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Biomedical subjects

Ashley M Groves

Publications and source records attributed to Ashley M Groves.

At least 19 recordsLinked to original sources
PubMed2006

Can 16-detector multislice CT exclude skeletal lesions during tumour staging? Implications for the cancer patient.

Current imaging guidelines recommend that many cancer patients undergo soft-tissue staging by computed tomography (CT) whilst the bones are imaged by skeletal scintigraphy (bone scan). New CT technology has now made it feasible, for the first time, to perform a detailed whole-body skeletal CT. This advancement could save patients from having to undergo duplicate investigations. Forty-three patients with known malignancy were investigated for bone metastasis using skeletal scintigraphy and 16-detector multislice CT. Both studies were performed within six weeks of each other. Whole-body images were taken 4 h after injection of 500 Mbq (99m)Tc-MDP using a gamma camera. CT was performed on a 16-detector multislice CT machine from the vertex to the knee. The examinations were reported independently and discordant results were compared at follow-up. Statistical equivalence between the two techniques was tested using the Newcombe-Wilson method within the pre-specified equivalence limits of +/-20%. Scintigraphy detected bone metastases in 14/43 and CT in 13/43 patients. There were seven discordances; four cases were positive on scintigraphy, but negative on CT; three cases were positive on CT and negative on scintigraphy. There was equivalence between scintigraphy and CT in detecting bone metastases within +/-19% equivalence limits. Patients who have undergone full whole-body staging on 16-detector CT may not need additional skeletal scintigraphy. This should shorten the cancer patient's diagnostic pathway.

Adult↗
PubMed2006

The role of positron emission tomography in the management of pancreatic cancer.

The role of positron emission tomography (PET) and PET/computed tomography (CT) in the assessment of a patient presenting with cancer of the pancreas is discussed in the overall context of the management of this condition. The clinical limitations persist, with many patients presenting late with unresectable disease and poor prospects for novel drug therapies. PET and PET/CT are best at diagnosing and staging but are relatively inefficient in the detection of nodal disease. The detection of late disease manifestations such as metastatic spread is often of little clinical consequence. PET/CT may be considered as a first-line imaging investigation but evidence for this approach needs to accrue. Overall detection sensitivity at diagnosis varies between 90% and 95% and specificity from 82% to 100%, whereas for staging, sensitivity data vary from 61% to 100% and specificity data from 67% to 100%.

Adenocarcinoma↗
PubMed2006

CT pulmonary angiography versus ventilation-perfusion scintigraphy in pregnancy: implications from a UK survey of doctors' knowledge of radiation exposure.

PURPOSE: To prospectively investigate the fetal dosimetry knowledge of health care professionals involved in the management of pulmonary embolism. MATERIALS AND METHODS: One hundred sixty-one health care professionals consented to participate in this study, which had ethical board approval. The individuals surveyed were from 14 hospitals (seven university and seven community hospitals) in the United Kingdom, and 68 trainees were included. These health care professionals included 102 radiologists, 13 nuclear physicians, seven dual-accredited radiologist-nuclear medicine physicians, 16 medical physicists, and 23 pulmonologists. The interview included eight questions. Two questions asked which examination-computed tomographic (CT) pulmonary angiography or ventilation-perfusion (V/Q) scintigraphy-gave (a) the larger radiation exposure (effective dose) to an adult and (b) the larger fetal dose. Two questions assessed the magnitude of the dose differences between these two tests. Four questions asked for an estimate of the dose to both adult and fetus from CT pulmonary angiography and scintigraphy. Subgroup analysis was performed by using the Fisher exact test. RESULTS: Of the 161 professionals surveyed, 93 (58%) appreciated correctly that V/Q scintigraphy delivers a higher fetal dose than does CT pulmonary angiography. Three of 161 professionals were able to answer all eight questions correctly. In terms of the knowledge that V/Q scintigraphy has a higher fetal dose than does CT, there was no statistically significant difference in correct answers between specialties (P > .05), between university and community hospitals (P = .13), or between attending physicians and residents (P = .52). CONCLUSION: This survey reveals that there is a lack of knowledge of fetal dosimetry in the imaging of pregnant women suspected of having pulmonary embolism.

