The subperitoneal space and peritoneal cavity: basic concepts.

The subperitoneal space and peritoneal cavity are two mutually exclusive spaces that are separated by the peritoneum. Each is a single continuous space with interconnected regions. Disease can spread either within the subperitoneal space or within the peritoneal cavity to distant sites in the abdomen and pelvis via these interconnecting pathways. Disease can also cross the peritoneum to spread from the subperitoneal space to the peritoneal cavity or vice versa.

ACR Appropriateness Criteria pelvic floor dysfunction.

Pelvic floor dysfunction is a common and potentially complex condition. Imaging can complement physical examination by revealing clinically occult abnormalities and clarifying the nature of the pelvic floor defects present. Imaging can add value in preoperative management for patients with a complex clinical presentation, and in postoperative management of patients suspected to have recurrent pelvic floor dysfunction or a surgical complication. Imaging findings are only clinically relevant if the patient is symptomatic. Several imaging modalities have a potential role in evaluating patients; the choice of modality depends on the patient's symptoms, the clinical information desired, and the usefulness of the test. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions; they are reviewed every 3 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 instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR appropriateness Criteria® infertility.

Appropriate imaging for women undergoing infertility workup depends upon the clinician's suspicion for potential causes of infertility. Transvaginal US is the preferred modality to assess the ovaries for features of polycystic ovary syndrome (PCOS), the leading cause of anovulatory infertility. For women who have a history or clinical suspicion of endometriosis, which affects at least one third of women with infertility, both MRI and pelvic US can provide valuable information. If tubal occlusion is suspected, whether due to endometriosis, previous pelvic inflammatory disease, or other cause, hysterosalpingogram (HSG) is the preferred method of evaluation. To assess for anatomic causes of recurrent pregnancy loss (RPL) such as Müllerian anomalies, synechiae, and leiomyomas, saline infusion sonohysterography, MRI and 3-D US are most appropriate. Up to 10% of women suffering recurrent pregnancy loss have a congenital Müllerian anomaly. When assessment of the pituitary gland is indicated, MRI is the imaging exam of choice.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.

CT features of low grade serous carcinoma of the ovary.

OBJECTIVE: To evaluate the CT features of pathologically proven low grade serous carcinoma (LGSC) of the ovary. METHODS: Patients with a pathologic diagnosis of LGSC and CT prior to oophorectomy were retrospectively identified. The CT scans in 14 patients were available and were analyzed for an adnexal mass, peritoneal mass and ascites. The adnexal mass was characterized as complex primarily cystic, mixed cystic solid, or primarily solid. Calcification in the adnexal and peritoneal masses and nodes was noted. RESULTS: Pathology revealed 6 patients had LGSC and 8 patients had a combined diagnosis of LGSC and serous borderline tumor (SBT) of the ovary. Of the 6 patients with only LGSC, 4 had primarily solid or mixed solid cystic adnexal masses and 5 had peritoneal masses. Calcification was present in the adnexal and peritoneal masses in 4 patients, and in nodes in 2 patients. Of the 8 patients with co-existing LGSC and SBT, 7 had complex primarily cystic adnexal masses and 6 had peritoneal masses. Calcification was present in the adnexal and peritoneal masses in 5 patients and in nodes in 2 patients. CONCLUSION: LGSC can appear as a solid, mixed solid cystic, or complex primarily cystic ovarian mass, and the appearance may be due to a co-existing SBT. Calcification of the adnexal and peritoneal masses appears to be common. LGSC is a diagnostic consideration in patients with a calcified adnexal mass and concurrent peritoneal masses or calcified nodes on CT.

ACR Appropriateness Criteria® pretreatment evaluation and follow-up of endometrial cancer.

Endometrial cancer is the most common gynecologic and the fourth most common malignancy in women in the United States. Cross-sectional imaging plays a vital role in pretreatment assessment of endometrial cancers and should be viewed as a complementary tool for surgical evaluation and planning of these patients. Although transvaginal US remains the preferred examination for the screening purposes, MRI has emerged as the modality of choice for the staging of endometrial cancer and imaging assessment of recurrence or treatment response. A combination of dynamic contrast-enhanced and diffusion weighted MRI provides the highest accuracy for the staging. Both CT and MRI perform equivalently for assessing nodal involvement or distant metastasis. PET-CT is more appropriate for assessing lymphadenopathy in high-grade FDG-avid tumors or for clinically suspected recurrence after treatment. An appropriate use and guidelines of imaging techniques in diagnosis, staging, and detection of endometrial cancer and treatment of recurrent disease are reviewed.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.

