[Improvement of pulmonary angiography in the framework of a maintenance of certification]

PURPOSE

This evaluation of clinical practices (pulmonary embolus) was performed to evaluate the quality of CT pulmonary angiograms for suspected acute pulmonary embolus.

MATERIALS AND METHODS

Five validated criteria evaluating both the acquisition technique and the quality of image interpretation were selected: slice thickness, pulmonary arterial enhancement over 250 HU, caudocranial acquisition, visualization of fifth order pulmonary arterial branches, and right-left ventricular ratio in the presence of pulmonary embolus. Forty CT pulmonary angiograms were reviewed before and after implementation of a practice quality improvement program: modification of acquisition protocol, training of medical and paramedical staff, and implementation of a standardized radiology report.

RESULTS

Thin collimation was already implemented. The implementation of two other technical parameters significantly improved the technical quality of the examinations. The detection of findings with adverse clinical outcome was also significantly improved. Only the accuracy of detection of embolus involving fifth order pulmonary arterial branches could not be improved, a criteria allowing formal exclusion of pulmonary embolus.

CONCLUSION

This study resulted in an improvement in the quality of CT pulmonary angiograms and increased awareness of radiologists for the prognostic value of right ventricular dilatation. It has also underscored the need for quality control of a CT pulmonary angiogram prior to interpretation.

[Urokinase in the management of occluded PICC lines]

PURPOSE

To determine the efficacy and safety of urokinase in the management of occluded PICC lines.

MATERIALS AND METHODS

A total of 587 PICC lines were placed over an 11 month period. During this period, 28 PICC lines (4.8%) became occluded: 12 occluded PICC lines were successfully managed by simple flushing with normal saline while 16 PICC lines were thrombolyzed with urokinase.

RESULTS

After urokinase, 93.8% (15/16) of occluded PICC lines were completely patent. A single infusion of urokinase, 20,000 IU over 30 minutes, was used in all cases. No secondary occlusion or complication was noted after urokinase.

CONCLUSION

Urokinase is effective and safe to restore patency to occluded PICC lines. The procedure is simple, and could be performed at the bedside by nursing staff after medical prescription. It is an alternative to over the wire PICC line exchange, that could reduce the risk of complication related to manipulations, patient discomfort and cost.

[Imaging of mediastinal tumors]

Imaging of mediastinal tumors is an important part of the diagnostic workup in patients presenting symptoms suggestive of compression of one or more of the mediastinal components. In other cases, lesions growing within the mediastinum remain asymptomatic and are diagnosed when chest X-ray or CT are routinely performed for other indications. CT remains the most available and reliable tool among the different imaging methods. Due to its permanent technical improvements, it can be used as the one-step answer to all the requirements of the pretherapeutic evaluation of a mediastinal mass. Chest plain film is still needed as the first line examination in order to carefully select the acquisition protocol for CT. MR did not demonstrate any superiority to CT except for the preoperative workup of lesions arising in the posterior part of the mediastinum. MR remains an interesting tool for tissue characterisation. Topography of mediastinal lesions (based upon the definition of mediastinal compartments) is one of the guides through the diagnostic pathway in imaging these tumors. The other one is their main tissue component, so that cystic, fatty and soft tissue masses can be differentiated.

[Mesenteric venous ischemia secondary to portal stenosis following liver transplantation]

We report a case of portal vein stenosis six months after previous orthotopic liver transplantation. The patient presented with mesenteric venous ischemia. He underwent successful percutaneous transhepatic portal vein angioplasty and stent placement.

[Cervical lymph nodes]

Imaging plays a chief role in the care and monitoring of patients in cervico-facial oncology. The radiologist must know the anatomy of different lymph nodes as well as signs of malignancy (hypertrophy, enhancement, necrosis, capsular rupture, etc.). CT is still the first-line examination because of its high reliability, its accessibility and its ability to make an assessment of the upper aero digestive ways at the same time. Ultrasound is very accuracy, and allows the realization of cytoponction, but does not provide a complete exploration of the neck. MRI does not appear to be indicated for the first intention, but the new rapid sequences (STIR, diffusion) seem interesting. The PET-CT is useful in post-therapeutic management of patients, and probably in the initial staging, but its accessibility is poor.

