Pitfalls in CT diagnosis of appendicitis: Pictorial essay

Despite the high diagnostic accuracy of CT for appendicitis, numerous pitfalls exist that may result in a misdiagnosis. This pictorial review outlines the potential pitfalls in the CT diagnosis of appendicitis that includes atypical position of the appendix and coexisting pathologies. Various mimickers of appendicitis and clinical dilemmas will be highlighted. Upon completion, the reviewer should have an improved ability to recognise appendicitis mimickers and identify equivocal or atypical findings.     

Effects of nasal ZnSO4 irrigation and olfactory bulbectomy on rat pups

Rat pups underwent bilateral olfactory bulbectomy (BOB) or irrigation of the nasal cavities with a 5% ZnSO₄ solution (Zn) at 2, 7, 11, or 13 days of age to determine whether the effects of these treatments are similar. Control pups were sham operated, handled only, or had their nasal cavities irrigated with saline. Both Zn and BOB pups lost weight, sometimes to the point of death, and exhibited deficiencies in attachment and suckling behavior compared to control animals. Histological investigation indicated degeneration in the olfactory epithelium and shrinkage of the glomerular layer of the olfactory bulb as a result of the nasal ZnSO₄ treatment. The vomeronasal organs of the Zn animals appeared to be intact. As a control for possible toxic effects of nasal ZnSO₄ irrigation, 12-day-old pups had their oral cavities irrigated with a 5% ZnSO₄ solution. Their weight gain and attachment and suckling behavior was like that of control pups.     

Tetralogy of Fallot: MR findings

Surgical treatment of patients with tetralogy of Fallot requires accurate definition of all anatomic structures, particularly the central pulmonary arteries. Magnetic resonance (MR) images of 22 patients with tetralogy of Fallot were studied to assess their usefulness in providing information regarding the spectrum of anatomic abnormalities in this condition. MR findings were compared with information obtained at catheterization (in 16 patients) and at surgery (in nine patients), both of which were performed within 3 months of MR imaging. Ventricular chamber enlargement and wall hypertrophy were clearly delineated in most of the 17 patients who were examined before definitive surgical repair, and ventricular septal defects were visualized in all 17. Palliative systemic-to-pulmonary shunts were visualized in 11 patients and could be evaluated for patency. Most important, the morphology and size of the right ventricular outflow tract and central pulmonary arteries could be accurately assessed. Pulmonary artery measurements obtained from MR images demonstrated excellent correlation with angiographic measurements. In six patients examined after complete surgical repair, MR images accurately reflected changes in pulmonary artery outflow tract morphology and complications, such as residual pulmonary artery stenosis and thrombosis. The findings suggest that MR imaging can complement or obviate catheterization in the evaluation of tetralogy of Fallot with regard to suitability for definitive surgical repair.     

Craniosynostosis in X-linked hypophosphataemic rickets

A report of three cases of craniosynostosis in X-linked hypophosphataemic rickets (XLH) is presented. The literature is reviewed, suggesting that craniosynostosis is relatively common in XLH and that boys may be more at risk than girls. It is recommended that radiological screening be offered to all patients with XLH.     

B cell stimulating factor 2/interleukin 6 is a costimulant for human thymocytes and T lymphocytes

Growth and differentiation of thymocytes and mature T lymphocytes is regulated by cellular interactions that are in part mediated by soluble factors. We identify IL-6, formerly called B cell stimulating factor (BSF-2). IFN-beta 2, or hybridoma-plasmacytoma growth factor (HPGF) as a novel T cell costimulant rIL-6 induced a six-to seven-fold increase in proliferation of human thymocytes stimulated with suboptimal doses of PHA. A similar effect with added IL-6 could be observed using peripheral blood T lymphocytes, but only if the cultures were first rigorously depleted of monocytes that release high levels of IL-6. Analysis of the mechanism of the IL-6 effect on thymocytes and T lymphocytes showed that IL-6 did not lead to an increase in IL-2-R expression. Concentrations of antibody to IL-2-R inhibiting IL-2 effects did not block the IL-6-induced proliferation, indicating that the IL-6 effect was relatively IL-2 independent. These results identify IL-6 as a novel costimulant of human thymocytes and mature T lymphocytes, and suggest that IL-6 is also an important regulatory of cellular immunity.     

The thoracic aorta studied by MR imaging

Thirty-three patients with a variety of disorders of the thoracic aorta (aneurysm, dissection, Marfan syndrome, coarctation/pseudocoarctation, L-transposition, and Takayasu disease) were evaluated with magnetic resonance (MR) imaging. MR imaging delineated the presence and extent of thoracic aortic aneurysms and showed the relationship of the aneurysm to arch vessels; it also demonstrated intimal flaps and individual lumina in types A and B aortic dissection. Dilation of the ascending aorta in Marfan syndrome and focal narrowing of the aorta in coarctation were well visualized. The anteroposterior and side-to-side relationships of the aorta and pulmonary artery in L-transposition were demonstrated, as were aortic wall thickening and branch vessel narrowing in Takayasu arteritis. Initial experience suggests that MR imaging may provide a noninvasive method for evaluating thoracic aortic disease. Limitations include inferior spatial resolution, occasional difficulty in imaging the entire region of interest in one section, lack of signal from calcifications, and inability to monitor critically ill patients.