Sixty-four multi-slice computed tomography and magnetic resonance imaging in evaluation of hepatic focal lesions

Objective

The diagnostic accuracy of MSCT and MRI for evaluation of hepatic focal lesions.

Design

An analytic comparative study.

Setting

Radiology Department, Farwania Hospital.

Subjects

Ninety-five hepatic focal lesions, 61 patients were examined from October 2006 to March 2010. Gold standard was biopsy, radiological and clinical follow up.

Main outcome

The value of CT and MRI in characterizing these lesions was assessed.

Results

The mean sensitivity of MRI was (72.5%) and CT (72.6%) in the detection of overall hepatic focal lesions. However, the positive predictive value for MRI was 96.1% and for CT was 91.5%. False negative results were the problem of MRI and CT in lesions ?2 cm (33.8% and 30.5%, respectively). About lesion characterization, MRI was relatively highly specific for diagnosis of HCC (87.5%), hemangioma (91.2%) and metastases (87.8%).

Conclusion

An analytic comparative study.     

Development of hepatic pseudotumors for image-guided interventional and surgical research in a large animal model

Purpose

Real-time image guidance and navigation have become increasingly important in an era of minimally invasive interventional and surgical procedures in the liver. To develop, test, and implement tools for real-time image guidance, the authors sought to create an in vivo tumor mimic with realistic imaging and treatment capabilities.

Materials and Methods

Hepatic pseudotumors were created by injecting 1–2 mL of alginate (a hydrocolloid) directly into the liver parenchyma in eight live pigs and two dog cadavers. Tumors were imaged by B-mode ultrasound (US), US elasticity imaging, multi–detector row computed tomography (CT), CT fluoroscopy, and magnetic resonance (MR) imaging to assess imaging capabilities. Procedures performed with the alginate pseudotumors included radiofrequency (RF) ablation and robotic needle guidance.

Results

Twenty-four hepatic pseudotumors were created, ranging in size from 10 mm to 28 mm at an average depth of 6 mm. Average time of preparation and insertion was 3 minutes. All tumors were palpable under the surface of the liver and were easily visible on B-mode US, US elasticity imaging, CT, and MR imaging. Tumors were successfully “treated” with RF ablation, and gross examination of the liver showed good encompassment of the tumor by the zone of thermal coagulation. In addition, the pseudotumors allowed for easy introduction of various types of needles, including RF ablation probes and experimental steerable needles.

Conclusions

Alginate pseudotumors can easily be imaged and allow for different procedures to be performed. This model can be used for various research purposes.     

Computed radiography in musculoskeletal imaging

In conclusion, CR offers many advantages in comparison with conventional radiography. Musculoskeletal radiology particularly benefits from the wide dynamic range and image-processing capabilities of CR. Most studies have not shown a statistically significant difference in observer performance (diagnostic accuracy) of CR in comparison with conventional radiography in musculoskeletal applications. In addition, dose reduction in the range of 25% to 50% is possible with many musculoskeletal images. However, disadvantages are also apparent and include reduced spatial resolution, increased noise, and change in image size and format. Overall, the advantages of CR and digital technology outweigh its limitations and for these reasons continue to promote the conversion from conventional radiography.     

N-butyl cyanoacrylate embolization as the primary treatment of acute hemodynamically unstable lower gastrointestinal hemorrhage

Purpose

To evaluate N-butyl cyanoacrylate (NBCA) embolization as the primary treatment for patients with severe and acute hemodynamically unstable lower gastrointestinal bleeding.

Materials and Methods

Twenty-seven patients with acute, unstable hemodynamics caused by lower gastrointestinal bleeding underwent therapeutic NBCA microcatheter embolization over a period of 27 months. The inclusion criteria were hematochezia or melena and hypotension refractory to conservative treatment and requiring blood transfusion. Bleeding was localized to the rectum, colon, or small intestine in all nine such cases. Fifteen patients had severe underlying comorbidities, including sepsis, respiratory failure, malignancy, or renal failure.

Results

The procedure was technically successful in all patients. Twenty-six patients were treated solely with NBCA, and one required microcoil embolization. Embolization was performed at the level of the arteria recta or as close as possible to the point of bleeding. Immediate hemostasis occurred in all cases. Four patients experienced repeat hemorrhage, one of whom died. The other three were treated successfully with repeat NBCA embolization. None of the surviving patients had evidence of bowel ischemia. In addition, none of the patients with severe underlying disease died during the follow-up period (range, 3 mo to 2 y).

Conclusions

The present findings suggest that NBCA embolization may be a safe alternative treatment for the management of lower gastrointestinal bleeding. Further studies are warranted to confirm the findings.     

Hepatocellular Carcinoma: Prediction of Blood Supply from an Intercostal Artery with Multidetector Row Computed Tomography

Purpose

To evaluate the ability of multidetector row computed tomography (CT) to detect blood supply from the intercostal artery in patients with hepatocellular carcinoma (HCC).

