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Uncertainty regarding the reproducibility of the apparent diffusion coefficient (ADC) hampers the use of quantitative diffusion-weighted imaging (DWI) in evaluation of the prostate with magnetic resonance imaging MRI. The quantitative imaging biomarkers alliance (QIBA) profile for quantitative DWI claims a within-subject coefficient of variation (wCV) for prostate lesion ADC of 0.17. Improved understanding of ADC reproducibility would aid the use of quantitative diffusion in prostate MRI evaluation.Evaluation of the repeatability (same-day) and reproducibility (multi-day) of whole-prostate and focal-lesion ADC assessment in a multi-site setting.Prospective multi-institutional.Twenty-nine males, ages 53 to 80 (median 63) years, following diagnosis of prostate cancer, 10 with focal lesions.3T, single-shot spin-echo diffusion-weighted echo-planar sequence with four b-values.Sites qualified for the study using an ice-water phantom with known ADC. Readers performed DWI analyses at visit 1 ("V1") and visit 2 ("V2," 2-14 days after V1), where V2 comprised scans before ("V2pre") and after ("V2post") a "coffee-break" interval with subject removal and repositioning. A single reader segmented the whole prostate. Two readers separately placed region-of-interests for focal lesions.Reproducibility and repeatability coefficients for whole prostate and focal lesions derived from median pixel ADC. We estimated the wCV and 95% confidence interval using a variance stabilizing transformation and assessed interreader reliability of focal lesion ADC using the intraclass correlation coefficient (ICC).The ADC biases from bThis study met the QIBA claim for prostate ADC. Test-retest repeatability and multi-day reproducibility were largely equivalent. Interreader reliability for focal lesion ADC was high across time points.1 TECHNICAL EFFICACY: Stage 2 TOC CATEGORY: Pelvis.

Background Since coronavirus disease 2019 (COVID-19) was declared a worldwide pandemic in March 2020, many authors have noted the collateral damage on non-COVID-19-related illnesses. These indirect effects of the pandemic have resulted in people presenting later and with more severe stages of disease, even if their diagnoses are not directly related to SARS-CoV-2, the virus that causes COVID-19. Objective We studied these indirect effects of COVID-19 on the imaging workup and outcomes for pediatric patients at our center who had acute appendicitis during the pandemic. Materials and methods We performed a retrospective review of cases in children ≤18 years who were evaluated for acute appendicitis during the same period, March 1 to May 31, in both 2019 and 2020. We compared demographic and clinical data as well as surgical and pathological findings, and we graded imaging findings according to severity. Differences in patient outcomes were assessed using the Wilcoxon rank sum test and the Pearson chi-square test. Results The total number of pediatric patients evaluated with imaging for acute appendicitis dropped by 43% between 2019 and 2020 (298 vs. 169), but the total number of children treated remained similar (59 vs. 51). There was proportionate use of US and CT in each timeframe but a higher percentage of positive imaging findings in 2020 (50/169, 29.6% vs. 56/298, 18.7% in 2019, P=0.04). There were more imaging examinations with features of complicated appendicitis among positive cases (9/51, 18% vs. 5/59, 8% in 2019, P=0.08) and more pathologically proven perforated cases during the pandemic (14/51, 27% vs. 6/59, 10% in 2019, P=0.11), although these results did not reach statistical significance. There were no changes in surgical management, vital signs, laboratory values, length of stay or complication rates. Conclusion There was a large drop in the number of pediatric patients imaged for acute appendicitis during the acute phase of the COVID-19 pandemic despite similar numbers of patients treated. The utilization trends of US vs. CT remained stable between time periods. The differences in imaging findings and perforation rates were less pronounced compared to other published studies.

The purpose is to develop a model-based image-reconstruction method using wavelet sparsity regularization for maintaining restoration of through-plane resolution but with improved retention of SNR versus linear reconstruction using Tikhonov (TK) regularization in high through-plane resolution (1 mm) Tsub2/sub-weighted spin-echo (T2SE) images of the prostate.A wavelet sparsity (WS)-regularized image reconstruction was developed that takes as input a set of ≈80 overlapped 3-mm-thick slices acquired using a T2SE multislice scan and typically 30 coil elements. After testing in contrast and resolution phantoms and calibration in 6 subjects, the WS reconstruction was evaluated in 16 consecutive prostate T2SE MRI exams. Results reconstructed with nominal 1-mm thickness were compared with those from the TK reconstruction with the same raw data. Results were evaluated radiologically. The ratio of magnitude of prostate signal to periprostatic muscle signal was used to assess the presence of noise reduction. Technical performance was also compared with a commercial 3D-T2SE sequence.The new WS reconstruction was assessed as superior statistically to TK for overall SNR, contrast, and multiple evaluation criteria related to sharpness while retaining the high (1 mm) through-plane resolution. Wavelet sparsity tended to provide improved overall diagnostic quality versus TK, but not significantly so. In all 16 studies, the prostate-to-muscle signal ratio increased.Model-based WS-regularized reconstruction consistently provides improved SNR in high (1 mm) through-plane resolution images of prostate T2SE MRI versus linear reconstruction using TK regularization.

Urothelial cancer is the second most common cancer, and cause of cancer death, related to the genitourinary tract. The goals of surveillance imaging after the treatment of urothelial cancer of the urinary bladder are to detect new or previously undetected urothelial tumors, to identify metastatic disease, and to evaluate for complications of therapy. For surveillance, patients can be stratified into one of three groups: 1) nonmuscle invasive bladder cancer with no symptoms or additional risk factors; 2) nonmuscle invasive bladder cancer with symptoms or additional risk factors; and 3) muscle invasive bladder cancer. This document is a review of the current literature for urothelial cancer and resulting recommendations for surveillance imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Background Rib fractures are associated with considerable morbidity and mortality. Surgical stabilization of rib fractures (SSRF) can be performed to mitigate complications. Sarcopenia is in general known to be associated with poor clinical outcomes. We investigated if sarcopenia impacted number of days of mechanical ventilation, intensive care unit (ICU) stay, and total hospital stay in patients who underwent SSRF. Methods A retrospective single institutional review was performed including patients who underwent SSRF (2009–2017). Skeletal muscle index (SMI) was semiautomatically calculated at the L3 spinal level on computed tomography (CT) images and normalized by patient height. Sarcopenia was defined as SMI 2/m2 in males and 2/m2 in females. Demographics, operative details, and postoperative outcomes were reviewed. Univariate and multivariate analyses were performed. Results Of 238 patients, 88 (36.9%) had sarcopenia. There was no significant difference in number of days of mechanical ventilation (2.8 ± 4.9 versus 3.1 ± 4.3, p = 0.304), ICU stay (5.9 ± 6.5 versus 4.9 ± 5.7 days, p = 0.146), or total hospital stay (13.3 ± 7.2 versus 12.9 ± 8.2 days, p = 0.183) between sarcopenic and nonsarcopenic patients. Sarcopenic patients demonstrated increased modified frailty index scores (1.5 ± 1.1 versus 0.9 ± 0.9, p < 0.001) compared to nonsarcopenic patients. Conclusions For patients who underwent SSRF for rib fractures, sarcopenia did not increase the number of days of mechanical ventilation, ICU stay, or total hospital stay. Sarcopenia should not preclude the utilization of SSRF in these patients.

