ABSTRACT
AIM: To assess computed tomography (CT) pulmonary angiography (CTPA) dose and image quality in a large teaching hospital, and subsequently, to optimise the protocol in order to reduce the dose without affecting image quality. MATERIALS AND METHODS: Dose-length product (DLP), patient size, and objective quality parameters (contrast-to-noise ratio and signal-to-noise ratio on standardised levels) were recorded from 31 patients undergoing CTPA, where also a subjective image quality evaluation was carried out independently by three specialist cardiothoracic consultant radiologists. An equivalent objective and subjective quality assessment was carried out on a cohort of the same size in a different tertiary healthcare centre. Moreover, experimental tests using anthropomorphic chest phantoms were performed, using different scan parameters. In light of the above analysis, two of the scanner settings for CTPA were modified, i.e., the SureExposure pre-set was changed to "Standard" noise level, quantified with standard deviation (SD) of 19, and the minimum amperage setting lowered from 80 to 40 mA. A second cohort of patients using this new protocol was audited, following the same methodology. RESULTS: The average DLP of patients undergoing CTPA was initially found to be higher than both local and national dose reference levels (DRLs; 559 versus 300 mGy·cm and 400 mGy·cm, respectively). The new protocol led to a reduction in average DLP (359 mGy·cm) while the image quality, assessed by three cardiothoracic consultant radiologists, was preserved. CONCLUSION: The CTPA protocol was implemented in the Royal Infirmary of Edinburgh resulting in significant dose reduction, and is now compliant with national and local DRLs. The image quality was maintained.
Subject(s)
Computed Tomography Angiography/methods , Pulmonary Embolism/diagnostic imaging , Adult , Aged , Aged, 80 and over , Contrast Media , Female , Humans , Male , Middle Aged , Phantoms, Imaging , Radiation Dosage , Retrospective Studies , Sensitivity and Specificity , Signal-To-Noise RatioABSTRACT
Autoimmune pancreatitis (AIP) remains one of the rarer forms of pancreatitis but has become increasingly well recognized and widely diagnosed as it is an important differential, particularly due to the dramatic response to appropriate therapy. It is now best considered as part of a multisystem disease and the notion of "IgG4-related systemic sclerosing disease" has become widely recognized as the number of extra-pancreatic associations of AIP grows. More recently AIP has been classified into two subtypes: lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct-centric pancreatitis (IDCP) with distinct geographical, age and sex distributions for the two subtypes, in addition to different pathological characteristics. The role of imaging is crucial in AIP and should be considered in conjunction with clinical, serological, and histopathological findings to make the diagnosis. Radiologists are uniquely placed to raise the possibility of AIP and aid the exclusion of significant differentials to allow the initiation of appropriate management and avoidance of unnecessary intervention. Radiological investigation may reveal a number of characteristic imaging findings in AIP but appearances can vary considerably and the focal form of AIP may appear as a pancreatic mass, imitating pancreatic carcinoma. This review will illustrate typical and atypical appearances of AIP on all imaging modes. Emphasis will be placed on the imaging features that are likely to prove useful in discriminating AIP from other causes prior to histopathological confirmation. In addition, examples of relevant differential diagnoses are discussed and illustrated.
Subject(s)
Autoimmune Diseases/diagnosis , Diagnostic Imaging/methods , Pancreatitis/diagnosis , Cholangiopancreatography, Endoscopic Retrograde/methods , Diagnosis, Differential , Humans , Magnetic Resonance Imaging/methods , Pancreas/diagnostic imaging , Pancreas/pathology , Tomography, X-Ray Computed/methods , Ultrasonography/methodsABSTRACT
An attempt has been made to assess the pituitary response to the nasal application of synthetic gonadotropin-releasing hormone (GnRH) in three oligospermic and two azoospermic men. Intranasal administration of 3 mg of GnRH in aqueous or natural plant gum solution produced a pituitary response pattern similar to that produced by the intramuscular injection of 100 microng, with respect to plasma concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). No technical difficulties or side effects were observed. GnRH in a nasal drop preparation seems to be effective in releasing LH and FSH in men. These findings may have a practical application in those cases where long-term therapy with the hormone is indicated.
