Abdominal Imaging最新文献

Purpose: The study aims to perform a meta-analysis to compare the diagnostic value of FDG PET with PET/CT in detecting peritoneal carcinomatosis (PC) to identify the potentially most useful diagnostic modality.

Methods: A computer-aided search was performed in the Cochrane Library, PubMed, EMBASE, Web of Science, the China Biological Medicine Database, VIP, China National Knowledge Infrastructure database, and Wanfang databases for articles concerning diagnosis of peritoneal metastases with PET or PET/CT. QUADAS was used to evaluate the included articles' quality.

Results: On a per-patient basis, the pooled sensitivity of PET/CT (84%) was significantly higher than that of PET (60%), and the pooled specificity of PET (98%) was markedly higher than that for PET/CT (94%). On a per-lesion basis, the pooled sensitivity and specificity of PET/CT were 87 and 95%, respectively. Only 1 PET study on a per-lesion basis, its sensitivity is 65.8 and specificity is 94.1%.

Conclusions: PET and PET/CT are powerful imaging techniques for detection and characterization of PC. PET/CT can be used as a screening tool and it may be acceptable to use PET as a diagnosis tool.

Objective: To investigate the feasibility of using Spectral CT imaging with low contrast medium in abdominal CT angiography (CTA).

Subjects and methods: 70 consecutive patients (40 men, 42.6 ± 20.4 years; 30 women, 46.7 ± 18.8 years) with suspected abdominal focal lesions were referred to CTA exam. They were randomly assigned into two groups. Group A: 35 patients underwent conventional CT scan of Tube voltage 120 kVp, automatic current modulation with a Noise Index of 12, ASIR 30%, and injected with Iohexol (350 mgI/ml). Group B: 35 patients underwent Spectral CT Imaging, with Tube current of 600 mA, injected with Iodixanol (270 mgI/ml). The optimal mono-energy keV was achieved using the optimal contrast noise ratio in abdominal aorta at the renal artery level relative to the erector spine muscle. Both groups were injected with an injection rate of 3.5 ml/s, and a contrast volume of 1.5 ml/kg body weight. The Hounsfield units (HU) and noise of the bilateral renal arteries and muscle of both groups, as well as the optimal monochromatic image set of Group B were measured. Two radiologists assessed all images with a 5-points scale. CTDIvol and DLP were recorded. Data were analyzed using student t test.

Results: The total iodine intake of Group B was 28% lower than that of Group A. The CNR of abdomen artery, celiac trunk, superior mesenteric artery, and renal artery in spectral group (at the best mono-energy of 53.0 keV) were higher than those in conventional CTA group (p < 0.001). The subjective image quality score of spectral CTA group was also rated higher than conventional CTA group (p < 0.001). CTDIvol, DLP, and effective dose of spectral group were all lower than conventional group, but there were no significant differences (p > 0.05).

Conclusion: With 28% contrast medium reduction and reduced radiation dose, CT angiography using spectral imaging and lower concentration contrast agent provided better image quality than conventional CTA.

Objective: The purpose of this article is to present a contemporary review of the imaging appearance of diseases which affect the deeper layers of the urinary bladder, including both suburothelial and extrinsic pathologies, using radiologic-pathologic correlation.

Conclusion: Compared to the more common urothelial lesions, at cystoscopy, suburothelial and extrinsic diseases of the urinary bladder wall often have a non-specific appearance or may be occult. Cross-sectional imaging, in particular MRI, plays an integral role in diagnosis. Mesenchymal tumors have distinct imaging features on MRI. Leiomyomas are characteristically low signal intensity on T2-weighted (T2W) imaging and progressively enhance. Lipomas and lipomatous hypertrophy are diagnosed by the presence of macroscopic fat. Neurofibromas, hemangiomas, and paragangliomas are hyperintense on T2W sequences and hypervascular. Reactive lesions occur in the setting of chronic inflammation and include: nephrogenic adenoma, cystitis cystica, and cystitis glandularis. Imaging findings are commonly non-specific; however, a mass with internal cystic spaces in association with pelvic lipomatosis is suggestive of cystitis glandularis. Urachal anomalies may be complicated by infection or malignancy. Urachal mucinous adenocarcinoma has a poor prognosis and may present as a T2-hyperintense suburothelial/extrinsic mass centered in the bladder dome. Other diseases may extrinsically involve the urinary bladder by hematogenous and peritoneal spread, including infection, endometriosis, and malignancy. A familiarity with suburothelial and extrinsic pathologies of the urinary bladder is critical for the radiologist, who may be the first to suggest these diagnoses.

Purpose: The purpose of our study was to evaluate the sensitivity, specificity, and accuracy of ultrasound (US) as compared to magnetic resonance imaging (MRI) in pregnant patients with suspected appendicitis for visualization of the appendix, accuracy at diagnosing acute appendicitis, the ability of each modality to identify alternate diagnoses of pain and whether gestational age (GA) has an association with appendix identification rates.