ACR appropriateness criteria staging and follow-up of ovarian cancer.

Imaging is used to detect and characterize adnexal masses and to stage ovarian cancer both before and after initial treatment, although the role for imaging in screening for ovarian cancer has not been established. CT and MRI have been used to determine the resectability of tumors, the candidacy of patients for effective cytoreductive surgery, the need for postoperative chemotherapy if debulking is suboptimal, and the need for referral to a gynecologic oncologist. Radiographic studies such as contrast enema and urography have been replaced by CT and other cross-sectional imaging for staging ovarian cancer. Contrast-enhanced CT is the procedure of choice for preoperative staging of ovarian cancer. MRI without and with contrast may be useful after equivocal CT, but is usually not the best initial procedure for ovarian cancer staging. Fluorine-18-2-fluoro-2-deoxy-D-glucose-PET/CT may not be needed preoperatively, but its use is appropriate for detecting and defining post-treatment recurrence. Ultrasound is useful for evaluating adnexal disease, but has limited utility for staging ovarian cancer. 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.

ACR appropriateness Criteria® second and third trimester bleeding.

Vaginal bleeding occurring in the second or third trimesters of pregnancy can variably affect perinatal outcome, depending on whether it is minor (i.e. a single, mild episode) or major (heavy bleeding or multiple episodes.) Ultrasound is used to evaluate these patients. Sonographic findings may range from marginal subchorionic hematoma to placental abruption. Abnormal placentations such as placenta previa, placenta accreta and vasa previa require accurate diagnosis for clinical management. In cases of placenta accreta, magnetic resonance imaging is useful as an adjunct to ultrasound and is often appropriate for evaluation of the extent of placental invasiveness and potential involvement of adjacent structures. MRI is useful for preplanning for cases of complex delivery, which may necessitate a multi-disciplinary approach for optimal care.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.

ACR Appropriateness Criteria® growth disturbances - risk of intrauterine growth restriction.

Fetal growth disturbances include fetuses at risk for intrauterine growth restriction. These fetuses may have an estimated fetal weight at less than the 10% or demonstrate a plateau of fetal growth with an estimated fetal growth greater than the 10%. Uteroplacental insufficiency may play a major role in the etiology of intrauterine growth restriction. Fetuses at risk for intrauterine fetal growth restriction are susceptible to the potential hostility of the intrauterine environment leading to fetal hypoxia and fetal acidosis. Fetal well-being can be assessed using biophysical profile, Doppler velocimetry, fetal heart rate monitoring, and fetal movement counting.Fetal growth disturbances include fetuses at risk for intrauterine growth restriction. These fetuses may have an estimated fetal weight at less than the 10% or demonstrate a plateau of fetal growth with an estimated fetal growth greater than the 10%. Uteroplacental insufficiency may play a major role in the etiology of intrauterine growth restriction. Fetuses at risk for intrauterine fetal growth restriction are susceptible to the potential hostility of the intrauterine environment leading to fetal hypoxia and fetal acidosis. Fetal well-being can be assessed using biophysical profile, Doppler velocimetry, fetal heart rate monitoring, and fetal movement counting.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.

ACR appropriateness Criteria® first trimester bleeding.

Vaginal bleeding is not uncommon in the first trimester of pregnancy. Ultrasound is the foremost modality for evaluating normal development of the gestational sac and embryo and for discriminating the causes of bleeding. While correlation with quantitative ßHCG and clinical presentation is essential, sonographic criteria permit diagnosis of failed pregnancies, ectopic pregnancy, gestational trophoblastic disease and spontaneous abortion. The American College of Radiology Appropriateness Criteria guidelines have been updated to incorporate recent data. A failed pregnancy may be diagnosed when there is absence of cardiac activity in an embryo exceeding 7 mm in crown rump length or absence of an embryo when the mean sac diameter exceeds 25 mm. In a stable patient with no intrauterine pregnancy and normal adnexae, close monitoring is advised. The diagnosis of ectopic pregnancy should be based on positive findings rather than on the absence of an intrauterine sac above a threshold level of ßHCG. Following abortion, ultrasound can discriminate retained products of conception from clot and arteriovenous fistulae. 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.

Enhancement of ovarian malignancy on clinical contrast enhanced MRI studies.