Angiography↗
PubMed2006

Ventilation-perfusion scintigraphy to predict postoperative pulmonary function in lung cancer patients undergoing pneumonectomy.

OBJECTIVE: The American College of Chest Physicians (ACCP) recommends using quantitative perfusion scintigraphy to predict postoperative lung function in lung cancer patients with borderline pulmonary function tests who will undergo pneumonectomy. However, previous scintigraphic data were gathered on small cohorts more than a decade ago, when surgical populations were significantly different with respect to age and sex compared with typical lung cancer patients undergoing pneumonectomy in 2005. We therefore revisited the use of V/Q scintigraphy in pneumonectomy patients in predicting postoperative pulmonary function and the appropriateness of current clinical guidelines. CONCLUSION: Contrary to ACCP guidelines, we found that ventilation scintigraphy alone provided the best correlation between the predicted and actual postoperative values and recommend its use to predict postoperative lung function. However, scintigraphic techniques may underestimate postoperative lung function, so caution is required before unnecessarily preventing a patient from undergoing surgery that offers a potential cure.

Adult↗
PubMed2006

An international survey of hospital practice in the imaging of acute scaphoid trauma.

OBJECTIVE: Scaphoid fractures are relatively common. If not treated promptly there may be risk of long-term disability. However, unnecessary wrist immobilization is inconvenient and may hinder professional activities. Therefore, early accurate diagnosis is essential. Currently, the American College of Radiology deems MRI and radiographs as the most appropriate investigations in imaging acute scaphoid trauma. Our objective was to assess scaphoid imaging protocols. MATERIALS AND METHODS: To assess scaphoid imaging protocols, an international survey of imaging practice was performed. Two hundred hospitals worldwide were sent a survey regarding their scaphoid trauma imaging protocols. Only replies from hospitals that had full CT, MRI, and scintigraphy facilities were accepted. RESULTS: Data were obtained from 105 hospitals, of which 23 had fixed protocols. The number of scaphoid radiographic views varied from two to six. Before second-line investigations were initiated, repeat radiographs were usually performed in 76 of the 105 hospitals. In 29 hospitals, other imaging techniques were used without further radiography. The usual second-line investigation was MRI in 31/105, CT in 19/105, and scintigraphy in 14/105. Further protocols included CT or MRI in 10/105, CT or scintigraphy in 6/105, scintigraphy or MRI in 6/105, CT then MRI (if CT was negative) in 1/105, both CT and scintigraphy in 1/105, and scintigraphy then CT (if positive) in 1/105. There was equal preference among MRI, CT, and scintigraphy in 10/105 centers, and clinical examination and radiographs were used alone in 6/105. CONCLUSION: The survey reveals marked inconsistency in the imaging of acute scaphoid injury. Although other factors may have played a role, limited scientific evidence regarding the ideal imaging in acute scaphoid trauma may be the root of this inconsistency.

Acute Disease↗
PubMed2005

Oral contrast medium in PET/CT: should you or shouldn't you?

PURPOSE: It has been suggested that the use of computed tomography (CT) positive contrast agents has led to attenuation-induced artefacts on 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) systems. Consequently, centres may withhold the use of such agents. Whilst there is theoretical evidence to support the aforementioned claim, the clinical relevance of the induced artefacts has not been widely established. Moreover, the potential benefits of bowel enhancement on PET/CT have yet to be formally evaluated. We therefore prospectively examined PET/CT studies to assess whether the use of oral contrast medium induces clinically relevant artefacts and whether the use of these agents is diagnostically helpful. METHODS: Over a 2-month period, 18F-FDG PET/CT images were prospectively reviewed from 200 patients following Gastrografin administration 2 h prior to examination. Both a radiologist and a nuclear medicine physician reviewed the images for contrast medium-mediated clinically relevant artefacts. Artefacts were sought on the CT attenuation-corrected images and were compared with the appearance on non-attenuated-corrected images. The number of examinations in which the oral contrast aided image interpretation was also noted. RESULTS: There were no oral contrast medium-induced clinically significant artefacts. In 38 of the 200 patients, oral contrast aided image interpretation (owing to differentiation of mass/node from bowel, discrimination of intestinal wall from lumen or definition of the anatomy of a relevant site). In 33 of these 38 patients, the anatomical site of interest was the abdomen/pelvis. CONCLUSION: The use of oral contrast medium in 18F-FDG PET studies should not be withheld as it improves image interpretation and does not produce clinically significant artefacts.

