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Although prostate cancer can be effectively treated, recurrent or residual disease after therapy is not uncommon and is usually detected by a rise in prostate-specific antigen. Patients with biochemical prostate-specific antigen relapse should undergo a prompt search for the presence of local recurrence or distant metastatic disease, each requiring different forms of therapy. Various imaging modalities and image-guided procedures may be used in the evaluation of these patients. Literature on the indications and usefulness of these radiologic studies and procedures in specific clinical settings is reviewed. The ACR Appropriateness Criteria((R)) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. [ABSTRACT FROM AUTHOR]

Obstructive voiding symptoms are most commonly due to prostatic hyperplasia, but other causes include bladder neck contractures, prostatic carcinomas, neurogenic bladder, and urethral stricture. Symptoms include hesitancy, dribbling, decreased force of stream, and postvoid fullness. Imaging is useful in evaluating the presence and degree of hydronephrosis, estimation of renal function, evaluation of the bladder and prostate, and detection of incidental upper tract malignancies or stones. Various modalities have been used for evaluation of the cause of obstruction. Literature on the indications and usefulness of these radiologic studies for obstructive voiding symptoms in different clinical settings is reviewed. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) is a burgeoning problem globally, and more than a billion adults were affected as of 2016, with 1.2 million people dying from renal failure in 2017. To arrest the seemingly relentless progression of CKD to renal failure, there is a need to detect CKD early in the community. A community-based study was carried out to look at the prevalence and risk factors of CKD. Anthropometric and other clinical variables were measured. Blood samples were taken for determining creatinine, uric acid, urea, and lipids. CKD was defined as an estimated glomerular filtration rate of ≤60 mL/min/1.73 m2. Electrocardiograms and renal ultrasound scans were performed. In total, 201 people were recruited. Those with CKD had a male:female ratio of 1:3.9 and were older. The prevalence of autosomal-dominant polycystic kidney disease and CKD was 531.9 persons/100,000 population and 46.3%, respectively. Systolic blood pressure, pulse pressure, total cholesterol, triglycerides, high-density lipoprotein (HDL), uric acid, QTc interval, and electrocardiographic left ventricular hypertrophy were higher in those with CKD. Age, female sex, and HDL were independently associated with CKD. There was a steep rise in CKD at the community level. Increased awareness of CKD and prompt interventions are therefore imperative., (Copyright © 2022 Copyright: © 2022 Saudi Journal of Kidney Diseases and Transplantation.)

Cancer patients have a high risk of thromboembolic events including splenic infarct (SI). However, risk factors for SI in cancer patients are poorly understood, and the utility of systemic anticoagulation in such patients is uncertain. We performed a retrospective cohort study of all cancer patients with SI treated at Yale New Haven Hospital from 2008 to 2017. Central review of radiology imaging was performed to confirm the diagnosis of SI. Baseline differences in variables among patients with and without recurrent SI were compared using Fisher's exact test, Pearson's χ 2 test, and t-test. Multivariable regression models were conducted to identify factors associated with recurrent SI. Of 206 patients with cancer and SI, 42 had a prior venous thromboembolic event, while 29 had atrial fibrillation/flutter. At a median follow-up of 11.4 months (range: 0-142.3 months), 152 patients underwent follow-up imaging, with only 6 having recurrent SI. The use of anticoagulation after initial SI was associated with a nonsignificant increase in recurrent SI (p = 0.054) and was not associated with development of venous thromboembolism after SI (p = 0.414). In bivariate analyses, the risk of recurrent SI showed a significant association with lower platelet counts (p < 0.001) and with atrial fibrillation/flutter (p = 0.036). In a multivariable logistic regression model, no variables were identified that were associated with a higher risk of recurrent SI. SI in cancer patients is typically an isolated event with low recurrence risk. Anticoagulation use should be guided by other thromboembolic risk factors., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Hypertension is the commonest cardiovascular risk factor globally and is a cause of untold morbidity and mortality. However, its clinical correlates at the community level have not been well elucidated., Methods: History taking, anthropometric measurements, electrocardiograms and laboratory investigations were done for all the study subjects. Ethical approval was obtained from the institution's ethical body. Analysis was done using SPSS version 20. Two hundred people were recruited for the study. The prevalence of hypertension in the community was 58.5% with 31(15.5%) being newly diagnosed. The Body Mass Index [BMI] (28.2±6vs 25.6±5.3; P=0.003),Waist-Hip ratio (0.9±0.08 vs 0.86±0.06; p= 0.001), total cholesterol (5.675±1.8 vs 4.6±1.7, P=0.000), triglycerides (1.19±0.85 vs 0.91±0.59; p=0.019), LDL cholesterol (3.38±1.6 vs 2.66±1.5; p=0.002), heart rate (82.4±15.8 vs 76.8±11.2; p=0.018) QRS duration (84.8±13.4 vs 80.5±11.2; p=0.040), and QTc (0.423±0.041 vs 0.402±0.035; p=0.001) were higher in those with hypertension. NYHA functional class was worse in hypertensives (p=0.041). Prevalence of left ventricular hypertrophy (LVH) in hypertensives ranged from 2.6 to 48.2%, depending on the criteria used. Systolic blood pressure, pulse pressures, HDL levels and hip circumferences were higher in those with electrocardiographic LVH. Systolic blood pressure (OR:1.045, P=0.006; CI: 1.013-1.079) and a normal BMI (OR: 0.159, p= 0.004; CI: 0.045-0.559) were the independent predictors of LVH in this study., Conclusion: The prevalence of hypertension is rising, even in rural populations, with accompanying LVH, higher QTc and florid cardiovascular risk factors. It is therefore imperative to tighten the reins of control of blood pressure and other cardiovascular risk factors before the cardiovascular morbidity and mortality explode in the rural communities., Competing Interests: The Authors declare that no competing interest exists.

