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Biomedical subjects

J T Murchison

Publications and source records attributed to J T Murchison.

18 recordsLinked to original sources
PubMed2005

Features of cardiac disease demonstrated on CT pulmonary angiography.

The heart and mediastinal structures can be overlooked at CT pulmonary angiogram (CTPA). This pictorial review will demonstrate the features of cardiac disease that may be evident on a CTPA. CTPA allows assessment of not only the pulmonary arteries for embolism, but also of the bronchi, lung parenchyma, mediastinum and heart. Co-existent underlying or incidental cardiac disease is often present. Potentially life-threatening alternative diagnoses in a patient with chest symptoms can be reliably identified. Pathologies of the myocardium including hypertrophic cardio myopathy, pericardial disease, valvular disease, coronary artery disease, and intracardiac abnormalities are demonstrated pictorially. CTPA is increasingly used for the detection of pulmonary embolism. Most patients investigated have pathology other than PE as a cause of their symptoms. Frequently information about the heart is produced that provides important clues to determine the cause for the presenting symptoms and signs or reveals co-existing pathology. It is important to have a clear understanding of the features of cardiac disease which may be seen on a CTPA.

Calcinosis↗
PubMed2005

Endobronchial and endoscopic ultrasound-guided real-time fine-needle aspiration for mediastinal staging.

Accurate staging of the mediastinum in lung cancer is essential for optimising treatment strategies. Conventional transbronchial needle aspiration (TBNA) is a blind procedure, reliant upon prior computed tomography (CT) or ultrasound imaging, but has low sensitivity. The current study reports the initial experience of using a prototype endobronchial ultrasound (EBUS) probe that allows TBNA under real-time imaging. In 20 patients selected by CT scanning, a linear-array ultrasound bronchoscope was used to visualise paratracheal and hilar lymph nodes, and TBNA was performed under direct ultrasonic control. In seven cases, sequential endoscopic ultrasound (EUS) was used to assess postero-inferior mediastinal lymph nodes. All procedures were performed under conscious sedation. EBUS-TBNA was undertaken in 18 out of 20 cases and EUS-guided fine-needle aspiration in six out of seven cases. Cytology showed node (N)2/N3 disease in 11 out of 18 EBUS-TBNA cases and provided a primary diagnosis for eight patients. EBUS-TBNA cytology was negative in six cases, which was confirmed by mediastinoscopy or clinical follow-up in four. EUS provided additional information in all cases. There were no procedural complications. Sensitivity, specificity and accuracy for EBUS-TBNA were 85%, 100% and 89%, respectively. In conclusion, endobronchial ultrasound with real-time transbronchial needle aspiration offers improved sensitivity and accuracy for staging of the middle mediastinum, and, combined with endoscopic ultrasound, should allow investigation of the majority of the mediastinum.

Aged↗
PubMed2005

Effect of the introduction of helical CT on radiation dose in the investigation of pulmonary embolism.

The aim of this study was to assess the change in patient radiation dose in the radiological investigation of pulmonary embolism since the introduction of helical CT pulmonary angiography (CTPA) in a large teaching hospital. All radiological investigations performed as an integral part of the imaging protocol in the investigation of clinically suspected pulmonary embolism (PE) were retrospectively reviewed. The protocol for the investigation of PE changed in our institution after the introduction of CTPA. Protocols 1 and 2 were the protocols in place before and after the introduction of CTPA, respectively. An in-depth evaluation was made of the imaging records and radiation dose for 30 consecutive patients investigated for clinically suspected PE in 1995 (protocol 1) and 2002 (protocol 2). Radiation doses were then extrapolated for the total number of patients investigated in each year. The number of radiological investigations performed per patient decreased from a mean of 1.17 in protocol 1 to 1.06 in protocol 2. There was a 44% increase in the total number of patients investigated. The effective dose per patient increased from 1.30 mSv to 1.35 mSv with the introduction of CTPA into the imaging protocol, an increase of only 4%. First line investigations showed a significant decrease in indeterminate examinations from 25.7% to 8.5%. Two different imaging protocols are reviewed with respect to type and number of procedures required for the investigation of PE and the resulting patient effective dose incurred. Results demonstrate an increase in the number of patients being investigated for suspected PE and a small increase in effective dose per patient since the introduction of helical CTPA. Although CTPA in itself incurs a higher effective dose, this is offset by the significant decrease in the number of non-diagnostic and total number of investigations per patient. In addition the ventilation component of lung scintigraphy was not required in protocol 2, thus reducing the dose further. We believe this small increase in effective dose is justified by the decrease in non-diagnostic studies and the reduction in total number of investigations per patient. We hope this paper will serve as a stimulus for the radiology community to examine current protocols in all areas of diagnostic imaging. We stress the importance of assessing new and established imaging investigative protocols to maximize the benefit and reduce any risk to patients.

