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Das Prostatakarzinom stellt die am haufigsten diagnostizierte Krebserkrankung in der mannlichen Bevolkerung dar. Die genaue Atiologie ist nach wie vor nicht genau bekannt. Verschiedene Faktoren werden diskutiert, u. a. hormonelle Faktoren, Ernahrung, Infektionen und Umweltfaktoren. Als gesichert gilt ein erhohtes individuelles Risiko bei familiarer Belastung.

Die Prostata (Vorsteherdruse) ist ein kastaniengroses Organ, das dem Blasenboden anliegt und den proximalen Teil der Harnrohre umschliest. Sie wiegt rund 20-25 g und besteht aus glandularen und fibromuskularen Anteilen. Die ausere Form ist annahernd pyramidenformig, wobei die Basis prostatae zur Harnblase und der Apex prostatae nach kaudal weist.

Nach erfolgter transurethraler Resektion der Prostata (TUR-P) dient die transrektale Sonographie dem Abschatzen der Restdruse (◘ Abb. 20.1 bis ◘ Abb. 20.3). Dies ist v. a. bei wiederkehrenden Miktionsbeschwerden wichtig.

Purpose To evaluate the diagnostic accuracy of multiparametric ultrasonography (US) consisting of gray-scale US, color Doppler US, strain elastography, and contrast agent-enhanced US in the assessment of intratesticular lesions. Materials and Methods Institutional review board approval was obtained for this retrospective study. From January 2012 to December 2015, 55 focal testicular lesions that were indeterminate on gray-scale US scans were further characterized with color Doppler US, strain elastography, and contrast-enhanced US. Strain elastography was performed to assess tissue elasticity, and hard lesions were defined as malignant. Color Doppler US and contrast-enhanced US were performed to determine the absence or presence of vascularization. Avascular lesions were defined as benign. Histopathologic results or follow-up examinations served as reference standards. Correct classification rate, sensitivity, specificity, and likelihood ratio were calculated. Results Of 55 testicular lesions, 43 (78.2%) were benign and 12 (21.8%) were malignant. Single-modality sensitivities and specificities were 66.7% and 88.4% for color Doppler US, 100% and 76.7% for contrast-enhanced US, and 100% and 72.1% for strain elastography, respectively. Among 12 malignant lesions, color Doppler US failed to demonstrate vascularization in four (33.3%) lesions, which were positive for cancer at contrast-enhanced US. By combining strain elastography and contrast-enhanced US, a sensitivity of 100% and specificity of 93.0% were achieved in differentiating benign and malignant focal testicular lesions. Positive likelihood ratio was 5.7 for color Doppler US, 4.3 for contrast-enhanced US, 3.6 for strain elastography, 14.3 for strain elastography combined with color Doppler US, and 14.3 for strain elastography combined with contrast-enhanced US. Conclusion Multiparametric US allows for a reliable differentiation of benign and malignant intratesticular lesions and can potentially be useful in deciding whether orchiectomy can be replaced with follow-up or less invasive organ-sparing strategies. © RSNA, 2017.

