Ureteral stricture rate after endoscopic treatments for urolithiasis and related risk factors: systematic review and meta-analysis.

PURPOSE: We aimed to accurately determine ureteral stricture (US) rates following urolithiasis treatments and their related risk factors. METHODS: We conducted a systematic review and meta-analysis following the PRISMA guidelines using databases from inception to November 2023. Studies were deemed eligible for analysis if they included ≥ 18 years old patients with urinary lithiasis (Patients) who were subjected to endoscopic treatment (Intervention) with ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), or shock wave lithotripsy (SWL) (Comparator) to assess the incidence of US (Outcome) in prospective and retrospective studies (Study design). RESULTS: A total of 43 studies were included. The pooled US rate was 1.3% post-SWL and 2.1% post-PCNL. The pooled rate of US post-URS was 1.9% but raised to 2.7% considering the last five years' studies and 4.9% if the stone was impacted. Moreover, the pooled US rate differed if follow-ups were under or over six months. Patients with proximal ureteral stone, preoperative hydronephrosis, intraoperative ureteral perforation, and impacted stones showed higher US risk post-endoscopic intervention with odds ratio of 1.6 (P = 0.05), 2.6 (P = 0.009), 7.1 (P < 0.001), and 7.47 (P = 0.003), respectively. CONCLUSIONS: The overall US rate ranges from 0.3 to 4.9%, with an increasing trend in the last few years. It is influenced by type of treatment, stone location and impaction, preoperative hydronephrosis and intraoperative perforation. Future standardized reporting and prospective and more extended follow-up studies might contribute to a better understanding of US risks related to calculi treatment.

Radiofrequency versus microwave ablation for treatment of the lung tumours: LUMIRA (lung microwave radiofrequency) randomized trial.

The LUMIRA trial evaluated the effectiveness of radiofrequency (RFA) and microwave ablation (MWA) in lung tumours ablation and defining more precisely their fields of application. It is a controlled prospective multi-centre random trial with 1:1 randomization. Fifty-two patients in stage IV disease (15 females and 37 males, mean age 69 y.o., range 40-87) were included. We randomized the patients in two different subgroups: MWA group and RFA group. For each group, we evaluated the technical and clinical success, the overall survival and complication rate. Inter-group difference was compared using Chi-square test or Fisher's exact test for categorical variables and one-way ANOVA test for continuous variables. For RFA group, there was a significant reduction in tumour size only between 6 and 12 months (p value = 0.0014). For MWA group, there was a significant reduction in tumour size between 6 and 12 months (p value = 0.0003) and between pre-therapy and 12 months (p value = 0.0215). There were not significant differences between the two groups in terms of survival time (p value = 0.883), while the pain level in MWA group was significantly less than in RFA group (1.79 < 3.25, p value = 0.0043). In conclusion, our trial confirms RFA and MWA are both excellent choices in terms of efficacy and safety in lung tumour treatments. However, when compared to RFA therapy, MWA produced a less intraprocedural pain and a significant reduction in tumour mass.

Tratamiento de tumores de células Leydig del testículo: ¿puede la cirugía conservadora de testículo reemplazar la orquiectomía radical? Resultados de una revisión sistemática / Treatment of leydig cell tumours of the testis: can testis-sparing surgery replace radical orchidectomy? Results of a systematic review

Introducción: El modelo de referencia para los tumores de células de Leydig todavía se considera la orquiectomía radical, pero la cirugía conservadora de testículo en conjunción con la congelación intraoperatoria de secciones ha sido recientemente tratada con resultados prometedores. Adquisición de evidencia: Se identificaron estudios mediante búsquedas en bases de datos electrónicas y exploración de las listas de referencias de los artículos. Se llevó a cabo una búsqueda bibliográfica que abarca el período comprendido entre enero de 1980 a diciembre 2012 mediante las bases de datos PubMed/MEDLINE y EMBASE. Se consideraron las búsquedas adicionales a mano de las listas de referencias de los estudios incluidos, opiniones, metaanálisis y guías sobre el manejo quirúrgico de TCL de los testículos. Síntesis de evidencia: El presente análisis se basa en un total de 13 estudios que cumplían con los criterios de inclusión predefinidos. Un total de 247 participantes se incluyeron en los 13 estudios examinados en esta revisión sistemática. Ciento cuarenta y cinco fueron tratados con orquiectomía radical y 102 con TSS. En el grupo de cirugía radical 7 estudios informaron del seguimiento de los pacientes que va desde 6 a 249 meses. En el grupo de TSS 10 estudios informaron del seguimiento de los pacientes que va desde 6 a 192 meses. La congelación de secciones se realizó en un total de 96 pacientes. La sensibilidad fue del 87,5%. Ninguno de los pacientes tratados con TSS presentó una recurrencia metastásica, mientras que en los pacientes tratados con orquiectomía radical 3 pacientes presentaron recurrencia metastásica. Nuestro análisis añade información completa a las recientes directrices internacionales, que es altamente recomendable realizar un procedimiento de preservación de órganos en cada lesión intraparenquimatosa pequeña. Conclusiones: Los resultados confirman el curso favorable de TCL tratados con TSS. Los resultados obtenidos son alentadores y el concepto es atractivo para convertirse en el tratamiento estándar en todos los pacientes, y no solo en las personas afectadas por la (sub) fertilidad o con testículo solitario

