Comparison of the Wells and Revised Geneva Scores for the diagnosis of pulmonary embolism: an Australian experience

BACKGROUND/AIMS

Clinical prediction rules form an integral component of guidelines on the diagnostic approach to pulmonary embolism (PE). The Wells Score is commonly used but is subjective, while the newer Revised Geneva Score is based entirely on objective variables. The aim of this study was to compare the diagnostic accuracy of the Wells and Revised Geneva Scores for the diagnosis of PE.

METHODS

Patients presenting to the emergency department with clinically suspected PE and referred for CT pulmonary angiogram or ventilation/perfusion scintigraphy were evaluated. The Wells and Revised Geneva Scores were calculated on the same cohort of patients and dichotomized into low and intermediate/high probability groups. The sensitivities and specificities were compared using McNemar's test. Overall accuracy was determined using receiver operator characteristic curve analysis.

RESULTS

A total of 98 consecutive patients was included. The overall prevalence of PE was 15.3%. The frequency of PE in the low, intermediate and high probability groups was similar for both clinical prediction rules. Compared with the Revised Geneva Score, the Wells Score showed a lower sensitivity with borderline significance (46.7% vs 80.0%, P= 0.06) and a significantly higher specificity (67.5% vs 47.0%, P= 0.002). The overall accuracy of both rules was similar (P= 0.617).

CONCLUSION

Using the accepted guidelines in which a high pretest probability leads to further imaging and a low probability leads to a D-dimer blood test, use of the more specific Wells Score could safely reduce the number of unnecessary scans. This would need to be confirmed with larger, prospective trials.

Time for guidelines in diagnostic imaging?

The increasing costs of health care in a modern developed country consume a high percentage of its economy's resources. In 2006, total spending for this sector in the UK represented 9.4% of the gross domestic product. This was substantially greater than 2001, when 7.1% of the gross domestic product was devoted to health (Griffin, 2007). The growth in expenditure is in part a result of the health requirements of an ageing population with inherent chronic medical conditions. Coupled with this, however, is the everemerging new and costly medical technologies that are available to diagnose and treat disease and the public expectation that health authorities will fund the provision of these services.

Primary gastrointestinal lymphomas: a radiological-pathological review. Part 2: Small intestine

Primary lymphoma of the small intestine is a heterogeneous group of diseases reflected in its protean imaging features. This review illustrates the widespread appearances seen on imaging methods (primarily CT and barium studies) with pathological correlation.

Primary gastrointestinal lymphomas: A radiological-pathological review. Part 1: Stomach, oesophagus and colon

Primary gastrointestinal lymphomas are most common in the stomach, followed by small intestine and then colon. The most frequently used pathology classification of lymphomas is the Revised European and American Lymphoma /World Health Organization classification. The correlation of radiological morphology with histology is relatively poor, although characteristic subtypes will be discussed. In the stomach, the majority of primary lymphomas are of B-cell origin of mucosa-associated lymphoid tissue (MALT) type. Low-grade MALT lymphomas are associated with Helicobacter pylori infection and often respond to eradication of this organism. Radiological features include thickened folds, nodularity, depressed lesions, ulcers, prominent areae gastricae. High-grade (large B-cell) tumour patterns include infiltrative, polypoid, nodular, ulcerated or a combination. Endoscopy, endoscopic ultrasound and CT are important in diagnosis and staging, although appearances on barium studies should be recognized. Primary colonic lymphomas are rare. Most are of B-cell origin. Focal and diffuse forms are seen, the former producing polypoid or nodular or cavitating masses and the latter producing ulcerative or nodular (polyposis) patterns on imaging. Even when circumferential, lymphoma rarely causes obstruction. Small bowel lymphomas will be discussed in the forthcoming part 2 of this review.

Randomized single blind trial of two low-volume bowel preparations for screening computed tomographic colonography

BACKGROUND

Bowel preparation is an important part of computed tomographic colonography (CTC); we evaluated two small-volume preparations for screening CTC with regard to quality of preparation and patient acceptability.

METHODS

Asymptomatic subjects at average risk for colorectal cancer from a community-based CTC screening program were randomized to bowel preparation comprising magnesium/bisacodyl/picolax or polyethylene glycol (PEG)/picolax. CTC images were evaluated by a blinded investigator for residual feces and fluid; subjects completed a questionnaire regarding acceptability of the preparation.

RESULTS

In 176 subjects randomized to magnesium/bisacodyl/picolax (n = 82) or PEG/picolax (n = 94), the former preparation was discontinued because of syncope or presyncope in four (5%) subjects. Another 137 subjects received PEG/picolax without a significant adverse event. There were no other major differences in acceptability of the preparations as reported by subjects. The quality of bowel preparations for reporting CTC was similar.