Background Accurate lymph node (LN) staging in bladder cancer before radical cystectomy is essential as LN metastases have an independent prognostic value. Most studies used a cutoff of > 10 mm in detecting pelvic LN spread. The aim of this study was to evaluate the diagnostic accuracy of contrast-enhanced computed tomography (CT) and 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography (PET) alone, or combined for preoperative pelvic LN staging. Patients and Methods We retrospectively analyzed the data of 70 bladder cancer patients that were staged with 18 F-FDG-PET/CT before radical cystectomy between 2012 and 2015. 18 F-FDG-PET images were analyzed visually and semi-quantitatively by calculating the maximum standardized uptake value. CT scans were reviewed using different cutoffs of pelvic LNs, with the best cutoff at 8 mm (area under the curve = 0.684). Results Metastatic LNs were confirmed in 53 (2.8%) of 1906 resected LNs in 11 (15.7%) patients. Sensitivity, specificity, and accuracy were 54.5%, 89.8%, and 84.3% for 18 F-FDG-PET alone; 45.5%, 91.5%, and 84.3% for CT (LNs > 8 mm) alone; and 27.3%, 96.6%, and 85.7% for CT (LNs > 10 mm) alone, respectively. Combined 18 F-FDG-PET/CT resulted in a nonsignificant increase of diagnostic accuracy using a cutoff > 8 mm for LN evaluation (63.6%, 86.4%, and 82.9%, respectively). A significant improvement of sensitivity to 63.6% was achieved only when LNs > 10 mm were considered suspicious ( P = .046), but this reduced specificity to 88.1% ( P = .025). Conclusions Combined 18 F-FDG-PET/CT does not seem to be justified in preoperative staging if the threshold of pelvic LNs is set > 8 mm.

Aim To evaluate the feasibility of ultrasound (US) computed tomography (CT) or magnetic resonance imaging (MRI) fusion imaging (FI) for localization and assessment of kidney lesions. Materials and methods Twenty-eight patients with kidney lesions previously detected on CT or MRI were included in this retrospective study. All 28 patients with kidney lesions, which were indefinable (42.9%) or hard to localize (57.1%) on gray-scale US alone, underwent FI of US with CT/MRI datasets. In 23 (82%) patients with indeterminate kidney lesions, FI including contrast-enhanced US was conducted. Results FI was successfully performed in 25 out of 28 (89.3%) patients. FI with contrast-enhanced US was able to clarify the previously detected kidney lesions in 21 out of 23 patients (91.3%). Conclusion FI is a feasible technique for localizing kidney lesions that are hard to define by grayscale US alone and the additional application of contrast-enhanced US is useful in clarifying indeterminate CT or MRI findings.

Objectives To assess demographical and clinical data in a Middle‐European cohort of patients with Adamantiades–Behçet's disease (ABD), together with the use of medication in adherence to international guidelines. Methods In a retrospective cohort study, in‐ and outpatients of an Austrian secondary and tertiary university hospital center were analyzed independent from the medical discipline involved. After ethics approval, screening for ABD‐patients in the clinical information system resulted in 1821 documents from 1997 to 2016. Patients fulfilling the International Criteria for Behçet's Disease were included, and ABD symptoms and signs together with medical interventions for immunosuppression, anticoagulation and pain management were identified by individual chart reviews and evaluated for conformity with international recommendations. Results A total of 76 ABD patients were identified with 39.1% Austrian and 37.0% Turkish origin. Genital aphthae and skin manifestations were more frequent, neurological, gastrointestinal and vascular manifestations less frequent in ABD patients of Turkish origin living in Austria compared to those living in Turkey (each P

Dual-energy contrast-enhanced mammography is one of the latest developments in breast care. Imaging with contrast agents in breast cancer was already known from previous magnetic resonance imaging and computed tomography studies. However, high costs, limited availability-or high radiation dose-led to the development of contrast-enhanced spectral mammography (CESM). We reviewed the current literature, present our experience, discuss the advantages and drawbacks of CESM and look at the future of this innovative technique.

Accurate lymph node (LN) staging in bladder cancer before radical cystectomy is essential as LN metastases have an independent prognostic value. Most studies used a cutoff of10 mm in detecting pelvic LN spread. The aim of this study was to evaluate the diagnostic accuracy of contrast-enhanced computed tomography (CT) andWe retrospectively analyzed the data of 70 bladder cancer patients that were staged withMetastatic LNs were confirmed in 53 (2.8%) of 1906 resected LNs in 11 (15.7%) patients. Sensitivity, specificity, and accuracy were 54.5%, 89.8%, and 84.3% forCombined

Radiation dose reduction strategies in coronary CT angiography are paramount to ensure the lowest radiation exposure. This review provides basic knowledge of radiation physics. The technical background and the clinical implementations of various radiation dose-saving strategies for coronary CT angiography are discussed.

