Martin P. Smith

ACR appropriateness Criteria® right lower quadrant pain - Suspected appendicitis

The most common cause of acute right lower quadrant (RLQ) pain requiring surgery is acute appendicitis (AA). This narratives focus is on imaging procedures in the diagnosis of AA, with consideration of other diseases causing RLQ pain. In general, Computed Tomography (CT) is the most accurate imaging study for evaluating suspected AA and alternative etiologies of RLQ pain. Data favor intravenous contrast use for CT, but the need for enteric contrast when intravenous contrast is used is not strongly favored. Radiation exposure concerns from CT have led to increased investigation in minimizing CT radiation dose while maintaining diagnostic accuracy and in using algorithms with ultrasound as a first imaging examination followed by CT in inconclusive cases. In children, ultrasound is the preferred initial examination, as it is nearly as accurate as CT for the diagnosis of AA in this population and without ionizing radiation exposure. In pregnant women, ultrasound is preferred initially with MRI as a second imaging examination in inconclusive cases, which is the majority.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three 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.

ACR appropriateness criteria right upper quadrant pain

Acute right upper quadrant pain is a common presenting symptom in patients with acute cholecystitis. When acute cholecystitis is suspected in patients with right upper quadrant pain, in most clinical scenarios, the initial imaging modality of choice is ultrasound. Although cholescintigraphy has been shown to have slightly higher sensitivity and specificity for diagnosis, ultrasound is preferred as the initial study for a variety of reasons, including greater availability, shorter examination time, lack of ionizing radiation, morphologic evaluation, confirmation of the presence or absence of gallstones, evaluation of bile ducts, and identification or exclusion of alternative diagnoses. CT or MRI may be helpful in equivocal cases and may identify complications of acute cholecystitis. When ultrasound findings are inconclusive, MRI is the preferred imaging test in pregnant patients who present with right upper quadrant pain. The ACR Appropriateness Criteria 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.

Prospective Cohort Study of Nephrogenic Systemic Fibrosis in Patients With Stage 3–5 Chronic Kidney Disease Undergoing MRI With Injected Gadobenate Dimeglumine or Gadoteridol

OBJECTIVE The purpose of this study was to determine the incidence of nephrogenic systemic fibrosis (NSF) in patients with chronic kidney disease (CKD) and moderate-to-severe impairment of kidney function who had not previously been exposed to gadolinium-based contrast agents (GBCAs) or referred to undergo contrast-enhanced MRI with gadobenate dimeglumine or gadoteridol. SUBJECTS AND METHODS Two multicenter prospective cohort studies evaluated the incidence of unconfounded NSF in patients with stage 3 CKD (estimated glomerular filtration rate [eGFR] in cohort 1, 30-59 mL/min/1.73 m(2)) or stage 4 or 5 CKD (eGFR in cohort 2, < 30 mL/min/1.73 m(2)) after injection of gadobenate dimeglumine (study A) or gadoteridol (study B). A third study (study C) determined the incidence of NSF in patients with stage 4 or 5 CKD who had not received a GBCA in the 10 years before enrollment. Monitoring for signs and symptoms suggestive of NSF was performed via telephone at 1, 3, 6, and 18 months, with clinic visits occurring at 1 and 2 years. RESULTS For studies A and B, the populations evaluated for NSF comprised 363 and 171 patients, respectively, with 318 and 159 patients in cohort 1 of each study, respectively, and with 45 and 12 patients in cohort 2, respectively. No signs or symptoms of NSF were reported or detected during the 2 years of patient monitoring. Likewise, no cases of NSF were reported for any of the 405 subjects enrolled in study C. CONCLUSION To our knowledge, and consistent with reports in the literature, no association of gadobenate dimeglumine or gadoteridol with unconfounded cases of NSF has yet been established. Study data confirm that both gadoteridol and gadobenate dimeglumine properly belong to the class of GBCAs considered to be associated with the lowest risk of NSF.