CONCLUSION

For subjects having screening CTC, both small-volume bowel preparations are generally well tolerated and result in minimal fluid and fecal residue; however, the magnesium/bisacodyl/picolax preparation was accompanied by an unacceptable incidence of syncope and is no longer used by us.

Preoperative assessment of pancreatic malignancy using endoscopic ultrasound

BACKGROUND

Endoscopic ultrasound (EUS) has been regarded as the most accurate modality for locoregional staging of pancreatic malignancy. However, several recent studies have questioned this. The current study assessed the accuracy of EUS in determining preoperative resectability of pancreatic neoplasia.

METHODS

A retrospective review was performed of patients with pancreatic malignancy who had preoperative EUS and underwent surgery. EUS-predicted resectability was compared with surgical resectability. Where available, accuracies of vascular and nodal staging were also assessed.

RESULTS

Forty-five patients were identified (mean age 60 years, age range = 36-79 years). All patients underwent surgical exploration; vascular staging was available in 32 cases and 17 cases underwent surgical resection. The sensitivity, specificity, and accuracy of EUS in determining unresectability were 66%, 100%, and 78% respectively. Overall EUS stage concurred with surgical stage in 56%, greater than surgical stage in 4%, and less than surgical stage in 40%. Vascular staging on EUS had a sensitivity of 69% and a specificity of 100%. Accuracy of nodal staging was 71%.

CONCLUSION

EUS had a high specificity for assessing unresectable pancreatic malignancy. This technique should be used to avoid unnecessary surgical exploration of incurable lesions. However, EUS had only a moderate sensitivity, and a proportion of patients staged preoperatively as having resectable disease will not be surgically resectable.

Computed tomography colonography

Computed tomography colonography (virtual colonoscopy) is an exciting technique that continues to evolve but promises to be a valuable tool for diagnosis of and screening for colorectal neoplasia.

Extracolonic findings at virtual colonoscopy: implications for screening programs

OBJECTIVE

Virtual colonoscopy (VC) is an evolving technology proposed as a possible screening tool for colorectal cancer. In contrast to conventional colonoscopy, VC may detect extracolonic abdominal pathology. This may lead to unnecessary investigation of benign lesions, or may benefit the patient by identifying serious pathology at an early stage. The aim of this study was to assess the prevalence and characteristics of extracolonic pathology found in patients undergoing VC.

METHODS

A total of 100 patients aged > or = 55 yr, referred for colonoscopy for bowel symptoms or family history of bowel cancer, underwent VC. Axial views of the abdomen were reviewed prospectively by a single radiologist for extracolonic pathology. Patients with extracolonic abnormalities were referred to their local doctor or to a specialist clinic when appropriate. Case records were reviewed and treating doctors contacted to document subsequent investigations and procedures generated.

RESULTS

Fifteen patients (15%) had extracolonic abnormalities detected. In four patients, the pathology had been diagnosed previously (umbilical hernia, gallbladder and renal calculi, 3.5-cm aortic aneurysm, ovarian cyst). Eleven patients had new abnormalities detected: ovarian cysts (three), liver cysts (two), uterine fibroids (two), gallstones (one), splenic calcifications (one), aortic aneurysm (one), and renal tumor (one). Two patients with ovarian cysts underwent surgery, and histology showed benign cysts.

CONCLUSIONS

Extracolonic abnormalities are common at VC. Most are benign, but may lead to investigative and procedural costs. These data should be carefully evaluated in feasibility and cost-effectiveness studies on colorectal cancer screening using VC.

Virtual colonoscopy compared with conventional colonoscopy: a developing technology

AIM

To determine the accuracy of computed tomography colography (virtual colonoscopy) in detecting colorectal polyps and colorectal cancer.

DESIGN

Blinded comparison of virtual colonoscopy (initially supine-only scans and later supine plus prone scans) with the criterion standard of conventional colonoscopy.

SUBJECTS AND SETTING

100 patients aged 55 years or over referred to a public teaching hospital for colonoscopy, July 1997 to January 2000, because of colonic symptoms or a family history of bowel cancer.

MAIN OUTCOME MEASURES

Presence and size of polyps and other lesions; certainty of polyp identification on virtual colonoscopy (on 100-point visual analogue scale); sensitivity and predictive values of virtual colonoscopy.