Abdominal Neoplasms↗
PubMed2005

Characterization of pure high-grade DCIS on magnetic resonance imaging using the evolving breast MR lexicon terminology: can it be differentiated from pure invasive disease?

Magnetic resonance imaging (MRI) is now a recognized method of imaging the breast. Unfortunately, there is lack of standardization in the MRI terminology used to characterize the appearance of breast lesions. Moreover, cases of mixed histologies are often imaged. We retrospectively identified cases of pure high-grade ductal carcinoma in situ (DCIS) using the recently introduced breast MRI lexicon and characterized the lesions in order to try and identify features that might distinguish high-grade DCIS from invasive disease. Five-year review of our institution's database revealed 637 patients underwent gadolinium-enhanced breast MRI examination. Twenty patients had histologically proven pure high-grade DCIS. After excluding patients with previous chemotherapy or inadequate MRI examination, 13 patients were analyzed and compared to the 13 most recent cases of pure invasive breast carcinoma. The morphological and dynamic features were then compared. High-grade DCIS cases were significantly more likely to show focal branching pattern (P=.03) and to have an irregular contour (P=.03), compared with invasive disease. Although of marginal statistical significance, DCIS lesions are more likely to have a lower morphological score than invasive carcinoma (P=.06), whilst the latter is more likely to show ring enhancement (P=.07). Use of breast MRI for staging at our institution shows that pure DCIS and pure invasive cancers are both rare entities. Despite the relatively limited numbers, we identified features that would help to differentiate high-grade DCIS from invasive carcinoma on MRI.

Adult↗
PubMed2005

How often do patients undergo repeat PET or PET/CT examinations? Experience from a UK institution.

BACKGROUND AND AIM: According to the report of the Intercollegiate Standing Committee on Nuclear Medicine, the UK requires 40-60 positron emission tomography (PET) machines in the next decade (Intercollegiate Standing Committee on Nuclear Medicine). Positron Emission Tomography: a Strategy for Provision in the UK. London: Royal College of Physicians of London; 2003, pp. 1-9). This figure is based mainly on patients receiving only one examination and restricting the clinical indication to three primary diagnoses. The aim of this study was to assess the appropriateness of this figure and the assumptions made in the Intercollegiate report on UK PET provision. METHODS: We examined retrospectively our institution's entire PET and PET/computed tomography (CT) database, which spans 4 years and 9 months. We recorded the number of patients who received repeat examinations. RESULTS: Reports were available for 3354 PET/CT or PET-only studies; 418 of 2268 patients (18.4%) received at least one repeat PET/CT examination. The three main indications for PET examination in the Intercollegiate report only accounted for approximately 60% of the examinations undertaken. CONCLUSION: Our records suggest that basing the UK's future PET provision on a single examination and on three clinical indications only is no longer realistic.

Humans↗
PubMed2005

Cardiopulmonary exercise tests and lung cancer surgical outcome.

STUDY OBJECTIVES: Surgical resection remains the treatment of choice for anatomically resectable non-small cell lung cancer. However, the presence of associated comorbid conditions increases the risk of death and surgical complications. Several studies have evaluated the usefulness of preoperative exercise testing for predicting postoperative morbidity and mortality. The aim of this study was to establish whether exercise testing could predict poor surgical outcome in lung cancer surgery and whether the absolute value or percentage of predicted value is the better predictor of the surgical outcome. DESIGN: The study was designed as a prospective study. PATIENTS AND SETTING: One hundred thirty patients with potentially operable lung cancer at Papworth Hospital over 2 years were recruited; of these, 101 underwent curative surgery. INTERVENTIONS: Spirometry and cardiopulmonary exercise tests were performed for every patient (n = 99), except for two patients with back problems. We also recorded the outcome of surgery, in particular, complications and mortality. MEASUREMENTS AND RESULTS: Mean maximum oxygen transport at peak exercise (Vo(2)peak) was 18.3 mL/kg/min (SD, 4.7 mL/kg/min), and mean percentage of predicted Vo(2)peak value was 84.4% (SD, 30%). Poor surgical outcome was significantly related to Vo(2)peak percentage of predicted (p < 0.01) but not to the actual oxygen uptake value. CONCLUSIONS: The use of the percentage of predicted Vo(2)peak value would be a better indicator of surgical outcome, since it predicts the surgical outcome better, and corrects for normal physiologic ranges. The threshold of Vo(2)peak for surgical intervention could be set between 50% and 60% of predicted without excess surgical mortality.

