Impact of measurement method on interobserver variability of apparent diffusion coefficient of lesions in prostate MRI.

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).

Complications of liver transplant.

Liver transplantation has become a definitive treatment for patients with end-stage liver disease and those meeting Milan criteria for hepatocellular carcinoma. The morbidity and mortality associated with liver transplantation continues to decrease thanks to refinements in surgical technique, immunosuppression, and imaging. In particular, imaging plays a vital role by facilitating early detection of post-operative complications and enabling prompt treatment. Post-operative complications that lead to graft failure and patient morbidity/mortality can be generally categorized as vascular, biliary, parenchymal, and malignant. Vascular complications include stenosis and thrombosis of the hepatic artery, portal vein, and inferior vena cava; hepatic artery pseudoaneurysm; arteriovenous fistula; and celiac stenosis. Biliary abnormalities include strictures, bile leak, obstruction, recurrent disease, and infection. While imaging is not primarily utilized to diagnose allograft rejection, it plays an important role in excluding mechanical causes of graft dysfunction that can mimic rejection. Ultrasound is routinely performed as the first-line imaging evaluation for the detection and follow-up of early and delayed complications. Cholangiography and magnetic resonance cholangiopancreatography are useful in detecting and characterizing biliary complications. Computed tomography is often used to further evaluate abnormal findings on ultrasound or for the characterization of post-operative fluid collections. The aim of this review is to discuss and illustrate the imaging findings of complications associated with liver transplantation and their role in facilitating treatment.

Multiparametric MR for Solid Renal Mass Characterization.

Multiparametric MR provides a noninvasive means for improved differentiation between benign and malignant solid renal masses. Although most large, heterogeneous renal masses are due to renal cell carcinoma, smaller "indeterminate" renal masses are being identified on cross-sectional imaging. Although definitive diagnosis of a solid renal mass may not always be possible by MR imaging, integrated evaluation of multiple MR imaging parameters can result in concise differential diagnosis. Multiparametric MR should be considered a critical step in the triage of patients with a solid renal mass for whom treatment options are being considered in the context of morbidity, prognosis, and mortality.

Imaging assessment of local recurrence of prostate cancer after radical prostatectomy.

Definitive therapy for prostate cancer includes radical prostatectomy and radiation therapy. Treatment is elected based on patient preference, biological tumor factors, and underlying health. Post prostatectomy, men are surveyed for disease recurrence with serial PSA measurements, digital rectal exam, and imaging studies depending on nomogram predicted risk of local disease recurrence and distant metastasis. In men with rising PSA levels, pathologically incomplete surgical margins or, if symptoms of metastasis develop, imaging may be obtained to localize disease. In cases of known biochemical recurrence, imaging is used to target biopsy, to contour in salvage radiation therapy and to assess disease response. For local disease recurrence, the most commonly performed exams are pelvic MRI and transrectal US. CT can evaluate for lymph node metastasis, but is suboptimal in the evaluation of the prostatectomy bed. PET/CT and PET/MRI have been used successfully to evaluate for local disease recurrence. The PI-RADSv2.1 manual provides a risk level and lexicon for use in description of prostate carcinoma prior to prostatectomy, but does not address imaging features post-surgery. A detailed description of nodal, bony, and visceral metastasis is given elsewhere. This manuscript outlines the context in which appropriate imaging exams may be obtained and focuses on imaging findings concerning for local disease recurrence after prostatectomy on various imaging modalities including CT, US, MRI, and PET.

Nodular Fat-Sparing Hepatic Parenchyma as 11C-Choline-Avid Finding on PET/CT.

Focal nodular fat sparing of the liver may show, on PET/CT imaging, prominent tracer uptake over a background of less metabolic features of steatosis. This finding, already reported with F-FDG, may mimic primary or secondary neoplasms of the liver. The authors present an additional case of nodular fat-sparing hepatic parenchyma exhibiting C-choline avidity during PET/CT assessment for biochemical recurrence of prostate cancer.

MRI in acute pancreatitis.

