Utility of additional abdominopelvic CT in detecting occult cancer in patients with unprovoked venous thromboembolism.

AIM: To analyse the positive rate for cancer on additional abdominopelvic computed tomography (CT) in patients with unprovoked venous thromboembolism (VTE), evaluate the subsequent emergence of a cancer diagnosis in the clinical follow-up period, and identify any possible predictive factors of cancer in this cohort, which may allow better selection of patients for additional imaging. MATERIALS AND METHODS: Consecutive adult patients with VTE were retrospectively identified in two large teaching hospitals between January 2013 and June 2014, including a subset of those with unprovoked VTE. Relevant demographic data were extracted and analysed. All patients had a minimum of 12 months clinicoradiological follow-up. RESULTS: One thousand four hundred and forty-six patients with VTE were deemed eligible, of which 699 (48%) were male; the median age (range) was 66 (16-102) years. The prevalence of pre-existing cancer in these patients was 343/1446 (24%), and 388/1446 (27%) were classified as unprovoked VTE. In 12/1446 (0.8%), cancer was diagnosed synchronously with VTE on the initial imaging investigation. Additional screening imaging was performed in 232/388 (60%) including abdominopelvic CT in 205 (53%) patients with unprovoked VTE. Only five additional cancers were identified, all of these occurring in patients with clinical symptoms suspicious for cancer. None of the additional CT examinations identified any clinically occult cancer in asymptomatic patients, and subsequent mean follow-up of 22 (SD=6) months also failed to reveal any further cancer diagnosis. CONCLUSION: Contrary to the National Institute of Health and Care Excellence (NICE) guidance, the yield of performing additional abdominopelvic CT as a screening tool for occult cancer in asymptomatic patients with unprovoked VTE is negligible. A more selective and clinically-driven assessment of these patients is recommended.

Duplex sonography in the planning and evaluation of arteriovenous fistulae for haemodialysis.

This paper describes how to perform duplex sonography in the planning and evaluation of arteriovenous fistulae in haemodialysis patients, discusses its roles in these settings, and presents a review of commonly encountered complications.

Magnetic resonance imaging in fetal medicine: a pictorial review of current and developing indications.

Improvements in magnetic resonance (MR) imaging now permit diagnostic images of the fetus to be obtained. Ultrasound remains vital in all aspects of fetal imaging but MR provides a useful second line imaging test. Its value is best researched in fetal central nervous system disorders but it can be applied in other areas too. This pictorial review shows many of the commonly encountered problems. The pictures have a powerful impact on parental understanding. Future research must involve determination of the prognosis of abnormalities found at MR.

Barentsz is essential for the posterior localization of oskar mRNA and colocalizes with it to the posterior pole.

The localization of Oskar at the posterior pole of the Drosophila oocyte induces the assembly of the pole plasm and therefore defines where the abdomen and germ cells form in the embryo. This localization is achieved by the targeting of oskar mRNA to the posterior and the localized activation of its translation. oskar mRNA seems likely to be actively transported along microtubules, since its localization requires both an intact microtubule cytoskeleton and the plus end-directed motor kinesin I, but nothing is known about how the RNA is coupled to the motor. Here, we describe barentsz, a novel gene required for the localization of oskar mRNA. In contrast to all other mutations that disrupt this process, barentsz-null mutants completely block the posterior localization of oskar mRNA without affecting bicoid and gurken mRNA localization, the organization of the microtubules, or subsequent steps in pole plasm assembly. Surprisingly, most mutant embryos still form an abdomen, indicating that oskar mRNA localization is partially redundant with the translational control. Barentsz protein colocalizes to the posterior with oskar mRNA, and this localization is oskar mRNA dependent. Thus, Barentsz is essential for the posterior localization of oskar mRNA and behaves as a specific component of the oskar RNA transport complex.

Discriminative MRI features of fallopian tube masses.

Fallopian tube disease, both acute and chronic, is a common cause of a sonographically indeterminate adnexal mass and may mimic ovarian cancer. Magnetic resonance imaging (MRI) is now widely used as a problem-solving tool in these circumstances. The purpose of this review is to provide the discriminative MRI features of Fallopian tube masses and illustrate the key signs that establish their origin and nature. Familiarity with these characteristics enables distinction of tubal disease from malignant adnexal disease with major impact on management. On MRI, Fallopian tube disease exhibits features that parallel the classical sonographic findings, but which can be more reliably recognized due to improved contrast and spatial resolution, multiplanar capacity, effective field of view, and tissue characterization. Recognition of these characteristic morphological features and specific MRI signal patterns are key to a specific diagnosis. The anatomical and histopathological basis of these MRI signs is emphasized, covering also the differential diagnosis and pitfalls. Two new signs, "synechiae" and "amorphous shading", are also described that have not been well described previously in MRI of tubal disease.