Background: Obstructive sleep apnoea (OSA) is a common medical condition which has long been recognized as a major contributor to morbidity and mortality in developed countries but that remains underdiagnosed, particularly in rural communities. This study aimed to assess the prevalence of adults who have a high risk of obstructive sleep apnoea in a sample of adults living in Ejigbo, a rural community in south western Nigeria., Methods: This was a community-based cross-sectional descriptive study done to assess the prevalence of high risk of obstructive sleep apnoea in adult residents of the community using the STOP-BANG questionnaire. Data collected include socio-demographic characteristics, anthropometric measurements and blood pressure. A blood sample was also taken for lipid profile. Factors associated with a high risk of obstructive sleep apnoea were identified., Results: The study involved 257 participants out of which 88 (34.2%) had a high risk of OSA. Risk of obstructive sleep apnoea was significantly associated with male sex (p<0.001), age (p<0.001), body mass index (BMI) (p=0.001), neck circumference (p<0.001), cigarette smoking (p=0.039) and low density lipoprotein (p=0.043)., Conclusion: Obstructive sleep apnoea is relatively common in the study area. This calls for urgent preventive measures to stem the tide and mitigate the associated morbidity and mortality.

Annular pancreas (AP) is a rare diagnosis in the adult population but can cause significant morbidity if not correctly identified. In adults, the most common symptoms are abdominal pain, nausea and vomiting. While these are not specific to AP, they are important clues to this diagnosis in the right clinical context. We present the case of a 24-year-old woman presenting with a 6-year history of progressive abdominal pain and dyspepsia in the context of an extensive negative workup. Upper gastrointestinal (GI) series and MRI revealed partial duodenal obstruction, concerning for AP. While patients with chronic abdominal pain and vague GI complaints may be diagnosed with functional bowel disorders, it is important to appropriately address the possibility of an underlying structural lesion such as AP. This strategy is not only cost-effective but also saves the patient discomfort associated with unnecessary procedures and allows a timely intervention., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: This study aimed to evaluate magnetic resonance imaging (MRI) features and interobserver agreement of endometrial polyps., Methods: After institutional review board approval, our database was searched for women older than 18 years who underwent MRI pelvis and pelvic surgical intervention from 2012 to 2016. Seventy-two patients with polyps and 75 controls composed the study cohort. Two radiologists evaluated the MRIs retrospectively for polyps. Polyp characteristics and enhancement were assessed., Results: Sensitivity and specificity of readers 1 and 2 were 59.7% and 88.0%, and 44.4 and 96.0%, respectively. There was moderate agreement for presence of polyps (κ = 0.556, P ≤ 0001), T2 fibrous core, and intratumoral cysts, with slight agreement for T2 signal and enhancement. Polyp size moderately correlated with pathology (κ = 0.465 [P = 0.025] for reader 1, κ = 0.562 [P = 0.029] for reader 2). The most common enhancement was same as myometrium., Conclusion: Magnetic resonance imaging is moderately sensitive for detecting endometrial polyps, demonstrating features that are not sensitive but can be specific, with moderate interobserver agreement.

The ACR Incidental Findings Committee (IFC) presents recommendations for renal masses that are incidentally detected on CT. These recommendations represent an update from the renal component of the JACR 2010 white paper on managing incidental findings in the adrenal glands, kidneys, liver, and pancreas. The Renal Subcommittee, consisting of six abdominal radiologists and one urologist, developed this algorithm. The recommendations draw from published evidence and expert opinion and were finalized by informal iterative consensus. Each flowchart within the algorithm describes imaging features that identify when there is a need for additional imaging, surveillance, or referral for management. Our goal is to improve quality of care by providing guidance for managing incidentally detected renal masses., (Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Objective: Hydrogel spacers have a novel role in the treatment of low- and intermediate-risk prostate cancer with dose-escalated radiation therapy. Given the growing number of patients undergoing treatment with radiation therapy, the use of hydrogel spacers is expected to increase. The purpose of this article is to review what a radiologist needs to know about the imaging of hydrogel spacers, including MRI technique and appearance on CT and MRI., Conclusion: MRI has a critical role in the evaluation of hydrogel spacer placement and is used to facilitate contouring by the radiation oncologist. The radiologist should be familiar with the imaging appearance of hydrogel spacers on CT and MRI to avoid interpretation pitfalls and errors.

The ACR Incidental Findings Committee presents recommendations for managing adrenal masses that are incidentally detected on CT or MRI. These recommendations represent an update to the adrenal component of the JACR 2010 white paper on managing incidental findings in the adrenal glands, kidneys, liver, and pancreas. The Adrenal Subcommittee, constituted by abdominal radiologists and an endocrine surgeon, developed this algorithm. The algorithm draws from published evidence coupled with expert subspecialist opinion and was finalized by a process of iterative consensus. Algorithm branches categorize incidental adrenal masses on the basis of patient characteristics and imaging features. For each specified combination, the algorithm concludes with characterization of benignity or indolence (sufficient to discontinue follow-up) and/or a subsequent management recommendation. The algorithm addresses many, but not all, possible pathologies and clinical scenarios. Our goal is to improve the quality of patient care by providing guidance on how to manage incidentally detected adrenal masses., (Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this study is to compare the attenuation and homogeneity of renal neoplasms with those of cysts on contrast-enhanced CT., Materials and Methods: A total of 129 renal neoplasms and 24 simple cysts were evaluated. Two readers determined whether each mass was qualitatively heterogeneous or homogeneous. Mean, minimum, and maximum attenuation values were measured. Statistical analysis was performed., Results: A total of 116 heterogeneous renal cell carcinomas (RCCs) (99 clear cell, four papillary, four oncocytic, seven chromophobe, and two unclassified RCCs), 13 homogeneous RCCs (10 papillary, two oncocytic, and one chromophobe RCC), and 24 cysts (all of which were homogeneous) were evaluated. All homogeneous RCCs had mean attenuation values of more than 42 HU, whereas renal cysts had mean attenuation values of up to 30 HU (p < 0.001). Two readers qualitatively and identically categorized all RCCs as homogeneous or heterogeneous (κ = 1.0; p < 0.001)., Conclusion: Homogeneous simple renal cysts can have mean attenuation values of up to 30 HU, as determined by contrast-enhanced CT, whereas homogeneous RCCs have mean attenuation values as low as 42 HU, with no overlap occurring between the two groups. These data suggest that further evaluation of a homogeneous renal mass with a mean attenuation value of 30 HU or less on a contrast-enhanced CT scan likely is unwarranted.