Computed tomography (CT) is the most commonly performed imaging test for acute pancreatitis. Nevertheless, magnetic resonance (MRI) imaging is useful in many specific situations. These include evaluating patients with acute pancreatitis who cannot receive iodinated CT contrast, elucidating the underlying cause of acute pancreatitis, assessing ductal disconnection and for guiding intervention of necrotic collections. Non-contrast MRI is superior to non-contrast CT and MRI for the diagnosis of acute pancreatitis. We discuss these specific uses of MRI in acute pancreatitis. We highlight the future advances in MRI including faster, free-breathing scans that allow MRI to be completed within 10 min.

ACR Appropriateness Criteria® Penetrating Trauma-Lower Abdomen and Pelvis.

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.

ACR Appropriateness Criteria® Acute Onset of Scrotal Pain-Without Trauma, Without Antecedent Mass.

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.

Resident Case Volume Correlates with Clinical Performance: Finding the Sweet Spot.

RATIONALE AND OBJECTIVES: To determine whether the total number of studies interpreted during radiology residency correlates with clinical performance as measured by objective criteria. MATERIALS AND METHODS: We performed a retrospective cohort study of three graduating classes of radiology residents from a single residency program between the years 2015-2017. The total number of studies interpreted by each resident during residency was tracked. Clinical performance was determined by tracking an individual resident's major discordance rate. A major discordance was recorded when there was a difference between the preliminary resident interpretation and final attending interpretation that could immediately impact patient care. Accreditation council for graduate medical education milestones at the completion of residency, Diagnostic radiology in-training scores in the third year, and score from the American board of radiology core exam were also tabulated. Pearson correlation coefficients and polynomial regression analysis were used to identify correlations between the total number of interpreted films and clinical, test, and milestone performance. RESULTS: Thirty-seven residents interpreted a mean of 12,709 studies (range 8898-19,818; standard deviation [SD] 2351.9) in residency with a mean major discordance rate of 1.1% (range 0.34%-2.54%; stand dev 0.49%). There was a nonlinear correlation between total number of interpreted films and performance. As the number of interpreted films increased to approximately 16,000, clinical performance (p = 0.004) and test performance (p = 0.01) improved, but volumes over 16,000 correlated with worse performance. CONCLUSION: The total number of studies interpreted during radiology training correlates with performance. Residencies should endeavor to find the "sweet spot": the amount of work that maximizes clinical exposure and knowledge without overburdening trainees.

ACR Appropriateness Criteria® Acute Pyelonephritis.

Pyelonephritis refers to infection involving the renal parenchyma and renal pelvis. In most patients, uncomplicated pyelonephritis is diagnosed clinically and responds quickly to appropriate antibiotic treatment. If treatment is delayed, the patient is immunocompromised, or for other reasons, microabscesses that form during the acute phase of pyelonephritis may coalesce, forming a renal abscess. Patients with underlying diabetes are more vulnerable to complications, including emphysematous pyelonephritis in addition to abscess formation. Additionally, diabetics may not have the typical flank tenderness that helps to differentiate pyelonephritis from a lower urinary tract infection. Additional high-risk populations may include those with anatomic abnormalities of the urinary tract, vesicoureteral reflux, obstruction, pregnancy, nosocomial infection, or infection by treatment-resistant pathogens. Treatment goals include symptom relief, elimination of infection to avoid renal damage, and identification of predisposing factors to avoid future recurrences. The primary imaging modalities used in patients with pyelonephritis are CT, MRI, and ultrasound. 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.

Current concepts in molecular genetics and management guidelines for pancreatic cystic neoplasms: an essential update for radiologists.

Cystic neoplasms in the pancreas are encountered frequently on imaging, often detected incidentally during evaluation for other conditions. They can have a variety of clinical and imaging presentations, and similarly, wide-ranging prognostic and treatment implications. In the majority, imaging helps in diagnosis of pancreatic cystic neoplasms (PCNs) and guides management decisions. But, a significant minority of the PCNs remain indeterminate. There have been multiple recent advances in biomarkers and molecular genetics which will likely prove helpful in risk stratification of PCNs. Several prominent national and international societies, as well as consensus groups have put forth recommendations to help guide management of PCNs. The purpose of this article is to discuss the role of imaging in evaluation of PCNs, review the recent advances in molecular genetics and pancreatic cyst fluid analysis, and analyze the pros and cons of major evidence-based and consensus guidelines for management of PCNs.