Purpose. To assess if there is a significant difference in enhancement of high grade serous carcinoma of the ovary compared with other ovarian malignancies on clinically performed contrast enhanced MRI studies. Methods. In this institutional-review-board-approved study, two radiologists reviewed contrast enhanced MRI scans in 37 patients with ovarian cancer. Readers measured the signal intensity (SI) of ovarian mass and gluteal fat pre- and postcontrast administration. Percentage enhancement (PE) was calculated as [(post-pre)/precontrast SI] × 100. Results. Pathology revealed 19 patients with unilateral and 18 patients with bilateral malignancies for a total of 55 malignant ovaries-high grade serous carcinoma in 25/55 ovaries (45%), other epithelial carcinomas in 12 ovaries (22%), nonepithelial cancers in 8 ovaries (14%), and borderline tumors in 10 ovaries (18%). Enhancement of high grade serous carcinoma was not significantly different from other invasive ovarian malignancies (Reader 1 P = 0.865; Reader 2 P = 0.353). Enhancement of invasive ovarian malignancies was more than borderline tumors but did not reach statistical significance (Reader 1P = 0.102; Reader 2 P = 0.072). Conclusion. On clinically performed contrast enhanced MRI studies, enhancement of high grade serous ovarian carcinoma is not significantly different from other ovarian malignancies.

ACR Appropriateness Criteria® clinically suspected adnexal mass.

Adnexal masses are a common problem clinically and imaging-wise, and transvaginal US (TVUS) is the first-line imaging modality for assessing them in the vast majority of patients. The findings of US, however, should be correlated with the history and laboratory tests, as well as any patient symptoms. Simple cysts are uniformly benign, and most warrant no further interrogation or treatment. Complex cysts carry more significant implications, and usually engender serial ultrasound(s), with a minority of cases warranting a pelvic MRI.Morphological analysis of adnexal masses with gray-scale US can help narrow the differential diagnosis. Spectral Doppler analysis has not proven useful in most well-performed studies. However, the use of color Doppler sonography adds significant contributions to differentiating between benign and malignant masses and is recommended in all cases of complex masses. Malignant masses generally demonstrate neovascularity, with abnormal branching vessel morphology. Optimal sonographic evaluation is achieved by using a combination of gray-scale morphologic assessment and color or power Doppler imaging to detect flow within any solid areas.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.

ACR Appropriateness Criteria® Multiple gestations.

Multiple gestations are high-risk compared with singleton pregnancies. Prematurity and intrauterine growth restrictions are the major sources of morbidity and mortality common to all twin gestations. Monochorionic twins are at a higher risk for twin-twin transfusion, fetal growth restriction, congenital anomalies, vasa previa, velamentous insertion of the umbilical cord and fetal death. Therefore, determination of multiple gestation, amnionicity and chorionicity in the first trimester is important. Follow up examinations to evaluate fetal well-being include assessment of fetal growth and amniotic fluid volume, umbilical artery Doppler, nonstress test and biophysical profile. To date, there is a paucity of literature regarding imaging schedules for follow-up. At the very least, antepartum testing in multiple gestations is recommended in all situations in which surveillance would ordinarily be performed in a singleton pregnancy.The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed biennially 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 procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging.

MRI diagnosis of pelvic organ prolapse compared with clinical examination.

RATIONALE AND OBJECTIVES: The aims of this study were to determine agreement between clinical examination and magnetic resonance imaging (MRI) (rectal contrast and noncontrast MRI) for pelvic organ prolapse using both the pubococcygeal line (PCL) and the midpubic line (MPL) and to assess the relationship between measurements performed relative to each line. MATERIALS AND METHODS: Dynamic MRI exams in 88 women (with rectal contrast, n = 39; noncontrast, n = 49) were evaluated, followed by review of clinical exam notes. Agreement between clinical exam and MRI and the difference between PCL and MPL measurements were evaluated. RESULTS: Agreement of rectal contrast MRI with clinical exam was 79% for PCL and 85% for MPL (P = .17) for cystoceles, 50% for PCL and 59% for MPL (P = .20) for vaginal prolapse, 56% for PCL for enteroceles, and 61% for rectoceles. Agreement of noncontrast MRI with clinical exam was 67% for PCL and 78% for MPL (P = .19) for cystoceles, 58% for PCL and 71% for MPL (P = .10) for vaginal prolapse, 65% for enteroceles, and 40% for rectoceles. The average difference between the PCL and the MPL was 3.12 ± 0.24 cm at the bladder base and 4.88 ± 0.37 cm at the vaginal apex. CONCLUSIONS: Agreement of MRI with clinical exam was highest for cystoceles. There was no significant difference in agreement using the MPL or PCL, suggesting that either line can be used on MRI. The average differences between the PCL and MPL at the bladder base and vaginal apex were approximately 3 and 5 cm, respectively.