Angiography↗
PubMed2004

Helical CTPA in the investigation of pulmonary embolism: a 6-year review.

AIM: To assess the change in practice and resulting diagnostic outcome in the radiological investigation of pulmonary embolism (PE) since the introduction of helical CTPA in a large teaching hospital. MATERIALS AND METHODS: A retrospective review was undertaken of all radiological investigations performed over a 6-year period before and after the introduction of CTPA (protocols 1 and 2, respectively) as an integral part of the imaging protocol in the investigation of clinically suspected PE. The total numbers and results of all investigations are assessed for each protocol. RESULTS: A substantial increase in both the total number of patients and the number of investigations performed for the investigation of PE since the introduction of CTPA occurred. Five hundred and twenty-six patients underwent 617 investigations in 1995-1996, and 760 patients underwent 805 investigations in 2001-2002. There was a significant decrease in the number of investigations per patient, 1.17 in 1995-1996 versus 1.06 in 2001-2002. Primary investigation showed a significant decrease in indeterminate examinations from 25.7 to 8.5% and an increase in positive results for PE from 18 to 24%. CONCLUSION: In the study population there was a significant increase in the number of patients being investigated for PE, with a decrease in both the number of non-diagnostic investigations and the total investigations per patient since the introduction of helical CTPA. This is probably due to the ready availability of a new imaging technique and physicians awareness that CTPA has significantly improved specificity, which encourages the referral of patients for investigation.

Adolescent↗
PubMed2003

Small bowel obstruction--the water-soluble follow-through revisited.

AIMS: The aim of the present study to examine the use of a modified water-soluble follow-through in the diagnosis and management of small bowel obstruction (SBO). MATERIALS AND METHODS: Sixty-two patients were recruited to the study: 33 into the control group and 29 into the study group. A modified small bowel follow-through (SBFT) was performed in the study group patients. The control group was managed conventionally. Assessment was made by questionnaire documenting initial surgical diagnosis and likelihood of operative intervention, final diagnosis and surgical outcome (operative versus non-operative). RESULTS: SBFT changed the diagnosis in 12/24 of the study group (p<0.01). In the study group 8/24 proceeded to surgery whereas 19/33 underwent laparotomy in the control group, representing a relative risk reduction of 52%, but this was not statistically significant (0.10>p>0.05, chi-squared test). CONCLUSION: SBFT remains a valid and useful tool in surgical management of SBO. In particular it aids diagnostic confidence in planning surgical intervention, particularly in uncomplicated patients.

Case-Control Studies↗
PubMed2003

The prevalence of simple renal and hepatic cysts detected by spiral computed tomography.

AIM: To provide a definitive evaluation of the prevalence of simple renal and hepatic cysts using spiral computed tomography (CT). PATIENTS AND METHODS: Contrast-enhanced abdominal CT studies from 617 patients (295 women, 322 men) attending for investigations unrelated to renal or hepatic pathology were included. The number of renal cysts, their location and the diameter of the largest cyst were recorded. Hepatic cysts were recorded as being either present or absent. RESULTS: Two hundred and fifty-four patients (41%) were found to have simple renal cysts and 110 patients were found to have simple hepatic cysts (18%). Both renal and hepatic cysts became more common with age. Renal cysts were significantly more common at all ages in men (p=0.001), and increased in both size (p=0.02) and number (p<0.05) with age. CONCLUSION: A major discrepancy has, until now, existed between autopsy prevalence of renal cysts and prevalence as reported by in-vivo third-generation CT or sonography studies. Using newer spiral CT machines, we have generated prevalence data closer to post-mortem findings. We have also shown a significant, but age dependent, association between the presence of simple hepatic and simple renal cysts (p=0.001)

Adult↗
PubMed2001

Do preliminary chest X-ray findings define the optimum role of pulmonary scintigraphy in suspected pulmonary embolism?