To compare image quality and radiation dose of high-pitch dual-source computed tomography (DSCT), dual energy CT (DECT) and conventional single-source spiral CT (SCT) for pulmonary CT angiography (CTA) on a 128-slice CT system.Pulmonary CTA was performed with five protocols: high-pitch DSCT (100 kV), high-pitch DSCT (120 kV), DECT (100/140 kV), SCT (100 kV), and SCT (120 kV). For each protocol, 30 sex, age, and body-mass-index (mean 25.3 kg/m(2)) matched patients were identified. Retrospectively, two observers subjectively assessed image quality, measured CT attenuation (HU±SD) at seven central and peripheral levels, and calculated signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR). Radiation exposure parameters (CTDIvol and DLP) were compared.Subjective image quality was rated good to excellent in92% (138/150) with an interobserver agreement of 91.4%. The five protocols did not significantly differ in image quality, neither by subjective, nor by objective measures (SNR, CNR). By contrast, radiation exposure differed between protocols: significant lower radiation was achieved by using high-pitch DSCT at 100 kV (p 0.01 in all). Radiation exposure of DECT was in between SCT at 100 kV and 120 kV.SCT, high-pitch DSCT, and DECT protocols techniques result in similar subjective and objective image quality, but radiation exposure was significantly lower with high-pitch DSCT at 100 kV.New CT protocols show promising results in pulmonary embolism assessment. High-pitch dual-source CT (DSCT) at 100 kV provides radiation dose savings for pulmonary CTA. High-pitch DSCT at 100 kV maintains diagnostic image quality for pulmonary CTA. Dual energy CT uses more radiation but also provides lung perfusion evaluation. Whether the additional perfusion data is worth the extra radiation remains undetermined.

Objective Ultrasound imaging is an economical and noninvasive technique for studying musculoskeletal diseases such as Duchenne muscular dystrophy (DMD). Duchenne muscular dystrophy results from the loss of the cytoskeletal protein dystrophin. This in turn increases muscle susceptibility to injury, resulting in myofiber membrane leakage, inflammation, and degeneration. The purpose of this study was to detect dystrophic changes in muscle noninvasively. High-frequency ultrasound (HFU; 40 MHz) was used to obtain a resolution of 80 microm, which is not achievable with lower-frequency clinical scanners. Methods Using HFU, we were able to visualize musculoskeletal abnormalities as hyperechoic lesions within the dystrophic muscle. To validate the imaging findings, fiducial markers were placed in close proximity to lesions under HFU guidance. The nature of the lesion was then investigated histologically. This was repeated in the lower limbs of 10 mdx (mutated dystrophin gene) mice, a transgenic murine model of DMD. Results The abnormalities in the dystrophic muscle consisted of large influxes of leukocytic infiltrates, fibrotic scars, and calcified lesions. Conclusions Although macrophages and fibrosis are commonly noted in DMD, to our knowledge, the presence of intramuscular calcific necrosis in dystrophic muscle has not been reported. This novel dystrophic feature of muscle degeneration may be useful in longitudinal studies of murine DMD and regenerative studies.