To evaluate the relationship between imperceptible T1 enhancement of papillary renal cell carcinoma (pRCC) on MR and intratumoral hemosiderin deposition. One hundred ten pRCCs (≤ 7 cm) were evaluated by MR with in- and opposed-phase spoiled gradient echo (GRE) and T1-weighted spoiled GRE with fat suppression before and after contrast. Hemosiderin deposition was assessed by SIindex and Dindex on in- and opposed-phase images. SIindex and Dindex are calculated as (SIin − SIopp)/(SIin) × 100, where SIin and SIopp are tumor signal intensities on in- and opposed-phase images and (Din)/(Dopp), where Din and Dopp are tumor diameters on in- and opposed-phase images, respectively. The degree of tumor enhancement was classified as grade 1 (no), grade 2 (subtle), or grade 3 (definite). Tumor enhancement on CT was assessed when available. Five (5%), 10 (9%), and 95 (86%) tumors were categorized as grades 1, 2, and 3 enhancement, respectively. The mean SIindex was − 33.9, − 25.3, and 1.00, whereas the mean Dindex was 1.26, 1.05, and 1.00 in tumors with grades 1, 2, and 3 enhancement, respectively. Tumors with grade 1 enhancement had significantly lower SIindex (p = 0.001) and higher Dindex (p = 0.005) than those with grade 3 enhancement. Among six tumors with grade 1 or 2 enhancement and available CT, four tumors showed > 20 HU enhancement. pRCC with no subjective enhancement on contrast-enhanced MR showed hemosiderin deposition evident by lower SIindex and higher Dindex. Hemosiderin deposition might mask the tumor enhancement on MR. • 5% of papillary renal cell carcinoma showed imperceptible enhancement on contrast-enhanced MR. • Hemosiderin deposition in papillary renal cell carcinoma might mask the tumor enhancement on contrast-enhanced MR due to T2/T2*-shortening effects. • A renal lesion with extensive hemosiderin deposition but no perceptible enhancement on MR should be considered suspicious for papillary renal cell carcinoma.

Purpose To reduce slice-to-slice motion effects in multislice T 2 -weighted fast-spin-echo ( T 2 FSE) imaging, manifest as "scalloping" in reformats, by modification of the acquisition strategy and to show applicability in prostate MRI. Methods T 2 FSE images of contiguous or overlapping slices are typically acquired using multiple passes in which each pass is comprised of multiple slices with slice-to-slice gaps. Combination of slices from all passes provides the desired sampling. For enhancement of through-plane resolution with super resolution or for reformatting into other orientations, subtle ≈1 mm motion between passes can cause objectionable "scalloping" artifact. Here we address this by subdivision of each pass into multiple segments. Interleaving of segments from the multiple passes causes all slices to be acquired over substantially the same time, reducing pass-to-pass motion effects. This was implemented in acquiring 78 overlapped T 2 FSE axial slices and studied in phantoms and in 14 prostate MRI patients. Super-resolution axial images and sagittal reformats from the original and new segmented acquisitions were evaluated by 3 uroradiologists. Results For all criteria of sagittal reformats, the segmented acquisition was statistically superior to the original. For all sharpness criteria of axial images, although the trend preferred the original acquisition, the difference was not significant. For artifact in axial images, the segmented acquisition was significantly superior. Conclusions For prostate MRI the new segmented acquisition significantly reduces the scalloping motion artifact that can be present in reformats due to long time lags between the acquisition of adjacent or overlapped slices while retaining image sharpness in the acquired axial slices.

Relapsing level of prostate-specific antigen (PSA) after initial curative-intent local therapy for organ-confined prostate cancer is often the first sign of recurrence. However, PSA level recurrence does not enable accurate differentiation of locally recurrent tumor from metastatic disease or a combination of both. Metastatic prostate cancer most frequently involves bones and lymph nodes, followed by other organs such as the liver, lung, pleura, adrenal gland, ureter, peritoneum, penis, testis, and meninges. Conventional imaging including CT and bone scintigraphy has long been the standard of care but has limited sensitivity in depicting early local recurrence or metastatic disease. Multiparametric MRI has been shown to be more sensitive in detecting locally recurrent tumor in the prostatectomy bed as well as in situ recurrence in a prostate gland that has been treated with radiation therapy or thermal ablation. In addition, lesions detected with multiparametric MRI may be amenable to targeted biopsy for definitive diagnosis of recurrence. PET/CT or PET/MRI using the U.S. Food and Drug Administration (FDA)-approved tracers carbon 11 choline or fluorine 18 fluciclovine has demonstrated markedly increased sensitivity and specificity for diagnosis of early metastatic disease such as small-volume lymph node metastasis, as have a range of investigational gallium 68 prostate-specific membrane antigen (PSMA) radioactive PET tracers. With recent advances in imaging modalities and techniques, more accurate early detection, localization, and characterization of recurrent prostate cancer have become possible. The authors present a contemporary review of the strengths and limitations of conventional and advanced imaging modalities in evaluation of patients with recurrent prostate cancer and a systematic review of the clinical and imaging features of locally recurrent and metastatic disease.©RSNA, 2020See discussion on this article by Barwick and Castellucci.