Introduction: The gold standard for Leydig cell tumours (LCTs) is still considered radical orchidectomy, but testis sparing surgery (TSS) in conjunction with intraoperative frozen section (FSE) has been recently attempted with promising results. Acquisition of evidence: Studies were identified by searching electronic databases. A bibliographic search covering the period from January 1980 to December 2012 was conducted using PubMed/MEDLINE and EMBASE database. Studies were excluded if they were single case reports, meeting abstracts and conference proceedings. Synthesis of evidence: The present analysis is based on a total of 13 studies that fulfilled the predefined inclusion criteria. A total of 247 participants were included in the 13 studies examined in this systematic review. 145 were treated with radical orchiectomy and 102 with TSS. In the radical surgery group, the follow-up varied from 6 to 249 months). In the TSS group, the follow-up varied from 6 to 192 months. Frozen section was performed in a total of 96 patients. Sensitivity was 87.5%. None of the patients treated with TSS presented a metastatic recurrence, while in patients treated with radical orchiectomy three patients presented with metastatic recurrence. In selected cases radical surgery appears excessive and the potential for a shift to TSS as the standard management is gathering momentum. Conclusions: The results confirm the favourable course of LCT treated with TSS. The results obtained are encouraging and the concept is attractive to become the standard therapy in all patients and not only in people affected by (sub)fertility or with solitary testis

Treatment of leydig cell tumours of the testis: Can testis-sparing surgery replace radical orchidectomy? Results of a systematic review. / Tratamiento de tumores de células Leydig del testículo: ¿puede la cirugía conservadora de testículo reemplazar la orquiectomía radical? Resultados de una revisión sistemática.

INTRODUCTION: The gold standard for Leydig cell tumours (LCTs) is still considered radical orchidectomy, but testis sparing surgery (TSS) in conjunction with intraoperative frozen section (FSE) has been recently attempted with promising results. ACQUISITION OF EVIDENCE: Studies were identified by searching electronic databases. A bibliographic search covering the period from January 1980 to December 2012 was conducted using PubMed/MEDLINE and EMBASE database. Studies were excluded if they were single case reports, meeting abstracts and conference proceedings. SYNTHESIS OF EVIDENCE: The present analysis is based on a total of 13 studies that fulfilled the predefined inclusion criteria. A total of 247 participants were included in the 13 studies examined in this systematic review. 145 were treated with radical orchiectomy and 102 with TSS. In the radical surgery group, the follow-up varied from 6 to 249 months). In the TSS group, the follow-up varied from 6 to 192 months. Frozen section was performed in a total of 96 patients. Sensitivity was 87.5%. None of the patients treated with TSS presented a metastatic recurrence, while in patients treated with radical orchiectomy three patients presented with metastatic recurrence In selected cases radical surgery appears excessive and the potential for a shift to TSS as the standard management is gathering momentum. CONCLUSIONS: The results confirm the favourable course of LCT treated with TSS. The results obtained are encouraging and the concept is attractive to become the standard therapy in all patients and not only in people affected by (sub)fertility or with solitary testis.

Epididymis microlithiasis and semen abnormalities in young adult kidney transplant recipients.

