Computer-aided diagnosis improves detection of small intracranial aneurysms on MRA in a clinical setting.

BACKGROUND AND PURPOSE: MRA is widely accepted as a noninvasive diagnostic tool for the detection of intracranial aneurysms, but detection is still a challenging task with rather low detection rates. Our aim was to examine the performance of a computer-aided diagnosis algorithm for detecting intracranial aneurysms on MRA in a clinical setting. MATERIALS AND METHODS: Aneurysm detectability was evaluated retrospectively in 48 subjects with and without computer-aided diagnosis by 6 readers using a clinical 3D viewing system. Aneurysms ranged from 1.1 to 6.0 mm (mean = 3.12 mm, median = 2.50 mm). We conducted a multireader, multicase, double-crossover design, free-response, observer-performance study on sets of images from different MRA scanners by using DSA as the reference standard. Jackknife alternative free-response operating characteristic curve analysis with the figure of merit was used. RESULTS: For all readers combined, the mean figure of merit improved from 0.655 to 0.759, indicating a change in the figure of merit attributable to computer-aided diagnosis of 0.10 (95% CI, 0.03-0.18), which was statistically significant (F(1,47) = 7.00, P = .011). Five of the 6 radiologists had improved performance with computer-aided diagnosis, primarily due to increased sensitivity. CONCLUSIONS: In conditions similar to clinical practice, using computer-aided diagnosis significantly improved radiologists' detection of intracranial DSA-confirmed aneurysms of ≤6 mm.

Prepubertal girls with Turner syndrome and children with isolated SHOX deficiency have similar bone geometry at the radius.

CONTEXT: The low bone mineral density (BMD) and alterations in bone geometry observed in patients with Turner syndrome (TS) are likely caused by hypergonadotropic hypogonadism and/or by haploinsufficiency of the SHOX gene. OBJECTIVE: Our objective was to compare BMD, bone geometry, and strength at the radius between prepubertal girls with TS and children with isolated SHOX deficiency (SHOX-D) to test the hypothesis that the TS radial bone phenotype may be caused by SHOX-D. DESIGN AND SETTING: This comparative cross-sectional study was performed between March 2008 and May 2011 in 5 large centers for pediatric endocrinology. PATIENTS: Twenty-two girls with TS (mean age 10.3 years) and 10 children with SHOX-D (mean age 10.3 years) were assessed using peripheral quantitative computed tomography of the forearm. MAIN OUTCOMES: BMD, bone geometry, and strength at 4% and 65% sites of the radius were evaluated. RESULTS: Trabecular BMD was normal in TS (mean Z-score = -0.2 ± 1.1, P = .5) as well as SHOX-D patients (mean Z-score = 0.5 ± 1.5, P = .3). At the proximal radius, we observed increased total bone area (Z-scores = 0.9 ± 1.5, P = .013, and 1.5 ± 1.4, P = .001, for TS and SHOX-D patients, respectively) and thin cortex (Z-scores = -0.7 ± 1.2, P = 0.013, and -2.0 ± 1.2, P < .001, respectively) in both groups. Bone strength index was normal in TS as well as SHOX-D patients (Z-scores = 0.3 ± 1.0, P = .2, and 0.1 ± 1.3, P = .8, respectively). CONCLUSIONS: The similar bone geometry changes of the radius in TS and SHOX-D patients support the hypothesis that loss of 1 copy of SHOX is responsible for the radial bone phenotype associated with TS.

Bone geometry and volumetric bone density at the radius in patients with isolated SHOX deficiency.

UNLABELLED: The short stature homeobox-containing gene (SHOX) plays an important role in bone development and growth. We aimed to assess bone geometry and volumetric bone mineral density at the radius in patients with isolated SHOX deficiency and to relate these bone parameters to the severity of disproportion between the upper and the lower body segment. 17 patients with isolated SHOX deficiency (median age 12.3 yrs, range 6.7-37.2, 12 children and 5 adults) were examined by peripheral quantitative CT (pQCT) at the non-dominant forearm. Results were expressed as Z-scores using published reference data. Linear regression analyses were performed to describe associations between pQCT parameters and the severity of disproportion expressed as sitting height to standing subischial leg height ratio. Trabecular volumetric bone mineral density (vBMD) at the distal radius was normal, whereas cortical vBMD was decreased (mean Z-scores 0.34±1.5, n.s., and -2.2±2.2, p<0.001, respectively). Total bone cross-sectional area was enlarged at the diaphysis (2.1±1.2, p<0.001), while cortical bone cross-sectional area was normal (-0.51±1.4, n.s.). Consequently, cortical thickness was decreased (-1.2±1.3, p<0.01). The polar strength-strain index as a surrogate of long bone strength was normal (0.40±1.4, n.s.). We found no associations between pQCT parameters and the severity of disproportion. CONCLUSIONS: Patients with isolated SHOX deficiency are characterized by decreased cortical vBMD and cortical thickness and enlarged diaphysis. As similar changes have been described in girls with Turner syndrome, these findings suggest that haploinsufficiency of SHOX could cause characteristic skeletal anomalies at the radius.