OBJECTIVE. The purpose of this article is to evaluate the MR findings of prostatic remnant after prostatectomy and estimate the prevalence of prostatic remnant in patients that undergo MRI after prostatectomy. MATERIALS AND METHODS. Sixty-six patients who had undergone radical prostatectomy with pathologically proven benign prostatic remnant between 2007 and 2017 were retrospectively reviewed. Pathologically proven benign prostatic remnant was determined on the basis of initial pathologic report. Of the 66 initial patients, 30 patients with biopsy-proven benign prostatic remnant without coexisting recurrent prostate carcinoma and three patients who underwent repeat resection for completion prostatectomy were enrolled. MRI characteristics including location, size, signal intensity on T2-weighted images and DWI, and contrast enhancement pattern were analyzed. Nine additional patients were found to have a prostatic remnant by imaging without biopsy. The prevalence of prostatic remnant among those undergoing MRI for suspected recurrence during the same period was estimated. RESULTS. Prostatic remnant was detected in 23 of 33 patients on MRI. The remaining 10 patients did not have any visible abnormality. The 23 detected lesions were located in three regions: under the vesicourethral anastomosis in five patients, in the bladder neck in 12 patients, and posterior to the bladder in six patients. On T2-weighted imaging, 17 of 23 lesions showed heterogeneous hyperintensity. On DWI, 14 lesions showed hyperintensity. Dedicated MRI studies were performed for suspected prostate cancer recurrence in 2466 patients during the same period. Prevalence of exclusively benign prostate remnant detectable on MRI was approximately 1% of that population (23/2466-35/2466), and overall prevalence of any prostate remnant detectable on MRI was 3% (75/2466). CONCLUSION. Benign prostate remnant after prostatectomy occurs at three common sites and typically shows heterogeneous hyperintensity on T2-weighted imaging. The prevalence of detectable prostatic remnant in men who undergo MRI for suspected recurrence was approximately 1-3%.

Our goal was to evaluate the long-term prognostic value of magnetic resonance imaging of the prostatectomy bed in patients with biochemical recurrence after radical prostatectomy for prostate cancer.Men with biochemical recurrence after radical prostatectomy who were studied by prostatectomy bed magnetic resonance imaging for suspected local recurrence were retrospectively evaluated. Locally recurrent tumors were noted and measured from imaging reports. Patients with nodal/bone lesions at the time of imaging were excluded. Kaplan-Meier and Cox regression analyses were used to assess systemic progression-free and prostate cancer-specific survival.A total of 896 men were enrolled and the imaging positive and negative groups for local recurrent tumor consisted of 441 and 455 men, respectively. On univariate analysis, preoperative prostate specific antigen (p=0.02), clinical tumor stage (p=0.006), pathological Gleason score from prostatectomy (p=0.02), subsequent salvage radiotherapy (p0.001), biochemical recurrence to magnetic resonance imaging time interval (p0.001), age at magnetic resonance imaging (p=0.047) and prostate specific antigen at magnetic resonance imaging (p0.001) were significantly different between magnetic resonance imaging positive and negative groups. Patients with negative magnetic resonance imaging results had worse systemic progression-free survival rates (p=0.025) and better prostate cancer-specific survival (p=0.016) than those with recurrence. Larger lesion size significantly increased risk of prostate cancer death (hazard ratio: 1.07; p0.001). On multivariable analysis, pathological Gleason scores ≥7 were independent prognostic factors of systemic progression (p0.05).Prostatectomy bed magnetic resonance imaging provides long-term prognostic information for the evaluation of patients with biochemical recurrence after prostatectomy. Post-prostatectomy patients with recurrent lesions on imaging had longer progression-free survival but shorter prostate cancer-specific survival compared to those without lesions. Additionally, those with larger lesions were associated with poorer cancer-specific survival.

Purpose To compare the inter-observer variability of apparent diffusion coefficient (ADC) values of prostate lesions measured by 2D-region of interest (ROI) with and without specific measurement instruction. Methods Forty lesions in 40 patients who underwent prostate MR followed by targeted prostate biopsy were evaluated. A multi-reader study (10 readers) was performed to assess the agreement of ADC values between 2D-ROI without specific instruction and 2D-ROI with specific instruction to place a 9-pixel size 2D-ROI covering the lowest ADC area. The computer script generated multiple overlapping 9-pixel 2D-ROIs within a 3D-ROI encompassing the entire lesion placed by a single reader. The lowest mean ADC values from each 2D-small-ROI were used as reference values. Inter-observer agreement was assessed using the Bland-Altman plot. Intraclass correlation coefficient (ICC) was assessed between ADC values measured by 10 readers and the computer-calculated reference values. Results Ten lesions were benign, 6 were Gleason score 6 prostate carcinoma (PCa), and 24 were clinically significant PCa. The mean±SD ADC reference value by 9-pixel-ROI was 733 ± 186 (10−6 mm2/s). The 95% limits of agreement of ADC values among readers were better with specific instruction (±112) than those without (±205). ICC between reader-measured ADC values and computer-calculated reference values ranged from 0.736–0.949 with specific instruction and 0.349–0.919 without specific instruction. Conclusion Interobserver agreement of ADC values can be improved by indicating a measurement method (use of a specific ROI size covering the lowest ADC area).

Objective The aim of this study was to compare the contrast enhancement differences between gadolinium-based and iodine-based contrast agents at different single-energy tube potentials and dual-energy-based virtual monochromatic energies. In addition, we describe the application of a gadolinium-based contrast agent in computed tomography (CT) cystography for a patient with contraindications to iodine. Methods A phantom study was performed using 3 iodine samples (concentrations: 5, 10, and 15 mgI/mL) and 3 gadolinium samples (concentrations: 3.3, 6.6, and 9.9 mgGd/mL). The prepared phantom was scanned by a dual-energy CT (DECT) at 80, 100, 120, and 140 kV in the single-energy mode and at 100/Sn140 kV in the dual-energy mode. Virtual monoenergetic images (VMIs) at 50 keV were generated from the DECT scan. In addition, a DECT cystogram was performed using a gadolinium-based contrast agent in a patient with contraindications to iodinated contrast. Results Strong linear correlations between mean signal of contrast enhancement and mass concentration were found for both iodine and gadolinium samples across all single-energy CT (SECT) and DECT scan conditions. The VMI at 50 keV provided the highest contrast enhancement for both types of contrast samples at each concentration level, and single-energy CT scans at low-energy beams showed higher contrast enhancement than higher beam energies. In addition, the contrast enhancement for pure gadolinium solution was constantly higher than pure iodine solution at an identical mass concentration level. The DECT cystogram was performed with excellent technical success. The urinary bladder was appropriately distended with intravesical contrast measuring 606 Hounsfield units and no evidence of bladder leak or fistula. Conclusions Imaging of gadolinium-based contrast agents is improved using a DECT technique, with VMI at 50 keV providing the highest contrast enhancement among our tested parameters. Dual-energy CT cystography using a gadolinium-based agent can be a safe and effective alternative when iodinated agents are contraindicated.