Purpose: To determine the magnitude of subject-level and population-level cost savings that could be realized by moving from fixed-volume low-osmolality iodinated contrast material administration to an effective weight-based dosing regimen for contrast-enhanced abdominopelvic CT., Methods: HIPAA-compliant, institutional review board-exempt retrospective cohort study of 6,737 subjects undergoing contrast-enhanced abdominopelvic CT from 2014 to 2015. Subject height, weight, lean body weight (LBW), and body surface area (BSA) were determined. Twenty-six volume- and weight-based dosing strategies with literature support were compared with a fixed-volume strategy used at the study institution: 125 mL 300 mgI/mL for routine CT, 125 mL 370 mgI/mL for multiphasic CT (single-energy, 120 kVp). The predicted population- and subject-level effects on cost and contrast material utilization were calculated for each strategy and sensitivity analyses were performed., Results: Most subjects underwent routine CT (91% [6,127/6,737]). Converting to lesser-volume higher-concentration contrast material had the greatest effect on cost; a fixed-volume 100 mL 370 mgI/mL strategy resulted in $132,577 in population-level savings with preserved iodine dose at routine CT (37,500 versus 37,000 mgI). All weight-based iodine-content dosing strategies (mgI/kg) with the same maximum contrast material volume (125 mL) were predicted to contribute mean savings compared with the existing fixed-volume algorithm ($4,053-$116,076/strategy in the overall study population, $1-$17/strategy per patient). Similar trends were observed in all sensitivity analyses., Conclusions: Large cost and material savings can be realized at abdominopelvic CT by adopting a weight-based dosing strategy and lowering the maximum volume of administered contrast material., (Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Ultrasonography (US) has a fundamental role in the initial examination of patients who present with symptoms indicating abnormalities of the inguinal canal (IC), an area known for its complex anatomy. A thorough understanding of the embryologic and imaging characteristics of the contents of the IC is essential for any general radiologist. Moreover, an awareness of the various pathologic conditions that can affect IC structures is crucial to preventing misdiagnoses and ensuring optimal patient care. Early detection of IC abnormalities can reduce the risk of morbidity and mortality and facilitate proper treatment. Abnormalities may be related to increased intra-abdominal pressure, which can result in development of direct inguinal hernias and varicoceles, or to congenital anomalies of the processus vaginalis, which can result in development of indirect hernias and hydroceles. US is also helpful in assessing postoperative complications of hernia repair, such as hematoma, seroma, abscess, and hernia recurrence. In addition, it is often the modality initially used to detect neoplasms arising from or invading the IC. US is an important tool in the examination of patients suspected of having undescended testes or posttraumatic testicular retraction and is essential for the examination of patients suspected of having torsion or infectious inflammatory conditions of the spermatic cord. Online supplemental material is available for this article. © RSNA, 2016.

With imaging, most incidental renal masses can be diagnosed promptly and with confidence as being either benign or malignant. For those that cannot, management recommendations can be devised on the basis of a thorough evaluation of imaging features. However, most renal masses are either too small to characterize completely or are detected initially in imaging examinations that are not designed for full evaluation of them. These masses constitute a group of masses that are considered incompletely characterized. On the basis of current published guidelines, many masses warrant additional imaging. However, while the diagnosis of renal cancer at a curable stage remains the first priority, there is the additional need to reduce unnecessary healthcare costs and radiation exposure. As such, emerging data now support foregoing additional imaging for many incompletely characterized renal masses. These data include the low risk of progression to metastases or death for small renal masses that have undergone active surveillance (including biopsy-proven cancers) and a better understanding of how specific imaging features can be used to diagnose their origins. These developments support (a) avoidance of imaging entirely for those incompletely characterized renal masses that are highly likely to be benign cysts and (b) delay of further imaging of small solid masses in selected patients. Although more evidence-based data are needed and comprehensive management algorithms have yet to be defined, these recommendations are medically appropriate and practical, while limiting the imaging of many incompletely characterized incidental renal masses.

This article reviews a spectrum of gallbladder conditions that are either uncommon or represent unusual manifestations of common diseases. These conditions are divided into four major categories: (a) congenital anomalies and normal variants including duplication, ectopia, and lymphangioma; (b) inflammatory processes and stone-related diseases and complications including adenomyomatosis, emphysematous cholecystitis, xanthogranulomatous cholecystitis, gangrenous and hemorrhagic cholecystitis, perforation, gallstone ileus, and Bouveret and Mirizzi syndromes; (c) gallbladder neoplasms including adenocarcinoma with associated porcelain gallbladder, squamous cell carcinoma, lymphoma, melanoma, and neurofibroma. A thorough understanding of the imaging characteristics of each condition can help the radiologist to make a timely and accurate diagnosis, thus avoiding potentially harmful delays in patient management and decreasing morbidity and mortality rates.

Background: Hematotrachelos, distension of the uterine cervix with accumulated blood, is an extremely rare condition resulting from a congenital anomaly or an acquired condition. We present a case in which an acquired hematotrachelos was the presenting sign of endometrial cancer., Case: An asymptomatic 66-year-old woman was found to have a bulging cervix during a well-woman visit. Further workup revealed a hematotrachelos and an underlying endometrial adenocarcinoma. She was treated with surgery and adjuvant radiotherapy., Conclusion: A hematotrachelos, although rare, can prevent vaginal bleeding, which is often the earliest symptom of a uterine malignancy. This case report illustrates the potential importance of the pelvic examination as part of the well-woman physical examination, because it led to the discovery of early-stage endometrial cancer.