Adult↗
PubMed2005

16-MDCT in the detection of occult wrist fractures: a comparison with skeletal scintigraphy.

OBJECTIVE: Our objective was to assess the potential use of MDCT in the detection of occult scaphoid fractures. Fifty-one patients with suspected radiographically occult scaphoid fractures at 10-14 days after trauma were investigated prospectively with skeletal scintigraphy and CT on the same day. Planar images of the wrist were taken 3 hr after IV injection of 400 MBq of (99m)Tc-methylene diphosphonate using a single-head gamma camera. CT was performed on a 16-MDCT machine using 0.75-mm detectors and reconstruction in 0.5-mm slices. Multiplanar reformatted images were then viewed in interactive cine mode. The examinations were reported independently, and discordant results were compared at follow-up. CT was positive for wrist fracture in 14 (27.4%) of 51 patients and skeletal scintigraphy in 23 (45.1%) of 51 patients. Even after retrospective review, there were seven discrepant cases (13.7%), all of which were positive for wrist fracture on scintigraphy but negative on CT. Four of these seven patients with discordant findings underwent further radiography at 6 weeks, which did not show fracture. CONCLUSION: Although CT was preferred by most patients and was quicker, scintigraphy appears to detect bony abnormality more frequently. However, there appears to be an interesting group of patients (7/51) with normal initial radiography findings but positive scintigraphy findings who would normally be considered to have a fracture but for whom CT results were negative. In some of these patients, the results of follow-up radiography at 6 weeks were also negative, suggesting that this group of patients warrants further study.

Adolescent↗
PubMed2004

Use of quantitative lung scintigraphy to predict postoperative pulmonary function in lung cancer patients undergoing lobectomy.

BACKGROUND: In patients with non-small cell lung cancer, the only realistic chance of cure is surgical resection. However, in some of these patients there is such poor respiratory reserve that surgery can result in an unacceptable quality of life. In order to identify these patients, various pulmonary function tests and scintigraphic techniques have been used. The current American College of Physicians and British Thoracic Society guidelines do not recommend the use of quantitative ventilation-perfusion scintigraphy to predict postoperative function in lung cancer patients undergoing lobectomy. These guidelines may have been influenced by previous scintigraphic studies performed over a decade ago. Since then there have been advances in both surgical techniques and scintigraphic techniques, and the surgical population has become older and more female represented. METHODS: We prospectively performed spirometry and quantitative ventilation-perfusion scintigraphy on 61 consecutive patients undergoing lobectomy for lung cancer. Spirometry was repeated one-month postsurgery. Both a simple segment counting technique alone and scintigraphy were used to predict the postoperative lung function. RESULTS: There was statistically significant correlation (p < 0.01) between the predicted postoperative lung function using both the simple segment counting technique and the scintigraphic techniques. However, the correlation using simple segment counting was of negligible difference compared to scintigraphy. CONCLUSIONS: In keeping with current American Chest Physician and British Thoracic Society guidelines, our results suggest that quantitative ventilation-perfusion scintigraphy is not necessary in the preoperative assessment of lung cancer patients undergoing lobectomy. The simple segmenting technique can be used to predict postoperative lung function in lobectomy patients.

Aged↗
PubMed2004

Relationship of shuttle walk test and lung cancer surgical outcome.