Lower urinary tract symptoms due to benign prostatic enlargement have a high prevalence in men over 50 years of age. Diagnosis is made with a combination of focused history and physician examination and validated symptom questionnaires. Urodynamic studies can help to differentiate storage from voiding abnormalities. Pelvic ultrasound may be indicated to assess bladder volume and wall thickness. Other imaging modalities, including prostate MRI, are usually not indicated in the initial workup and evaluation of uncomplicated lower urinary tract symptoms from an enlarged prostate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Urothelial cancer is the second most common cancer, and cause of cancer death, related to the genitourinary tract. The goals of surveillance imaging after the treatment of urothelial cancer of the urinary bladder are to detect new or previously undetected urothelial tumors, to identify metastatic disease, and to evaluate for complications of therapy. For surveillance, patients can be stratified into one of three groups: (1) nonmuscle invasive bladder cancer with no symptoms or additional risk factors; (2) nonmuscle invasive bladder cancer with symptoms or additional risk factors; and (3) muscle invasive bladder cancer. This article is a review of the current literature for urothelial cancer and resulting recommendations for surveillance imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

An acute scrotum is defined as testicular swelling with acute pain and can reflect multiple etiologies including epididymitis or epididymo-orchitis, torsion of the spermatic cord, or torsion of the testicular appendages. Quick and accurate diagnosis of acute scrotum and its etiology with imaging is necessary because a delayed diagnosis of torsion for as little as 6 hours can cause irreparable testicular damage. Ultrasound duplex Doppler of the scrotum is usually appropriate as the initial imaging for the acute onset of scrotal pain without trauma or antecedent mass in an adult or child. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The purpose of this study is to report the patient safety and image quality of 1.5-T multiparametric MRI of the prostate in patients with cardiac implantable electronic devices (CIEDs).In this retrospective study, a database was searched to identify prostate multiparametric 1.5-T MRI examinations performed with endorectal coils for patients with CIEDs from 2012 to 2016 (study group) and matched patients without CIEDs (control group). Clinical safety in the study group was reviewed. The specific absorption rate (SAR) and signal-to-noise ratio (SNR) were measured in both groups. Imaging quality and artifact on T2-weighted images, DW images, and dynamic contrast-enhanced images were rated on a 5-point scale by two independent readers.The study group consisted of total 28 multiparametric MRI examinations in 25 patients. There were no serious device-related adverse effects observed (0/28; 0%), and the estimated whole-body SAR in the study group was never greater than 1.5 W/kg. The SNR values tended to be lower in the study group than in the control group. However, overall perceived image preferences and influences of artifacts on image quality for the study group were not significantly different from those for the control group (p0.05), which were rated above average (rating 3) by both readers 1 and 2.Multiparametric 1.5-T MRI examination of the prostate can be safely performed in selected patients with CIEDs under controlled conditions with applicable image quality while maintaining a SAR less than 1.5 W/kg.

Purpose The goal of this work is to demonstrate 1 mm through-plane resolution in multislice T2SE MRI using k Z -space processing of overlapping slices and show applicability in prostate MRI. Methods Multiple overlapped slices are acquired and Fourier transformed in the slice-select direction. The slice profile is incorporated into a Tikhonov-regularized reconstruction. Through-plane resolution is tested in a resolution phantom. An anthropomorphic prostate phantom is used to study the SNR, and results are compared with theoretical prediction. The proposed method is tested in 16 patients indicated for clinical prostate MRI who gave written informed consent as overseen by our IRB. The "proposed" vs. "reference" multislice images are compared using multiple evaluation criteria for through-plane resolution. Results The modulation transfer function (MTF) plots of the resolution phantom show good modulation at frequency 0.5 lp/mm, demonstrating 1 mm through-plane resolution restoration. The SNR measurements experimentally match the theoretically predicted values. The radiological evaluation shows that the proposed method is superior to the reference method for five criteria of sharpness but inferior with respect to artifacts. Conclusions In conjunction with overlapped slices a k Z -space-based reconstruction approach can be used to improve through-plane resolution in multislice T2SE MRI. 1 mm resolution is demonstrated from 3.2 mm thick slices. The in vivo results from prostate MRI show improved sharpness when compared to the standard multislice method.

Radiographs play an important role in ascertaining appropriate placement of the intra-aortic balloon pump catheter. This imaging essay highlights correct and incorrect positioning of these catheters, with emphasis on the variability of radiopaque markers used with different catheter models and on axillary versus femoral catheter placement routes. Keywords: Conventional Radiography, CT, Percutaneous, Cardiac, Vascular, Aorta, Anatomy, Cardiac Assist Devices, Catheters © RSNA, 2022

Background Due to their easy accessibility, CT scans have been increasingly used for investigation of gastrointestinal (GI) bleeding. Purpose To estimate the performance of a dual-phase, dual-energy (DE) GI bleed CT protocol in patients with overt GI bleeding in clinical practice and examine the added value of portal phase and DE images. Materials and Methods Consecutive patients with GI bleeding underwent a two-phase DE GI bleed CT protocol. Two gastroenterologists established the reference standard. Performance was estimated using clinical CT reports. Three GI radiologists rated confidence in GI bleeding in a subset of 62 examinations, evaluating first mixed kV arterial images, then after examining additional portal venous phase images, and finally after additional DE images (virtual non-contrast and virtual monoenergetic 50 keV images). Results 52 of 176 patients (29.5%) had GI bleeding by the reference standard. The overall sensitivity, specificity, and positive and negative predictive values of the CT GI bleed protocol for detecting GI bleeding were 65.4%, 89.5%, 72.3%, and 86.0%, respectively. In patients with GI bleeding, diagnostic confidence of readers increased after adding portal phase images to arterial phase images ( p = 0.002), without additional benefit from dual energy images. In patients without GI bleeding, confidence in luminal extravasation appropriately decreased after adding portal phase, and subsequently DE images ( p = 0.006, p = 0.018). Conclusion A two-phase DE GI bleed CT protocol had high specificity and negative predictive value in clinical practice. Portal venous phase images improved diagnostic confidence in comparison to arterial phase images alone. Dual-energy images further improved radiologist confidence in the absence of bleeding.