AIM: To investigate if preliminary chest radiograph (CXR) findings can define the optimum role of lung scintigraphy in subjects investigated for pulmonary embolism (PE). MATERIALS AND METHODS: The CXR and scintigraphy findings from 613 consecutive subjects investigated for suspected PE were retrieved from a radiological database. Of 393 patients with abnormal CXRs, a subgroup of 238 was examined and individual radiographic abnormalities were characterized. CXR findings were related to the scintigraphy result. RESULTS: Scintigraphy was normal in 286 subjects (47%), non-diagnostic in 207 (34%) and high probability for PE in 120 (20%). In 393 subjects (64%) the preliminary CXR was abnormal and 188 (48%) of scintigrams in this group were non-diagnostic. Individual radiographic abnormalities were not associated with significantly different scintigraphic outcomes. If the preliminary CXR was normal (36%), the proportion of non-diagnostic scintigrams decreased to 9% (19 of 220 subjects) (P < 0.05). CONCLUSION: In subjects investigated for PE, an abnormal CXR increases the prevalence of non-diagnostic scintigrams. A normal pre-test CXR is more often associated with a definitive (normal or high probability) scintigram result. The chest radiograph may be useful in deciding the optimum sequence of investigations.Forbes, K. P. N., Reid, J. H., Murchison, J. T.(2001). Clinical Radiology56, 397-400.

Chi-Square Distribution↗
PubMed2000

Randomized controlled trial of the effect of early enteral nutrition on markers of the inflammatory response in predicted severe acute pancreatitis.

BACKGROUND: Recent evidence suggests that intestinal dysfunction has a role in sustaining the systemic inflammatory response in acute pancreatitis and may be ameliorated by the introduction of enteral nutrition. This study therefore assessed the effect of early enteral nutrition on the systemic inflammatory response in patients with prognostically severe acute pancreatitis. METHODS: Patients with prognostically severe acute pancreatitis within 72 h of disease onset were randomized to receive either enteral nutrition or conventional therapy consisting of a nil-by-mouth regimen. Serum interleukin (IL) 6, soluble tumour necrosis factor receptor I (sTNFRI) and C-reactive protein (CRP) were used as markers of the inflammatory response. Intestinal function was assessed using a differential sugar permeability technique. RESULTS: Of 27 patients, 13 received enteral nutrition. A median of 21 (range 0-100) per cent of calorific requirements was delivered over the first 4 days by enteral nutrition. There were no significant complications of enteral nutrition. The introduction of enteral nutrition did not affect the serum concentrations of IL-6 (P = 0.28), sTNFRI (P = 0.53) or CRP (P = 0.62) over the first 4 days of the study. Although there were no significant differences in intestinal permeability between the two patient groups at admission (chi2 = 2.33, d.f. = 1, P = 0.13), by day 4 abnormal intestinal permeability occurred more frequently in patients receiving enteral nutrition (chi2 = 4.94, d.f. = 1, P = 0.03) CONCLUSION: Early enteral nutrition did not ameliorate the inflammatory response in patients with prognostically severe acute pancreatitis. Furthermore, it did not have a beneficial effect on intestinal permeability. Presented in part to the Pancreatic Society of Great Britain and Ireland in Leeds, UK, November 1998 and at Digestive Disease Week in Orlando, Florida, USA, May 1999

Acute Disease↗
PubMed1999

Spiral CT in acute non-cardiac chest pain.

