Marjorie W. Stein

Managing Incidental Findings on Abdominal and Pelvic CT and MRI, Part 1: White Paper of the ACR Incidental Findings Committee II on Adnexal Findings

This white paper describes adnexal (ovarian and paraovarian) incidental findings found on CT and MRI in nonpregnant postmenarchal patients in whom no adnexal disorder is clinically known or suspected. This represents the first of 4 such papers from the ACR Incidental Findings Committee II, which used a consensus method based on repeated reviews and revisions and a collective review and interpretation of relevant literature. Recommendations for the management of incidental adnexal findings are organized into 4 main categories: benign-appearing cysts, probably benign cysts, adnexal masses with characteristic features, and all other adnexal masses, with pathways on the basis of patient menstrual status or age (when last menstrual period is unknown). A table and flowchart are provided for reference.

Sonographic Comparison of the Tubal Ring of Ectopic Pregnancy With the Corpus Luteum

Objective. Pregnant patients without a sonographically visible intrauterine pregnancy and with a thick‐walled cystic adnexal structure present a dilemma. This study compared the utility of various sonographic features in differentiating between the tubal ring of ectopic pregnancy and the corpus luteum. Methods. Retrospective review of first‐trimester transvaginal sonograms revealed a cystic adnexal structure in 79 women. Each structure was evaluated for 6 specific sonographic characteristics: echogenicity of its wall compared with that of the ovary and endometrium, wall thickness in 2 planes, color Doppler flow distribution and percentage of wall circumference, and internal texture. Results. Forty‐one (52%) of the 79 women had ectopic pregnancies, and 38 (48%) had corpora lutea. Eleven (32%) of 35 ectopic walls were more echogenic than the endometrium, compared with none of the corpora lutea. A cyst wall less echogenic than the endometrium was more likely in corpora lutea (84% versus 31%; P < .0001). More than twice as many ectopic rinds were more echogenic than ovarian tissue compared with corpora lutea (76% versus 34%; P < .0001). The only predictive internal texture feature was a clear pattern, which was more common in the corpora lutea (P < .01, Fisher exact test). There was no significant difference in mural flow distribution or extent between the 2 groups. Conclusions. Ancillary sonographic signs to distinguish between an ectopic pregnancy and a corpus luteum include decreased wall echogenicity compared with the endometrium and an anechoic texture, which suggests a corpus luteum.

Efficacy of Contrast-Enhanced CT in Assessing the Endometrium

OBJECTIVE The purpose of our study was to determine the efficacy of contrast-enhanced CT in detecting a thickened endometrium. We used transvaginal sonography as the reference standard. MATERIALS AND METHODS Between March 2005 and January 2007, data from 259 patients (mean age, 47 years; age range, 18-90 years) who underwent transvaginal sonography and contrast-enhanced CT of the pelvis were analyzed retrospectively. The endometrium was quantitatively measured in millimeters on sonography. On CT it was qualitatively categorized as normal, thickened, indeterminate, or not visualized and compared with the sonography findings and original radiology reports. When the endometrium was indeterminate (thickened or triangular in shape on axial images), sagittal reconstructions were performed for final categorization. Two reviewers evaluated the CT scans and sonograms jointly with differences resolved by consensus. Kappa, Wilcoxons rank sum test, and intraclass correlation statistics were derived. RESULTS The overall sensitivity and specificity of CT in detecting the thickened endometrium was 53.1% and 93.5%, respectively, relative to transvaginal sonography. The positive and negative predictive values were 66.7% and 89.1%, respectively. Kappa, the statistical measure of agreement between CT and sonography data, was 0.5049. All cases of a triangular endometrium were normal in size on sagittal reconstruction images. CONCLUSION Routine pelvic CT correctly identifies a normal endometrium in most patients. Sagittal reconstruction images are helpful to further evaluate the endometrium on CT in cases with a prominent or triangular endometrium because these are often related to uterine version. CT is relatively insensitive in detecting the thickened endometrium but better able to identify gross rather than subtle thickening, which must be further characterized by transvaginal sonography.

