MR-based simplified extraprostatic extension evaluation: comparison of performances of different predictive models.

OBJECTIVES: To test reproducibility and predictive value of a simplified score for assessment of extraprostatic tumor extension (sEPE grade). METHODS: Sixty-five patients (mean age ± SD, 67 years ± 6.3) treated with radical prostatectomy for prostate cancer who underwent 1.5-Tesla multiparametric magnetic resonance imaging (mpMRI) 6 months before surgery were enrolled. sEPE grade was derived from mpMRI metrics: curvilinear contact length > 15 mm (CCL) and capsular bulging/irregularity. The diameter of the index lesion (dIL) was also measured. Evaluations were independently performed by seven radiologists, and inter-reader agreement was tested by weighted Cohen K coefficient. A nested (two levels) Monte Carlo cross-validation was used. The best cut-off value for dIL was selected by means of the Youden J index to classify values into a binary variable termed dIL*. Logistic regression models based on sEPE grade, dIL, and clinical scores were developed to predict pathologic EPE. Results on validation set were assessed by the main metrics of the receiver operating characteristics curve (ROC) and by decision curve analysis (DCA). Based on our findings, we defined and tested an alternative sEPE grade formulation. RESULTS: Pathologic EPE was found in 31/65 (48%) patients. Average κw was 0.65 (95% CI 0.51-0.79), 0.66 (95% CI 0.48-0.84), 0.67 (95% CI 0.50-0.84), and 0.43 (95% CI 0.22-0.63) for sEPE grading, CLL ≥ 15 mm, dIL*, and capsular bulging/irregularity, respectively. The highest diagnostic yield in predicting EPE was obtained by combining both sEPE grade and dIL*(ROC-AUC 0.81). CONCLUSIONS: sEPE grade is reproducible and when combined with the dIL* accurately predicts extraprostatic tumor extension. KEY POINTS: • Simple and reproducible mpMRI semi-quantitative scoring system for extraprostatic tumor extension. • sEPE grade accurately predicts extraprostatic tumor extension regardless of reader expertise. • Accurate pre-operative staging and risk stratification for optimized patient management.

CT angiography for pulmonary embolism in the emergency department: investigation of a protocol by 20 ml of high-concentration contrast medium.

OBJECTIVES: To retrospectively compare semi-qualitative and quantitative CT pulmonary angiography (CTPAs) image metrics testing diagnostic performance between protocols performed by 20 or 40 ml of contrast medium (CM) in patients with suspected pulmonary embolism (PE). METHODS: A total of 102 CTPAs performed by 20 ml (ultra-low volume: ULV) and 74 CTPAs performed by 40 ml (low volume: LV) protocol for the diagnosis of clinically suspected PE performed between October 2012 and September 2013 were retrieved. High-concentration CM (Iomeprol 400 mgI/ml) was injected at 3 ml/s (iodine delivery rate 1.2 mgI/s). Two radiologists (blinded and independent) semi-qualitatively scored vascular enhancement and image noise according to a five-point visual scoring system. Quantitative analysis was performed by regions of interest quantifying densitometric parameters, such as central and peripheral pulmonary arteries vascular contrast enhancement (CE, threshold for diagnostic CE ≥ 250 HU), and metrics for image noise. Continuous variables were compared by the Student's t test between groups if normally distributed while categorical variables were analyzed with the Chi-squared test. Interobserver agreement was calculated by the weighted kappa test; correlation coefficients were calculated using Pearson's correlation tests. RESULTS: The semi-qualitative scores for central and peripheral pulmonary arteries vascular CE were sufficient by ULV, yet inferior than LV (p < 0.001). Semi-qualitative image noise was comparable between ULV and LV, and the interobserver agreement was only fair for quality of peripheral vessels. Agreement on nondiagnostic semi-qualitative parameters was seen in 9/102 (8.8%) ULV CTPAs, in particular associated with massive PE (2/9), pleuro-pulmonary abnormalities (5/9) or without major abnormalities (2/9). Quantitative analysis showed that mean CE was lower in ULV group (p < 0.001), though greater than the diagnostic threshold of 250 HU in both groups. CONCLUSIONS: Diagnostic vascular CE (> 250 HU) was obtained in both 20 ml and 40 ml CTPAs. CTPA by 20 ml of CM rendered diagnostic CE for the assessment of pulmonary arteries in patients with clinical suspicion of acute PE. Decreased image quality was mostly associated with massive PE or concomitant pleuro-parenchymal abnormalities.

High-pitch dual-source CT angiography without ECG-gating for imaging the whole aorta: intraindividual comparison with standard pitch single-source technique without ECG gating.