Background— Ischemia/reperfusion injury is a major factor in graft quality and subsequent function in the transplantation setting. We hypothesize that the process of RNA interference may be used to “engineer” a graft to suppress expression of genes associated with inflammation, apoptosis, and complement, which are believed to cause ischemia/reperfusion injury. Such manipulation of pathological gene expression may be performed by treatment of the graft ex vivo with small interfering RNA (siRNA) as part of the preservation procedure. Methods and Results— Heart grafts from BALB/c mice were preserved in UW solution (control) or UW solution containing siRNAs targeting tumor necrosis factor-α, C3, and Fas genes (siRNA solution) at 4°C for 48 hours and subsequently transplanted into syngeneic recipients. Tumor necrosis factor-α, C3, and Fas genes were elevated by ischemia/reperfusion injury after 48 hours of preservation in UW solution. Preservation in siRNA solution knocked down gene expression at the level of messenger RNA and protein in the grafts after transplantation. All grafts preserved in siRNA solution showed strong contraction, whereas grafts preserved in control solution demonstrated no detectable contraction by high-frequency ultrasound scanning. siRNA solution–treated organs exhibited improved histology and diminished neutrophil and lymphocyte infiltration compared with control solution–treated organs. Furthermore, the treated heart grafts retained strong beating up to the end of the observation period (>100 days), whereas all control grafts lost function within 8 days. Conclusion— Incorporation of siRNA into organ storage solution is a feasible and effective method of attenuating ischemia/reperfusion injury, protecting cardiac function, and prolonging graft survival.

US guided procedures for diagnosis or treatment of different forms of arthritis are becoming more and more important. This review describes general considerations for fluid aspiration, articular or periarticular injections and biopsies by US guidance according to the recent literature. Guidelines regarding instrumentation, different techniques, pre- and postprocedural care as well as complications are outlined and in the second part a more detailed overview of different interventions in joints, tendons and other periarticular regions (nerves, bursae, etc.) is included. Furthermore, some newer, more sophisticated techniques are briefly discussed.

Real-time sonoelastography is a new ultrasound-based technique able to assess tissue elasticity that has already shown feasibility in tumor diagnosis. The aim of this study was to assess the performance of real-time sonoelastography in depicting the Achilles tendons of healthy volunteers and to compare sonoelastography findings with conventional ultrasound findings.Eighty asymptomatic Achilles tendons of 40 healthy volunteers (19 men, 21 women; mean age, 38 years; range, 20-76 years) were examined on real-time sonoelastography and ultrasound. The Achilles tendons were divided into the following thirds for image evaluation: proximal (musculotendinous junction), middle (2-6 cm above insertion at the calcaneus), and distal (insertion at the calcaneus). Longitudinal and axial images of each tendon third were obtained using ultrasound and real-time sonoelastography. Real-time sonoelastography images were evaluated by reviewers using an experimentally proven color grading system.The Achilles tendons showed mainly a hard structured pattern (86.7%) (208/240 tendon thirds) on sonoelastography; however, mild softening was found in 12.1% (29/240) of the tendons. Distinct softening corresponding to alterations found also on ultrasound and, therefore, suggesting subclinical changes was detected in 1.3% (3/240). The overall correlation (kappa) between real-time sonoelastography and ultrasound findings was 1.00.In healthy volunteers, the Achilles tendon appeared hard on real-time sonoelastography with excellent correlation to ultrasound. Further investigation including pathologic tendons should be performed to prove the value of real-time sonoelastography in the assessment of Achilles tendinopathy.

Data from in vitro and animal studies support a neuroprotective role of glatiramer acetate (GA) in multiple sclerosis (MS). We investigated prospectively whether treatment with GA leads to clinical and paraclinical changes associated with neuroprotection in patients with relapsing-remitting (RR) MS. Primary aim of this clinical study was to determine serum BDNF levels in RR-MS patients who were started on GA as compared to patients who remained therapy-naive throughout 24 months. Secondary outcomes included relapses and EDSS, cognition, quality of life, fatigue and depression, BDNF expression levels on peripheral immune cells (FACS, RT-PCR), serum anti-myelin basic peptide (MBP) antibody status, evoked potential and cerebral MRI studies. While GA treatment did not alter serum levels or expression levels on peripheral immune cells of BDNF over time it resulted in a transient increase of serum IgG antibody response to MBP, mainly due to subtype IgG1 (p