Sorting the Alphabet Soup of Renal Pathology: A Review.

Diseases of the kidney often have their names shortened, creating an arcane set of acronyms which can be confusing to both radiologists and clinicians. This review of renal pathology aims to explain some of the most commonly used acronyms within the field. For each entity, a summary of the clinical features, pathophysiology, and radiological findings is included to aid in the understanding and differentiation of these entities. Discussed topics include acute cortical necrosis, autosomal dominant polycystic kidney disease, angiomyolipoma, autosomal recessive polycystic kidney disease, acute tubular necrosis, localized cystic renal disease, multicystic dysplastic kidney, multilocular cystic nephroma, multilocular cystic renal cell carcinoma, medullary sponge kidney, paroxysmal nocturnal hemoglobinuria, renal papillary necrosis, transitional cell carcinoma, and xanthogranulomatous pyelonephritis.

Do Residency Selection Factors Predict Radiology Resident Performance?

RATIONALE AND OBJECTIVES: The purpose of our study is to determine what information in medical student residency applications predicts radiology residency success as defined by objective clinical performance data. MATERIALS AND METHODS: We performed a retrospective cohort study of residents who entered our institution's residency program through the National Resident Matching Program as postgraduate year 2 residents and completed the program over the past 2 years. Medical school grades, selection to Alpha Omega Alpha (AOA) Honor Society, United States Medical Licensing Examination (USMLE) scores, publication in peer-reviewed journals, and whether the applicant was from a peer institution were the variables examined. Clinical performance was determined by calculating each resident's cumulative major discordance rate for on-call cases the resident read and gave a preliminary interpretation. A major discordance was defined as a difference between the preliminary resident and the final attending interpretations that could immediately impact the care of the patient. A multivariate logistic regression was performed to determine significant variables. RESULTS: Twenty-seven residents provided preliminary reports on call for 67,145 studies. The mean major discordance rate was 1.08% (range 0.34%-2.54%). Higher USMLE Step 1 scores, publication before residency, and election to AOA Honor Society were all statistically significant predictors of lower major discordance rates (P values 0.01, 0.01, and <0.001, respectively). CONCLUSIONS: Overall resident performance was excellent. There are predictors that help select the better performing residents, namely higher USMLE Step 1 scores, one to two publications during medical school, and election to AOA in the junior year of medical school.

ACR Appropriateness Criteria® Hematospermia.

Most men with hematospermia or hemospermia (HS) are young (<40 years of age), presenting with transient or episodic HS without other signs or symptoms of disease. The condition is self-limiting in most cases and idiopathic in nature. When a cause can be identified, infections of the urogenital tract are the most common. Imaging does not play a role in this patient population. In older men (>40 years of age), clinical screening for prostate cancer is advised. Furthermore, when HS is persistent or has symptoms, causes include obstruction or stricture at the level of the verumontanum, calcifications or calculi in the prostate, ejaculatory ducts or seminal vesicles, and cysts arising within these structures. Noninvasive imaging, predominantly transrectal ultrasound (TRUS) and MRI, can be used in men of any age with persistent or refractory HS, or other associated symptoms or signs. TRUS is considered as the first-line imaging with MRI used when TRUS is inconclusive or negative. 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.

ACR Appropriateness Criteria® Renal Transplant Dysfunction.

Renal transplantation is the treatment of choice in patients with end-stage renal disease because the 5-year survival rates range from 72% to 99%. Although graft survival has improved secondary to the introduction of newer immunosuppression drugs and the advancements in surgical technique, various complications still occur. Ultrasound is the first-line imaging modality for the evaluation of renal transplants in the immediate postoperative period and for long-term follow-up. In addition to depicting many of the potential complications of renal transplantation, ultrasound can also guide therapeutic interventions. Nuclear medicine studies, CT, and MRI are often helpful as complementary examinations for specific indications. Angiography remains the reference standard for vascular complications and is utilized to guide nonsurgical intervention. 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.