Aim To determine the operational characteristics of pelvic magnetic resonance imaging (MRI) prior to salvage radiation therapy (SRT) for biochemically recurrent prostate cancer following radical prostatectomy. Methods and materials We reviewed the medical records of 386 patients who underwent MRI prior to SRT. We assessed associations of pre-SRT MRI findings with biochemical recurrence (BCR), distant metastasis (DM), prostate cancer-specific mortality (PCSM), and salvage androgen deprivation therapy (ADT) use following SRT. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRI for detecting local recurrence were also calculated. Results Pre-SRT MRI was positive for local recurrence in 216 patients (56%), indeterminate in 46 (12%), and negative in 124 (32%). On univariate analysis, BCR following SRT was significantly less likely for patients with positive (HR: 0.58, 95% CI: 0.42–0.8) or indeterminate (HR: 0.6: 0.36–1) MRI findings, compared to patients with negative imaging (p = 0.003). These associations remained significant on multivariate analysis (p For the entire cohort, the sensitivity of MRI for local recurrence was 61.0% (53.5–68.1%), specificity 60.0% (44.3–73.0%), PPV 86.1% (78.9–91.5%) and NPV 27.6% (19.0–37.5%). Sensitivity of MRI was better in men with higher pre-SRT PSA (80.0% for PSA > 1.0), and specificity was improved with lower pre-SRT PSA (73.9% for PSA 0.1–0.5). Conclusions Positive or indeterminate MRI findings prior to SRT were associated with improved biochemical control following SRT, across PSA levels. The sensitivity and specificity of MRI for local recurrence were 61% and 58.7%, respectively.

Purpose Previous studies have indicated an increased risk of prostate carcinoma (PCa) associated with inflammatory bowel disease (IBD). Prostate MRI of IBD patients could be expected to show a mixture of inflammation as well as higher than normal rates of PCa, which could impact interpretation and MRI performance. The purpose of this study is to evaluate the characteristics of prostate MRI in patients with IBD. Methods 3140 patients with prostate MRI were evaluated. Coexisting IBD, PI-RADS score, and pathological results of prostate lesions (clinically significant PCa [csPCa]: Gleason score [GS] 7+, Non-csPCa: benign or GS 6) were assessed. The distribution of PI-RADS scoring and pathological result was assessed by chi-square test. Results 71 patients had IBD (IBD group), whereas the remaining 3069 patients did not (Non-IBD group). The proportion of abnormal MRI (PI-RADS 3, 4 or 5) was 51 % (36/71) in IBD group and 47 % (1436/3069) in Non-IBD groups (p = 0.513). Total of 1285 patients underwent biopsy or prostatectomy. The proportion of csPCa at pathology was 35 % (12/34) in IBD group and 56 % (699/1251) in non-IBD groups (p = 0.017). The positive predictive value of abnormal MRI for csPCa was significantly lower in IBD group (39 %, 19/31) compared to Non-IBD group (63 %, 657/1047) (p = 0.007). Conclusion The proportion of csPCa at pathology and positive predictive value of abnormal MR for csPCa were lower in patients with IBD group compared to Non-IBD group.

Item does not contain fulltext Background Prostate MRI is used widely in clinical care for guiding tissue sampling, active surveillance, and staging. The Prostate Imaging Reporting and Data System (PI-RADS) helps provide a standardized probabilistic approach for identifying clinically significant prostate cancer. Despite widespread use, the variability in performance of prostate MRI across practices remains unknown. Purpose To estimate the positive predictive value (PPV) of PI-RADS for the detection of high-grade prostate cancer across imaging centers. Materials and Methods This retrospective cross-sectional study was compliant with the HIPAA. Twenty-six centers with members in the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel submitted data from men with suspected or biopsy-proven untreated prostate cancer. MRI scans were obtained between January 2015 and April 2018. This was followed with targeted biopsy. Only men with at least one MRI lesion assigned a PI-RADS score of 2-5 were included. Outcome was prostate cancer with Gleason score (GS) greater than or equal to 3+4 (International Society of Urological Pathology grade group >/=2). A mixed-model logistic regression with institution and individuals as random effects was used to estimate overall PPVs. The variability of observed PPV of PI-RADS across imaging centers was described by using the median and interquartile range. Results The authors evaluated 3449 men (mean age, 65 years +/- 8 [standard deviation]) with 5082 lesions. Biopsy results showed 1698 cancers with GS greater than or equal to 3+4 (International Society of Urological Pathology grade group >/=2) in 2082 men. Across all centers, the estimated PPV was 35% (95% confidence interval [CI]: 27%, 43%) for a PI-RADS score greater than or equal to 3 and 49% (95% CI: 40%, 58%) for a PI-RADS score greater than or equal to 4. The interquartile ranges of PPV at these same PI-RADS score thresholds were 27%-44% and 27%-48%, respectively. Conclusion The positive predictive value of the Prostate Imaging and Reporting Data System was low and varied widely across centers. (c) RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Milot in this issue.

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which presents an unprecedented challenge to medical providers worldwide. Although most SARS-CoV-2-infected individuals manifest with a self-limited mild disease that resolves with supportive care in the outpatient setting, patients with moderate to severe COVID-19 will require a multidisciplinary collaborative management approach for optimal care in the hospital setting. Laboratory and radiologic studies provide critical information on disease severity, management options, and overall prognosis. Medical management is mostly supportive with antipyretics, hydration, oxygen supplementation, and other measures as dictated by clinical need. Among its medical complications is a characteristic proinflammatory cytokine storm often associated with end-organ dysfunction, including respiratory failure, liver and renal insufficiency, cardiac injury, and coagulopathy. Specific recommendations for the management of these medical complications are discussed. Despite the issuance of emergency use authorization for remdesivir, there are still no proven effective antiviral and immunomodulatory therapies, and their use in COVID-19 management should be guided by clinical trial protocols or treatment registries. The medical care of patients with COVID-19 extends beyond their hospitalization. Postdischarge follow-up and monitoring should be performed, preferably using telemedicine, until the patients have fully recovered from their illness and are released from home quarantine protocols.