OBJECTIVE: Surgery remains the treatment of choice in patients with potentially resectable lung carcinoma. Both the British Thoracic Society and American Chest Physician guidelines for the selection of patients with lung cancer surgery suggest the use of a shuttle walk test to predict outcome in patients with borderline lung function. The guidelines suggest that if the patient is unable to walk 250 m during a shuttle walk test, they are high risk for surgery. However, there is no published evidence to support this recommendation. Therefore, we undertook a prospective study to examine the relationship between shuttle walk test and surgical outcome in 139 patients undergoing assessment for possible lung cancer surgery. METHODS: The shuttle walk test was performed in 139 potentially resectable patients, recruited over a 2 year period, prior to surgery. One hundred and eleven patients underwent surgery. Outcome of surgery, including duration of hospital stay, complication and mortality rates was recorded. Student's t-test was used to compare the shuttle walk distance in patients with good and poor outcome from surgery. RESULTS: Mean age of patients undergoing surgery was 69 years (42-85). Mean shuttle walk distance was 395 m (145-780), with a mean oxygen desaturation of 4% (0-14) during the test. Sixty nine patients had a good surgical outcome and 34 had a poor outcome. The shuttle walk distance was not statistically different in the two outcome groups. CONCLUSION: Shuttle walk distance should not be used to predict poor surgical outcome in lung cancer patients, contrary to current recommendations. It is therefore advisable to perform a formal cardiopulmonary exercise test if at all possible. The usefulness of a shuttle walk test might be improved. It could be compared to a predicted value, as for a formal cardiopulmonary exercise test.

Adult↗
PubMed2004

Adult mesoblastic nephroma: appearances on magnetic resonance imaging.

Mesoblastic nephroma presenting in an adult is extremely unusual. The magnetic resonance imaging (MRI) appearances of this tumor in adulthood have not been widely reported. We present a 55-year-old patient who was diagnosed with this rare neoplasm and describe the MRI findings.

Diagnosis, Differential↗
PubMed2004

Autoimmune hemolytic anemia: magnetic resonance findings.

Idiopathic autoimmune hemolytic anemia (AIHA) is a rare hematological disease typically characterized by extracellular hemolysis. An unusual case of AIHA with interesting magnetic resonance imaging (MRI) appearances is presented. Possible explanations for the MRI findings are discussed.

Adult↗
PubMed2004

Thyroid hormone and parathyroid hormone competing to maintain calcium levels in the presence of vitamin D deficiency.

Weight loss and bone disease in the elderly are very often attributed to malignancy. Rarely, benign treatable conditions may be overlooked. Thyrotoxicosis, a benign treatable condition, needs to be excluded in such patients. The diagnosis may be delayed, since the symptoms are often subtle, and secondary complications including bone disease (osteoporosis) are therefore more frequent at the time of presentation. The case presented here illustrates this well, and also highlights the value of measuring vitamin D levels in such patients. The most interesting aspect of this case was the reciprocal relationship between thyroxine and parathyroid hormone observed in maintaining calcium homeostasis in this thyrotoxic patient with low vitamin D levels.

Calcium↗
PubMed2004

16-Detector multislice CT-skeletal scintigraphy image co-registration.

OBJECTIVE: Co-registration of bone scintigrams with radiographs has been used in the diagnosis of wrist injuries, although co-registration of tomographic bone scintigraphy with computed tomography (CT) has not been widely reported. We describe a co-registration technique in patients with possible wrist fracture. METHODS: The technique was used on three patients and involved placing the wrist on a Perspex board and tracing the outline of the forearm and hand with a pen to try and ensure accurate repositioning on the board for the two sets of imaging. Four point source markers were attached to the board during both examinations. Single photon emission computed tomography (SPECT) was performed 4 h after injection Tc-methylenediphosphonate (MDP), using a dual-headed gamma camera. CT images were acquired on a 16-detector CT unit. The SPECT and CT images were co-registered with commercially available image fusion software. The centre of the four markers was identified in both sets of images and a rigid body point match algorithm was used. Before patient studies, the technique was tested using a phantom. RESULTS: In all the phantom and clinical studies it was possible to identify the positions of all the markers. There were varying degrees of success in patient repositioning. CONCLUSION: We describe a technique that may aid the fusion of functional images from skeletal scintigraphy with the exquisite anatomical detail from the latest CT technology, in the detection of occult wrist fractures. The technique may aid fracture localization and/or detection and might help distinguish the clinically important scaphoid fractures from other benign carpal lesions.

Algorithms↗