The purpose of this study was to investigate the value of real-time sonoelastography (RTS) of salivary glands for the diagnosis and assessment of glandular damage in primary Sjögren's syndrome (pSS). After institutional review board approval, 45 pSS patients, 24 sicca patients and 11 healthy controls were investigated prospectively. Questionnaires were completed and Saxon and Schirmer tests and routine blood tests carried out in all patients. All patients underwent B-mode ultrasonography and RTS of parotid and submandibular glands. Abnormal findings were graded from 0 to 48 and from 0 to 16, respectively. Sialoscintigraphy was done according to a routine protocol; scoring ranged from 0 to 12. Statistical analysis comprised receiver operating characteristic curve and multivariate regression analysis. Patients with pSS had higher B-mode (median score = 25 [range: 2-44] vs. 9 [1-20], p0.001) and RTS (6.5 [2-13] versus 4 [1-9], p0.001) scores than controls with sicca syndrome, yielding areas under the curve of 0.83 and 0.85 (p0.05 each), respectively for pSS diagnosis. In cases with an inconclusive B-mode ultrasonography result, RTS (cutoff score: ≥ 6) led to a sensitive (66.7%) and specific (85.7%) classification of patients and sicca controls. In multivariate regression analysis, RTS (regression coefficient = -0.48, p = 0.005), but not B-mode ultrasonography, reflected impaired salivary gland function according to the Saxon test, whereas none of the subjective measures of dryness or discomfort were related to ultrasonography results. B-mode and RTS results were both associated with sialoscintigraphy scores (regression coefficient = 0.66, p0.001, and regression coefficient = 0.55, p = 0.001, respectively). Reproducibility of B-mode ultrasonography and RTS was good, with intra-class correlation coefficients of 0.93 (95% confidence interval: 0.57-0.98) and 0.93 (95% confidence interval: 0.79-0.98), respectively. In summary, RTS might be a useful adjunct to B-mode ultrasonography for diagnosis and assessment of salivary gland impairment in primary Sjögren's syndrome.

Ultrasonography is the standard modality to image the scrotum because it can provide information about volume, echo texture, tissue stiffness and functional information that includes macrovascularization and microvascularization. Indeed, ultrasound imaging is indicated in the presentation of acute scrotal pain and swelling to differentiate between testicular torsion, infarction and inflammation, as well as being the modality of choice when an intrascrotal mass is suspected. Advances in ultrasonography technology have produced new innovative techniques for imaging the scrotum, including grey-scale ultrasound, Doppler ultrasonography, contrast-enhanced ultrasonography and real-time sonoelastography. Each of these techniques provides information that can be useful when diagnosing diseases and disorders of the testicles. Consequently, the standard approach to accurate diagnosis should rely on multiparametric ultrasonography techniques, rather than just one or two techniques in isolation.

To evaluate if image fusion, a technology matching real-time ultrasonography (US) and a previously obtained computed tomographic (CT) scan, is a feasible aid for sacroiliac (SI) joint injections in cadavers and patients.This study was approved by institutional review board, and written informed consent was obtained from each patient. In five human cadavers (10 joints) and seven consecutive patients (10 joints; four male, three female patients; mean age, 33.6 years; range, 22-44 years), SI joint injections were performed by using image fusion guidance technology. Registration errors were calculated automatically by the software and reported as mean registration error. In cadavers, needle placement was confirmed by means of CT, while in patients, a subjective rating of pain (score of 0-10) was recorded before and 3 months after injection. Procedure time was calculated.Matching of real-time US and CT images by image fusion software was reliable in all tests (mean registration error, 0.3 mm). In all cadavers, correct intraarticular needle positioning by using image fusion guidance was confirmed on CT scans. In patients, no intraprocedural complications were noted, and 3 months after injection pain score decreased (mean pain score before procedure, 8.05; after, 0.3). In patients, mean time for the whole procedure was 20.4 minutes (range, 17-22 minutes), with a mean duration of 15.4 minutes (range, 14-17 minutes) for image matching and 5 minutes (range, 3-7 minutes) for needle placement.Image fusion of real-time US and previously obtained CT scans is feasible to guide needle insertion into the SI joint.