PURPOSE Provide evidence- and expert-based recommendations for optimal use of imaging in advanced prostate cancer. Due to increases in research and utilization of novel imaging for advanced prostate cancer, this guideline is intended to outline techniques available and provide recommendations on appropriate use of imaging for specified patient subgroups. METHODS An Expert Panel was convened with members from ASCO and the Society of Abdominal Radiology, American College of Radiology, Society of Nuclear Medicine and Molecular Imaging, American Urological Association, American Society for Radiation Oncology, and Society of Urologic Oncology to conduct a systematic review of the literature and develop an evidence-based guideline on the optimal use of imaging for advanced prostate cancer. Representative index cases of various prostate cancer disease states are presented, including suspected high-risk disease, newly diagnosed treatment-naïve metastatic disease, suspected recurrent disease after local treatment, and progressive disease while undergoing systemic treatment. A systematic review of the literature from 2013 to August 2018 identified fully published English-language systematic reviews with or without meta-analyses, reports of rigorously conducted phase III randomized controlled trials that compared ≥ 2 imaging modalities, and noncomparative studies that reported on the efficacy of a single imaging modality. RESULTS A total of 35 studies met inclusion criteria and form the evidence base, including 17 systematic reviews with or without meta-analysis and 18 primary research articles. RECOMMENDATIONS One or more of these imaging modalities should be used for patients with advanced prostate cancer: conventional imaging (defined as computed tomography [CT], bone scan, and/or prostate magnetic resonance imaging [MRI]) and/or next-generation imaging (NGI), positron emission tomography [PET], PET/CT, PET/MRI, or whole-body MRI) according to the clinical scenario.

Acute gastrointestinal (GI) bleeding is common and necessitates rapid diagnosis and treatment. Bleeding can occur anywhere throughout the GI tract and may be caused by many types of disease. The variety of enteric diseases that cause bleeding and the tendency for bleeding to be intermittent may make it difficult to render a diagnosis. The workup of GI bleeding is frequently prolonged and expensive, with examinations commonly needing to be repeated. The use of computed tomography (CT) for evaluation of acute GI bleeding is gaining popularity because it can be used to rapidly diagnose active bleeding and nonbleeding bowel disease. The CT examinations used to evaluate acute GI bleeding include CT angiography and multiphase CT enterography. Understanding the clinical evaluation of acute GI bleeding, including the advantages and limitations of endoscopic evaluation, is necessary for the appropriate selection of patients who may benefit from CT. Multiphase CT enterography is used primarily to evaluate stable patients who have undergone upper and lower endoscopy without identification of a bleeding source. CT angiography is used to examine stable and unstable patients who respond to resuscitation, are believed to be actively bleeding, and are considered unlikely to have an upper GI source of hemorrhage. In the emergent setting, CT may yield critical information regarding the presence, location, and cause of active bleeding-data that can guide the choice of subsequent therapy. Recent developments in the use of and techniques for performing CT angiography have made it a potential first-line tool for evaluating acute GI bleeding. ©RSNA, 2018.

Muscle-invasive bladder cancer (MIBC) has a tendency toward urothelial multifocality and is at risk for local and distant spread, most commonly to the lymph nodes, bone, lung, liver, and peritoneum. Pretreatment staging of MIBC should include imaging of the urothelial upper tract for synchronous lesions; imaging of the chest, abdomen, and pelvis for metastases; and MRI pelvis for local staging. CT abdomen and pelvis without and with contrast (CT urogram) is recommended to assess the urothelium and abdominopelvic organs. Pelvic MRI can improve local bladder staging accuracy. Chest imaging is also recommended with chest radiograph usually being adequate. FDG-PET/CT may be appropriate to identify nodal and metastatic disease. Chest CT may be useful in high-risk patients and those with findings on chest radiograph. Nonurogram CT and MRI of the abdomen and pelvis are usually not appropriate, and neither is radiographic intravenous urography, Tc-99m whole body bone scan, nor bladder ultrasound for pretreatment staging of MIBC. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diagnosis and management of prostate cancer post treatment is a large and complex problem, and care of these patients requires multidisciplinary involvement of imaging, medical, and surgical specialties. Imaging capabilities for evaluation of men with recurrent prostate cancer are rapidly evolving, particularly with PET and MRI. At the same time, treatment options and capabilities are expanding and improving. These recommendations separate patients into three broad categories: (1) patients status post–radical prostatectomy, (2) clinical concern for residual or recurrent disease after nonsurgical local and pelvic treatments, and (3) metastatic prostate. This article is a review of the current literature regarding imaging in these settings and the resulting recommendations for imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Limited data are available to guide the use of abdominal radiographs in the setting of constipation, especially in adults. Anecdotally, there has been a recent increase in such examinations. We sought to determine ordering trends for abdominal radiographs ordered to assess constipation, as well as to better understand referring clinician and radiologist opinion on such examinations. We conducted a retrospective review of all abdominal radiographs performed between 2004 and 2014 at our institution with a primary indication of constipation. We also surveyed clinicians and radiologists regarding their opinions and practices involving such examinations. Constipation radiograph volume increased by approximately 56% over the 10-year period, while volume of all other abdominal radiographs decreased. Growth was greatest in adult females. Both radiologists and clinicians agree that constipation is a clinical diagnosis and are neutral as to whether radiographs help make the diagnosis. Clinicians somewhat agree that radiographs are helpful in determining management and find quantitation of stool burden within the radiology report helpful. Radiologists tend to find radiographs inaccurate at quantifying stool burden. Clinicians tend to agree that the increasing use of radiographs for constipation is appropriate while radiologists disagree. Education on these trends did not affect the intended future ordering practice of referring clinicians. Constipation abdominal radiograph volume has disproportionately increased, especially in adult women. Clinicians and radiologists agree that constipation is a clinical diagnosis. Otherwise, the groups tend to have differing opinions on the utility of such examinations. Clinicians indicated no intention to change their ordering practices. Further investigation is needed to better define the role of imaging for this indication, including how the radiologist may best interpret and report such examinations.