Boys with haemophilia have low trabecular bone mineral density and sarcopenia, but normal bone strength at the radius.

Although a decreased areal bone mineral density (BMD) has been reported in patients with haemophilia, data are lacking that would reflect the three-dimensional structure of the bone and the muscle-bone relationship. We aimed to assess volumetric BMD, bone geometry and muscle-bone phenotype in boys with haemophilia, and to describe the association between clinical characteristics of haemophilia and bone quality and structure. A cross-sectional study was conducted in 41 boys with haemophilia (mean age 12.4, range 6.6-19.8 years) using peripheral quantitative CT (pQCT) at the nondominant forearm. Results were transformed into Z-scores using previously published reference data. Significant differences were tested by one-sample t-test or sign test. Two-sample t-test and anova were used to compare results between subgroups of patients divided according to the severity of the disease, the fracture history and the number of joint and muscle bleedings. Boys with haemophilia had a decreased trabecular volumetric BMD (mean Z-score -0.5, P < 0.01), while their cortical volumetric BMD was increased (mean Z-score 0.4, P < 0.05). The volumetric bone mineral content and the bone geometry at the radial diaphysis were normal when adjusted for patients' shorter body height. Muscle area was decreased (mean Z-score -1.0, P < 0.001), irrespective of age. No association was observed of bone quality parameters and bone geometry with the disease severity, fracture history or number of bleedings. Bone strength measured at the diaphysis of the radius is not impaired in boys with haemophilia. The finding of the decreased trabecular bone density can be most likely attributed to their sarcopenia.

Percutaneous interventions for vascular dialysis access.

A prerequisite for the long-term patency of vascular access is early detection of a failing shunt, i.e., at the stage of stenosis. Fistulography performed to locate the lesion is followed by percutaneous transluminal angioplasty using a balloon catheter. The procedure takes 30-60 minutes to complete; the clinical success rate varies between 85% and 98%. A more serious condition of failled vascular access is its occlusion secondary to thrombosis. The high costs of hospitalisation and treatment of thrombosed shunts require effective yet less invasive outpatient procedures. Recent years have seen an explosion in the development of mechanical devices on the principle of mechanical dissolution, fragmentation, and aspiration of the clot. Post-procedural dialysis can be performed immediately thus reducing the need for a central venous catheter. The procedure, particularly in the treatment of native fistula occlusion, is more complicated and about twice as time consuming as treatment of stenosis. The clinical success rate is usually between 71% and 100%. The incidence of serious complications of percutaneous treatment is low.

Mechanical thrombolysis of thrombosed hemodialysis native fistulas with use of the Arrow-Trerotola percutaneous thrombolytic device: our preliminary experience.

PURPOSE: To evaluate the feasibility of use of the Arrow-Trerotola percutaneous thrombolytic device (PTD) in the treatment of thrombosed hemodialysis native fistula occlusions. MATERIALS AND METHODS: Ten patients with native fistula occlusion underwent mechanical thrombolysis with use of the PTD. The standard PTD was used in seven patients and the over-the-wire device was used in three patients. Major outcomes of our study included procedure time, clinical success, complication rate, and 3- and 6-month patency rates. RESULTS: The technical success rate was 100% and the clinical success rate was 90% (9 of 10). In all 10 cases, the procedure was associated with angioplasty. There were no major complications. The mean time of successful procedures was 126.1 minutes. The 3- and 6-month primary patency rates were 70% and 60%, respectively; the assisted primary patency rate at 6 months was 80%. CONCLUSION: The PTD is an effective mechanical device for percutaneous treatment of thrombosed hemodialysis access. Our clinically successful initial experience with the PTD shows that the technique is rapid and safe for treatment of native fistula occlusions.