Another Time, Another Space: The Evolution of the Virtual Journal Club.

Virtual journal clubs (VJCs) provide a standardized, easily accessible forum for evidence-based discussion. The new virtual reality setting in which journal clubs and other online education events now take place offers great advantages and new opportunities for radiologists in academic medicine and private practice. VJCs continue to evolve, largely due to many emerging technologies and platforms. VJCs will continue to play an increasingly important role in medical education, interdisciplinary interaction, and multi-institutional collaboration. In this article, we discuss how to conduct and lead a critical review of medical literature in the setting of a virtual or traditional journal club. We discuss the current applications of VJCs in medical and graduate medical education and continued lifelong learning. We also explain the advantages and disadvantages of VJCs over traditional venues. Finally, the reader will be given the tools to successfully implement and run a VJC.

Congenital and Acquired Disorders of Ureteral Course.

A wide variety of entities can alter the course of the ureter in the abdomen and pelvis. These include conditions both intrinsic and extrinsic to the ureter leading to a number of different ureteral abnormalities including thickening, displacement, dilatation, etc. An understanding of ureteral pathology, as with any organ, first requires understanding of the normal anatomic appearance. The ureter can be evaluated in a number of ways, including radiographs, such as intravenous pyelogram and retrograde pyelogram, as well as computed tomography or magnetic resonance urography. The unopacified ureter can also be evaluated on examinations tailored for evaluation of other pathologic entities. Although the full spectrum of ureteral pathology is rather broad, this article serves as a review of the normal embryology and anatomy of the ureter, methods of evaluating the ureter at imaging, and entities that can alter the course of the ureter. These potential disorders of ureteral course include embryologic causes; surgical procedures; and displacement by inflammatory, neoplastic, and anatomic abnormalities.

Non-focal liver signal abnormalities on hepatobiliary phase of gadoxetate disodium-enhanced MR imaging: a review and differential diagnosis.

Gadoxetate disodium (Gd-EOB-DTPA) is a linear, non-ionic paramagnetic MR contrast agent with combined extracellular and hepatobiliary properties commonly used for several liver indications. Although gadoxetate disodium is commonly used for detection and characterization of focal lesions, a spectrum of diffuse disease processes can affect the hepatobiliary phase of imaging (i.e., when contrast accumulates within the hepatocytes). Non-focal signal abnormalities during the hepatobiliary phase can be seen with multiple disease processes such as deposition disorders, infiltrating tumors, vascular diseases, and post-treatment changes. The purpose of this paper is to review the different processes which result in non-focal signal alteration during the hepatobiliary phase and to describe imaging patterns that may order a differential diagnosis and facilitate patient management.

Surgical Techniques and Imaging Complications of Liver Transplant.

Liver transplant is the treatment of choice for end-stage liver disease. Management of transplant patients requires a multidisciplinary approach, with radiologists playing a key role in identifying complications in both symptomatic and asymptomatic patients. Ultrasonography remains the investigation of choice for the initial evaluation of symptomatic patients. Depending on the clinical situation, further evaluation with CT, MRI, or biopsy may be performed or clinical and imaging surveillance may be continued. This article discusses the various normal and abnormal imaging presentations of liver transplant patients, including various acute and chronic complications, and their management.

Imaging Complications of Renal Transplantation.

Renal transplant complications are categorized as those related to the transplant vasculature, collecting system, perinephric space, renal parenchyma, and miscellaneous complications including posttransplant lymphoproliferative disorder. Many of these renal transplant complications are diagnosed with imaging. Medical complications including rejection, acute tubular necrosis, and drug toxicity also can impair renal function. These medical complications are typically indistinguishable at imaging, and biopsy may be performed to establish a diagnosis. Normal transplant anatomy, imaging techniques, and the appearances of renal transplant complications at ultrasound, computed tomography, and MR imaging are reviewed.