Microlithiasis of the epididymis is a rare ultrasound finding in the general population, but the incidence of calcifications in various organs of patients with end-stage renal disease (ESRD) is extremely high. The aim of this study was to describe epididymal microlithiasis in 22 previously dialysed patients who received kidney transplantations at a median age of 19 years (range 9-30). The patients underwent scrotum ultrasonography, semen analysis and laboratory tests (renal function, sexual hormones, Ca, P and PTH) and were administered the International Index of Erectile Function questionnaire. Seventeen presented calcifications of the epididymis, two of whom had concomitant testicular calcifications; a further three patients had isolated testicular calcifications without epididymis involvement. It was not possible to investigate the fertility of all of the patients but 12 of the 13 whose semen was analysed showed abnormalities: five were azoospermic and seven oligospermic with various degrees of morphological anomalies. To the best of our knowledge, these are the first published data concerning the prevalence of epididymal calcifications in young dialysed patients undergoing renal transplantation. Epididymal microlithiasis and infertility were common findings and so performing a spermiogram and preserving semen before ESRD for future paternity may be good advice in this selected population.

High prevalence of testicular cancer in azoospermic men without spermatogenesis.

BACKGROUND: An increased risk of testicular cancer in men with infertility and poor semen quality has been reported. Our aim was to investigate the prevalence of testicular nodules and cancer in azoospermic subjects with different spermatogenetic patterns. METHODS: A total of 1443 consecutive infertile men were investigated, out of which 145 (10.0%) were found to be azoospermic. By using clinical examination and testicular ultrasound, 11 out of the 145 patients showed testicular nodules (2.8-26 mm). To obtain spermatozoa for assisted reproduction, 97 subjects required testicular sperm extraction (TESE) and biopsy, including the 11 patients with nodules. They were divided into two groups according to biopsy results: Group A (n = 38) with complete Sertoli cell-only syndrome (SCOS) and Group B (n = 59) with varying spermatogenetic patterns. Ten nodules were found in Group A and one in Group B. RESULTS: In azoospermic men, the overall prevalence of nodules was 7.5%. In complete SCOS, the prevalence of nodules and cancer was 10/38 (26.3%) and 4/38 (10.5%), respectively. Amongst the cancers, one embryonal carcinoma, one seminoma and two in-situ carcinomas were found. CONCLUSION: The prevalence of testicular nodules and cancer in azoospermic men with complete SCOS is very high. In these subjects, the role of clinical evaluation, ultrasound and biopsy should be emphasized.

Restoration of posterior aspect of rhabdosphincter shortens continence time after radical retropubic prostatectomy.

PURPOSE: Prolonged postoperative incontinence is a major drawback of RRP. Age, scars in the rhabdosphincter, nonnerve sparing surgery and postoperative sphincter insufficiency can cause temporary or definitive urinary incontinence. We believe that sphincter deficiency is the main cause of early incontinence. Urinary leakage results from the shortening of anatomical and functional sphincter length due to caudal retraction of the urethral sphincteric complex and disruption of the median posterior fibrous raphe. We describe a modification of the Walsh RRP that overcomes caudal retraction, reconstructs the posterior fibrous raphe and decreases time to continence. The primary study end point was early continence rate assessment. Long-term continence (1 year) and erectile function assessment were secondary end points. MATERIALS AND METHODS: To avoid caudal retraction of the urethrosphincteric complex, before completing the vesicourethral anastomosis the posterior semicircumference of the sphincter is joined to the residuum of Denonvilliers' fascia and fixed to the posterior bladder wall 1 to 2 cm cranial and dorsal to the new bladder neck. Vesicourethral anastomosis is subsequently performed with care taken not to involve the neurovascular bundles. A total of 161 patients with clinically confined disease underwent modified RRP (group 1). They were compared with a historical series of 50 patients who underwent standard RRP (group 2). Early continence was defined as no pad use but patients using 1 diaper were also considered continent. Continence, assessed prospectively as the number of pads daily, was evaluated 3, 30 and 90 days, and 1 year after catheter removal. The continence state was assessed by a multivariate logistic model. Erectile function was evaluated using the International Index of Erectile Function questionnaire preoperatively and after 18 months in patients younger than 65 years who underwent nerve sparing surgery. RESULTS: In group 1, 116 (72%), 127 (78.8%) and 139 patients (86.3%) were continent 3, 30 and 90 days after catheter removal compared with 7 (14%), 15 (30%) and 23 (46%), respectively, in group 2. One-year continence rates were 96% and 90%, respectively. Erectile function was similar in groups 1 and 2 (46% and 42%, respectively). Multivariate analysis showed that continence was significantly influenced by operation type, stage and patient age. CONCLUSIONS: Careful reconstruction of the posterior aspect of the rhabdosphincter markedly shortens time to continence.

CT in acute stroke: improved detection of dense intracranial arteries by varying window parameters and performing a thin-slice helical scan.

