Mycotic aneurysm of the thoracic aorta presenting as pneumonia.

Mycotic aneurysms of the thoracic aorta rarely occur in children. We report an unusual case of a mycotic aneurysm of the descending aorta in a 4-year-old boy presenting with respiratory tract infection, which was rapidly complicated by atelectasis of the left lung. The patient's mycotic aortic aneurysm was diagnosed by contrast-enhanced spiral CT, whereas conventional chest radiographs did not detect its presence. An unsuspected mild aortic coarctation was also diagnosed at the time of admission. This case demonstrates that an aortic aneurysm may clinically and radiologically manifest itself with respiratory tract infection and atelectasis and that contrast-enhanced spiral CT is a fast and powerful tool for establishing the diagnosis.

[Application of spiral computerized tomography in the study of traumatic lesions of the thoracic aorta]. / Applicazioni della Tomografia Computerizzata spirale nello studio delle lesioni traumatiche dell'aorta toracica.

PURPOSE: Acute thoracic aortic injuries account for up to 10-20% of fatalities in high-speed deceleration road accidents and have an estimated immediate fatality rate of 80-90%. Untreated survivors to acute trauma (10-20%) have a dismal prognosis: 30% of them die within 6 hours, 40-50% die within 24 hours, and 90% within 4 months. We investigated the diagnostic accuracy of Helical Computed Tomography (Helical CT) in acute traumatic injuries of the thoracic aorta, and the role of this technique in the diagnostic management of trauma patients with a strong suspicion of aortic rupture. MATERIAL AND METHODS: We compared retrospectively the chest Helical CT findings of 256 trauma patients examined June 1995 through August 1999. All patients underwent a plain chest radiograph in supine recumbency when admitted to the Emergency Room. Chest Helical CT examinations were performed according to trauma score, to associated traumatic lesions and to plain chest radiographic findings. All the examinations were performed with no intravenous contrast agent administration and the pitch 2 technique. After a previous baseline study, contrast-enhanced scans were acquired with pitch 1 in 87 patients. All examinations were assessed for the presence of mediastinal hematoma, periaortic hematoma, traumatic pseudodiverticulum, irregular aortic wall or contour and intimal flap as signs of aortic rupture. RESULTS: Helical CT showed thoracic aortic lesions in 9 of 256 patients examined. In all the 9 cases we found a mediastinal hematoma and all of them had positive plain chest radiographic findings of mediastinal enlargement. Moreover, in 6 cases aortic knob blurring was also evident on plain chest film and in 5 cases depressed left mainstem bronchus and trachea deviation rightwards were observed. All aortic lesions were identified on axial scans and located at the isthmus of level. Aortic rupture was always depicted as pseudodiverticulum of the proximal descending tract and intimal flap. We also found periaortic hematoma in 6 cases and intramural hematoma in 1 case. There were no false positive results in our series: 7 patients with Helical CT diagnosis of aortic rupture were submitted to conventional aortography that confirmed both type and extension of the lesions as detected by Helical CT, and all findings were confirmed by gross inspection at surgery. No false negative results have been recorded so far: untreated aortic ruptures are fatal within 4 months in 90% of patients, or they may evolve into chronic pseudoaneurysm in about 5% of survivors. CONCLUSIONS: In our experience Helical CT had much higher diagnostic sensitivity and specificity than plain chest radiography. In agreement with larger published series, in our small one the diagnostic accuracy of Helical CT was 100% in the evaluation of traumatic aortic ruptures. Moreover, Helical CT is faster and less invasive than conventional aortography, which makes this diagnostic modality increasingly used and markedly improves the management of the serious trauma patient. The more widespread use of this diagnostic tool has permitted to standardize the technique and now Helical CT can be used not only as a screening modality for patients that undergo digital aortography, but also as a reliable diagnostic method for surgical planning.

[Comparison of various parameters (pitch 1 and 2) in the study of the lung with spiral computerized tomography]. / Confronto tra diversi parametri (pitch 1 e 2) nello studio del polmone con tomografia computerizzata spirale.

INTRODUCTION: In Spiral CT, the pitch is the ratio of the distance the tabletop travels per 360 degrees rotation to nominal slice width, expressed in mm. Performing Spiral CT examinations with pitch 2 allows to reduce examination time, exposure and contrast dose, and X-ray tube overload. We investigated the yield of pitch 2 in lung parenchyma studies, particularly relative to diagnostic image quality. MATERIAL AND METHODS: Thirty patients were submitted to Spiral CT with pitch 1 [10 mm slice thickness, 10 mm/s table feed; 10 mm (a') and 5 mm (a") reconstruction index: protocol A] and with pitch 2 [10 mm slice thickness, 20 mm/s table feed; 10 mm (b') and 5 mm (b") reconstruction index: protocol B]. Five expert radiologists evaluated the images separately and blindly, grading noise, bronchial wall resolution and diagnostic yield on a 0-5 point scale. The results of protocol A versus protocol B images were analyzed statistically using the Mann-Whitney U-test. RESULTS: The mean scores for each parameter ranged 4.13 (.70 standard deviation) for protocol B with 5 mm reconstruction index (b") to 4.81 (.44 standard deviation) for protocol A with 10 mm reconstruction index (a'). These values (max: 5) indicate very positive results on both protocol A and B images. There were no statistically significant interprotocol differences, except for bronchial wall resolution, in favor of protocol A with 5 mm reconstruction index (a") (p = .025), and for diagnostic yield, in favor of protocol A with 10 mm reconstruction index (a') (p = .018). CONCLUSIONS: Spiral CT with pitch 2 is a reliable tool for lung parenchyma studies which permits to reduce examination time and contrast dose, as well as X-ray tube overload and exposure dose.