Comparative clinical and transcriptomal profiles of breast cancer between French and South Mediterranean patients show minor but significative biological differences

BACKGROUND

In Western countries, breast cancer incidence and mortality are higher than in Mediterranean countries. These differences have been ascribed to environmental factors but also to late-stage diagnostic and biological specific characteristics.

PATIENTS AND METHODS

Between September 2002 and September 2005, we collected clinical data by phone counselling 180 French and Mediterranean breast cancer patients and performed microarray experiments.

RESULTS

Characteristics of breast cancer in patients from Lebanon, Tunisia and Morocco were more aggressive (more SBR grade III and positive node invasion) and patients were 10 years younger at diagnosis. Sixteen differentially expressed genes such as MMP9, VEGF, PHB1, BRCA1, TFAP2C, GJA1 and TFF1 were also found. Additionally, an up-regulation of cytokeratins KRT8 and KRT18 may indicate a luminal B subtype in "South" (Lebanon, Tunisia and Morocco) tumors while "North" (France) tumors may more frequently be luminal A type.

CONCLUSION

This study allowed the identification of specific clinical and transcriptomic parameters in patients from South Mediterranean countries.

Acoustic emission associated with the bursting of a gas bubble at the free surface of a non-Newtonian fluid

We report experimental measurements of the acoustic emission associated with the bursting of a gas bubble at the free surface of a non-Newtonian fluid. On account of the viscoelastic properties of the fluid, the bubble is generally elongated. The associated frequency and duration of the acoustic signal are discussed with regard to the shape of the bubble and successfully accounted for by a simple linear model. The acoustic energy exhibits a high sensitivity to the dynamics of the thin film bursting, which demonstrates that, in practice, it is barely possible to deduce from the acoustic measurements the total amount of energy released by the event. Our experimental findings provide clues for the understanding of the signals from either volcanoes or foams, where one observes respectively, the bursting of giant bubbles at the free surface of lava and bubble bursting avalanches.

Traitement radiologique des malformations artérioveineuses périphériques

Management of high-flow arteriovenous malformation remain often problematic. Complete eradication of the nidus is the only potential cure, but this, however, is often difficult if not impossible. Frequently, a multidisciplinary approach is required. In these article, techniques and results of the endovascular management of MAV are discussed.

Usefulness of transjugular intrahepatic portosystemic shunt in the management of bleeding ectopic varices in cirrhotic patients

PURPOSE

To evaluate the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) in the control of bleeding from ectopic varices.

METHODS

From 1995 to 2004, 24 cirrhotic patients, bleeding from ectopic varices, mean age 54.5 years (range 15-76 years), were treated by TIPS. The etiology of cirrhosis was alcoholic in 13 patients and nonalcoholic in 11 patients. The location of the varices was duodenal (n = 5), stomal (n = 8), ileocolic (n = 6), anorectal (n = 3), umbilical (n = 1), and peritoneal (n = 1).

RESULTS

TIPS controlled the bleeding in all patients and induced a decrease in the portacaval gradient from 19.7 +/- 5.4 to 6.4 +/- 3.1 mmHg. Postoperative complications included self-limited intra-abdominal bleeding (n = 2), self-limited hemobilia (n = 1), acute thrombosis of the shunt (n = 1), and bile leak treated by a covered stent (n = 1). Median follow-up was 592 days (range 28-2482 days). Rebleeding occurred in 6 patients. In 2 cases rebleeding was observed despite a post-TIPS portacaval gradient lower than 12 mmHg and was controlled by variceal embolization; 1 patient underwent surgical portacaval shunt and never rebled; in 3 patients rebleeding was related to TIPS stenosis and treated with shunt dilatation with addition of a new stent. The cumulative rate of rebleeding was 23% and 31% at 1 and 2 years, respectively. One- and 2-year survival rates were 80% and 76%, respectively.

CONCLUSION

The present series demonstrates that bleeding from ectopic varices, a challenging clinical problem, can be managed safely by TIPS placement with low rebleeding and good survival rates.