Materials and Methods

Between January 2003 and December 2007, angiography of the intercostal artery was performed in 93 patients (76 men and 17 women, mean age 58 years) with HCC who had also undergone multidetector row CT. CT scans and digital subtraction angiograms of these patients were retrospectively reviewed by two investigators in consensus to evaluate tumor feeding vessels. Multiple logistic regression analysis was used to identify factors that predict the presence of an HCC blood supply from an intercostal artery.

Results

Tumor staining fed by an intercostal artery was noted in 65 patients (70%; 112 tumor feeding vessels) by intercostal angiography. Readers interpreted that tumor feeding vessels were evident by CT in 35 (54%) of these 65 patients with tumor staining supplied by an intercostal artery by angiography. Multiple logistic regression analysis showed that a visible tumor feeding vessel by CT (P = .003) and hepatic artery attenuation by angiography (P = .014) were significantly related to the presence of a blood supply from an intercostal artery.

Conclusions

Visualization of a tumor feeding vessel from the intercostal artery by multidetector row CT is an important sign of parasitic supply to an HCC.     

Sclerotherapy of abdominal lymphatic malformations with doxycycline

Purpose

To assess the safety and efficacy of percutaneous image-guided sclerotherapy with doxycycline as primary treatment of intraabdominal lymphatic malformations (LMs).

Materials and Methods

Retrospective review was performed of all cases of abdominal, mesenteric, or retroperitoneal LMs referred to a single center that were subsequently treated with image-guided percutaneous sclerotherapy.

Results

Ten patients were included, of whom six were male. The mean age was 13 years (range, 2–28 y). Preprocedural cross-sectional imaging demonstrated a macrocystic malformation in nine patients and a mixed macrocystic/microcystic malformation in one. The malformation was accessed under sonographic guidance, followed by injection of opacified sclerosant agent under fluoroscopic guidance. A drainage catheter was placed in eight cases, in which sclerotherapy was repeated through the catheter for another 1 day (n = 2) or 2 days (n = 6). Doxycycline was reconstituted at 10 mg/mL, with a mean per-session dose of 608 mg (range, 80–1,000 mg) and a mean total dose of 1,230 mg (range, 80–3,000 mg). Peritoneal spill was identified in one case, but the patient remained asymptomatic. No other complications were encountered. Follow-up imaging was available in eight patients: complete resolution was seen in seven, with partial resolution in one. There was no recurrence of clinical symptoms in the follow-up period.

Conclusions

Initial results indicate that percutaneous image-guided sclerotherapy of macrocystic intraabdominal LMs with doxycycline is a safe and effective procedure.     

CT fluoroscopy-guided placement of inferior vena cava filters: feasibility study in pigs

Purpose

To evaluate the feasibility of computed tomography (CT)–guided placement of inferior vena cava (IVC) filters in a swine model.

Materials and Methods

Five domestic pigs (60–70 kg) underwent transfemoral and transjugular IVC filter placement under real-time CT fluoroscopic guidance. Filter position was confirmed by contrast-enhanced CT and digital subtraction angiography. Filter tilt, distance to target position, and fluoroscopy time were analyzed.

Results

A total of 10 filters were successfully implanted (five via transfemoral approach, five via transjugular approach) without complications. The mean distance to the target position was 0.3 cm ± 0.2. Mean filter tilt was 3.2° ± 2.3 (range, 0°–7°), without differences between deployment techniques (P = .8486). Average fluoroscopy time was 25.9 s ± 6.9 per procedure.

Conclusions

CT fluoroscopy–guided placement of IVC filters is safely feasible. Use of this technique may avoid the need to move critically ill patients.     

Digital radiography of the chest

Digital radiography is an appropriate method for both bedside and in-department chest radiographs. Its major advantage in bedside chest radiography is its control of the displayed optical density of these radiographs. With dynamic range control processing, it improves the visibility of tubes and lines superimposed on the mediastinal tissues. When used for in-department chest radiography, it may offer slight advantages in the evaluation of disease in the mediastinum, but in general is equivalent to film-screen chest radiography. The main reasons for using digital chest radiography for in-department chest radiographs relate mainly to its use as a data entry point method of projection radiography for high-quality teleradiology or for its use in a picture archiving and communication system. Apart from these advantages, there is no reason to change from conventional to digital chest radiographs. Digital radiographs are, with certain systems, printed at smaller than life size. Because of this, there is a necessary period of learning as radiologists adjust to the new image size. The most important change in radiologists' work pattern appears to be the need to sit closer to the film. Findings of disease are smaller, but, with experience, just as easy to see.     