RESULTS

Conventional colonoscopy identifed 121 polyps in 47 patients; 28 of these polyps, in 19 patients, were identified by virtual colonoscopy. Sensitivity of virtual colonoscopy for detecting polyps (using supine plus prone scans) was 73% for polyps with diameter > or = 10 mm (95% CI, 39%-94%) and 19% for smaller polyps (95% CI, 10%-31%) (P < 0.001); corresponding figures for supine-only scans were 57% (95% CI, 18%-90%) and 11% (95% CI, 4%-24%), respectively. Ten polyps identified at virtual colonoscopy were considered false-positive findings (8%). The value of finding a polyp on virtual colonoscopy (with thresholds of 5 mm for diameter and 30 points for certainty score) was assessed as a predictor of finding a polyp (diameter > 5 mm) on conventional colonoscopy. Positive and negative predictive values were 88% and 89%, respectively, for supine plus prone scans.

CONCLUSION

Although virtual colonoscopy shows potential as a diagnostic tool for colorectal neoplasia, it is currently not sufficiently sensitive for widespread use.

Granular cell tumour of the oesophagus: endoscopic ultrasound appearances

A case of granular cell tumour of the oesophagus in a middle-aged woman is reported. The pathological features and appearances on endoscopic ultrasound (EUS) are described, and the role of EUS in the characterization of intramural oesophageal tumours is discussed.

The role of the barium enema in the diagnosis of colorectal neoplasia

The recent interest in guidelines for colorectal cancer diagnosis, management and in screening has important implications for radiologists. The present article reviews the role of the barium enema in colorectal neoplasia diagnosis in symptomatic patients, and in the context of screening programmes.

Liposarcoma of the hypopharynx

A case of the unusual condition of liposarcoma of the hypopharynx extending submucosally down the oesophagus in a 64 year old male is reviewed. The clinical, radiological and pathological features are presented and the role of various radiological modalities is discussed.

The whirl sign: a non-specific finding of mesenteric rotation

The whirl sign has been described as a computed tomography (CT) finding of volvulus of the gut. Six cases are presented with a range of clinical diagnoses (a volvulus, adhesive obstruction with volvulus and previous left hemicolectomy, adhesions alone, transverse colectomy, and right hemicolectomy). All demonstrated a whirl sign. A further case simulating a whirl sign is also presented. We propose that the whirl sign, although a finding highly suggestive of volvulus, can occur in any situation that produces rotation or twisting of bowel and its mesenteric attachment.

Duodenal haemorrhage resulting from renal cell carcinoma metastases

A case of duodenal haemorrhage resulting from renal cell carcinoma metastases is presented. This is an uncommon method of presentation and is often difficult to diagnose requiring multiple imaging regimes. This case demonstrates the problems that may be encountered in identifying the source of bleeding.

A combined flexible sigmoidoscopy and double-contrast barium enema service: initial experience

BACKGROUND

A service has been instituted offering a combined single-stage procedure of flexible sigmoidoscopy and double-contrast barium enema (FS/DCBE). The results have been reviewed in the first 80 patients to undergo this examination (45 male: 35 female; mean age 61.4 years).

METHODS

Indications for investigation were abdominal pain or suspected diverticular disease (22 patients), altered bowel habit (19), rectal bleeding (17), iron deficiency anemia (6), and miscellaneous (16). FS was followed immediately by DCBE. Radiographs were reviewed by two radiologists unaware of the FS findings.

RESULTS

The extent of FS was to the proximal sigmoid or sigmoid descending colon or splenic flexure in 12.5%, and mid or distal sigmoid in 37.5%. Biopsies were performed at FS in 26 patients (33%). In 67 (84%) of DCBEs the barium coating was assessed as satisfactory or better. FS yielded pathological findings not seen at DCBE in 21 patients (26%). DCBE demonstrated additional abnormalities within the range of the FS examination in 15 patients (19%), almost entirely due to its increased sensitivity for diverticular disease.

CONCLUSION

FS/DCBE is feasible as a one-stage combined procedure. The quality of DCBE following FS is satisfactory, and the extra yield of FS and its potential for biopsy make the combined FS/DCBE a useful technique in the investigation of large bowel disease.

Retroperitoneal lymphangioma

Five cases of retroperitoneal lymphangioma are presented. In three patients the lesions were symptomatic, with resolution of the symptoms following resection. In two elderly patients the lesions were asymptomatic. Ultrasound demonstrated masses that ranged from 4 to 15 cm in maximal extent, and which were predominantly anechoic. Two contained septations and two echogenic debris. Computed tomography demonstrated the masses to be of water density, and allowed better delineation of the lesions to adjacent structures within the anterior pararenal space. Fine needle aspiration (FNA) produces a characteristic cytology of abundant lymphocytes, which may be intermingled with macrophages. It is considered that retroperitoneal lymphangioma has characteristic imaging features that allows a presumptive diagnosis, which can be confirmed by FNA.