[Potential of ultrasonography and ultrasonography-guided biopsy in the diagnosis of local recurrence following radical prostatectomy]. / Possibilità dell'ecografia e della biopsia ecoguidata nella diagnosi delle recidive locali dopo prostatectomia radicale.

INTRODUCTION: [corrected] We investigated the diagnostic role of combined transrectal US (TRUS) and biopsy to detect recurrent cancer after radical prostatectomy, in patients with negative bone scintigraphy and elevated prostate specific antigen (PSA) levels. MATERIALS AND METHODS: From March, 1997, to May, 1998, we examined 12 patients with persistently detectable serum PSA levels and negative bone scintigraphy. At the time of diagnosis, an average 36 months had elapsed since prostatectomy. Digital rectal examination (DRE) and disease stage at the time of surgery were also considered. Patients age ranged 47 to 83 years (mean: 65). All patients underwent TRUS with a 7.5 MHz biplane probe; biopsy was performed with a 16 G cutting needle. TRUS findings were considered suspicious if the scan showed any unusual hypoechoic tissue adjacent to the bladder neck, in retrotrigone or peri-retroanastomotic site. In these cases a transperineal US-guided biopsy was performed. RESULTS: The biopsy proved cancer in 10/12 cases (in 12 cases after two biopsies), showing a better diagnostic accuracy than DRE, which poorly distinguished postoperative changes from recurrent or residual cancer. CONCLUSIONS: The early detection of recurrences after radical prostatectomy in patients with negative bone scintigraphy is feasible when the above examinations are performed in the same order as described: PSA levels, if altered, indicate the patients to be submitted to TRUS. The latter may be falsely negative in some cases because small recurrences may exhibit no findings at US, and therefore US-guided biopsy of peri-retro-anastomotic regions should be always performed too. The recurrence must be confirmed at histology because histologic findings help choose adjuvant treatment and/or radical irradiation.

[Paranasal sinusitis: study with conventional and spiral computerized tomography]. / Flogosi dei seni paranasali: studio mediante Tomografia Computerizzata tradizionale e Tomografia Computerizzata spirale.

This study was aimed at comparing the diagnostic value of conventional computed tomography (CCT) with that of spiral computed tomography (SCT) in sinonasal structures and ostiomeatal complex in thirty patients with inflammatory disease. Ten patients were examined with CCT (3-mm slice thickness, 120 kV, 100 mA, 2-s gantry rotation) and 20 were examined with SCT (3-mm slice thickness, 120 kV, 200 mA, 1-s gantry rotation and computed image reconstruction every 3 mm); table gain was 3 mm (Pitch 1) in 10 patients and 5 mm (Pitch 1.6) in the other 10 patients. With the latter study protocol, diagnostic image quality was the same as with the other two protocols. Moreover, examination time was reduced, with increased patients' comfort; the exposure dose and X-ray tube overload were also reduced, with increased system yield.

[Nodular lesions simulated on an anthropomorphic thoracic phantom. A comparison between analog and digital images of the thorax]. / Lesioni nodulari simulate su fantoccio antropomorfo toracico. Confronto tra immagini analogiche e digitali del torace.

Aim of this work is to evaluate the diagnostic accuracy of different modalities of digital radiology, compared with conventional radiology, in the detection of lung nodules. Forty images of an anthropomorphic chest phantom, on which simulated nodules had been previously set, were analyzed by 6 radiologists with 4 different viewing modalities: a) conventional radiography; b) photostimulable plates digital radiography; c) photostimulable plates digital image on dedicated monitor; d) conventional radiography digitized with Film Laser Digitizer and viewed on Display Workstation. For each image the radiologists had to transfer on a sketch the site of the detected nodules giving an opinion on their detectability (uncertain-presumable-probable-certain presence) with a 1 to 4 score. The statistical analysis of the results was made using modified ROC curves. No statistically significant difference was found between the areas under a) and c) ROC curves (p = 0.262). A statistically significant difference resulted between the areas under a) and d) ROC curves (p < 0.05) and, particularly, between the a) and b) areas (p < 0.001), in favor of a).

[Conventional radiology, digital radiology with photostimulable phosphor, laser digitalization of thoracic radiographic films at the bedside. A comparative study]. / Radiologia tradizionale, radiologia digitale con fosfori fotostimolabili, digitalizzazione laser delle pellicole radiografiche negli esami toracici dei pazienti a letto. Studio comparativo.

The bedside chest images obtained with conventional radiology and with "on line" and "off line" digital modalities were compared to evaluate the respective capabilities in visualizing chest anatomical structures. Seventy patients were submitted to bedside chest examinations with a portable unit; both a conventional film and a digital system (PCR Graphics 1, Philips) with photostimulable phosphor imaging plate were fitted in the radiographic cassette. The former was digitized using an "off line" laser beam unit (FD 2000, Dupont); the latter was subsequently postprocessed by modifying contrast, optical density and spatial frequencies. Thus, 4 different viewing modalities were obtained for each examination: a) conventional radiography; b) standard digital radiography; c) postprocessed digital radiography; d) digitized conventional radiography. Detectability rates of chest anatomical structures were analyzed by 4 independent radiologists on the different images and expressed by a score 1-4. The values were always higher with digital modalities than with the conventional one and the differences were statistically significant (Student's t-test modified by Bonferroni). In particular, the greatest difference was found between c) and a) in retrocardiac lung parenchyma and in skeletal structures, in favour of c). Concerning the comparative adequacy of the various digital modalities, higher detectability rates of chest anatomical structures were obtained with c), but also with b), than with d).