Radiological assessment of gynecologic malignancies.

Patients with gynecologic malignancies are evaluated with a combination of imaging modalities including ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging. US has a primary role in detecting and characterizing endometrial and adnexal pathology. CT is one of the primary modalities in staging malignancy and detecting recurrence. MR imaging is characterized by superior contrast resolution and specificity. This article reviews the role of radiologic imaging for the characterization of gynecologic masses and for staging, planning, and monitoring treatment, as well as for the assessment of tumor recurrence of the most common gynecologic malignancies.

Radiological Assessment of Gynecologic Malignancies.

Patients with gynecologic malignancies are evaluated with a combination of imaging modalities including ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging. US has a primary role in detecting and characterizing endometrial and adnexal pathology. CT is one of the primary modalities in staging malignancy and detecting recurrence. MR imaging is characterized by superior contrast resolution and specificity. This article reviews the role of radiologic imaging for the characterization of gynecologic masses and for staging, planning, and monitoring treatment, as well as for the assessment of tumor recurrence of the most common gynecologic malignancies.

IV contrast infusion for coronary artery CT angiography: literature review and results of a nationwide survey.

OBJECTIVE: The purpose of our study was to review investigations that evaluated contrast infusion using MDCT with submillimeter detector configuration for coronary artery CT angiography (CTA). Published data are supplemented with 2006 survey results from centers practicing 64-MDCT coronary artery angiography. CONCLUSION: Literature and survey results suggest a consensus for the use of IV contrast volumes < 100 mL, infusion rate of 5 mL/s, and a saline chaser. A range of concentrations can be used to attain target coronary artery attenuation levels.

Comparison of supine magnetic resonance imaging with and without rectal contrast to fluoroscopic cystocolpoproctography for the diagnosis of pelvic organ prolapse.

PURPOSE: To compare supine magnetic resonance imaging (MRI), with and without rectal contrast, with fluoroscopic cystocolpoproctography (CCP) for the diagnosis of pelvic organ prolapse. MATERIALS AND METHODS: Supine MRI and CCP studies were reviewed in 82 patients. All patients were women with an average age of 58.8 years, and the studies were done a mean of 25 days apart. Magnetic resonance imaging was performed with rectal contrast (n = 35) and without rectal contrast (n = 47). Fluoroscopic cystocolpoproctography was performed with rectal (n = 82), vaginal (n = 82), small bowel (n = 81), and bladder (n = 78) contrast, and images were corrected for magnification. Each study was independently reviewed by 2 readers, and outcome variables were presence/absence of cystocele, vaginal prolapse, enterocele, sigmoidocele, and anterior rectocele. Sigmoidoceles were included with enteroceles for data analysis. RESULTS: For the entire patient group, the prevalence of cystoceles was 89% on CCP and 80% on MRI; vaginal prolapse was 81% on CCP and 56% on MRI; enteroceles, 38% on CCP and 24% on MRI; and anterior rectoceles, 45% on CCP and 37% on MRI. There were significantly more cystoceles (odds ratio [OR] 4.7, P = 0.003), vaginal prolapses (OR 5.2, P < 0.0005), and enteroceles (OR 3.8, P< 0.0005) on CCP than on MRI. For MRI with rectal contrast versus CCP, the prevalence of cystoceles was 94% on CCP and 91% on MRI; vaginal prolapse, 74% on CCP and 70% on MRI; enteroceles, 36% on CCP and 19% on MRI; and anterior rectoceles, 51% on CCP and 59% on MRI. There was statistical significance only for enteroceles, more of which were found on CCP (OR 7.4, P = 0.003). For MRI without rectal contrast versus CCP, the prevalence of cystoceles was 85% on CCP and 72% on MRI; vaginal prolapse, 86% on CCP and 46% on MRI; enteroceles, 40% on CCP and 28% on MRI; and anterior rectoceles, 39% on CCP and 21% on MRI. There were significantly more cystoceles (OR 6.6, P = 0.003), vaginal prolapses (OR 20.8, P < 0.0005), enteroceles (OR 2.9, P = 0.015), and rectoceles (OR 4.9, P = 0.001) on CCP than on noncontrast MRI. CONCLUSIONS: Magnetic resonance imaging without rectal contrast showed statistically fewer pelvic floor abnormalities than CCP. Except for enteroceles, MRI with rectal contrast showed statistically similar frequency of pelvic organ prolapse as CCP.