MR imaging has proven to be a versatile modality in evaluation of the kidneys, collecting system, and adrenal glands. By performing a comprehensive MR examination, it is not only possible to accurately characterize cystic and solid lesions of the kidneys, as well as urothelial masses, but also to provide important preoperative information to the surgeon. In addition, MR imaging can characterize many adrenal lesions and can frequently obviate biopsy. The continued development and growth of MR technology combined with the current trend toward minimally invasive surgery will expand the role of MR imaging in the future., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: The objective of our study was to catalog the anatomic features shown on preoperative CT that precluded living-donor liver donation., Materials and Methods: We retrospectively reviewed the records of 159 consecutive candidates who were evaluated for potential right or left lobe liver donation from November 2007 to January 2012 using MDCT angiography and cholangiography. For the potential donors who were excluded secondary to findings depicted on preoperative imaging, we determined which findings precluded donation., Results: In two (1%) patients who had no prohibitive preoperative imaging findings, anatomic abnormalities were detected intraoperatively that precluded transplantation. Sixty-one (38%) candidates were excluded from liver donation on the basis of imaging findings. Of these patients, 40 (66%) had inadequate liver volume, 14 (23%) had vascular or biliary variants, five (8%) had steatosis, and two (3%) were found to have renal cell carcinoma. Arterial and biliary variants were the most common reason for exclusion based on anatomic findings., Conclusion: Inadequate liver volume was the most common reason for exclusion based on preoperative imaging. Arterial and biliary anatomic variants precluded both right and left lobe transplantation in a number of cases.

Background: Medullary sponge kidney (MSK) is characterized by malformation of the terminal collecting ducts and is associated with an increased risk of nephrolithiasis, nephrocalcinosis, urinary tract infections, renal acidification defects, and reduced bone density. It has been historically diagnosed with intravenous pyelography (IVP), which is falling out of favor as an imaging modality. CT urography (CTU) performed with multidetector CT (MDCT) has been shown to create images of the renal collecting system with similar detail as IVP; however, its utility in diagnosing MSK has not been defined., Case Report: We present the first 15 patients with recurrent symptomatic nephrolithiasis who were evaluated in our renal stone clinic with CTU. Four patients were diagnosed with MSK after visualization of the characteristic radiologic findings., Discussion: CTU effectively demonstrates the characteristic radiologic findings of MSK including collecting tubule dilatation, medullary nephrocalcinosis, nephrolithiasis, and medullary cysts. Dose reduction protocols can reduce radiation exposure below that associated with conventional IVP. We propose CTU be considered for the diagnosis of MSK.

Objective: The purpose of this article is to retrospectively investigate the diagnostic accuracy, image quality, and radiation dose of renal artery CT angiography (CTA), at 80 kVp compared with 120 kVp, in adult kidney donors., Materials and Methods: CTA examinations of 258 consecutive potential kidney donors were retrospectively evaluated; 189 patients were scanned using 64-MDCT scanners (higher maximal tube current), and 69 patients were scanned using 16-MDCT scanners (lower maximal tube current). On the basis of the tube potential and scanners, the study population was divided into four groups. Qualitative and quantitative analysis include vascular attenuation measurements, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Volume CT dose index (CTDIvol) was recorded, and size-specific dose estimate was also estimated., Results: Using 80 kVp for the 16-MDCT scanner, there was a 64.9% reduction in size-specific dose estimate (66.1% reduction in CTDIvol), increased noise, and tube current saturation in all cases. Axial image quality was significantly lower compared with that obtained at 120 kVp (p = 0.02), but image quality and visibility of renal artery branch order were comparable. Using 80 kVp for the 64-MDCT scanner, there was a 40.5% reduction in size-specific dose estimate (43.6% reduction in CTDIvol) and increased SNR and CNR (p < 0.001). No significant differences in 3D image quality and branch order visibility were observed. Tube current saturation was reached in 31% of cases. One hundred fifty-one patients (86 imaged at 80 kVp and 65 imaged at 120 kVp) underwent donor nephrectomy; CTA diagnostic accuracy was 100%., Conclusion: Renal artery CTA using 80 kVp combined with limiting the tube current results in a significant reduction in radiation dose and improved SNR and CNR, without deterioration of image quality.

D-penicillamine, used to treat cystinuria, is known to cause impaired collagen deposition and dysfunction in elastic fibers. D-penicillamine also has been associated with glomerular abnormalities, typically membranous glomerulonephritis. We describe a patient with severe bilateral cystic kidney disease that developed after long-term D-penicillamine use for treatment of cystinuria. The cysts in the kidneys were noted during an evaluation for acute kidney injury. The patient had no evidence of cysts on prior renal imaging at a time when his kidney function was normal. Simultaneously, he presented with multiorgan manifestations of D-penicillamine toxicity, including the skin findings of cutix laxa and elastosis perforans serpiginosa. Consequently, D-penicillamine treatment was discontinued, after which the progression of cystic kidney disease gradually ceased, along with the other systemic manifestations of toxicity. To our knowledge, this is the first report of cystic kidney disease associated with and perhaps caused by long-term d-penicillamine therapy. The proposed mechanism of cyst formation is the malfunction of the extracellular matrix of the kidney by d-penicillamine that leads to an impaired repair process after kidney injury., (Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to compare the radiation exposure and image quality of contrast-enhanced multidetector computed tomography angiography (CTA) and computed tomography cholangiography (CTC) performed for living liver donor evaluation using 80 and 120 kVp., Methods: Ninety-three potential liver donors who underwent preoperative contrast-enhanced 64 multidetector CTA and CTC were retrospectively divided into 2 groups: at 80 and at 120 kVp. An institutional review board waiver was obtained. Signal-to-noise ratio and contrast-to-noise ratio of the hepatic artery and common bile duct were obtained. The dose-length product was recorded. Image quality and visibility of hepatic artery and biliary tract anatomy were evaluated. Mann-Whitney U test was used for statistical evaluation., Results: Mean hepatic artery/common bile duct signal-to-noise ratio was 28.9/28.6 (SD, 14.2/10.0) at 80 kVp and 27.6/25.8 (SD, 8.0/6.2) at 120 kVp (P = 0.61/0.099). Mean hepatic artery/common bile duct contrast-to-noise ratio was 24.8/23.3 (SD, 12.9/8.6) at 80 kVp and 22.2/19.3 (SD, 7.7/5.0) at 120 kVp (P = 0.76/0.005). Mean CTA/CTC dose-length product was 279/281 (SD, 42/52) mGy-cm at 80 kVp and 407/451 (SD, 208/243) mGy-cm at 120 kVp (P = 0.026/0.002). Computed tomography cholangiography image quality and visibility of biliary tract anatomy were not significantly different at 80 versus 120 kVp (all P > 0.13). Computed tomography angiography image quality was significantly lower (P < 0.01), and the noise scores significantly higher (P < 0.01) at 80 versus 120 kVp, but diagnostic., Conclusions: Contrast-enhanced CTA and CTC performed at 80 kVp result in comparable image quality and anatomical evaluation with reduced radiation exposure when compared with 120 kVp.