We evaluated the possibility of improving detection of a dense intracranial artery on CT in acute stroke by narrowing window width, varying window level and performing a thin-slice helical scan for the circle of Willis, in some cases followed by postprocessing maximum-intensity projections. We carried out 32 examinations of 31 patients with a documented cerebral ischaemic attack, performing cranial CT within 6 h of the onset of symptoms. Patients with intracranial haemorrhage were excluded, as were patients who went on to thrombolytic therapy. Varying window width and centre level on standard 5 mm thick contiguous axial slices, we detected a dense proximal middle cerebral artery (MCA) in a higher proportion of patients. A 1.1 mm thick helical scan through the circle of Willis improved recognition of a dense distal horizontal segment and the temporoinsular branches of the MCA and of a dense posterior cerebral artery.

Transient hepatic attenuation differences (THAD) not connected to focal lesions.

PURPOSE: To report our experience with helical CT evaluation of transient hepatic attenuation differences (THAD), and in particular of those not associated with focal lesions, in an attempt to provide an aetiopathogenetic picture that accounts for the morphology, evolution and density of THAD. MATERIALS AND METHODS: Between January 1998 and January 2001 we observed THAD in 130/988 biphasic helical CT liver examinations performed in the arterial and portal dominant phase. THAD were associated to focal hepatic lesions in 87 patients; in 43 patients there was no such association. This second group of patients, composed of 23 males and 20 females ranging in age from 17 to 80 years (average = 58.8), was enrolled in the study. THAD were associated to: Budd-Chiari syndrome (9), portal venous thrombosis (10), liver cirrhosis (7), acute inflammation of an adjacent organ (4), dilatation of the entire biliary tree (3), hepatic stasis caused by heart failure (2) and constrictive pericarditis (1), fine-needle percutaneous biopsy (2), arterioportal shunting (2), parenchymal compression by fractured ribs (2) and by a strengthened phrenic pillar (1). THAD were evaluated according to extension, morphology and density. For each case at least 10 density measurements were performed by sampling regions of interest on the parenchyma with THAD and on the contralateral parenchyma. The results (mean and standard deviation) were compared to those relative to 30 healthy patients. 22/43 patients were followed up for 6#150;24 months by at least one US and helical CT examination. During CT, the direct appreciation of vascular thrombus during the portal dominant phase was also considered. RESULTS: We detected 18 localised and 25 diffuse THAD. The localised sectoral THAD (11), wedge-shaped with clear border sign, were associated to thrombosis of a portal branch (6), fine-needle percutaneous biopsy (2), arterioportal shunting (2) and partial Budd-Chiari syndrome (1). The localised non-sectoral THAD (7), with variable morphology and without the clear border sign, were associated to acute inflammation of an adjacent organ (4) and to parenchymal compression by the ribs or diaphragm (3). Diffuse THAD associated to Budd-Chiari syndrome (8) and to heart failure (3) showed mosaic enhancement of hepatic parenchyma (patchy pattern); those linked to portal trunk thrombosis (4) and cirrhosis (7) revealed predominant enhancement of external hepatic parenchyma (central-peripheral phenomenon); finally, those concurrent with dilatation of the entire biliary tree showed parenchymal enhancement close to the dilated bile ducts (peribiliary pattern). Follow-up (22/43) demonstrated complete THAD regression after removal (5/22) and less conspicuity of THAD after partial overcome of the stoppage (1/22). In 2/22 cases of arterioportal shunting no substantial changes were seen. The remaining 14/22 cases showed a gradual, slow tendency towards THAD regression with hypotrophy of the involved parenchyma and compensatory contralateral hypertrophy even in the case of endurance of the causative agents. CONCLUSIONS: Based on our experience and the literature we suggest a classification for THAD unrelated to focal hepatic lesions. We recognise 4 causes: portal vein stoppage-obstruction, portal in-flow diversion, trauma and inflammation. When THAD is related to the first three causes pathogenesis is portal hypoperfusion. In the fourth group the mediators of the arterial phenomena are those of inflammation even though portal hypoperfusion might be involved as well. THAD identification makes the detection of vascular thrombi easier by comparison with their direct finding during the portal dominant phase. Finally, THAD are to be investigated for their potential utility in the detection and characterisation of several hepatic diseases. As a consequence, hepatic CT studies cannot ignore arterial dominant phase evaluation, even if no focal hepatic lesions are expected.

[Anatomy of the urethral sphincteric vesico-prostatic complex]. / Anatomia del complesso sfinterico vescico-prostatico uretrale.