Adrenal Cysts: Natural History by Long-Term Imaging Follow-Up

OBJECTIVE The purpose of this article is to determine the natural history of adrenal cysts on the basis of long-term imaging follow-up. MATERIALS AND METHODS This retrospective study included patients with adrenal cysts who had at least 12 months of imaging follow-up (1993-2010). Medical records were reviewed. Two radiologists reviewed imaging examinations in consensus and recorded wall thickness (thin, ≤ 3 mm; thick, > 3 mm), septations, and calcification. CT attenuation value, MRI signal intensity, the presence or absence of enhancement, and typical sonographic features were used to confirm fluid content of the lesions. Cyst wall enhancement was recorded (thin, ≤ 3 mm and smooth; thick, > 3 mm). Cyst diameter on the initial and most remote follow-up examinations was compared. The Wilcoxon matched-pairs signed rank test was applied to assess statistically significant differences in size and CT attenuation on follow-up examinations. RESULTS Twenty patients with unilateral adrenal cysts (seven male and 13 female patients; mean age, 44 years; range, 10-75 years) had a mean imaging follow-up period of 64 months (range, 12-198 months). CT, MRI, and ultrasound examinations were obtained in 19, 11, and 13 patients, respectively. Cysts were diagnosed by lack of enhancement on CT or MRI in 12 patients, typical sonographic features in three patients, and combination of CT and sonographic or MRI features in five patients. Signal intensities typical for fluid were found on all MRI examinations, attenuations of less than 20 HU on 17 of 19 (89%) CT examinations, and features of either simple or mildly complicated cysts on all sonograms. Thin walls, wall calcifications, and thin septations were found in 20 (100%), 12 (60%), and four (20%) lesions, respectively. During the follow-up of 20 lesions, the median cyst diameter increased by 26.0% (interquartile range, 6.8-68.4%) in 12 (60%) patients, decreased by 32.9% (interquartile range, 7.1-42.8%) in six (30%) patients, and was unchanged in two (10%) patients. The median baseline CT attenuation values did not significantly change on follow-up CT examinations (p = 0.72). No patient developed a complication of adrenal cyst. Four patients had histologically confirmed benign adrenal cysts. CONCLUSION Interval enlargement of an adrenal cyst is frequent and as an isolated finding does not indicate malignancy or presence of a complication. However, some adrenal cysts may decrease or remain stable in size over time.

Etiology of Small Bowel Thickening on Computed Tomography

BACKGROUND Abdominal pain is often evaluated using imaging, most often with computed tomography (CT). While CT is sensitive and specific for certain diagnoses, small bowel thickening is a nonspecific finding on CT with a broad differential diagnosis including infection, inflammation, ischemia and neoplasm. METHOD A review of medical records of patients who underwent CT scans of the abdomen and pelvis over a one-year period and exhibited small bowel thickening were retrospectively evaluated to determine the final diagnosis. RESULTS The etiologies of small bowel thickening on CT were as follows: infection (113 of 446 [25.34%]); reactive inflammation (69 of 446 [15.47%]); primary inflammation (62 of 446 [13.90%]); small bowel obstruction (38 of 446 [8.52%]); iatrogenic (33 of 446 [7.40%]); neoplastic (32 of 446 [7.17%]); ascites (30 of 446 [6.73%]); unknown (28 of 446 [6.28%]); ischemic (24 of 446 [5.38%]); and miscellaneous (17 of 446 [3.81%]). CONCLUSION Infectious and inflammatory (primary or reactive) conditions were the most common cause of small bowel thickening in the present series; these data can be used to formulate a more specific differential diagnosis.

Multimodality imaging of normal hepatic transplant vasculature and graft vascular complications.

Orthotopic liver transplantation is an important treatment option for patients with end-stage liver disease. Advances in surgical technique, along with improvements in organ preservation and immunosuppression have improved patient outcomes. Post-operative complications, however, can limit this success. Ultrasound is the primary imaging modality for evaluation of hepatic transplants, providing real-time information about vascular flow in the graft. Graft vascular complications are not uncommon, and their prompt recognition is crucial to allow for timely graft salvage. A multimodality approach including CT angiography, MRI, or conventional angiography may be necessary in cases of complex transplant vascular anatomy or when sonography and Doppler are inconclusive to diagnose the etiologies of these complications. The purpose of this article is to familiarize radiologists with the normal post-transplant vascular anatomy and the imaging appearances of the major vascular complications that may occur within the hepatic artery, portal vein, and venous outflow tract, with an emphasis on ultrasound.