An assessment of whole blood impedance aggregometry using blood from normal subjects and haemodialysis patients.

Impedance aggregometry allows the measurement of platelet responses in whole blood as well as in PRP. The variability of haematocrit values encountered when applying this technique to haemodialysis patients prompted an investigation of the effects of red cells on platelet aggregation in whole blood. Collagen induced aggregation was measured in both PRP and whole blood from haemodialysis patients and healthy controls. Platelets from haemodialysis patients were less aggregable than those from the controls when tested in PRP, but more aggregable when tested in whole blood. Blood samples with a range of haematocrit values were prepared by mixing PRP and autologous red cells, and used to study the effect of haematocrit on platelet aggregation. In blood from control subjects aggregation rate was reduced by rising haematocrit but no reduction of maximum aggregation occurred until haematocrit exceeded 40%. In contrast uraemic platelets showed increased responses in the presence of red cells. In a limited cross over study no significant difference was found in the effect on platelet aggregation of washed erythrocytes from uraemic and non-uraemic donors. It is concluded that red cell presence influences platelet aggregation by complex mechanisms during impedance aggregometry and that this effect must be considered when interpreting results.

Reduction of dialyzer fibrin deposition with sulphinpyrazone.

To determine whether sulphinpyrazone reduces thrombus formation within artificial kidneys, dialyzer 125I-fibrinogen and platelet and fibrinogen levels during dialysis were compared during a non-treatment control period and while patients were receiving sulphinpyrazone. Mean fibrin deposition within the dialyzers, measured as gram X 10(-3) of clottable fibrinogen, was significantly less during sulphinpyrazone treatment (2.5) than during the control period (5.3). Arterial blood platelet counts and plasma fibrinogen levels during dialysis were higher on treatment despite similar predialysis values during control and treatment periods. The results indicate that sulphinpyrazone reduces fibrin formation within artificial kidneys and, since the reduction in deposition of fibrin alone is insufficient to explain the higher plasma fibrinogen levels during treatment with sulphinpyrazone, suggests that this therapy reduces fibrinogen consumption within the patient during hemodialysis.

Dialysis in the treatment of renal failure in patients with liver disease.

The value and effects of treating renal failure by dialysis are analyzed in a series of 84 patients with various types of liver disease. Although none of the 25 patients with cirrhosis survived, six of 50 with fulminant hepatic failure recovered completely as did seven of nine patients with renal failure secondary to extrahepatic biliary tract obstruction or with liver and renal damage following episodes of severe hypotension. Dialysis was required for seven weeks before diuresis occurred in one patient in the latter group. Both peritoneal and hemodialysis satisfactorily controlled plasma urea and creatinine levels, except in patients with fulminant hepatic failure in whom this was only achieved by hemodialysis. Complications of dialysis were most common in patients with cirrhosis and fulminant hepatic failure and included hypotension, gastrointestinal bleeding, and intraperitoneal sepsis. Overall, the results show that dialysis is only worth attempting in those patients in whom recovery of the underlying liver lesion is possible, and even then treatment for prolonged periods may be necessary.

An audit of a radiographer based ultrasound service.

A general ultrasound service has evolved over several years. Radiographers undertake the general ultrasound lists, and show the request card and the hard copy films to a radiologist prior to the patient leaving the department. Whilst it is generally accepted for radiographers to carry the burden of obstetric scanning, this is less so for general work. This audit is of a sample of 100 patients out of the general ultrasound lists. These patients underwent the standard service examination by a radiographer and subsequent report by the radiologist. They also had a separate examination and report by an independent radiologist. 42 patients were agreed to have normal findings. 75 diagnoses or observations were made in the remaining 58 patients. Discrepancies arose between the two limbs of the audit in 20 of the observations. Review of the hard copy films and repeat scanning of patients where necessary identified one relevant error by the auditing radiologist and three relevant errors by the standard service. Whilst errors are made both by radiologists and radiographers, it is concluded that the existing radiographer based ultrasound service provides a satisfactory level of accuracy.

The agreement between colour Doppler systems in measuring internal carotid artery peak systolic velocities.