As 27 different names have been proposed for the components of the urethral sphincter, it is difficult to build a clear anatomical model of it. Starting from a review of the literature and from some personal observations of surgical anatomy, our aim is to draw a vision as much organic as possible of the anatomy of the urethral sphincter. The components of the urethral sphincter are: the bladder neck (preprostatic sphincter), the smooth muscle urethral sphincter, the rhabdosphincter and levator ani muscle. Recently the rhabdosphincter has been proposed as a vertical structure that extends from the pelvic cavity (bladder base) to the perineal cavity. It can be round-shaped or omega-shaped. The anterior insertions are along the anterolateral aspect of the prostate (superiorly) and on the perineal fascia (inferiorly). The posterior insertions are on the Denonvilliers fascia and posterior aspect of the prostatic apex (superiorly) and on the central perineal tendon (inferiorly). The rhabdosphincter has strong means of fixations: anteriorly it is fixed to the pubis by the pubo-urethral ligaments, posteriorly it is supported by the medial fibrous raphe of the perineum. The anteromedial fibres of levator ani muscle are involved in the continence mechanism by their strong relation with the rhabdosphincter and the prostate.

[Physiology of the urethral sphincteric vesico-prostatic complex]. / Fisiologia del complesso sfinterico vescico-prostatico uretrale.

We propose a review of the literature about innervation and physiology of the urethral sphincteric complex. Parasympathetic innervation of the pelvic viscera comes from ventral branches of the sacral nerves (S2-S4). The orthosympathetic component derives from superior hypogastric plexus and runs down the hypogastric nerves to form the right and left pelvic plexus together with the parasympathetic component. The pelvic plexus is situated inferolaterally with respect to the rectum and runs on the surface of the levator ani muscle down to the prostatic apex. The pelvic plexus gives innervation to the rectum, the bladder, the prostate and the urethral sphincteric complex. The pelvic muscular floor is innervated by the somatic component (pudendal nerve) derived from the sacral branches (S2-S4). Bladder neck and smooth muscle urethral sphincter innervation is given mostly by the orthosympathetic component. The rhabdosphincter innervation comes from the pudendal nerve and from the pelvic plexus; its role in the continence mechanism is probably to give steady tonic urethral compression. Levator ani muscle takes part in the sphincteric complex with its anteromedial pubococcygeal portion. It plays its role strengthening the sphincteric tone during increase of the abdominal pressure or during active quick stop cessation of the urinary stream.

[Personal research: reconstruction of the urethral striated sphincter]. / Ricerca personale: la ricostruzione dello sfintere striato uretrale.

OBJECTIVE: Incontinence is one of the drawbacks of radical prostatectomy. The causes of post-operative incontinence are sphincter deficiency (SD) and bladder dysfunction (BD). SD seems to be the main cause of incontinence and long time to continence. We present a surgical modification of the anatomical radical retropubic prostatectomy consisting in the reconstruction of the posterior aspect of the striated urethral sphincter in order to obtain a quick recovery of continence postoperatively. MATERIALS AND METHODS: Caudal retraction of the urethro-sphincteric complex after apical dissection of the prostate often occurs. Furthermore posterior fibrous raphe interruption can cause shortening of anatomical and functional urethral length and affect continence. In order to avoid caudal retraction of the sphincteric complex, after completing vesico-urethral anastomosis, the posterior emicircumference of the striated sphincter is fixed to the posterior aspect of the bladder one centimeter cranially and posteriorly to the urethro-vesical anastomosis. The rabdosphincter is sutured separately from the urethro-vesical suturing. This technical modification makes it possible to obtain an anatomical length of the urethra of about a centimeter more than with the standard technique, replacing it in a more anatomical position. Furthermore, this technique provides the new posterior platform for the urethro-sphincteric complex. Twenty-four patients with clinical organ confined disease and age range 54-74 years (mean 64 years) underwent Walsh's anatomical radical retropubic prostatectomy with reconstruction of the rabdosphincter (group A). Catheter was removed 7 to 11 days postoperatively. Early continence was assessed objectively with the number of pads per day as follows: 0-1 mini pad = continent; 1-2 pads per day = mild incontinence; 2 or more pads per day = severe incontinence. Continence was evaluated at 3 days and one month after catheter removal. Group A compared to 21 patients (group B) who underwent standard anatomical RPP (historical control group). RESULTS: In group A 16/24 patients (66.7%) and 19/24 patients (79.2%) were continent respectively at three days after removal of the catheter and after one month; mild incontinence (1-2 pads/day) was present in 6/24 patients (25%) and 3/24 (12.5%) respectively, 2/24 patients (8.3%) suffered from severe incontinence after 3 days and one month. In group B 7/21 patients (33%) were continent at hospital discharge, 11/21 (52%) after one month. CONCLUSIONS: Careful reconstruction of the posterior aspects of the rabdosphincter shortens time to continence after RRP.