Mechanical thrombectomy of massive pulmonary embolism using an Arrow-Trerotola percutaneous thrombolytic device.

Mechanical thrombectomy of a large central thrombus in massive pulmonary embolism is a new option for the treatment of this serious condition. The special mechanical devices designed to fragmentize a blood clot include the Arrow-Trerotola percutaneous thrombolytic device (PTD), the use of which in the pulmonary arteries has not yet been reported. The case of massive embolism into the left pulmonary artery with subsequent collapse is to demonstrate the immediately clinically successful treatment using the PTD. Our initial experience with the PTD shows that its use is a safe and quick procedure.

Infarct Size Limitation: acute N-acetylcysteine defense (ISLAND trial): preliminary analysis and report after the first 30 patients.

Our previous experimental research and initial clinical observations regarding the use of N-acetylcysteine in the treatment of ischemic and reperfusion injury in acute myocardial infarction gave rise to a study entitled the Infarct Size Limitation: Acute N-acetylcysteine Defense (ISLAND) trial. Today, this randomized, echocardiographically and angiographically controlled study includes the first 30 patients with a first anterior wall myocardial infarction: Group A (n = 10) consisting of patients with successful recanalization of the infarct-related left anterior descending artery by streptokinase without any further treatment, Group B (n = 10) consisting of patients with failed infarct-related artery recanalization, and Group C (n = 10) comprising patients who had successful streptokinase-induced recanalization of the left anterior descending artery plus N-acetylcysteine administration at a dose of 100 mg/kg body weight. The parameters monitored in our study include changes in global and regional left ventricular ejection fraction of the infarct-related segment using echocardiography and, using electrocardiograms and the Wagner QRS scoring system, the amounts of acutely jeopardized and finally infarcted myocardium. In Group A, global left ventricular ejection fraction rose nonsignificantly within 2 weeks from 37.5 +/- 9.6% to 38.5 +/- 13.8%; it declined significantly in Group B from 36.2 +/- 6.1% to 30.1 +/- 6.7% (p < 0.05), while it considerably improved in Group C from 41.7 +/- 4.1% to 59.6 +/- 8.1% (p < 0.001). Regional left ventricular ejection fraction changed significantly only in Group C: from -4.5 +/- 27.3 to 45.6 +/- 16.3 (p < 0.001). In Group A, in which the amount of acutely jeopardized myocardium was 21.7 +/- 7.2, infarction actually occurred in 20.4 +/- 9.7% (practically no myocardial salvage). In Group B, risk area was 18.1 +/- 4.3%, but infarct size rose to a resulting 29.1 +/- 6.0%. Significant myocardial salvage was accomplished only in Group C: of 26.2 +/- 8.1% of jeopardized myocardium, infarct size was reduced to 10.8 +/- 7.1% (salvage by 58.8%). Also, basic division of patients by therapy showed that, although those with nonidentical findings on their coronary arteries were included into the same groups, patients treated with streptokinase plus N-acetylcysteine had significantly more favorable values of the monitored parameters than those treated with streptokinase alone. We conclude our interim analysis suggests that N-acetylcysteine has a beneficial effect, reducing the functional and structural impacts of myocardial infarction.

[An unusual cause of recurrent septic states]. / Neobvyklá prícina opakovaných septických stavu.

The authors describe the septic sequelae of an unobserved embolization of a central venous catheter into right-sided cardiac compartments. The finding of an embolized fragment of a catheter which was in the patient's circulation for 89 days was quite incidental. The previous period was associated with diagnostic doubts in various departments. The most frequent diagnosis of repeated septicaemia was bacterial endocarditis, although repeated echocardiographic examinations did not confirm it. Similarly, repeated X-rays did not contribute to the diagnosis--this can be explained by dilatation of the heart of the patient. Extraction of the embolized fragment by means of a catheter resolved the problem. The fragment was colonized by the causal agent of the febrile conditions--Staphylococcus aureus.

[Supravalvular aortic stenosis]. / Supravalvulární aortální stenóza.

The authors describe the case of an inborn supravalvular aortal stenosis in an adult patient who was successfully treated by a plastic operation of the stenotic portion of the ascendent aorta by means of a synthetic patch. At the same time also a plastic operation of an incompetent mitral valve was made.