Low dose (<3 mSv) noncontrast CT (NCCT) is the imaging study of choice for accurate evaluation of patients with acute onset of flank pain and suspicion of stone disease (sensitivity 97%, specificity 95%). NCCT can reliably characterize the location and size of an offending ureteral calculus, identify complications, and diagnose alternative etiologies of abdominal pain such as appendicitis. By comparison, the sensitivity of radiographs (59%) and ultrasound (24-57%) for the detection of renal and ureteral calculi is relatively poor. Ultrasound can accurately diagnose pelvicaliectasis and ureterectasis, but it may take several hours for these findings to develop. In the pregnant patient, however, ultrasound is a first line test as it does not expose the fetus to ionizing radiation. MR is an accurate test for the diagnosis of pelvicaliectasis and ureterectasis, but is less sensitive than CT for the diagnosis of renal and ureteral calculi. For patients with known stone disease whose stones are visible on radiographs, radiographs are a good tool for post-treatment follow-up.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Objective: The purpose of this article is to determine the diagnostic accuracy of identifying focal areas of increased density along the gallbladder fossa or in the periphery of segment IV for diagnosing hepatic steatosis., Materials and Methods: Five hundred consecutive three-phase CT examinations were retrospectively evaluated. Two reference standards for hepatic steatosis were determined using the unenhanced CT examination: a liver-spleen attenuation difference of greater than 10 HU and the absolute attenuation of the liver less than 40 HU. The portal venous phase was independently analyzed by two radiologists. Hepatic steatosis was diagnosed on the contrast-enhanced images if there was increased attenuation in the liver, either at the gallbladder fossa or in the posterior medial aspect of segment IV, when compared with background liver parenchyma., Results: The criterion of relative liver-spleen attenuation difference diagnosed 38 cases. The criterion of absolute liver attenuation less than 40 HU diagnosed 44 cases. Of these cases, hepatic steatosis was diagnosed on the portal venous phase in 23 cases (κ = 1.0), with no false-positive cases. The criterion of relative liver-spleen attenuation difference yielded sensitivity, specificity, positive predictive value, and negative predictive value of 60.5%, 100%, 100%, and 96.9%, respectively. The criterion of absolute liver attenuation less than 40 HU yielded sensitivity, specificity, positive predictive value, and negative predictive value of 52.5%, 100%, 100%, and 95.7%, respectively., Conclusion: Qualitative evaluation of the liver on a portal venous phase contrast-enhanced CT is highly specific for the diagnosis of hepatic steatosis; the sensitivity of the method, however, is rather low.

Men or boys, who present with acute scrotal pain without prior trauma or a known mass, most commonly suffer from torsion of the spermatic cord; epididymitis or epididymoorchitis; or torsion of the testicular appendages. Less common causes of pain include a strangulated hernia, segmental testicular infarction, or a previously undiagnosed testicular tumor. Ultrasound is the study of choice to distinguish these disorders; it has supplanted Tc-99 m scrotal scintigraphy for the diagnosis of spermatic cord torsion. MRI should be used in a problem solving role if the ultrasound examination is inconclusive. The ACR Appropriateness Criteria ® are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Introduction: Lymphangiomas of the gallbladder in adults are extremely rare with only 10 cases published worldwide to date., Case Presentation: We herein report a case of a 26-year-old male who presented with abdominal right upper quadrant pain, nausea, vomiting, and diarrhea. An ultrasound, computer tomography scan, and magnetic resonance imaging showed a cystic mass interposed between the gallbladder and the liver with characteristics identical to those of lymphangiomas in more common locations. The patient underwent an open excision of the large spongy mass en bloc with the gallbladder., Conclusion: Histological findings confirmed the diagnosis of lymphangioma. Also, we provide a review of 10 cases presented in the literature, with a discussion of the clinical features, diagnosis, and surgical approach.

Incidental renal masses are extremely common. Although most represent benign renal cysts, not all incidental renal masses are benign. Most renal cell carcinomas are discovered incidentally when an imaging examination is performed to evaluate a nonrenal complaint. Therefore, differentiating incidental benign renal masses from those that are potentially malignant is important. There are well-established, time-tested, image-based criteria that can be used to diagnose most renal masses definitively. However, some renal masses remain indeterminate even after a thorough evaluation with imaging. This article discusses the evaluation, diagnosis, and treatment options of the incidental renal mass., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to investigate the effect of patient size on the amount of radiation used to perform CT examinations of the chest, abdomen, and pelvis with automatic exposure control and on the corresponding patient doses., Materials and Methods: Ninety-one patients underwent CT of the chest, abdomen, and pelvis with a 64-MDCT scanner with automatic exposure control in the x, y, and z planes (noise index, 11.5; tube rotation speed, 1 second; maximal x-ray tube capacity, 800 mA; slice thickness, 5 mm; slice interval, 5 mm; table speed, 40 mm/rotation; pitch, 1; tube voltage, 120 kVp). Volume CT dose index was obtained from the scanner console at the completion of each examination. The volume CT dose index and a dosimetry calculator were used to determine the organ dose in a 70-kg patient. Patient organ doses were obtained by correction of the calculator organ doses by factors that accounted for size variations in the lung and abdomen among patients and the corresponding regions in the phantom., Results: The average volume CT dose index for a 60-kg patient was approximately 11 mGy, which increased to approximately 22 mGy for an 80-kg patient and to approximately 33 mGy for a 100-kg patient. The corresponding average liver doses for 60-kg patients was approximately 16 mGy, which increased to approximately 25 mGy for 80-kg patients and to approximately 34 mGy for 100-kg patients. For this patient cohort, the median doses to the colon, stomach, and liver were approximately 25 mGy; to the bladder, 31 mGy; and to the red bone marrow, 16 mGy. The 90th percentile organ doses were generally three to four times that of the corresponding 10th percentile organ doses., Conclusion: For body CT examinations performed with automatic exposure control, the radiation used to perform examinations of 100-kg patients is approximately three times that for a 60-kg patient and results in organ doses that are generally twice as high as those in a 60-kg patient.