AIM: Spiral CT in acute non-cardiac chest pain is usually requested to diagnose aortic dissection but a spectrum of other cardiovascular diseases may simulate this. The purpose of this study was to assess the impact of spiral computed tomography (CT) in patients with suspected aortic dissection and to determine the nature and frequency of other disorders simulating it. METHODS: Over a 26-month period, all patients undergoing CT for suspected acute aortic dissection were recruited. CT was performed using a standard protocol. The CT examinations and reports were reviewed along with other relevant imaging, clinical data, surgical findings and post-mortem results. The pattern of diagnoses and their associations were evaluated. RESULTS: Seventy-six CT examinations were performed on 70 patients of whom 47 were male. The age of the patients ranged from 24 to 84. Seven patients had previously undergone cardiothoracic surgery. Twenty-four patients had normal CT findings; 46 patients (66%) had abnormal findings. Seventy-three significant pathologies were identified including thoracic aortic aneurysm (16 cases), aortic dissection (14 cases), acute intramural aortic haematoma (nine cases), aortic rupture (eight cases), atherosclerosis (four cases) and penetrating atheromatous ulcer (two cases), pulmonary embolus (four cases), pericardial disease (12 cases) and complications following surgery (three cases). The majority of patients had a life-threatening disease. Five patients without dissection had CT findings that explained clinical pulse deficits. CONCLUSION: Sudden onset non-cardiac, non-pleuritic chest pain is common to several acute cardiovascular disorders. Patients have a high incidence of life-threatening disease. Of this group, classic aortic dissection is the most common diagnosis but comprises a minority of cases. Spiral CT is a reliable diagnostic test but requires conscientious technique for optimum sensitivity and accuracy. Most patients will have abnormal CT findings.

Acute Disease↗
PubMed1998

Acute right ventricular dilatation: a new helical CT sign of massive pulmonary embolism.

UNLABELLED: Acute right heart failure is a principal cause of circulatory collapse and death in patients with massive pulmonary embolism (PE). The purpose of this study was to investigate if helical computed tomography (CT) could contribute to the assessment of the right ventricle (RV) in those with massive PE. Over an 8-month period 79 helical CT pulmonary angiograms were performed to investigate suspected PE. Emboli were demonstrated in 28 (35%) patients and seven (9%) were considered to have had a major thromboembolic event. The CT scans of all patients were evaluated using parameters derived in the axial plane (maximum minor axis RV and LV dimensions, RV:LV minor axis ratio and RV wall thickness). Acute right ventricular dilatation with an RV:LV ratio> 1.5:1 (range 1.6:1-2.3:1, mean 2:1) was found in all seven patients who had sustained major PE. In the remaining group of 21 with lesser degrees of embolism no patient had an RV:LV ratio > 1.1:1 (range 0.8-1.1, mean 1.0). To our knowledge, this CT sign has not been described before. CONCLUSION: Helical CT can identify acute RV dilatation in addition to making the primary diagnosis in patients with massive PE. This observation may help identify those at greatest risk of a second fatal event and facilitate therapeutic strategy.

Acute Disease↗
PubMed1998

Interventricular septal shift due to massive pulmonary embolism shown by CT pulmonary angiography: an old sign revisited.

The computed tomographic (CT) pulmonary angiogram appearances of acute right ventricular dysfunction due to massive pulmonary embolus in a patient are described. Abnormal findings comprised right ventricular dilatation, interventricular septal shift, and compression of the left ventricle. These changes resolved following thrombolysis. Use of CT pulmonary angiography to diagnose pulmonary emboli is increasing. Secondary cardiac effects are established diagnostic features shown by echocardiography. These have not been previously described but are important to recognise as they may carry important prognostic and therapeutic implications.

Adult↗
PubMed1997

Clinical utilization of the non-diagnostic lung scintigram.