PURPOSE: We aimed to perform intraindividual comparison of computed tomography (CT) parameters, image quality, and radiation exposure between standard CT angiography (CTA) and high-pitch dual source (DS)-CTA, in subjects undergoing serial CTA of thoracoabdominal aorta. METHODS: Eighteen subjects with thoracoabdominal CTA by standard technique and high-pitch DS-CTA technique within 6 months of each other were retrieved for intraindividual comparison of image quality in thoracic and abdominal aorta. Quantitative analysis was performed by comparison of mean aortic attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Qualitative analysis was performed by visual assessment of motion artifacts and diagnostic confidence. Radiation exposure was quantified by effective dose. Image quality was apportioned to radiation exposure by means of figure of merit. RESULTS: Mean aortic attenuation and noise were higher in high-pitch DS-CTA of thoracoabdominal aorta, whereas SNR and CNR were similar in thoracic aorta and significantly lower in high-pitch DS-CTA of abdominal aorta (P = 0.024 and P = 0.016). High-pitch DS-CTA was significantly better in the first segment of thoracic aorta. Effective dose was reduced by 72% in high-pitch DS-CTA. CONCLUSION: High-pitch DS-CTA without electrocardiography-gating is an effective technique for imaging aorta with very low radiation exposure and with significant reduction of motion artifacts in ascending aorta; however, the overall quality of high-pitch DS-CTA in abdominal aorta is lower than standard CTA.

Erdheim-Chester Disease as a Mimic of IgG4-Related Disease: A Case Report and a Review of a Single-Center Cohort.

Immunoglobulin-G4 (IgG4)-related disease (IgG4RD) is a fibro-inflammatory disorder characterized by tissue-infiltrating IgG4 plasma cells, and, often, high serum IgG4. Several autoimmune, infectious, or proliferative conditions mimic IgG4RD. Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis, characterized by foamy histiocytic infiltration, fibrosis, and chronic inflammation. ECD and IgG4RD manifestations may overlap.A patient presented with huge fibrous retroperitoneal masses causing compression on neighboring structures; the case posed the challenge of the differential diagnosis between IgG4RD and ECD mainly because of a prominent serum and tissue IgG4 response.Retroperitoneal biopsy led to the diagnosis of ECD; the V600E BRAF mutation was found. Treatment with the BRAF inhibitor vemurafenib was started.Treatment failed to induce mass regression and the patient died after 3 months of therapy. Prompted by this case, we examined serum and tissue IgG4 in a series of 15 ECD patients evaluated at our center, and found that approximately one-fourth of the cases have increased IgG4 in the serum and often in the tissue.The differential diagnosis between IgG4RD and ECD can be challenging, as some ECD patients have prominent IgG4 responses. This suggests the possibility of common pathogenic mechanisms between ECD and IgG4RD.

An uncommon cause of ascites: uroperitoneum from iatrogenic bladder fistula detected by CT urography.

We report the case of a female who underwent laparoscopic hysterectomy and was referred to the emergency department with massive ascites 10 days later. Anamnestic background and clinical presentation suggested the occurrence of a urinary lesion, which was investigated by CT urography. CT urography with ultra-late excretory phase showed the leakage of iodinated contrast agent from the bladder dome into the peritoneal cavity, as expected in uroperitoneum from iatrogenic bladder laceration. CT cystography is the reference standard for the assessment of bladder leakage; however, this technique is quite invasive, time consuming and does not provide a panoramic overview of the entire excretory system. Conversely, CT urography provides a complete overview of the entire excretory system by means of an optimized protocol with optional ultra-late acquisition to gain adequate bladder distension and depict minor urinary leakage.

Chronic periaortitis with thoracic aorta and epiaortic artery involvement: a systemic large vessel vasculitis?

OBJECTIVE: Chronic periaortitis (CP) is a rare disease characterized by fibro-inflammatory tissue surrounding the abdominal aorta and the iliac arteries. Anecdotal reports have shown that CP may also involve other vascular districts, particularly the thoracic aorta. The aim of this study was to investigate the thoracic aorta and epiaortic artery involvement in CP. METHODS: Patients were eligible if they had undergone imaging studies assessing inflammatory involvement of the thoracic aorta and its major branches (e.g. contrast CT, MRI or PET-CT). We explored the patterns of thoracic vessel involvement and compared the clinical characteristics of patients with and without thoracic disease. Where available, we also reviewed the thoracic vascular/perivascular tissue biopsies. RESULTS: Of 153 CP patients seen between 1999 and 2012, 77 were eligible. Of these, 28 (36%) had thoracic involvement: 15 (54%) had thoracic periaortitis, with 7 also showing epiaortic artery involvement; 6 (21%) had periaortitis surrounding a thoracic aortic aneurysm, 2 of them with epiaortic artery involvement; 7 (25%) had a thoracic aortic aneurysm without periaortitis. Patients with thoracic disease were more frequently female (P = 0.01), were older (P = 0.001) and had a higher frequency of pain and constitutional symptoms (P = 0.02). Thoracic (peri)vascular biopsies revealed adventitial and peri-adventitial fibro-inflammatory patterns similar to those observed in abdominal CP. CONCLUSION: In about one-third of patients, CP also involves the thoracic aorta and the epiaortic arteries, which supports the hypothesis of a systemic inflammatory disease of the large arteries.