As multidetector CT has come to play a more central role in medical care and as CT image quality has improved, there has been an increase in the frequency of detecting "incidental findings," defined as findings that are unrelated to the clinical indication for the imaging examination performed. These "incidentalomas," as they are also called, often confound physicians and patients with how to manage them. Although it is known that most incidental findings are likely benign and often have little or no clinical significance, the inclination to evaluate them is often driven by physician and patient unwillingness to accept uncertainty, even given the rare possibility of an important diagnosis. The evaluation and surveillance of incidental findings have also been cited as among the causes for the increased utilization of cross-sectional imaging. Indeed, incidental findings may be serious, and hence, when and how to evaluate them are unclear. The workup of incidentalomas has varied widely by physician and region, and some standardization is desirable in light of the current need to limit costs and reduce risk to patients. Subjecting a patient with an incidentaloma to unnecessary testing and treatment can result in a potentially injurious and expensive cascade of tests and procedures. With the participation of other radiologic organizations listed herein, the ACR formed the Incidental Findings Committee to derive a practical and medically appropriate approach to managing incidental findings on CT scans of the abdomen and pelvis. The committee has used a consensus method based on repeated reviews and revisions of this document and a collective review and interpretation of relevant literature. This white paper provides guidance developed by this committee for addressing incidental findings in the kidneys, liver, adrenal glands, and pancreas., (Copyright © 2010 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) imaging with that of contrast material-enhanced (CE) MR imaging and to assess the performance of these examinations combined for the characterization of renal lesions, with MR follow-up and histopathologic analysis as the reference standards., Materials and Methods: The institutional review board waived the requirement of informed patient consent for this retrospective HIPAA-compliant study. One hundred nine renal lesions in 64 patients (46 men, 18 women; mean age, 60.7 years) were evaluated with CE MR imaging and breath-hold DW imaging performed with various b values. Renal lesions were characterized with use of CE MR criteria, and apparent diffusion coefficients (ADCs) were measured. The ADCs of benign and malignant lesions were compared at Mann-Whitney testing. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of DW imaging and CE MR imaging in the diagnosis of renal cell carcinoma (RCC)., Results: The 109 renal lesions--81 benign lesions and 28 RCCs--had a mean diameter of 4.2 cm +/- 2.5 (standard deviation). The mean ADC for RCCs (1.41 x 10(-3) mm(2)/sec +/- 0.61) was significantly lower (P < .0001) than that for benign lesions (2.23 x 10(-3) mm(2)/sec +/- 0.87) at DW imaging performed with b values of 0, 400, and 800 sec/mm(2). At a cutoff ADC of less than or equal to 1.92 x 10(-3) mm(2)/sec, the area under the ROC curve (AUC), sensitivity, and specificity of DW imaging for the diagnosis of RCCs (excluding angiomyolipomas) were 0.856, 86%, and 80%, respectively. The corresponding AUC, sensitivity, and specificity of CE MR imaging were 0.944, 100%, and 89%, respectively. Combined DW and CE MR imaging had 96% specificity. The AUC for the DW imaging-based diagnosis of solid RCC versus oncocytoma was 0.854. Papillary RCCs had lower ADCs than nonpapillary RCCs., Conclusion: DW imaging can be used to characterize renal lesions; however, compared with CE MR imaging, it is less accurate. DW imaging can be used to differentiate solid RCCs from oncocytomas and characterize the histologic subtypes of RCC.

Purpose: To test the hypothesis that not all embolic materials are equivalent by using postprocedural magnetic resonance (MR) imaging enhancement of uterine fibroids in patients treated with uterine artery embolization (UAE)., Materials and Methods: Approval and a waiver of consent from the institutional human investigations committee was received for this study. The study was HIPAA compliant. A total of 84 women who underwent 6-month MR imaging follow-up constituted this retrospective study. Within this group, 25 women were treated with Contour polyvinyl alcohol (PVA) particles, 23 were treated with Contour SE particles, 19 were treated with Embosphere microspheres, and 17 were treated with Bead Block microspheres. Pre- and postprocedural MR imaging results were analyzed for the total number of fibroids present in the uterus of each patient and for the percentage of individual fibroid enhancement. Enhancement of individual fibroids was measured with quartile intervals. Greater than 25% residual enhancement of a fibroid after embolization was considered an incomplete infarction. The overall percentage change in enhancement was calculated for each patient. Bivariate analysis by using generalized linear modeling and one-way analysis of variance was used to assess differences in infarction with different embolic materials., Results: Among patients treated with Contour and Embosphere, there was a mean reduction in enhancement by 76.60% and 83.07%, respectively, compared with a mean reduction of 52.53% and 49.78% in patients treated with Bead Block and Contour SE, respectively. There was a significant difference in postembolization enhancement between Bead Block and Embosphere, Bead Block and Contour, Contour SE and Embosphere, and Contour SE and Contour., Conclusion: Patients treated with Bead Block or Contour SE demonstrated a reduced degree of infarction at follow-up MR imaging compared with patients treated with Contour or Embosphere.