Ginseng et exercice supramaximal

Chronic ginseng intake did not appear to improve performance during supramaximal exercise. In the same way, the blood parameters analysed (lactate and testosterone) were not modified by ginseng vs placebo neither at rest or at exhaustion.     

L'aspartate et son potentiel ergogène

Since the discovery of the Krebs cycle, many experiments have tried to supplement this metabolic pathway with different intermediates in order to increase exercise performance. Since the first observations of Laborit on aspartate and exercise in 1957, more than 20 studies were published on the effect of aspartate on exercise capacity in man and various animal species. The results of these studies are quite equivocal. Many potential mechanisms suggested for the potential ergogenic effect of aspartate were also considered in these studies. A lower ammoniemia level during exercise was one effect attributed to aspartate administration. The involvement of aspartate in the urea cycle is another biologically plausible mechanism that could accelerate ammonia removal and as a consequence a decrease of the blood ammonia level. The involvement of aspartate as an amphibolic intermediate in the Krebs cycle should also to be considered. However, the suggested effects of aspartate on glycogen sparing and on a higher free fatty acids oxidation do not find support in the literature. Globally, studies with negative findings on endurance exercise were found in equal quantity to studies with positive results of aspartate on performance or its factors. In studies where an increase of endurance was observed in man, its magnitude was not related to the importance of the dosage, suggesting the absence of a biologic gradient. The analysis of experiments in the rat is less favorable to an increased endurance than results obtained in human studies. Studies on the effect of aspartate on ammonia level and performance during resistance exercise unanimously reported negative findings. This lack of effect could be the result of the difficulty for aspartate to access the cell compartment and the mitochondria in the skeletal muscle (DeHaan et al, 1985; Nakahara et al, 1964). To resolve the issue of the potential effect of aspartate on endurance performance, further research is needed, particularly regarding the effect of aspartate used in combinations. Other substances and nutritional procedures (carbohydrates and lipid loadings) used to decrease ammoniemia (monosodium glutamate, lactulose, sodium hydroxybutyrate, citrulline and sodium benzoate) are also briefly reviewed in this paper.     

Prophylactic embolization of renal angiomyolipomas: evaluation of therapeutic response using CT 3D volume calculation and density histograms

Purpose

To evaluate the efficacy and tolerance of prophylactic embolization of angiomyolipomas (AMLs) and to analyze the therapeutic response by using three-dimensional 3D volume calculation and 3D quantification of fatty and angiomyogenic components during computed tomography (CT) follow-up.

Materials and Methods

Over a 51-month period, 30 patients with 34 AMLs (mean diameter, 82 mm ± 37; range, 30–173 mm) underwent 37 prophylactic embolization procedures. The protocol included supraselective arterial embolization with a combination of absolute alcohol, microparticles, and coils. Mean clinical and imaging follow-up were 20.5 and 14.5 months, respectively. The 3D volume calculation and density histograms were retrospectively analyzed for treatment evaluation.

Results

Four technical failures were observed (11%), with one successful secondary reattempt, resulting in 31 AMLs (91.2%) being embolized. Thirty (88.2%) had CT follow-up and were included in the analysis. Embolization was complete after a single procedure for 25 AMLs (83%) and required two procedures in two cases. Three AMLs had incomplete embolization and were scheduled for a second procedure. Mean volume reductions were 43% ± 32 for AMLs followed for 1–6 months after embolization and 81% ± 19 for the 12 AMLs followed for more than 1 year. The volume reduction after embolization was significantly correlated with the AML initial composition, with fat-rich AMLs showing a much smaller reduction of size than predominantly angiomyomatous AMLs (P < .05).

Conclusions

Prophylactic embolization allows significant reduction of AML volume with a high success rate. Three-dimensional CT volume and density histogram calculations suggest that it is especially effective on angiomyogenic components and fat-poor AMLs.     

Blessures musculotendineuses à répétition survenant sur un terrain métabolique perturbé : à propos d'une observation de maladie de Gilbert chez un sprinter de niveau national

Gilbert's disease is a constitutional disorder of bilirubin glycosilation in the liver. Physical exercise increases free bilirubin in blood, and the disturbance of the liver's metabolic activity could be the origin of muscular and tendon injuries. The diagnosis of Gilbert's disease is made through biological tests, which are necessary as prevention can obviate critical situations. Other metabolic constitutional disorders could be responsible for similar situations, therefore in cases of frequent muscular and tendon injuries, accurate biological investigations must be made.     

Anatomie du plexus brachial en IRM

Magnetic resonance imaging (MRI) is the best imaging technique for the evaluation of the brachial plexus. This article recalls brachial plexus anatomy and details MRI radioanatomy. T1 weighted and STIR sequences are required. Gadolinium injection is not systematic. Oblique sagittal and coronal images are important considering the obliquity of the plexus. An oblique sagittal plane, perpendicular to the axis of the brachial plexus, is the most adapted for the cross-section study.