Interobserver reliability of the chest radiograph in pulmonary embolism.

This study was sought to evaluate the interobserver agreement for interpreting the chest radiograph of patients with suspected acute pulmonary embolism (PE). The chest radiographs of 300 patients with clinically suspected acute PE were reviewed by 4 radiologists. Observers assessed the chest radiographic abnormalities and classified the chest radiograph as normal or abnormal. We found that the overall interobserver agreement was good for the exclusion of any pleural or parenchymal abnormality (k = 0.6; 95% CI: 0.56-0.64) but fair (k = 0.28; 95% CI: 0.17-0.40) between junior radiologists when evaluating supine chest radiographs. The level of interobserver agreement for the interpretation of the chest radiograph as consistent or not with PE was fair (k = 0.24; 95% CI: 0.19-0.29), regardless of the observer experience. In conclusion, chest radiography may be reliably used for targeting patients with suspected acute PE for different subsequent diagnostic investigations.

Prednisone versus tamoxifen in patients with idiopathic retroperitoneal fibrosis: an open-label randomised controlled trial.

BACKGROUND: Glucocorticoids are the mainstay of treatment of idiopathic retroperitoneal fibrosis, but they often have substantial toxic effects. Several reports have suggested tamoxifen as an alternative to glucocorticoids. We compared the efficacy of prednisone with that of tamoxifen in maintainance of remission in patients with idiopathic retroperitoneal fibrosis. METHODS: In this open-label, randomised controlled trial, we enrolled patients aged 18-85 years with newly diagnosed idiopathic retroperitoneal fibrosis at the Parma Hospital, Parma, Italy, between Oct 1, 2000, and June 30, 2006. After induction therapy with 1 mg/kg daily of prednisone for 1 month, the patients who achieved remission were randomly assigned to receive tapering prednisone (initial dose 0·5 mg/kg daily) for 8 months or tamoxifen (fixed dose 0·5 mg/kg daily) for 8 months. The sequence of randomisation (1:1), blocked in groups of two and four (with block size randomly selected), was generated by the trial statistician with a computer programme. After the end of treatment, the patients were followed up for an additional 18 months. Neither patients nor those giving interventions or analysing the data were masked to group assignment. The two radiologists who assessed CT and MRI scans were masked. The primary endpoint was the relapse rate by the end of treatment (month 8), which was analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00440349. FINDINGS: After induction therapy, 36 of the 40 enrolled patients achieved remission and were randomly assigned to treatment (18 per group). One patient (6%) in the prednisone group and seven patients (39%) in the tamoxifen group relapsed by the end of treatment (difference -33% [95% CI -58 to -8, p=0·0408]. The difference in relapse rate between the groups was sustained after the additional 18-month follow-up: the 26-month estimated cumulative relapse probability was 17% with prednisone and 50% with tamoxifen (difference -33% [-62 to -3, p=0·0372]). Cushingoid changes and grade 2 hypercholesterolaemia were more common in the prednisone group than in the tamoxifen group (p=0·0116 and p=0·0408, respectively). INTERPRETATION: Prednisone is more effective in prevention of relapses than is tamoxifen in patients with idiopathic retroperitoneal fibrosis. Therefore, prednisone should be considered as first-line treatment for patients with newly diagnosed idiopathic retroperitoneal fibrosis. FUNDING: Parma University Hospital.

Extra-adrenal composite paraganglioma with ganglioneuroma component presenting as a pancreatic mass.

Paragangliomas may have composite forms in which they combine features of a typical paraganglioma with those of a neural component consisting of either neuroblastoma, ganglioneuroblastoma, or ganglioneuroma. These variants are rare and generally located in the adrenal. Herein, we describe a retroperitoneal, extra-adrenal composite paraganglioma-ganglioneuroma of a 57-year-old woman. Radiological evaluation revealed a nodular mass with apparent pancreatic location, with findings suggestive of an endocrine tumor, yielding the diagnosis of a pancreatic endocrine tumor. At histology the neoplasm, strictly adhering to the external surface of the pancreatic gland but well demarcated, displayed a main central region with typical paraganglioma features and cells arranged in cords and in a nesting "zellballen" pattern, positive for neuroendocrine markers, and a distinct peripheral area consisting of dense bundles of wavy spindled Schwann cells, with scattered ganglionic cells.