Despite substantial advances in the imaging-based diagnosis of renal masses, the increased detection of incidental renal masses with cross-sectional imaging poses problems to the radiologist and referring physician. Most incidental renal masses can be diagnosed with confidence and either ignored or treated without further testing. However, some renal masses, particularly small ones, remain indeterminate and require a management strategy that is both medically appropriate and practical. In this article, the literature will be reviewed and an approach to the diagnosis and management of the incidental renal mass will be suggested. Management recommendations, derived from data regarding the probability of malignancy in cystic and solid renal masses, are provided for two types of patients, those in the general population and those with limited life expectancy or co-morbidity. The Bosniak classification is used to guide the management of cystic masses, with observation reserved for selected patients, and the presumption of benignity recommended for simple-appearing cystic masses smaller than 1 cm. Among solid renal masses, a more aggressive overall approach is taken. However, additional imaging, and in selected patients, percutaneous biopsy, is recommended to diagnose benign neoplasms. Although additional studies are needed to establish risks and benefits, observation of solid masses may be considered in selected patients. Minimally invasive treatments of renal cancer (including percutaneous ablation) show promise but at the same time challenge the radiologist to review the approach to the incidental renal mass., ((c) RSNA, 2008.)

Characterization of renal masses with computed tomography (CT) and magnetic resonance (MR) imaging is usually clear-cut and accurate. However, potential pitfalls exist in diagnosis of renal masses, and it is necessary to understand these pitfalls to avoid misdiagnosis and possibly unnecessary surgery. Although some of the pitfalls are related to technical factors of the CT and MR imaging equipment, others are related to errors in image interpretation. To maximize detection and characterization of renal masses, the study should include images obtained before and after administration of intravenous contrast material, including images obtained during the nephrographic phase of enhancement. One should be aware of the potential unreliability of absolute Hounsfield unit measurements and of the existence of possible CT pseudoenhancement. When CT results are indeterminate, MR imaging may be helpful in demonstrating enhancement in renal masses. Before diagnosing a renal mass as a malignant neoplasm or suggesting surgery for a renal mass, one should consider alternative benign diagnoses; when appropriate, previous images or a supporting history should be obtained., ((c) RSNA, 2008.)

Purpose: To compare the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ultrasound (US) and MRI in evaluation of pregnant patients with a clinical suspicion of appendicitis., Materials and Methods: A total of 33 pregnant patients with suspected appendicitis underwent US and MRI. The original imaging reports generated at the time of presentation were used for data analysis. Pathology reports were used for disease confirmation in patients who underwent appendectomy. When surgery was not performed, a medical record review was performed. The sensitivity, specificity, PPV, and NPV were calculated for US and MRI in the diagnosis of appendicitis., Results: Five of the 33 patients had pathologically-proven appendicitis. Four of the five patients with appendicitis were correctly diagnosed at MRI while one was interpreted as indeterminate (appendix not seen). At US, one was correctly diagnosed, one was incorrectly diagnosed as normal, and three were interpreted as indeterminate (appendix not seen). In 13 patients, a normal appendix was diagnosed at MRI, none of whom had appendicitis. In three patients, a normal appendix was diagnosed at US, one of whom had appendicitis. When the appendix was visualized at MRI, the sensitivity, specificity, PPV, and NPV for the diagnosis of appendicitis was 100% for all parameters. When the appendix was visualized at US, the sensitivity, specificity, PPV, and NPV for the diagnosis of appendicitis was 50%, 100%, 100%, and 66%, respectively., Conclusion: Based on a relatively small number of true-positives, our data suggests that MRI is very useful for the diagnosis and exclusion of appendicitis in pregnant women., ((c) 2008 Wiley-Liss, Inc.)

Objective: The objective of our study was to determine the degree to which CT tube current saturates (tube current reaching its maximal capacity) if dose modulation and fast gantry rotation speeds are used when imaging the abdomen and pelvis and to determine whether saturated tube current affects image quality., Materials and Methods: We evaluated the CT scans of patients who underwent imaging of the abdomen and pelvis using dose modulation and the fastest gantry rotation time available on two different CT scanners. Ninety-five patients were scanned with a 64-MDCT scanner (noise index, 11; tube rotation speed, 0.5 second) with a maximal x-ray tube capacity of 695 mA. Ninety-four patients were scanned with a 16-MDCT scanner (noise index, 11.6; tube rotation speed, 0.6 second), which has a maximal x-ray tube capacity of 440 mA. The total number of images per examination, total number of images obtained at saturated tube current, image noise (SD of fluid attenuation), and patient width were recorded. A qualitative evaluation of image quality, with images obtained below and at the maximal tube current grouped separately, was performed by two independent radiologists who were not blinded to the type of scanner used using a scale of from 1 (best) to 4 (worst). Statistical analyses included the Kruskal-Wallis one-way analysis of ranks test for nonparametric ordinal data, the unpaired two-tailed Student's t test, and the chi-square test., Results: For images obtained with the stronger x-ray tube (maximum tube current = 695 mA), the average number of axial images per examination was 87.6. In 34 of 95 (36%) patients, at least one image was acquired with the tube current saturated. The average image noise was 12.4 H. Subjective evaluation yielded an average image quality score of 1.2 for images below saturated tube current and 1.2 for images at saturated tube current. For images obtained with the weaker x-ray tube (maximum tube current = 440 mA), the average number of axial images per examination was 88.9. In 84 of 94 (89%) patients, at least one image was acquired with the tube current saturated. The average image noise was 16.8 H. Qualitative evaluation showed average image quality scores of 1.3 and 1.8 for images below and at the saturated tube current, respectively. The percentage of images acquired at the saturated tube current was significantly greater for the weaker x-ray tube than the stronger x-ray tube (p < 0.0001), and qualitative analysis of images obtained at saturated tube current showed significantly decreased quality for the weaker x-ray tube when compared with images obtained with nonsaturated current (p = 0.001)., Conclusion: On the MDCT scanners investigated, when dose modulation is combined with fast tube rotation times, tube current saturation occurs with weaker x-ray tubes resulting in deterioration of image quality.

Cardiac herniation is a rare condition, which is often lethal in unrecognized cases. It is most commonly seen after pneumonectomy with associated pericardiotomy or pericardiectomy but has been reported in patients with iatrogenic, traumatic, and congenital pericardial defects. It is important that the radiologist be aware of this entity, as delay in diagnosis may be fatal. In this paper, we will discuss a case of cardiac herniation after right pneumonectomy and review the radiologic literature.