[Systemic learning planification for residents during the 6-month pediatric radiology training]

Diagnostic Radiology and Medical Imaging residents of French University Hospitals benefit from a wide array of learning tools. However, the professors' clinical workload, lack of sufficient proper formal training, lack of practical applicability of existing standards, and absence of rigorous assessment during the specialized training, reduce their very good quality formation to the level of accidental learning. This study originates from the need to apply a systemic planification of learning activities to the French residents' formal training curriculum, such as the one originally designed and applied within the Quebec educational system. This presentation also benefits from the recent introduction of the CanMEDS 2000 objectives by the Royal College of Physicians and Surgeons of Canada, in order to design an adapted version for the professional and academic activities of French radiologists. Needless to say this work will respect the outlined systematic planning of any learning activity: learning requirements, definition of learning objectives, selection of learning methods, assessment of the participants' achievement of these objectives, and evaluation of the learning activity itself.

Embolization-driven Occlusion of the Abdominal Aortic Aneurysmal Sac as the Basis of Prevention of Endoleaks in a New Swine Model

OBJECTIVES

To assess the effect of a new polymer in embolization of endoleaks using an animal model.

METHODS

A modified aortic stent-graft was placed in 20 pigs. Embolization was performed at the time of graft insertion with non-cytotoxic n-butyl-2-cyanoacrylate-metacryloxysulpholane and lipiodol (0.2:0.8ratio, 2 ml). Angiography, scanning electron microscopy and immuno-histochemistry were obtained at day 0, 1 week and 3 months.

RESULTS

In control animals both type I and II endoleaks were demonstrated. In treated animals, neither type-I nor type-II endoleaks were observed and a fibro-proliferative response was demonstrated within the aneurysm thrombus.

CONCLUSIONS

Host vascular responses govern the fate of the excluded aneurysm. Embolization of the sac and feeding arteries with non-cytotoxic glue sealed all occlusions by stimulating a massive restenosis-like process.

[CT evaluation of total HIP prosthesis infection]

PURPOSE

To evaluate the ability of CT imaging to detect infectious lesions in total hip prosthesis.

PATIENTS AND METHODS

CT was performed in 17 cases of suspected total hip prosthesis infection. Images were reviewed to evaluate for the presence of soft tissue abscess, hip joint effusion or fistula and peri-prosthetic lucency or erosion at bone window setting. The feasibility of CT imaging is assessed with regards to metallic artifacts.

RESULTS

Infection was confirmed in 10 hips. A soft tissue abscess was present in 8 of these cases, in association to a joint effusion, presumably septic, in 7 cases. A fistula was identified in 8 cases. A peri-prosthetic lucency was present in 10 cases, 7 of which with infection, and erosions were noted in 4 patients, 2 of which with infection. Metallic artifacts reduced image quality but did not prevent detection of soft tissue abscesses.

CONCLUSION

CT is useful for detection of soft tissue abscesses in patients with infected hip prosthesis. CT is useful for surgical planning or follow-up of patients treated conservatively.

[Early cholangitis complicating percutaneous biliary drainage]

PURPOSE

To evaluate the prevalence, severity and outcome of cholangitis within two months after percutaneous transhepatic biliary drainage.

MATERIALS AND METHODS

One hundred and nineteen patients with obstructive jaundice but no septic symptoms underwent biliary drainage for biliary decompression. Biliary obstruction was malignant in 87 patients and benign in 32 patients. Clinical and biological criteria were developed to confirm and grade the cholangitis. Based on these, the prevalence, severity and outcome of cholangitis was determined and analysed through review of clinical records.

RESULTS

All patients had successful biliary drainage and internal drainage. Nine patients (7.5%) developed cholangitis after biliary drainage, three (2.5%) being of the severe type. Of these, 8 had malignant obstruction. All three patients with severe cholangitis had malignant obstruction. All patients with cholangitis except one (0.8%) responded to antibiotic and supportive therapy.

CONCLUSION

Severe cholangitis occurring within two months following PBD for obstructive jaundice was uncommon. It tended to occur in patients with malignant obstruction. Although most responded favorably to medical treatment, post procedural sepsis must be handled with great care since it is life-threatning.

[Stent-graft treatment of a ruptured aortic graft: a case report]

The authors report the clinical and imaging features of a patient with rupture of an aortoiliac graft successfully treated by endovascular approach. The endovascular treatment is easy to perform and effective. The main pitfall of this technique is the limited availability of stent-grafts.