Physical and clinical comparison between a screen-film system and a dual-side reading mammography-dedicated computed radiography system.

BACKGROUND: Digital mammography systems, thanks to a physical performance better than conventional screen-film units, have the potential of reducing the dose to patients, without decreasing the diagnostic accuracy. PURPOSE: To achieve a physical and clinical comparison between two systems: a screen-film plate and a dual-side computed radiography system (CRM; FUJIFILM FCR 5000 MA). MATERIAL AND METHODS: A unique feature of the FCR 5000 MA system is that it has a clear support medium, allowing light emitted during the scanning process to be detected on the "back" of the storage phosphor plate, considerably improving the system's efficiency. The system's physical performance was tested by means of a quantitative analysis, with calculation of the modulation transfer function, detective quantum efficiency, and contrast-detail analysis; subsequently, the results were compared with those achieved using a screen-film system (SFM; Eastmann Kodak MinR-MinR 2000). A receiver operating characteristic (ROC) analysis was then performed on 120 paired clinical images obtained in a craniocaudal projection with the conventional SFM system under standard exposure conditions and also with the CRM system working with a dose reduced by 35% (average breast thickness: 4.3 cm; mean glandular dose: 1.45 mGy). CRM clinical images were interpreted both in hard copy and in soft copy. RESULTS: The ROC analysis revealed that the performances of the two systems (SFM and CRM with reduced dose) were similar (P>0.05): the diagnostic accuracy of the two systems, when valued in terms of the area underneath the ROC curve, was found to be 0.74 for the SFM, 0.78 for the CRM (hard copy), and 0.79 for the CRM (soft copy). CONCLUSION: The outcome obtained from our experiments shows that the use of the dual-side CRM system is a very good alternative to the screen-film system.

Tracheobronchial stenosis: role of virtual endoscopy in diagnosis and follow-up after therapy.

PURPOSE: This study was done to evaluate whether virtual endoscopy can be employed as a preliminary technique to shorten the time required for the subsequent endoscopic procedure and be proposed for treatment planning and, postoperatively, for evaluating response to treatment in patients with cancer or severe stenotic lesions. MATERIALS AND METHODS: From December 2004 to October 2005, 25 patients with suspected obstructive tracheobronchial stenosis were studied by contrast-enhanced computed tomography (CT) with multiplanar reconstruction (MPR) and virtual bronchoscopic navigation, after a preliminary clinical and conventional radiology assessment. RESULTS: Quality of the virtual endoscopy images was excellent in all cases. Out of the 25 patients, four were affected by benign lesions and 21 by malignant lesions. With regard to lesion site, virtual endoscopy proved to be as informative as real endoscopy. The virtual endoscope was able to cross severe stenoses with a residual lumen of 3 mm. Follow-up studies were performed in 15 patients treated with laser and cryotherapy. In all cases, evaluation of the degree of post-treatment stenosis was similar to that obtained with conventional endoscopy. CONCLUSIONS: Our study indicates that virtual bronchoscopy has a high diagnostic potential. The technique, with the integration of MPR images, can be proposed as a preliminary study to obtain accurate characterisation of stenoses, to shorten the time required for the subsequent endoscopic procedure and to plan the most appropriate treatment.

Magnetic resonance imaging in evaluating functional disorders of female pelvic floor.

PURPOSE: To evaluate the diagnostic capabilities of MRI in the study of functional diseases of the female pelvic floor. MATERIALS AND METHODS: Ten healthy volunteers and 30 patients with clinically suspected pelvic floor deficiency, with or without pelvic organ prolapse, were evaluated by a high field strength magnet operating at 1.5 T. In each case SSFSE sequences (TR/TE:25720/67) in axial, coronal and sagittal planes, both at rest and during Valsalva's manoeuvre, were performed. Based on the MRI findings using fixed and mobile anatomical landmarks, the functional disease of the pelvic floor was diagnosed and quantified based on the identification and grading of visceral prolapse. The MRI findings were compared with the clinical findings in all cases and with the surgical data in the 7 patients who had undergone surgery. RESULTS: The MR image quality was adequate in all cases. In the group of symptomatic women MRI diagnosed: urethral hypermobility syndrome: 22 cases; isolated abnormalities of the anterior compartment: 8 cases of cystocele (low grade: 2, middle grade: 2, severe: 4); isolated abnormalities of the middle compartment: 6 cases of hysterocele (low grade: 2, middle grade: 4); isolated abnormalities of the posterior compartment: 5 cases of low-grade rectocele; 2 cases of enterocele (1 low grade, 1 middle grade); multi-compartment abnormalities: 11 cases; joint prolapse of anterior and middle compartment: 5 cases; joint prolapse of posterior and middle compartment: 3 cases; joint prolapse of anterior, middle and posterior compartment: 3 cases. The values of both fixed and mobile landmarks were significantly higher in the symptomatic group compared with the healthy volunteers. MRI confirmed the pelvic examination findings in all cases; in particular MRI findings were in total agreement with the clinical severity of prolapse, as defined by the Baden-Walker classification. In 7 cases MRI detected additional alterations (4 cases of hysterocele and 3 of enterocele) that had been missed at clinical evaluation. DISCUSSION AND CONCLUSIONS: In our experience MRI made an important contribution to the diagnosis and grading of functional disorders of the female pelvic floor and pelvic organ prolapse. The ability to simultaneously demonstrate both muscular and ligamentous structures and pelvic viscera, without using X-rays or contrast agents, is the main reason for the good results achieved by MRI and for its widespread use in this disorder. Furthermore the use of fast, breath-hold sequences can provide high-quality images both at rest and during Valsalva's manoeuvre. In conclusion MRI proved to be an accurate imaging tool that is more sensitive than clinical pelvic evaluation in diagnosing and grading functional disorders of the female pelvic floor and pelvic visceral prolapse.