Imaging of both benign and malignant anorectal diseases has traditionally posed a challenge to clinicians, and as a result history and physical exam have been relied on heavily. CT scanning and endorectal ultrasound have become popular in assessment of anatomy and staging of tumors, but have limitations. Magnetic resonance imaging (MRI) has the capability to fill in the gaps left open by more conventional imaging modalities and continues to be promising as the definitive imaging technique in the pelvis, especially with advancement of emerging technologies in this field. A comprehensive review of this topic has been undertaken. Anorectal disease is divided into three broad categories: cancer, fistula/abscess, and pelvic floor disorders. A review of the literature is performed to evaluate the use of MRI and other imaging modalities in these three areas. Preoperative imaging is useful in the evaluation of all three areas of anorectal disease. MRI is an effective tool in delineating anatomy and, when correlating with the specific clinical scenario, is an effective adjunct in clinical decision-making in order to optimize outcome. MRI continues to be a promising and novel approach to imaging various afflictions of the anorectum and the pelvic floor. Its role is more well-established in some areas than in others, and there are still significant limitations. As technology advances, MRI will shed more light on a complex anatomical area.

Purpose: To retrospectively determine if renal cell carcinoma can be differentiated from high-attenuation renal cysts at unenhanced computed tomography (CT) based on Hounsfield unit measurements and heterogeneity., Materials and Methods: The Human Investigation Committee at our institution approved this study with waiver of informed consent. This study was compliant with the HIPAA. Fifty-four pathologically proved renal cell carcinomas in 54 patients (36 men and 18 women; average age, 53 years; range, 23-90 years) and 56 high-attenuation renal cysts in 51 patients (30 men and 21 women; average age, 63 years; range, 28-86 years) were retrospectively evaluated at unenhanced CT. Two independent readers reviewed randomized unenhanced CT images and obtained Hounsfield unit readings of each mass. A subjective determination of lesion heterogeneity was also performed by using a four-point scale (1: homogeneous, 2: mildly heterogeneous, 3: moderately heterogeneous, 4: markedly heterogeneous). Statistical analysis was performed by using Bland-Altman regression tree, classification and regression tree, and Shapiro-Wilk normality test., Results: The average attenuation of cysts for reader 1 was 53.4 HU (range, 23-113 HU) and for reader 2 was 53.8 HU (range, 21-108 HU). The average attenuation of neoplasms for reader 1 was 34.7 HU (range, 21-60 HU) and for reader 2 was 38.4 HU (range, 22-60 HU). For cyst heterogeneity, a score of 1 was given in 55 of 56 (98%) cysts for reader 1 and in 53 of 56 (95%) cysts for reader 2. For neoplasm heterogeneity, a score of 1 was given in 35 of 54 (65%) neoplasms for reader 1 and in 36 of 54 (67%) for reader 2. Given the distribution of cyst and tumor attenuation values and lesion heterogeneity, a homogeneous mass measuring 70 HU or greater at unenhanced CT has a greater than 99.9% chance of representing a high-attenuation renal cyst., Conclusion: The findings from this study may help differentiate high-attenuation renal cysts from renal cell carcinomas at unenhanced CT and may suggest the next appropriate imaging study for definitive characterization.

Objective: The aim of this study was to compare the quality of images obtained with fast 3D T2-weighted turbo spin-echo (TSE) MR cholangiopancreatography (MRCP) sequences and 1-mm isotropic voxels with the quality of conventional 2D MRCP images., Subjects and Methods: Thirty consecutively registered patients (14 women, 16 men; average age, 60.2 years; age range, 32-87 years) underwent imaging at 1.5 T with a 6-element body array coil. All imaging was performed with three MRCP techniques: free-breathing 3D T2-weighted TSE (TR/TE, 1,300/680; flip angle, 180 degrees; field of view, 250-300 mm; matrix size, 256 x 256; slice thickness, 1 mm; parallel acquisition technique factor, 2); breath-hold 3D T2-weighted TSE (same parameters as the free-breathing 3D technique); breath-hold coronal and oblique coronal thick-slab 2D TSE without parallel acquisition technique (2,800/1,100; flip angle, 150-180 degrees). Quantitative measures of image signal and contrast were evaluated by analysis of variance and paired Student's t tests. A 5-point scale (1, nondiagnostic, to 5, high diagnostic confidence) was used to compare the 3D and 2D data sets for image quality and definition of biliary and pancreatic ductal anatomic features. Friedman's nonparametric and Wilcoxon's rank sum tests were performed for statistical analysis of the qualitative assessments., Results: Quantitative results showed free-breathing and breath-hold 3D TSE images had significantly higher relative signal intensity and contrast than 2D TSE images (p < 0.0001). The qualitative findings showed that both free-breathing and breath-hold 3D TSE techniques gave better delineation of biliary anatomy (p < 0.0001) than the 2D technique. The overall quality of 3D images was better than that of 2D images, and 3D imaging was better at depicting pancreatic ducts, although the difference did not reach statistical significance., Conclusion: Three-dimensional volumetric MRCP images are of superior quality and give better delineation of pancreaticobiliary anatomy than conventional 2D images and have the added advantage of multiplanar and postprocessing capabilities.

MRI of the kidney and urinary tract has evolved with advancements in MR technology combined with further radiologic experience. A combination of simple pulse sequences and the use of gadolinium (Gd) allow a comprehensive evaluation of the genitourinary system and facilitate the detection and accurate characterization of renal and urinary tract masses. In this review an MRI technique used to evaluate the kidneys and urinary tract is presented with an emphasis on the characterization of renal masses., (Copyright (c) 2006 Wiley-Liss, Inc.)

The standard treatment for renal cell carcinoma for many years was radical nephrectomy, but in the past decade there has been a trend toward elective nephron-sparing surgery. Initially, partial nephrectomy was performed with an open surgical approach; more recently and with increasing frequency, a laparoscopic approach has been used in selected cases. Nephron-sparing surgery with either approach is more complex than is traditional radical nephrectomy and more frequently results in complications. The possible complications of partial nephrectomy include vascular, collecting system, and technical complications as well as recurrent tumor and infection. For prompt diagnosis and appropriate management of these complications, radiologists must be familiar with normal and abnormal features in the postoperative appearance of the kidney at computed tomography and magnetic resonance imaging., (Copyright RSNA, 2006.)