Abdominal phlegmons in Crohn's disease: outcomes following antitumor necrosis factor therapy.

Background: An abdominal phlegmon is an inflammatory mass that can develop in the setting of penetrating Crohns disease (CD). Anti‐tumor necrosis factor (TNF) antibody therapy is typically avoided in CD complicated by phlegmon because of concern for peritoneal infection but may offer an effective alternative to surgical resection after infection has been controlled with antibiotics. The aim of this study was to examine outcomes for patients with CD who developed an abdominal phlegmon that was subsequently treated with an anti‐TNF antibody. Methods: We retrospectively reviewed the records of all CD patients attending Beth Israel Deaconess Medical Center between 2004 and 2010 with an abdominal phlegmon who were treated with an anti‐TNF antibody in order to evaluate the safety and efficacy of this treatment regimen. Results: There were 13 patients with CD complicated by a phlegmon treated with antibiotics and an anti‐TNF antibody at our center between 2004 and 2010. Ten were male. Median time (interquartile range) from diagnosis to development of the phlegmon was 5.9 (1.9–22.7) years. The phlegmon was associated with an abscess in 12 patients. In addition to anti‐TNF therapy, all patients were treated with broad‐spectrum antibiotics. Anti‐TNF therapy was effective without complications in all subjects. Two patients eventually had surgery more than a year after initiating anti‐TNF treatment. Conclusions: Penetrating CD complicated by phlegmon formation may be safely and effectively managed with a combination of antibiotics and anti‐TNF therapy. Larger, prospective trials are required to confirm these initial findings. (Inflamm Bowel Dis 2011;)

Noncardiac Pathology on Clinical Cardiac Magnetic Resonance Imaging

OBJECTIVES We sought to determine the prevalence of noncardiac pathology in a large consecutive series of patients referred for clinical cardiac magnetic resonance (CMR) studies. BACKGROUND The imaging field for many CMR sequences extends outside of the heart border. As a result, noncardiac pathology may be identified. These noncardiac findings have clinical significance because they often lead to subsequent imaging/testing and intervention. The prevalence of noncardiac findings on clinical CMR studies has not been well described. METHODS The reports of all 1,534 (62% male, age 50 +/- 15 years) clinical CMR studies performed at an academic medical center during calendar years 2002 to 2006 were reviewed. All studies had been interpreted by both a staff cardiologist (level III trained in CMR) and a board-certified radiologist (with fellowship training in CMR). For each study, sex, age, indication for CMR study, and reported noncardiac pathology were extracted. Follow-up for each major noncardiac pathology was evaluated by reviewing the patients medical center electronic medical record. These noncardiac pathologies were then categorized as significant if an intervention or change in the patients management ensued. RESULTS A total of 116 (7.6%) studies had at least one noncardiac finding. These findings included 55 major findings (e.g., lymphadenopathy, lung abnormalities, mediastinal masses) in 48 distinct reports (prevalence of 3.1%) and 74 minor findings (e.g., small pleural effusions, liver cysts, renal cysts) in 70 distinct reports (prevalence of 4.6%). The majority (62%) of major findings were previously known, with only 8 findings in 6 (0.4%) of 1,534 reports ultimately deemed to be new and clinically important/significant. The age of those with noncardiac pathology was greater (54 +/- 16 years vs. 49 +/- 16 years, p < 0.001). CONCLUSIONS In this large series of consecutive clinical CMR studies interpreted by both staff cardiologists and radiologists, noncardiac pathology is uncommonly reported. When reported, the majority of major findings are previously known. New major findings were detected in <0.5% of reports.

T2-weighted 3D fast spin echo imaging with water–fat separation in a single acquisition

To develop a robust 3D fast spin echo (FSE) T2‐weighted imaging method with uniform water and fat separation in a single acquisition, amenable to high‐quality multiplanar reformations.