[Interventional radiology in the palliative treatment of pancreatic cancer]. / La radiologia interventistica nella palliazione del carcinoma pancreatico.

AIMS AND BACKGROUND: Pancreatic carcinoma often involves the head of the pancreas and obstructive jaundice is its earliest sign. It sometimes extends to celiac plexus and duodenum causing pain and bowel obstruction respectively. Only 20% of cases are totally resectable (stage I) at the time of diagnosis. Palliative treatment is the only available therapeutic option when the tumor extends surrounding organs or has given lymphatic metastases (stage II, III, IV). The aim of this study is to evaluate effectiveness of interventional radiology procedures on unresectable cancer palliative treatment. METHODS: Between Jan 90 and Sep 98, 195 patients with unresectable pancreatic carcinoma received percutaneous treatments. They were 104 males and 91 females with mean age of 74 years (range, 48-95). One hundred eighty four patients underwent biliary drainage, six patients underwent celiac plexus block, two patients were treated by bowel stenting. Two patients received both biliary and bowel stents, one patient underwent biliary drainage and celiac plexus block. RESULTS: Jaundice treatment was performed by placement of drainage catheters in 48 patients, polymeric endoprostheses in 58 and metallic stents in 77 (67 Wallstents). Biliary drainage was successful in all cases obtaining appreciable bilirubin serum levels reduction and jaundice regression in 175 patients (95%). In 44 patients Wallstents were placed during a single PTC session time ("one step" technique). In 21 cases (11%) peri-procedural complications occurred. Follow-up related to 85 patients shows survival rate covered between 30 and 570 days (mean, 142). Best survival values occurred in patients who underwent "one step" technique. Celiac plexus block was successful in 5/7 cases (71%) with no complications, total pain relief and withdrawal of pharmacological treatment. Bowel stenting achieved complete recanalization of intestinal loop in 2 cases but showed troubles related to management of these patients. CONCLUSIONS: In patients with unresectable pancreatic carcinoma palliation is the only therapeutic option and has the purpose to achieve biliary tree decompression and eliminate jaundice associated symptoms, improving quality of life and reducing hospitalization. Jaundice relief is reachable by surgical, endoscopic or percutaneous approach. Surgical palliation is characterized by disadvantageous cost-effectiveness rate. Endoscopic and percutaneous palliations are alternative, although, in selected patients, percutaneous Wallstents placement by one step technique is perhaps the most successful procedure, showing high rate of technical outcome with low complications and short time spent in hospital. Celiac plexus block under CT guidance constitutes a reliable method for management of pain. At present bowel stricture treatment is surgical.

[Neural network based detection of pulmonary nodules on chest radiographs]. / Identificazione mediante reti neurali dei noduli polmonari nel radiogramma del torace.

PURPOSE: We investigated the capabilities of an artificial neural network-based Computer-Aided Diagnosis (CAD) system in improving early detection of pulmonary nodules on chest radiographs. MATERIAL AND METHODS: We used a data-set of 145 digitized chest films. Two different radiologists read the radiographs to detect the sites of possible nodules. The system uses two neural networks trained on a training-set of 100 radiographs selected from the data-set. The first network is used to focus attention on the sites of potential nodules while the second calculates the likeliness of nodule presence in ROIs. The clinical test was performed on 45 more radiographs from the training-set, but different from those in the data-set, which were positive for both benign and malignant nodules. These latter plain films showed 65 nodular lesions which differed by shape and acquisition technique. RESULTS: Sensitivity was 89% in all radiographs while specificity, evaluated by ROI, and accuracy, were 98%. CONCLUSIONS: There are potential limitations in nodule detection on plain radiographs. Some of them are operator-dependent, such as nonsystematic investigation, lesion underestimation, and poor reading, and some are technique-dependent, such as X-ray beam/tube, low voltage, patient positioning, focus-film distance and development process. CADs may contribute to improving detection of pulmonary nodules because the false-negative rate is decreased and sensitivity consequently increased. The high sensitivity and specificity rates of neural networks encourage further trials on wider data-sets to help the radiologist in the early detection of pulmonary nodules.