Comparison of ultrasonography with computed tomography in the diagnosis of incisional hernias.

BACKGROUND: The objective of this study is to determine the reliability and validity of ultrasonography (US) in diagnosing incisional hernias in comparison with computed tomography (CT). The CT scans were assessed by two radiologists in order to estimate the inter-observer variation and twice by one radiologist to estimate the intra-observer variation. Patients were evaluated after reconstruction for an abdominal aortic aneurysm or an aortoiliac occlusion. METHODS: Patients with a midline incision after undergoing reconstruction of an abdominal aortic aneurysm or aortoiliac occlusion were examined by CT scanning and US. Two radiologists evaluated the CT scans independently. One radiologist examined the CT scans twice. Discrepancies between the CT observations were resolved in a common evaluation session between the two radiologists. RESULTS: After a mean follow-up of 3.4 years, 40 patients were imaged after a reconstructed abdominal aortic aneurysm (80% of the patients) or aortoiliac occlusion. The prevalence of incisional hernias was 24/40 = 60.0% with CT scanning as the diagnostic modality and 17/40 = 42.5% with US. The measure of agreement between CT scanning and US expressed as a Kappa statistic was 0.66 (95% confidence interval [CI] 0.45-0.88). The sensitivity of US examination when using CT as a comparison was 70.8%, the specificity was 100%, the predictive value of a positive US was 100%, and the predictive value of a negative US was 69.6%. The likelihood ratio of a positive US was infinite and that of a negative US was 0.29. The inter- and intra-observer Kappa statistics were 0.74 (CI 0.54-0.95) and 0.80 (CI 0.62-0.99), respectively. CONCLUSIONS: US imaging has a moderate sensitivity and negative predictive value, and a very good specificity and positive predictive value. Consistency of diagnosis, as determined by calculating the inter- and intra-observer Kappa statistics, was good. The incidence of incisional hernias is high after aortic reconstructions.

A rational approach to dose reduction in CT: individualized scan protocols.

The aim of this study was to demonstrate that dose reduction and constant image quality can be achieved by adjusting X-ray dose to patient size. To establish the relation between patient size, image quality and dose we scanned 19 patients with reduced dose. Image noise was measured. Four radiologists scored image quality subjectively, whereby a higher score meant less image quality. A reference patient diameter was determined for which the dose was just sufficient. Then 22 patients were scanned with the X-ray dose adjusted to their size. Again, image noise was measured and subjective image quality was scored. The dose reduction compared with the standard protocol was calculated. In the first group the measured noise was correlated to the patient diameter (rho=0.78). This correlation is lost in the second group (rho=-0.13). The correlation between patient diameter and subjective image quality scores changes from rho=0.60 (group 1) to rho=-0.69 (group 2). Compared with the standard protocol, the dose was reduced (mean 28%, range 0-76%) in 19 of 22 patients (86%). Dose reduction and constant noise can be achieved when the X-ray dose is adjusted to the patient diameter. With constant image noise the subjective image quality increases with larger patients.

Impact of different hemodynamic criteria for stent placement after suboptimal iliac angioplasty. Dutch Iliac Stent Trial Study Group.

PURPOSE: To investigate the consequences of different hemodynamic criteria as indications for stent placement after suboptimal iliac angioplasty. MATERIALS AND METHODS: One hundred thirty-six patients with intermittent claudication, on the basis of atherosclerotic disease of the iliac artery, underwent angioplasty. Intraarterial systolic and mean pressures were simultaneously recorded above and below the lesion, with and without vasodilation, and before and after percutaneous angioplasty. These data were used to estimate what proportion of the study population would be eligible for stent placement according to different criteria reported in the literature. Subsequently, the authors compared peak systolic velocity (PSV) ratios during follow-up in their patients, with and without indication for stent placement according to two different criteria. RESULTS: Applying the different thresholds reported in the literature to the patient group shows that stent placement would be indicated in anywhere from 4% to 87% of cases. No difference was observed when PSV ratios were compared in patients with a residual mean pressure gradient of > or = 5 and < or = 10 mm Hg with patients with a residual mean pressure gradient of less than 5 mm Hg. CONCLUSIONS: Application of the various published thresholds as indications for secondary stent placement leads to a wide range in proportion of cases requiring stent placement. Lesions with a residual mean pressure gradient of > 5 and < 10 mm Hg fare as well as lesions with a residual mean pressure gradient of less than 5 mm Hg. The optimal criterion is still not clear.

Intramural hematoma of the esophagus: appearance on magnetic resonance imaging.

A 73-yr-old woman on anticoagulant therapy experienced progressive dyspnea and dysphagia due to a large compressing mass in the posterior mediastinum. Because her clinical condition deteriorated rapidly surgery was performed. A large intramural hematoma along the full length of the esophagus with dissection of the muscular layers of the esophagus was found. MRI findings of this case are reported.

Annual evaluation of hip joints and hands for radiographic signs of A beta 2M-amyloidosis in long-term hemodialysis patients.

Radiographs of hand and hip joints of 15 hemodialysis patients taken annually over at least 15 years were evaluated in this retrospective study. We looked for signs of A beta 2M-amyloidosis such as lucencies, erosions, and soft tissue swelling. The femoral head-soft tissue distance (FHSTD) was used to estimate the soft tissue swelling of the hips. The number and size of lucencies, the number of erosions, and the FHSTD increased during dialysis. Both hyperparathyroidism and failure of renal allograft transplantation influenced the development of lucencies and erosions after 15 years. The FHSTD at the start of the dialysis appeared to be an independent prognostic factor for the lucencies of the hips and hands. We conclude that the radiological signs of A beta 2M-amyloidosis are influenced not only by the duration of dialysis, but also by age, failure of renal transplantation, hyperparathyroidism and the FHSTD at the start of dialysis.

Mechanism of skin allograft enhancement across an H-2 class I mutant difference. Evidence for involvement of veto cells.

Intravenous injection of spleen cells across mutant class I H-2 incompatibility results in a drastic donor-specific prolongation of skin allograft survival and a marked decrease in the donor-specific cytotoxic T lymphocyte precursor (CTLp) frequency. This immunosuppressive effect depends on the presence of radiosensitive T cells in the donor cell inoculum. It was excluded that a graft-vs.-host reaction was responsible for the observed effects. In mixing experiments, spleen cells from animals transfused with allogeneic lymphocytes could not suppress a normal CTL response against the alloantigen, despite an excess of putative recipient-derived spleen suppressor cells. The data are compatible with the idea that donor T cells function as veto cells which inactivate recipient CTLp directed against the alloantigen expressed by the veto cell.