ACR Appropriateness Criteria Crohn Disease

Crohn disease is a chronic inflammatory disorder involving the gastrointestinal tract, characterized by episodic flares and times of remission. Underlying structural damage occurs progressively, with recurrent bouts of inflammation. The diagnosis and management of this disease process is dependent on several clinical, laboratory, imaging, endoscopic, and histologic factors. In recent years, with the maturation of CT enterography, and MR enterography, imaging has played an increasingly important role in relation to Crohn Disease. In addition to these specialized examination modalities, ultrasound and routine CT have potential uses. Fluoroscopy, radiography, and nuclear medicine may be less beneficial depending on the clinical scenario. The imaging modality best suited to evaluating this disease may change, depending on the target population, severity of presentation, and specific clinical situation. This document presents seven clinical scenarios (variants) in both the adult and pediatric populations and rates the appropriateness of the available imaging options. They are summarized in a consolidated table, and the underlying rationale and supporting literature are presented in the accompanying narrative. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three 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.

ACR Appropriateness Criteria® Colorectal Cancer Screening

Colorectal cancer is the third leading cause of cancer deaths in the United States. Most colorectal cancers can be prevented by detecting and removing the precursor adenomatous polyp. Individual risk factors for the development of colorectal cancer will influence the particular choice of screening tool. CT colonography (CTC) is the primary imaging test for colorectal cancer screening in average-risk individuals, whereas the double-contrast barium enema (DCBE) is now considered to be a test that may be appropriate, particularly in settings where CTC is unavailable. Single-contrast barium enema has a lower performance profile and is indicated for screening only when CTC and DCBE are not available. CTC is also the preferred test for colon evaluation following an incomplete colonoscopy. Imaging tests including CTC and DCBE are not indicated for colorectal cancer screening in high-risk patients with polyposis syndromes or inflammatory bowel disease. This paper presents the updated colorectal cancer imaging test ratings and is the result of evidence-based consensus by the ACR Appropriateness Criteria Expert Panel on Gastrointestinal Imaging. The ACR Appropriateness Criteria 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 where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Low dose pedal magnetic resonance angiography at 3 tesla with time-resolved imaging of contrast kinetics: a feasibility study.

Objectives:To assess the feasibility of low-dose time-resolved imaging of contrast kinetics (TRICKS) magnetic resonance (MR) angiography of the pedal vasculature at 3.0 Tesla (T) using a head coil. Materials and Methods:Eleven healthy volunteers were imaged using TRICKS MR angiography at 3.0 T with both feet positioned in a head coil. A dose of 7 mL was used for each of 3 acquisitions: images were obtained of each foot in the sagittal plane, and then both feet were imaged simultaneously in the transverse plane. The following parameters were used for acquisition: (TR/TE 4.7 milliseconds/ 1.3 milliseconds, field of view = 28 cm, Flip angle = 30 degrees, 384 × 256 matrix, section thickness = 1.6 mm, Bandwidth = 19.23). The dorsalis pedis, plantar arch, distal posterior tibial, lateral tarsal, and medial plantar arteries were graded for visualization, artifact, and overall image quality on a 4-point scale (1 = worst; 4 = best). Results:Superior visualization trended towards separate sagittal acquisitions when compared with that of bilateral transverse acquisitions for most of the individual vessels of the foot. Overall, separate sagittal acquisitions (average score = 2.9) were superior to bilateral transverse acquisitions (average score = 2.6). The average image quality score reflecting the amount of artifact was 2.6 for studies obtained using bilateral transverse acquisitions and 3.1 for studies obtained using separate sagittal acquisitions. Conclusion:Low-dose gadolinium multi-injection TRICKS and bolus-chase MR angiography at 3.0 T provides an effective and easily reproducible technique for imaging of the pedal vasculature in volunteers and has great potential for clinical application.

Water-silicone separated volumetric MR acquisition for rapid assessment of breast implants

To develop a robust T2‐weighted volumetric imaging technique with uniform water‐silicone separation and simultaneous fat suppression for rapid assessment of breast implants in a single acquisition.