Aortic coarctation diagnosed in a hypertensive child undergoing Doppler sonography for suspected renal artery stenosis

Abstract. A 5-year-old girl presented with hypertension, with no perceived blood pressure differential between the lower and upper extremities. Doppler ultrasound revealed a tardus-parvus pattern with diminished systolic acceleration and peak systolic velocities in the abdominal aorta and both main renal arteries. Doppler interrogation of the suprasternal aorta showed a normal waveform, suggesting a partial obstruction distally. Echocardiography and aortography confirmed severe discrete aortic coarctation with transverse arch hypoplasia. Because classic findings of aortic coarctation may not be present, especially in the older child, the radiologist must be aware that a tardus-parvus Doppler waveform in the abdominal aorta and bilateral renal arteries is suggestive of proximal aortic stenosis, which may be localized by spectral Doppler of the aortic arch.

Aesthetic surgery of the buttocks: imaging appearance

Familiarity with the imaging appearance and potential complications of buttocks aesthetic surgery is important for radiologists. In this review, we illustrate the spectrum of imaging features after buttocks implants, liposuction, fat injections and silicone injections. Complications such as fat necrosis, abscess, and silicone migration are also presented.

CT appearance of common cosmetic and reconstructive surgical procedures and their complications

In this review, we illustrate the spectrum of imaging features after plastic surgical procedures including transverse rectus abdominis myocutaneous flap, deep inferior epigastric perforators flap, latissimus dorsi flap, liposuction, abdominoplasty, and buttocks augmentation. Examples of complications, including seromas, abscesses, fat necrosis, abdominal hernia, and flap necrosis, will also be discussed.

Chest Radiographs Are Valuable in Demonstrating Clinically Significant Pacemaker Complications That Require Reoperation

Purpose To evaluate the utility of chest radiography in demonstrating clinically significant pacemaker complications that required reoperation. Methods In this retrospective case-controlled series, we identified 14 consecutive adults who required pacemaker reoperation and who had chest radiographs available for review (6 men, 8 women; mean age, 71 years [range, 43–95 years]). Ten patients had pacemakers implanted at our institution, and 4 were referred for reoperation. Forty-two controls, 3 for each patient, had postoperative chest radiographs and normal device function (25 men, 17 women; mean age 76 years [range, 37–96 years]). All postoperative chest radiographs, including 1-year follow-ups, were blindly reviewed by at least 2 of 4 radiologists for lead perforation and position of right atrial and right ventricular leads. Follow-up radiographs were assessed for lead perforation, lead displacement, and lead fracture. Data were analysed by using the Fisher exact test. Results Of the patients, 1.7% (10/581) required reoperation for pacemaker dysfunction (noncapture, oversensing, abnormal atrial and ventricular thresholds, failing impedance), extracardiac stimulation, and lead perforation and/or displacement. There were no lead fractures. Chest radiographs demonstrated pacemaker complications in 57% of patients (8/14) at a median of 2 days (<1–32 days) after implantation and in 5% of the controls (2/42) (P < .0001). None of the abnormalities were noted on the official reports. Among subgroups, chest radiographs were abnormal for the following indications: pacemaker dysfunction in 4 of 7 patients versus 0 of 21 controls (P = .0017), extracardiac stimulation in 1 of 3 patients vs 0 of 9 controls (P = .25), and lead perforation and/or displacement in 3 of 4 patients vs 2 of 12 controls (P = .06). Conclusions Chest radiographs are useful after pacemaker placement and demonstrate the majority of complications that require reoperation. Familiarity with the expected normal position of the leads, appearances of pacemaker complications, and comparison with prior radiographs is crucial in rendering a correct diagnosis that guides patient management.