conducted a prospective study to investigate the role of MR imaging in these patients. MATERIAL AND METHODS: Out of 40 Chinese patients presenting with dermatomyositis, based on clinical assessment and normal serum muscle enzymes 10 were diagnosed as having amyopathic dermatomyositis. These 10 patients underwent MR imaging for evaluation of any subclinical muscle involvement. RESULTS: Three patients demonstrated abnormal signal intensity in muscles on both T2- and fat suppression sequences. Thus, one-third of patients with dermatomyositis and clinically normal muscles may have detectable muscle inflammation on MR images, indicating that MR has a potential role for locating the relevant biopsy site and for longitudinal follow up. Six of the 10 patients had malignant disease diagnosed before or after diagnosis of the cutaneous manifestation. Nasopharyngeal carcinoma was the most common malignant disease in this group of patients. CONCLUSION: MR imaging is recommended for demonstrating subclinical muscle involvement in patients with the clinical diagnosis of amyopathic dermatomyositis. We also recommend screening for malignancy, particularly nasopharyngeal carcinoma, in Southern Chinese patients with dermatomyositis.

Adult↗
PubMed1999

Late radiation injury to the temporal lobes: morphologic evaluation at MR imaging.

PURPOSE: To study the morphologic characteristics of late radiation injury to the temporal lobes of the brain on magnetic resonance (MR) images. MATERIALS AND METHODS: This was a prospective study involving 34 patients (age range, 37-72 years) with known radiation injury to the temporal lobes from radiation therapy administered 2-10 years previously for nasopharyngeal carcinoma MR imaging was performed with T2-weighted gradient- and spin-echo, gradient-recalled echo, T1-weighted spin-echo, fluid-attenuated inversion-recovery, and T1-weighted postcontrast spin-echo sequences. RESULTS: Radiation injury was present in 57 of the 68 temporal lobes. The white matter lesions in radiation-induced injury were predominantly hyperintense on T2-weighted images, but in 37 (65%) of the 57 lobes, foci with heterogeneous signal intensity consistent with necrosis were detected. In the 57 involved lobes, gray matter lesions were detected in 50 (88%); blood-brain barrier disruption based on parenchymal contrast enhancement, in 51 (89%); and hemosiderin deposits, in 30 (53%). There was a significant correlation between white matter necrosis, gray matter lesions, and blood-brain barrier disruption, all of which were located mainly in the inferior temporal lobes that received the highest radiation dose. CONCLUSION: The lesion components of radiation-induced injury to the temporal lobes at MR imaging were more varied than have been previously described. In addition to the classic white matter lesions, gray matter lesions, blood-brain barrier disruption, and hemosiderin deposition also were frequently seen.

Adult↗
PubMed1999

Ultrasound, CT and colonoscopy of colonic cancer.

Barium enema and colonoscopy are commonly used for the investigation of suspected colonic cancer. These techniques are relatively invasive and both the investigation and the preceding bowel preparation are demanding, particularly in the elderly. A prospective, blinded trial was conducted to compare ultrasound (US) and CT with colonoscopy. CT and colonoscopy were performed on 50 patients with symptoms suggesting colonic cancer. Both radiological investigations were performed prior to the bowel preparation for colonoscopy. US was performed without any preparation and oral contrast medium was the only preparation used for CT. Colonoscopy detected six cancers, all of which were diagnosed by both US and CT. In addition, US and CT diagnosed a further cancer not seen on colonoscopy due to an incomplete study. US had a sensitivity and specificity of 100% and CT a sensitivity of 100% and a specificity of 84%. US and CT were poor at diagnosing polyps. If the detection of polyps greater than 2 cm is included then US sensitivity falls to 67% and CT sensitivity falls to 89% and specificity rises to 88%. In conclusion, both US and CT are possible alternatives to colonoscopy in the investigation of symptomatic patients with suspected colonic cancer. The use of these techniques could markedly reduce the need for colonoscopy in this patient population with attendant cost savings. Non-invasive imaging has particular advantages in the elderly who cope poorly with both the bowel preparation and the procedure.

Adult↗
PubMed1999

How sensitive is ultrasound in the detection of renal scars?

The English language medical literature was reviewed to determine the strength of the published evidence for the assertion that dimercaptosuccinic acid scintigraphy (DMSA) is superior to ultrasound (US) in the detection of established renal scarring in children. The MEDLINE database was used to identify papers published between 1985 and 1997 that claimed to be concerned with the detection of scars, and contained sufficient information to permit calculation of the sensitivity of US relative to DMSA. Only 10 studies were identified. The sensitivity of US for scarring, using DMSA as a gold standard, ranged from 37% to 100%, and its specificity from 65% to 99%. These wide ranges mean that evaluation of the role of US in the detection of scarring remains controversial. All papers contained methodological flaws. Allowing for these, the sensitivity of US appears to be acceptable. Further research that avoids these methodological problems is required.

Child↗
PubMed1999

MR features of the denervated tongue in radiation induced neuropathy.

The MR features of the denervated tongue have been described following nerve injury from radical neck dissection and tumour invasion. The purpose of the study was to determine whether similar features are present in the tongue following radiation induced neuropathy (RIN). The clinical records and MR images of 12 patients with RIN of the hypoglossal nerve were reviewed retrospectively. T1 weighted SE images were performed in 12, T2 weighted TSE images in 11, fat suppressed images in 10 and contrast enhanced T1 weighted images in nine patients. The denervated tongue revealed "oedemalike" changes in five, fatty infiltration in six, atrophy in 11 and pseudohypertrophy in one patient. Abnormal enhancement was not identified, and in five patients the signal intensity was normal on all sequences. The oedemalike changes, fatty infiltration and normal signal intensity were seen 2-48, 2-48, and 6-63 months, respectively, after the onset of RIN. In conclusion, there was no discernible relationship between the duration of RIN and the MR appearance of the denervated tongue. Oedemalike changes, previously described in the acute/subacute phase of denervation, were also seen in long-standing disease and there was no associated abnormal enhancement in any case. Furthermore, the signal intensity may be normal, the MR diagnosis relying on asymmetry of the size of the tongue. It is postulated that radiation causes incomplete and ongoing damage of the nerve, the course of which is unpredictable.

Adult↗
PubMed1999

Assessing chemotherapy response of squamous cell oesophageal carcinoma with spiral CT.

45 patients with squamous cell carcinoma of the oesophagus were examined prior to, and following, pre-operative chemotherapy by spiral CT. Oesophageal CT was performed following gaseous distention of the oesophagus. TNM stage and perceived resectability on CT before and after chemotherapy were compared and related to surgical resectability and pathological staging. T-stage changed in 26% and N-stage changed in 9% of tumours after chemotherapy. Post-chemotherapy CT predicted pathological T-stage with an accuracy of 88% and N-stage with an accuracy of 84%. Six of 14 tumours considered irresectable on CT pre-chemotherapy were considered resectable on post-chemotherapy CT. Five of these six tumours were resectable at surgery. Post-chemotherapy CT predicted surgical resectability with an accuracy of 88%, the main pitfall being underestimation and overestimation of tracheobronchial invasion. CT prediction of chemotherapy response as judged by change in tumour volume was compared with a quantitative pathological assessment of chemotherapy response. 93% of oesophageal tumours changed volume after chemotherapy with 51% having a volume reduction of > or = 50%. However, no correlation was found between tumour volume reduction on serial CT examinations and either a quantitative pathological assessment of tumour response or patient survival.

Carcinoma, Squamous Cell↗