Peri-renal collateral circles.

The figures illustrate the computed tomographic findings in 2 patients with idiopathic retroperitoneal fibrosis (IRF) who developed obstruction of the renal veins and peri-renal collateral circles late in the course of their disease. The involvement ab extrinseco of the renal veins is an overlooked feature of IRF. It often progresses slowly and only rarely leads to clinically overt thrombosis; collateral circles thus develop and, as in our patients, may be a late manifestation of the disease.

Tuberculosis as a trigger of retroperitoneal fibrosis.

Retroperitoneal fibrosis (RPF) is usually idiopathic but sometimes secondary to underlying diseases. In this report, we describe a case of apparently idiopathic RPF associated with a mediastinal tuberculous adenopathy. After a course of antituberculous treatment, a complete resolution of both adenopathy and RPF was observed. We discuss the potential pathogenetic mechanisms linking the 2 diseases.

Evaluation of quantitative CT indexes in idiopathic interstitial pneumonitis using a low-dose technique.

OBJECTIVE: To evaluate and compare histogram features (mean lung attenuation, skewness, kurtosis) of low-dose and standard-dose CT in a group of patients affected by idiopathic interstitial pneumonitis. METHODS: We analyzed 16 patients affected by idiopathic interstitial pneumonitis. Spiral whole lung thin-section CT acquisition at standard dose (100 mAs) and three additional low-dose (50 mAs) CT images were obtained. After obtained frequency histograms, mean lung attenuation (MLA), skewness and kurtosis and three range of density (-700/-200 HU; -700/-400 HU; -500/-200 HU) of the standard-and low-dose thin-section CT scans were analyzed and compared. RESULTS: The parameters obtained with low-dose and standard-dose spiral CT were correlated in a highly significant manner and were equivalent (p<0.01). The greatest correlation was found between standard-and low-dose kurtosis and standard and low-dose -700/-400 HU subrange of density (r=0.92; p<0.0001). CONCLUSIONS: Our results prove that a quantitative CT objective evaluation in lung fibrosis can be successfully obtained with low-dose spiral CT, with reduced mA.

Clinical usefulness of computed tomography study without contrast injection in the evaluation of acute pulmonary embolism.

OBJECTIVE: To evaluate the percentage of cases in which emboli can be detected in unenhanced scans and to identify the cases in which they appear hyperattenuating or hypoattenuating in comparison to the circulating blood. METHOD: An angio-computed tomography (CT) scan was performed before and after contrast injection in 140 consecutive patients after clinical suspicion of pulmonary embolism. A radiologist analyzed the examination results thus obtained. The enhanced scan was analyzed first, and after detecting the thrombus, the unenhanced scan was evaluated. RESULTS: Fifty-one examinations were positive for a pulmonary embolism; in 21 cases, it was possible to identify the embolus even in the unenhanced scans. In 10 cases, the clots were hyperattenuating in comparison to the circulating blood; in 5 cases, they were hypoattenuating; and in 6 cases, they were mixed hyper-hypoattenuating. CONCLUSION: In a relatively high percentage of cases, particularly those of central thromboembolism, it is possible to identify and characterize the clots even in unenhanced scans.

Assessment of organ volume with different techniques using a living liver model.

The purpose of this study was to compare different techniques for the estimation of liver volume, and to evaluate errors associated with volume estimation techniques based on linear measurements. Fifteen patients with focal liver lesion underwent spiral CTA for preoperative evaluation. The scan protocol was: collimation 3 mm; rotation time 0.75 s; pitch 2; and reconstruction index 1 mm. Reconstructed images were sent to a workstation running on a NT platform equipped with post-processing software allowing 3D reconstructions. Linear measurements and volume estimation through manual segmentation were obtained with preset window and magnification. Volume was calculated from linear measures using different equations. With equations based on linear measurements the right lobe was overestimated (mean=+53%; mean error=14.7%), the second and third segments were underestimated (mean=-47%; mean error=43.3%) and the total volume was underestimated (mean=-86%; mean error=36%). The volume calculated by summing the areas of all the sections and multiplying the result by the increment was not significantly different from the volume estimated using the manual volumetric segmentation technique. Volume estimation obtained through linear measurements is not reliable to appraise the volume of irregular-shaped solids, even assuming the prevalence of a particular morphology.