Objective To determine whether a recently available contrast-enhanced ultrasound (CEUS) technique using second-generation microbubbles allows for the detection of active sacroiliitis, and to measure CEUS enhancement depth at the dorsocaudal part of the sacroiliac (SI) joints in healthy volunteers compared with patients with sacroiliitis. Methods Forty-two consecutive patients (84 SI joints) presenting with a clinical diagnosis of sacroiliitis in 50 SI joints and 21 controls (42 SI joints) were investigated by CEUS using a standardized low mechanical index ultrasound protocol. Detected vascularity was used to retrospectively measure the enhancement depth in the dorsocaudal part of the SI joints. Results CEUS detected enhancement in all clinically active SI joints, showing an enhancement depth into the dorsal SI joint cleft of 18.5 mm (range 16–22.1), which was significantly higher compared with both inactive joints of patients (3.6 mm, range 0–12; P < 0.001) and healthy controls (3.1 mm, range 0–7.8; P < 0.001). All inactive joints were correctly classified based on a lack of deep enhancement in patients with sacroiliitis and controls (42 of 42, 100% sensitivity, 100% specificity; Cohen's κ = 1). Conclusion CEUS allowed the differentiation of active sacroiliitis from inactive SI joints, and proved to be a feasible method for the detection of vascularity in clinically active sacroiliitis by showing deep contrast enhancement into the SI joints not detectable in inactive joints of patients or controls. If this technique might add information to the earlier detection of sacroiliitis, it should be addressed in further studies.

To improve accuracy in the diagnosis of carpal tunnel syndrome (CTS) by comparing cross-sectional area (CSA) measurements of the median nerve obtained at the level of the carpal tunnel (CSAc) with those obtained more proximally (CSAp), at the level of the pronator quadratus muscle.The study protocol was approved by the institutional review board, and all subjects gave written informed consent. One hundred wrists of 68 consecutive patients with CTS (16 men, 52 women; mean age, 57.9 years; range, 25-85 years) and 93 wrists of 58 healthy volunteers (16 male, 42 female; mean age, 55.1 years; range, 17-85 years) were examined with ultrasonography (US). Electrodiagnostic test results confirmed the diagnosis of CTS in all 68 patients. The US examiner was blinded to these test results. The CSA of the median nerve was measured at the carpal tunnel and proximal levels, and the difference between CSAc and CSAp (Delta CSA) was calculated for each wrist.The mean CSAc in healthy volunteers (9.0 mm(2)) was smaller than that in patients (16.8 mm(2), P.01). The mean Delta CSA was smaller in asymptomatic wrists (0.25 mm(2)) than in CTS-affected wrists (7.4 mm(2), P.01). Receiver operating characteristic analysis revealed a diagnostic advantage to using the Delta CSA rather than the CSAc (P = .036). Use of a Delta CSA threshold of 2 mm(2) yielded the greatest sensitivity (99%) and specificity (100%) for the diagnosis of CTS.Receiver operating characteristic analysis revealed improved accuracy in the diagnosis of CTS determined with the Delta CSA compared with the accuracy of the diagnosis determined with the CSAc.

Objective Sacroiliitis is often caused by rheumatic diseases, and besides other therapeutic options, treatment consists of intraarticular injection of corticosteroids. The purpose of this study was to assess the feasibility of ultrasound (US)-guided sacroiliac joint (SI joint) injection at 2 different puncture levels in cadavers and patients when defined sonoanatomic landmarks were considered. Methods After defining sonoanatomic landmarks, US-guided needle insertion was performed in 10 human cadavers (20 SI joints) at 2 different puncture sites. Upper level was defined at the level of the posterior sacral foramen 1 and lower level at the level of the posterior sacral foramen 2. In 10 patients with unilateral sacroiliitis, injection at the most feasible level was attempted. Results Computed tomography confirmed correct intraarticular needle placement in cadavers by showing the tip of the needle in the joint and intraarticular diffusion of contrast media in 16 (80%) of 20 SI joints (upper level 7 [70%] of 10; lower level 9 [90%] of 10). In all 4 cases in which needle insertion failed, intraarticular SI joint injection at the other level was successful. In patients, 100% of US-guided injections were successful (8 lower level, 2 upper level), with a mean pain relief of 8.6 after 3 months. Conclusion US guidance of needle insertion into SI joints was feasible at both levels when defined sonoanatomic landmarks were used. If SI joint alterations do not allow for direct visualization of the dorsal joint space of the lower level, which is easier to access, the upper level might offer an appropriate alternative.