The study was undertaken to determine if the internal carotid artery peak systolic velocities (ICA PSVs) measured by two colour Doppler imaging systems (Acuson 128 and Siemens Quantum) agree sufficiently for the two systems to be interchangeable in evaluating carotid artery disease. One operator obtained blinded measurements of ICA PSV in 63 prospective nonrandomized patients at risk of stroke. The operator examined 20 patients in the first cohort to assess the intraobserver variation, and 43 patients in the second cohort to assess the limits of agreement between the systems. In vitro comparisons of the systems were also undertaken, using both string and flow phantoms. Excluding one outlier, the intraobserver reproducibility coefficient for both machines was 0.48 m s-1. The limits of agreement (within which 95% of differences lie) between systems were -0.47 to 0.45 m s-1. This reduced to -0.39 to 0.33 m s-1 when the one outlier was excluded. This is within the intraobserver reproducibility range. In vitro data show little intersystem variation with phantom velocity. Intratransducer differences increase when the Doppler angle is increased using the string phantom; maximum differences: Acuson 0.30 m s-1 (42%) and Siemens 0.32 m s-1 (32%). These are within the in vivo reproducibility range. Intratransducer difference decreases when the Doppler angle is increased using the flow phantom, maximum differences: Acuson 0.05 m s-1 and Siemens 0.07 m s-1. The results show the systems agree sufficiently to be interchangeable in evaluating carotid artery disease; however, errors in maximum PSVs, caused by operator or system variation, may lead to errors in percent stenosis grading of the carotid arteries.

The changing face of emphysematous cholecystitis.

Emphysematous cholecystitis is a variant of acute cholecystitis characterized by the presence of gas in the gall bladder lumen, wall or pericholecystic tissues in the absence of an abnormal communication between the biliary system and the gastrointestinal tract. In the past, the diagnosis has relied on the plain abdominal radiograph (AXR), since there are no clinical features to separate this condition from simple acute cholecystitis. The apparently high mortality and morbidity associated with emphysematous cholecystitis has previously emphasized the importance of emergency cholecystectomy. We have reviewed eight cases of emphysematous cholecystitis presenting to this hospital over the last 5 years. The diagnosis was made on AXR in only one of these cases. Ultrasound (US) scans were performed in all eight cases, of which five were positive and three negative, due to non-visualization of the gall bladder. In the three negative cases, the diagnosis was made on subsequent CT scans. On initial clinical examination, only one of the eight patients appeared systemically unwell and conservative management was employed in five of the patients. The remaining three patients underwent cholecystectomy within 3-5 days because of continuing signs or symptoms. It is concluded that the AXR is relatively insensitive in the diagnosis of emphysematous cholecystitis. As a result of the regular use of US in suspected hepatobiliary disease, emphysematous cholecystitis is being diagnosed with increased frequency, uncovering a broad spectrum of disease ranging from mild to severe. Previously, failure to separate milder cases from simple acute cholecystitis may have been responsible for reports of unremitting severity and progression requiring emergency cholecystectomy. Based on clinical assessment, conservative surgical management is possible in a significant proportion of patients.

Lower moiety pelvic-ureteric junction obstruction (PUJO) of the duplex kidney presenting with pyonephrosis in adults.

The most common congenital abnormality of the urinary tract is a duplex kidney. Pelvic-ureteric junction obstruction (PUJO) is a rare association that can affect the lower moiety of incomplete duplex kidneys. We report two adult cases of PUJO of the lower moiety in a duplex kidney that both presented with pyonephrosis. This late presentation of lower moiety PUJO with pyonephrosis has not been described previously. We describe the imaging appearances of this rare association and highlight this important diagnostic consideration in lower moiety hydronephrosis of the adult patient.

The influence of hemodialysis fistulas on circulatory dynamics and left ventricular function.

This study was designed to examine the influence of arteriovenous (A-V) fistulas on cardiac output and left ventricular performance in 13 uremic patients on regular hemodialysis. M-mode echocardiography and systolic time intervals were used to derive indices of left ventricular function, and cardiac output was measured by thermodilution. Measurements were performed before and after acute digital occlusion of the A-V fistulas. Occlusion of a single fistula caused systemic vascular resistance and the systolic diameter of the left ventricle to increase from 9.6 +/- 1 to 13.5 +/- 2 units (p less than 0.001) and from 3.2 +/- .3 to 3.4 +/- .4 (p less than 0.05) respectively. The increase in afterload caused a reduction in cardiac output from 11.0 +/- 1 to 9.6 +/- 1 l/min (p less than 0.001) and probably accounted for the minor, though not significant, "deterioration" in the indices of left ventricular function. Bilateral fistula occlusion in 8 patients exaggerated these changes, and the reduction in fractional shortening from 43 +/- 4 to 37 +/- 4% was significant at the 5% level. In two patients with severe left ventricular failure, fistula occlusion caused a more pronounced deterioration in cardiac performance. These results show that acute A-V fistula occlusion effectively lowers cardiac output and is, therefore, likely to be beneficial in the management of high output failure. However, when intrinsic left ventricular disease is the primary etiological factor in heart failure, fistula occlusion is unlikely to be helpful, and may worsen the hemodynamic derangement.

Duplex scanning may be used selectively in patients with primary varicose veins.