64 Slice multi-detector row cardiac CT.

Cardiac imaging is feasible with multi-detector row (MDCT) scanners. Coronary arterial anatomy and both non-calcified and calcified plaques are depicted at CT coronary angiography. Vessel wall pathology and luminal diameter are depicted, and secondary myocardial changes may also be seen. Diagnostic capacity has increased with technological advancement, and preliminary investigations confirm the utility of 64-MDCT in low- and intermediate-risk patients who present to the emergency department with acute chest pain. The clinical indications, 64-MDCT technique, and MDCT findings in coronary artery disease are reviewed.

Evaluation of the effectiveness of oral Beta-blockade in patients for coronary computed tomographic angiography.

OBJECTIVE: To determine the effectiveness of oral medications in lowering the resting heart rate (HR) for coronary computed tomographic angiography (CTA). BACKGROUND: The protocol of premedication for cardiac CTA is variable in terms of type, dose, route, and timing of administration. METHODS: Nursing records were retrospectively reviewed in 238 consecutive patients having coronary CTA and 217 patients evaluated for type and amount of oral medication administered. The HR on arrival to computed tomography (CT) and 30 and 60 minutes after medication was noted. RESULTS: One hundred twenty-three patients (56.6%) had a mean HR of 78.3 +/- 9.4 beats per minute (bpm) on arrival and were given medication. One hundred fourteen patients (92.6%) were given 50 mg of oral metoprolol, with the remaining receiving 25 to 100 mg and 1 patient receiving 30 mg of oral diltiazem. Sixty-eight patients (55.2%) were monitored for less than 1 hour and had a mean HR of 73.1 +/- 5.1 bpm on arrival, a 9.8 +/- 4.7-bpm decrease in HR at 30 minutes, and an HR of 56.5 +/- 7.2 bpm during CT. Thirty-nine patients (31.7%) had a mean HR of 81.3 +/- 7.2 bpm on arrival, a 9.8 +/- 7.4-bpm decrease in HR at 30 minutes, a 16.9 +/- 6.3-bpm decrease in HR at 60 minutes, and an HR of 59.8 +/- 4.8 bpm during CT. Sixteen patients were monitored for more than 1 hour, followed by intravenous metoprolol. These patients had a baseline HR of 93.5 +/- 8.9 bpm, a 13.1 +/- 6.4-bpm decrease in HR at 30 minutes, a 15.9 +/- 6.8-bpm decrease in HR at 60 minutes, and an HR of 68.1 +/- 7.9 bpm during CT. There were no complications due to metoprolol. CONCLUSION: Oral metoprolol given 1 hour before cardiac CT effectively and safely lowers the resting HR in most patients.

64-MDCT angiography of the coronary arteries: nationwide survey of patient preparation practice.

OBJECTIVE: The purpose of this study was to evaluate the current practice of patient preparation for 64-MDCT angiography (CTA) of the coronary arteries. MATERIALS AND METHODS: Sites in the United States that perform 64-MDCT coronary angiography were surveyed by mail in 2006. Information requested included physician specialty; experience level; details about patient preparation, including the use, dose, route, and timing of premedication; and acceptable heart rate and rhythm. A total of 142 surveys were analyzed, with comparison of parameters across specialties (radiology, cardiology, or shared) and experience levels. RESULTS: All facets of the study (premedication, data acquisition, cardiac interpretation) are performed exclusively by radiologists in 49% of sites and by cardiologists in 14%. All sites administer beta-blockers. Target heart rate was reported as < or = 65 beats per minute (bpm) by 89% of responders. Despite most centers aiming for a heart rate of < or = 65 bpm, the maximum allowable heart rate is > 65 bpm in 80% of centers. Patients with arrhythmia are scanned in at least 25% of sites. Most sites (84%) administer nitroglycerin. Significant differences between specialties were noted for experience levels, timing and route of beta-blocker administration, and for target heart rate. The likelihood of scanning in the setting of arrhythmia and beta-blocker timing correlated with experience levels. CONCLUSION: These 64-MDCT coronary artery data from 2006 reveal consensus for a range of patient preparation parameters. Use of beta-blockers and nitroglycerin is routine, and the target heart rate is usually < or = 65 bpm. However, differences were noted for beta-blocker protocols and acceptable heart rate and rhythm, and some differences in practice are associated with experience level and specialty.