Abdominal ultrasound. An overview for general practitioners

The authors review some of the commoner indications and pathologies encountered in the context of general practice in which ultrasound has a role. Gynaecological indications and paediatric ultrasound will not be discussed.

Ultrasound and liver disease

The widespread availability of ultrasound has revolutionised the investigation of hepatobiliary disease. Liver ultrasound should be the primary imaging modality in jaundice, suspected diffuse liver disease or focal liver disease and supplemented by other modalities where indicated. The advent of Duplex and Colour Doppler imaging has expanded the utility of ultrasound techniques in relation to the hepatic vasculature. This article presents an overview of the use of ultrasound in liver disease.

Computed tomography in acute small bowel obstruction

The abdominal computed tomograms of 28 patients with a clinical diagnosis of acute small bowel obstruction were reviewed. Computed tomography accurately identified the presence, severity and level of obstruction. Signs such as angulated bowel loops and adjacent streaks within the mesentery at points of luminal calibre change were recognized in 69% of cases with adhesive obstruction. Computed tomography may reveal non-adhesive causes and is the modality of choice for investigating patients with higher grades of bowel obstruction where early surgical intervention is contemplated.

The role of endoscopic ultrasonography in the upper gastrointestinal tract: a review with illustrative cases

In this article the current applications of endoscopic ultrasound in the upper gastrointestinal tract and its adnexa, as well as the areas of likely development, are reviewed. Illustrative cases are shown from the author's experience. Pitfalls and limitations of the technique are also discussed.

A case of fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma is an uncommon histologic subtype of hepatocellular carcinoma, comprising 3.5% of all hepatocellular carcinomas in one large study (Brandt et al 1988). It usually occurs in young people, the average age being 18 years (Farhi et al 1983). It is not associated with cirrhosis and the serum alphafetoprotein is usually normal (Craig et al 1980). Fibrolamellar hepatocellular carcinoma has a more favourable prognosis than the usual hepatocellular carcinoma, with an average survival of 32 months from onset of symptoms, compared to 6 months for the usual type. The resectability rate and 5 year survival figures are also much better (Craig et al 1980). Hence distinguishing this histological subtype is important for surgical management and survival prognosis. This report describes a full radiological evaluation of such a case, covering the wide spectrum of relevant imaging modalities.

Bile duct measurements after ceruletide as an aid to the ultrasound diagnosis of choledocholithiasis

Despite good results in gallbladder imaging, ultrasound (US) diagnosis of choledocholithiasis remains a challenge. The value of US before and after a provocative injection of the decapeptide ceruletide was examined in 25 patients with suspected common duct stones immediately prior to diagnostic retrograde cholangiography. An abnormal response (increase in US duct diameter) was seen in 4 of 6 patients with an obstructed duct, giving a sensitivity of 67% and predictive value of 80% for the procedure. There was a normal response (decrease in US diameter of a dilated duct or decrease/no change in a normal duct) in 14 of 19 with an unobstructed duct (specificity 79%, predictive value 93%) and an equivocal response (no change in diameter of a dilated duct) in 5 patients. In 1 patient a calculus not seen on the initial US became visible as the duct distended by ceruletide administration. Symptoms after ceruletide were few and not discriminatory. Although it added to the time and difficulty of performing biliary US, ceruletide administration proved a useful adjunct to the diagnosis of choledocholithiasis.

Atypical presentation of empyema of the gall bladder

A case of empyema of the gall bladder complicated by liver abscesses is reported. The mode of presentation was atypical for both the empyema and the abscesses and computed tomography (CT) played a significant role in the diagnosis and management.

Ceruletide for retained biliary stones

Images

The radiological features of chronic radiation enteritis

The radiological findings, using a single-contrast barium infusion technique, are described in a series of 13 patients with chronic radiation enteritis. The signs include evidence of submucosal thickening, single or multiple stenoses, adhesions and sinus or fistula formation. A combination of these signs characterises the condition. This technique is particularly suited to the investigation of radiation enteritis because of its ability to distend maximally the small intestine. A cause, stenosis and/or adhesions, was demonstrated in the eight of the 13 patients presenting with intermittent small-intestinal obstruction. Three patients had diarrhoea as their predominant complaint and a fistula was demonstrated in two.

The treatment of giardiasis

Very effective treatment for giardiasis is available. There is little to choose in efficacy between the major drugs I have mentioned, used at optimum dosage, but mepacrine probably has a higher frequency of unwanted effects than many of the newer drugs, and the required duration of treatment is longer. Tinidazole is a very promising drug, being effective in single dosage with infrequent side effects.