Reflux was assessed using hand-held Doppler (HHD) and duplex scanning in 72 patients with primary, previously untreated varicose veins (108 limbs). The aims of the study were (i) to compare the accuracy of HHD assessment with duplex scanning, (ii) to assess the benefit of tourniquet testing and (iii) to identify patients who would benefit from a policy of selective duplex scanning. HHD accurately assesses the saphenofemoral junction (SFJ) and long saphenous vein (LSV) reflux. HHD assessment of the saphenopopliteal junction (SPJ) reflux has a low positive predictive value. A high negative predictive value reflects absent SPJ reflux assessed using HHD accurately. Tourniquet testing is not helpful. Selective duplex scanning of limbs with suspected SPJ reflux, no identifiable site of reflux or posterior thigh perforator reflux on HDD (39% of limbs), would result in the appropriate surgical procedure being performed in 102 (94%) limbs, excessive surgery in 5 (5%) limbs and inadequate surgery in only 1 (1%) limb. The use of selective criteria for duplex scanning would reduce the workload of the vascular laboratory without compromising patient care.

Optimising a varicose vein service to reduce recurrence.

A prospective observational study of 63 legs in 49 patients was undertaken to evaluate the adequacy of primary varicose vein surgery performed by surgical trainees. Appropriate surgery was carried out by a surgical senior house officer (SHO) under direct consultant supervision. All patients underwent pre- and postoperative duplex scanning. The preoperative duplex scan demonstrated incompetence of the saphenofemoral junction (SFJ) or long saphenous vein (LSV) in 59 limbs, a mid-thigh perforator (MTP) in 11 limbs, and saphenopopliteal junction (SPJ) in 5 limbs. Surgery successfully abolished all sites of pre-existing reflux. The postoperative duplex scan revealed that 17 new sites of reflux, not identified preoperatively, had developed in 12 limbs. With a consultant-led service and accurate preoperative identification of sites of reflux, the surgical trainee can adequately perform varicose vein surgery. This would seem a reasonable approach to training and eliminating recurrence owing to inadequate surgery. The development of new sites of reflux within 6 months of varicose vein surgery may be owing to altered venous haemodynamics consequent upon this surgery.

Emergency department imaging protocol for suspected acute renal colic: re-evaluating our service.

OBJECTIVES: The objective of our study is to determine the positive rate for urolithiasis in male and female patients, and evaluate whether there has been any change at our institution in the use and outcome of unenhanced multidetector CT (CT KUB) performed in the emergency department (ER) for patients presenting with suspected acute renal colic. METHODS: A retrospective review of all 1357 consecutive cases between August 2007 and August 2009 admitted to the ER and investigated with CT KUB. RESULTS: The positive rate for urolithiasis was 47.5% and the rate of other significant findings was 10%. Female patients had a significantly lower positive rate than male patients (26.8% vs 61.6%, p<0.001). Urological intervention was required in 37% and these patients had a larger average stone size. In young female patients with a significantly sized ureteric calculus (>4 mm), the presence of hydronephrosis vs no hydronephrosis was 83% vs 17%, respectively. Among them, only three patients required ureteroscopy for stone removal. CONCLUSION: Contrary to other studies there has been no "indication creep" in the use of CT KUB at our institution. However, the young female patient presenting with suspected urolithiasis presents a particular diagnostic problem, and the significant percentage of negative examinations in females implies that an improvement in current practice is needed. The indiscriminate use of CT KUB in all female patients with flank pain should be avoided, and it is suggested that they should be initially evaluated with ultrasound to detect the presence of hydronephrosis.

Outcome following saphenopopliteal surgery: a prospective observational study.

OBJECTIVES: High recurrence rates following small saphenous varicose vein surgery have been reported. The aim of this study was to ascertain initial success rates following saphenopopliteal junction (SPJ) surgery using pre- and postoperative duplex scanning. METHODS: A prospective study was performed on patients with ultrasound-proven SPJ reflux. Patients underwent preoperative duplex skin marking and a postoperative quality assurance scan. RESULTS: Ninety procedures were performed in 88 patients. The SPJ was successfully ligated in 87 (96.7%) cases. Reflux was completely abolished in 51 (56.7%) cases, but persisted solely in the small saphenous vein (SSV) in 32.2%. Subsequently, 10 consecutive patients underwent 11 SPJ ligations with stripping of the SSV. Follow-up ultrasound scan demonstrated successful ligation of the SPJ and elimination of superficial venous reflux. CONCLUSION: This study demonstrates that preoperative duplex SPJ marking results in a high percentage of successful ligation. Given that residual persistent reflux was avoided in patients who underwent stripping of the SSV, we propose that patients who require SPJ surgery undergo duplex marking along with specific consideration with regard to treatment of the residual SSV.