The purpose of this review is to describe the spectrum of sonographic findings in rheumatic diseases with respect to the diagnostic potential using US contrast media which prove activity or inactivity in synovial tissue where new treatment regimes target. Synovial activity can be found in non-erosive and erosive forms of primary and secondary osteoarthritis, and in inflammatory forms of joint diseases like rheumatoid arthritis and peripheral manifestations of spondyloarthritis including, ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis and enteropathic arthritis. It can also be present in metabolic and endocrine forms of arthritis, in connective tissue arthropathies like systemic lupus erythematosus or scleroderma and in infectious arthritis. Ultrasound should be used as first-line imaging modality in suspected early cases of RA and other forms of arthritis, whereas contrast-enhanced ultrasound (CEUS) can further enable for sensitive assessment of vascularity which correlates with disease activity.

Objectives To develop prediction models that better estimate the pretest probability of coronary artery disease in low prevalence populations. Design Retrospective pooled analysis of individual patient data. Setting 18 hospitals in Europe and the United States. Participants Patients with stable chest pain without evidence for previous coronary artery disease, if they were referred for computed tomography (CT) based coronary angiography or catheter based coronary angiography (indicated as low and high prevalence settings, respectively). Main outcome measures Obstructive coronary artery disease (≥50% diameter stenosis in at least one vessel found on catheter based coronary angiography). Multiple imputation accounted for missing predictors and outcomes, exploiting strong correlation between the two angiography procedures. Predictive models included a basic model (age, sex, symptoms, and setting), clinical model (basic model factors and diabetes, hypertension, dyslipidaemia, and smoking), and extended model (clinical model factors and use of the CT based coronary calcium score). We assessed discrimination (c statistic), calibration, and continuous net reclassification improvement by cross validation for the four largest low prevalence datasets separately and the smaller remaining low prevalence datasets combined. Results We included 5677 patients (3283 men, 2394 women), of whom 1634 had obstructive coronary artery disease found on catheter based coronary angiography. All potential predictors were significantly associated with the presence of disease in univariable and multivariable analyses. The clinical model improved the prediction, compared with the basic model (cross validated c statistic improvement from 0.77 to 0.79, net reclassification improvement 35%); the coronary calcium score in the extended model was a major predictor (0.79 to 0.88, 102%). Calibration for low prevalence datasets was satisfactory. Conclusions Updated prediction models including age, sex, symptoms, and cardiovascular risk factors allow for accurate estimation of the pretest probability of coronary artery disease in low prevalence populations. Addition of coronary calcium scores to the prediction models improves the estimates.

Gastrointestinal stromal tumors (GIST) have been suggested to be the most common neurofibromatosis 1-associated gastrointestinal tumors. This case report describes and compares US and CT findings of both abdominal neurofibromas and a gastrointestinal stromal tumor. On US, the GIST appeared as a well-defined inhomogeneous lesion with a target-like pattern similar to CT. The neurofibromas appeared as well-demarcated round nodules with a relatively homogeneous hypoechoic internal structure and were accompanied by subtle posterior acoustic enhancement. US and CT were able to differentiate between neurofibromatomas and GIST in this neurofibromatosis 1 patient; however, a biopsy of the suspicious mass was performed to clarify the diagnosis. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 2010