To assess whether acquisition with 32 receiver coils rather than the vendor-recommended 12 coils provides significantly improved performance in 3D dynamic contrast-enhanced MRI (DCE-MRI) of the prostate.The study was approved by the institutional review board and was compliant with HIPAA. 50 consecutive male patients in whom prostate MRI was clinically indicated were prospectively imaged in March 2015 with an accelerated DCE-MRI sequence in which image reconstruction was performed using 12 and 32 coil elements. The two reconstructions were compared quantitatively and qualitatively. The first was done using signal-to-noise ratio (SNR) and g-factor analysis to assess sensitivity to acceleration. The second was done using a five-point scale by two experienced radiologists using criteria of perceived SNR, artifact, sharpness, and overall preference. Significance was assessed with the Wilcoxon signed rank test. Extension to T2-weighted spin-echo and diffusion sequences was assessed in phantom studies.Reconstruction using 32 vs. 12 coil elements provided improved performance in DCE-MRI based on intrinsic SNR (18% higher) and g-factor statistics (14% higher), with a median 32% higher overall SNR within the prostate volume over all subjects. Reconstruction using 32 coils was qualitatively rated significantly improved (p0.001) vs. 12 coils on the basis of perceived SNR and radiologist preference and equivalent for sharpness and artifact. Phantom studies suggested the improvement in intrinsic SNR could extend to T2-weighted spin-echo and diffusion sequences.Reconstruction of 3D accelerated DCE-MRI studies of the prostate using 32 independent receiver coils provides improved overall performance vs. using 12 coils.

In the present report we aimed to analyze the incremental value of preoperative magnetic resonance imaging (MRI), in addition to clinical variables and clinically-derived nomograms, in predicting outcomes radical prostatectomy (RP). All Mayo Clinic RP patients who underwent preoperative 1.5-Tesla MRI with endo-rectal coil from 2003 to 2013 were identified. Clinical and histopathological variables were used to calculate Partin estimates and Cancer of the Prostate Risk Assessment (CAPRA) score. MRI results in terms of extracapsular extension (ECE), seminal vesicle invasion (SVI), and lymph-node invasion (N+) were recorded. Using RP pathology as gold standard, we developed multivariate logistic regression models based on clinical variables, Partin Tables, and CAPRA score, and assessed their predictive accuracy before and after the addition of MRI results. Five hundred and one patients were included. MRI + clinical models outperformed clinical-based models alone for all outcomes. Comparing Partin and Partin + MRI predictive models, the areas under the curve were 0.61 versus 0.73 for ECE, 0.75 versus 0.82 for SVI, and 0.82 versus 0.85 for N+. Comparing CAPRA and CAPRA + MRI models, the areas under the curve were 0.69 versus 0.77 for ECE, 0.75 versus 0.83 for SVI, and 0.82 versus 0.85 for N+. Our data show that MRI can improve clinical-based models in prediction of nonorgan confined disease, particularly for ECE and SVI. Patient summary Magnetic resonance imaging, together with clinical information, can be useful in preoperative assessment before radical prostatectomy.

Despite the frequent statement that "most men die with prostate cancer, not of it," the reality is that prostate cancer is second only to lung cancer as a cause of death from malignancy in American men. The primary goal during baseline evaluation of prostate cancer is disease characterization, that is, establishing disease presence, extent (local and distant), and aggressiveness. Prostate cancer is usually diagnosed after the finding of a suspicious serum prostate-specific antigen level or digital rectal examination. Tissue diagnosis may be obtained by transrectal ultrasound-guided biopsy or MRI-targeted biopsy. The latter requires a preliminary multiparametric MRI, which has emerged as a powerful and relatively accurate tool for the local evaluation of prostate cancer over the last few decades. Bone scintigraphy and CT are primarily used to detect bone and nodal metastases in patients found to have intermediate- or high-risk disease at biopsy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Purpose: We identify sites and patterns of cancer recurrence in patients with post-prostatectomy biochemical relapse using 11C-choline positron emission tomography/computerized tomography and endorectal coil multiparametric magnetic resonance imaging.Materials and Methods: Between January 2008 and June 2015, 2,466 men underwent choline positron emission tomography for suspected prostate cancer relapse at our institution. Of these men 202 did not receive hormone or radiation therapy, underwent imaging with choline positron emission tomography and multiparametric magnetic resonance imaging, and were found to have disease recurrence. Overall patterns of recurrence were described, and factors associated with local only recurrence were evaluated using univariable and multivariable logistic regression.Results: Median prostate specific antigen at positive scan was 2.3 ng/ml (IQR 1.4–5.5) with a median time from prostate specific antigen relapse to lesion visualization of 15 months (IQR 4.8–34.2). Of these 202 me...

Objectives The value of multiparametric magnetic resonance imaging (mpMRI) in staging prostate cancer (PCa) before salvage prostatectomy is currently unclear because of the minimal data comparing mpMRI results to final pathologic stage at surgery. The aim of the study is to determine the diagnostic performance of mpMRI in characterizing viable recurrent tumor and lymph node metastasis following radiation therapy (RT) failure. Methods and materials Between January 2007 and July 2014, 19 patients with biopsy-proven recurrent PCa after primary RT underwent 3T mpMRI and subsequent salvage prostatectomy with extended pelvic lymphadenectomy. mpMRI images were independently reviewed by 2 genitourinary MRI radiologists (R1 and R2), blinded to the pathology results, to evaluate extraprostatic extension (EPE), seminal vesicle invasion (SVI), and pelvic lymph node metastasis (PLNM). Sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic curves, and interobserver agreement (R1 and R2) were evaluated for each outcome on a per-patient basis. Final pathologic results were used as a gold standard for comparison in all patients. A multivariate analysis was conducted to assess the relationship between the index lesion's apparent diffusion coefficient value and its enhancement characteristics with the Gleason score. Results EPE was found in 14 (73.7%) patients, SVI in 13 (68.4%), and PLNM in 5 (26.3%). mpMRI sensitivity for PLNM was 60.0% (R1 and R2) with specificity of 85.7% (R1) and 92.8% (R2). With regards to SVI, the sensitivity was 61.5% (R1) and 76.9% (R2), with a specificity of 66.6% (R1 and R2). Sensitivity for EPE was 50.0% (R1) and 71.43% (R2), with a specificity of 80.0% (R1) and 100.00% (R2). No significant associations were found at multivariate analysis. The evaluation of PLNM, SVI, and PCa recurrence within the prostate demonstrated moderate interobserver agreement (κ, 0.51-0.57). Conclusions mpMRI has good accuracy for detecting PLNM, SVI, and EPE after RT. mpMRI provides useful information in locally recurrent PCa following primary radiation therapy.