By virtue of the poor specificity of ventilation perfusion lung scintigraphy, a significant number of examinations for suspected pulmonary embolism (PE) result in a report which is neither normal nor high probability. These are unhelpful in establishing a firm clinical diagnosis. Patients with an indeterminate report should therefore undergo further investigation to establish the diagnosis particularly when treatment with anticoagulants is proposed. All lung scintigram reports issued over a 2-year period were reviewed and 102 indeterminate lung scintigram reports were identified. The case notes of 94 of these patients were examined and details of further investigation and management recorded. Fifty-one patients (55%) had no further radiological investigations and 19 (37%) of these were unequivocally categorized as having had pulmonary embolism by the referring clinician. Eighteen of these were treated with anticoagulation therapy. When patients proceeded to further radiological investigation then the result usually influenced the final clinical diagnosis. Clinicians frequently treat an intermediate report as the end point in investigation of suspected PE and consequently some patients may receive suboptimal management. By implementing a hospital wide policy of further investigation of non-diagnostic lung scintigrams, using a standard protocol, patient management could be improved.

Adult↗
PubMed1997

Serial MRI in the management of intramural haemorrhage of the thoracic aorta.

Acute intramural haematoma of the ascending and descending aorta was diagnosed by CT in a patient with chest pain and suspected thoracic aortic dissection. Surgical mortality from aortic replacement in this condition is high. Intramural haematoma has an unpredictable course but studies suggest that resolution of haematoma carries a favourable prognosis against further complications. Serial MR examinations over the next 6 weeks demonstrated resolution of the haematoma. This information influenced the decision not to undertake surgery and the patient was continued on antihypertensive medication. Serial MR examination is a safe and reliable method of monitoring the progress of intramural haematoma and thus guiding difficult treatment decisions.

Aged↗
PubMed1995

Status epilepticus presenting as progressive dysphasia.

Status epilepticus is usually a straightforward diagnosis when a patient has two or more seizures without regaining consciousness. However, when status is non-convulsive and, in particular, has a temporal lobe flavour the clinical presentation may be misleading. Presentation with automatic or psychic behaviour is well recorded. We report a patient with nonconvulsive status who presented with progressive dysphasia with widespread CT and MRI changes. The dysphasia and imaging changes led to a diagnosis of a probable neoplastic brain process but reversed with anticonvulsant treatment.

Adult↗
PubMed1992

Is radiology a 'nine to five' specialty?

The role of the radiologist in 'out of hours' radiology was prospectively studied in a single Scottish Health Board for a continuous 6 month period. Six hundred and sixty seven procedures were performed by radiologists. Computed tomography (CT) (274, 41%), ultrasound scans (190, 28.5%) and vascular/interventional procedures (60, 9%) were the most frequently performed procedures. Trauma accounted for 139 (24%) of all 'out of hours' work and overall 365 (54.7%) procedures yielded an abnormality. The workload varied widely between hospitals from two procedures per 100 beds to 137 procedures per 100 beds. Similarly the input from individual radiologists was very variable. A registrar was present for 227 (34%) procedures, a senior registrar for 360 (54%) and a consultant for 138 (20%) (there being two radiologists present for 8.7% of procedures). 'Consultant only' radiology departments offering a full radiological service may expect a substantial 'out of hours' commitment.

Medical Audit↗
PubMed1992

Conventional 15 G needle technique for renal biopsy compared with ultrasound-guided spring-loaded 18 G needle biopsy.

Two techniques for percutaneous renal biopsy were retrospectively reviewed to assess their relative safety and efficacy. Ultrasound localization of the kidney by a radiologists, with subsequent biopsy performed by a renal physician using a hand-held 15 G cutting needle (Tru-Cut), was compared with biopsy performed by a radiologist using an 18 G cutting needle with a spring-loaded biopsy device (Biopty) and real-time ultrasound guidance. The smaller needle with real-time ultrasound is more reliable at retrieving an adequate specimen for histological examination (93%) than the "conventional" technique (79%). Fewer complications occurred in the Biopty group although the difference did not reach statistical significance. The average length of stay in hospital was significantly shorter for elective biopsies with the Biopty device (1.80 compared with 2.93 nights, p less than 0.01). We recommend the use of the Biopty device with an 18 G needle and real-time ultrasound guidance as the method of choice for percutaneous renal biopsy.

Adolescent↗