To evaluate the relationship between imperceptible T1 enhancement of papillary renal cell carcinoma (pRCC) on MR and intratumoral hemosiderin deposition.One hundred ten pRCCs (≤ 7 cm) were evaluated by MR with in- and opposed-phase spoiled gradient echo (GRE) and T1-weighted spoiled GRE with fat suppression before and after contrast. Hemosiderin deposition was assessed by SIFive (5%), 10 (9%), and 95 (86%) tumors were categorized as grades 1, 2, and 3 enhancement, respectively. The mean SIpRCC with no subjective enhancement on contrast-enhanced MR showed hemosiderin deposition evident by lower SI• 5% of papillary renal cell carcinoma showed imperceptible enhancement on contrast-enhanced MR. • Hemosiderin deposition in papillary renal cell carcinoma might mask the tumor enhancement on contrast-enhanced MR due to T2/T2*-shortening effects. • A renal lesion with extensive hemosiderin deposition but no perceptible enhancement on MR should be considered suspicious for papillary renal cell carcinoma.

Pathology of Vaping-Associated Lung Injury This letter describes findings in 17 patients with a history of vaping who had lung biopsies after presenting with symptoms and bilateral pulmonary opacit...

Acute mesenteric ischemia (AMI) is a life-threatening condition that often presents with abdominal pain. Early diagnosis with contrast-enhanced computed tomography and revascularization can reduce the overall mortality in AMI. This article reviews practical etiological classification, pathophysiology of imaging manifestations and common pitfalls in intestinal ischemia.

Lower urinary tract injury is most commonly the result of blunt trauma but can also result from penetrating or iatrogenic trauma. Clinical findings in patients with a mechanism of penetrating trauma to the lower urinary tract include lacerations or puncture wounds of the pelvis, perineum, buttocks, or genitalia, as well as gross hematuria or inability to void. CT cystography or fluoroscopy retrograde cystography are usually the most appropriate initial imaging procedures in patients with a mechanism of penetrating trauma to the lower urinary tract. CT of the pelvis with intravenous contrast, pelvic radiography, fluoroscopic retrograde urethrography, and CT of the pelvis without intravenous contrast may be appropriate in some cases. Arteriography, radiographic intravenous urography, CT of the pelvis without and with intravenous contrast, ultrasound, MRI, and nuclear scintigraphy are usually not appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

INTRODUCTION AND OBJECTIVES:Prostate MRI is commonly used to evaluate a rising PSA after a prostate biopsy. However, the optimal timing of post-biopsy MRI is debated due to conflicting reports on t...

An acute scrotum is defined as testicular swelling with acute pain and can reflect multiple etiologies including epididymitis or epididymo-orchitis, torsion of the spermatic cord, or torsion of the testicular appendages. Quick and accurate diagnosis of acute scrotum and its etiology with imaging is necessary because a delayed diagnosis of torsion for as little as 6 hours can cause irreparable testicular damage. Ultrasound duplex Doppler of the scrotum is usually appropriate as the initial imaging for the acute onset of scrotal pain without trauma or antecedent mass in an adult or child. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Background Detection of small renal calculi has benefitted from recent advances in computed tomography (CT) scanner design. Information regarding observer performance when using state-of-the-art CT scanners for this application is needed. Purpose To assess observer performance and the impact of radiation dose for detection and size measurement of Material and Methods Twenty-nine Results Mean calculus size was 2.2 ± 0.7 mm. The CTDIvol values corresponding to the automatic exposure control settings of 160, 80, 40, 25, and 10 Quality Reference mAs (QRM) were 15.2, 7.9, 4.2, 2.7, and 1.3 mGy, respectively. JAFROC FOM was ≥ 0.97 at ≥ 80 QRM, ≥ 0.89 at ≥ 25 QRM, and was inferior to routine dose (160 QRM) at 10 QRM (0.72, P Conclusion Using low dose renal CT with iterative reconstruction and ≥ 25 QRM results in high sensitivity, but false positive detections increase for some readers at very low dose levels (≤ 40 QRM). At very low doses with iterative reconstruction, measured calculus size will artifactually decrease.

The objective of our study was to compare a flavored beverage containing a thickening agent for enterography with a low-Hounsfield-value barium suspension for side effects, taste, subjects' willingness to repeat the drinking protocol, and small-bowel distention.The following five drinking protocols were administered to 10 volunteers: 1000 mL of flavored beverage followed by 350 mL of water, 1500 mL of flavored beverage, 900 mL of low-Hounsfield-value barium suspension followed by 450 mL of water, 1350 mL of low-Hounsfield-value barium suspension followed by 150 mL of water, and 1500 mL of water. MR images were obtained 50 and 60 minutes after initiation of drinking. Subjects completed a questionnaire evaluating the side effects, the taste of the drink, and their willingness to repeat the drinking protocol. Reviewers assigned scores evaluating small-bowel distention and ranked the examinations in order of preference.There was no significant difference in nausea or vomiting among the protocols (p = 0.20 and 0.42, respectively), but larger volumes of flavored beverage and low-Hounsfield-value barium suspension resulted in more cramping and diarrhea (p = 0.001 and 0.002, respectively). The taste of the low-Hounsfield-value barium suspension was rated the worst (p0.0001). The subjects' willingness to repeat the drinking protocol was highest for the 1000 mL of flavored beverage or water alone (p0.05). There were no significant differences in subjective small-bowel distention except that water was rated the worst by two of the three readers (p0.02). There was no significant difference in the diameter of the most dis-tended small bowel for any segment or reader (p0.23).A flavored beverage containing a thickening agent has a similar side effect profile and results in equivalent small-bowel distention compared with a low-Hounsfield-value barium suspension, but subjects rate taste and their willingness to repeat the drinking protocol higher for this new agent.

Recurrent prostate cancer following primary treatment is common, and the population of men with biochemical recurrence is complex. Conventional management of recurrent prostate cancer involves nontargeted and/or systemic therapies, without defining an individual patient's specific disease. However, recent advances in imaging enable a shift in the management of recurrent prostate cancer to targeted, patient-specific approaches. Specifically, MRI can detect and define local prostate cancer recurrence early in the course of disease, and prostate-specific PET imaging greatly improves nodal staging and can detect previously unknown distant metastases. The significant advances in the imaging of both local and distant tumor recurrences allows for specific selection of treatment options tailored to patients and their disease with less associated morbidity.