Methods: We retrospectively reviewed the records of 140 pregnant patients with suspected appendicitis to determine the efficacy of US and MRI to identify the appendix, diagnose or exclude acute appendicitis, identify alternative etiologies for clinical presentation, and the affect of GA on identification of the appendix. Imaging results were correlated with surgical pathology in patients who underwent surgery. The electronic medical record was used to assess clinical outcomes in patients who did not undergo surgery.

Results: The appendix was visualized in 7% (8/117) of US exams and in 80% (91/114) of MRI exams. Alternate etiologies of pathology were determined in 3% (3/117) of US exams and 12% (14/114) of MRI exams. The sensitivity and specificity of MRI for acute appendicitis were both 100% and 98%, respectively, as compared to 18% and 99%, respectively, with US. GA did not affect MRI or ultrasound visualization rates of the appendix.

Conclusion: Given the low likelihood of visualization of the appendix at US, the excellent accuracy of MRI and the ability of MRI to identify alternate diagnoses, we suggest that at certain institutions MRI may be considered a first-line imaging modality for pregnant patients of any GA with suspected appendicitis.

This article presents our local experience in the implementation of a real-time web-based system for reporting and tracking quality issues relating to abdominal imaging examinations. This system allows radiologists to electronically submit examination quality issues during clinical readouts. The submitted information is e-mailed to a designate for the given modality for further follow-up; the designate may subsequently enter text describing their response or action taken, which is e-mailed back to the radiologist. Review of 558 entries over a 6-year period demonstrated documentation of a broad range of examination quality issues, including specific issues relating to protocol deviation, post-processing errors, positioning errors, artifacts, and IT concerns. The most common issues varied among US, CT, MRI, radiography, and fluoroscopy. In addition, the most common issues resulting in a patient recall for repeat imaging (generally related to protocol deviation in MRI and US) were identified. In addition to submitting quality problems, radiologists also commonly used the tool to provide recognition of a well-performed examination. An electronic log of actions taken in response to radiologists' submissions indicated that both positive and negative feedback were commonly communicated to the performing technologist. Information generated using the tool can be used to guide subsequent quality improvement initiatives within a practice, including continued protocol standardization as well as education of technologists in the optimization of abdominal imaging examinations.

Object of study: Retained products of conception (RPOC) displays variable vascularity, ranging from avascular to markedly vascular on color Doppler sonography. We hypothesize that variability in sonographic vascularity may be due to histopathologic variation in the placental tissue.

Materials, methods, and procedures: After institutional review board approval, sonographic images and pathologic specimens were retrospectively reviewed in 26 patients with pathologically proven RPOC. Ultrasound (US) images were scored 0-3 for the degree of vascularity by two radiologists blinded to the diagnosis. Corresponding pathologic specimens were evaluated for vascularization of chorionic villi, degree of inflammation, morphology of maternal arteries, chorionic villous preservation, and percentage of clot, membranes, chorionic villi, and decidua/myometrium. Statistical analysis, including multiple linear regression, was performed.

Results: RPOC with histologically avascular chorionic villi or those with markedly reduced vascularization had significantly lower US vascularity scores (p = 0.030) than those with chorionic villi showing normal or decreased vascularization. Sonographically avascular RPOC had a significantly lower percentage villi (p = 0.028) and higher percentage of decidua (p = 0.004) than specimens where US showed any Doppler vascularity. Histologic vascularity of villi (p = 0.049) and non-observation of maternal arteries (p = 0.001) were significant predictors of US vascularity scores in multivariate linear regression analysis, while inflammation of villi (p = 0.053) was a marginally significant predictor.

Significance of the conclusions: Histologic vascularity of villi appears to contribute to the observed variation in sonographic vascularity. This finding may underlie known differences in clinical outcomes between sonographic vascularity groups.

A 53-year-old woman underwent elective hysterectomy for symptomatic anemia secondary to abnormal uterine bleeding. She presented 15 months later with complaints of abdominal fullness. Abdominopelvic magnetic resonance imaging demonstrated multiple confluent enhancing solid masses centered in the pelvis and extending cranially to the level of the umbilicus. Additional separate nodules also were visible along the peritoneum. Biopsy demonstrated leiomyosarcoma. Additional clinical information was obtained, which revealed that the patient's prior hysterectomy was performed with morcellation. In November 2014, the United States Food and Drug Administration issued a warning discouraging the use of morcellation during hysterectomy and myomectomy because of the risk of seeding unsuspected malignancy. Radiologists should be aware of this potential complication of morcellation and its imaging appearance so that the correct diagnosis can be suggested in the imaging report.

Objectives: The present article provides an overview of the spectrum of abdominal findings of histiocytic disorders that may be observed in multimodality imaging illustrated by clinical cases from our Imaging Center.

Methods: We will review abdominal findings of Langerhans cell histiocytosis, Rosai-Dorfman disease, Erdheim-Chester disease, and hemophagocytic syndrome illustrated by clinical cases from our imaging department with histologic correlation.

Results: Abdominal involvement of histiocytic disorders is rare and may occur in the liver, biliary tract, kidney, retroperitoneum, kidney, gastrointestinal tract, and lymph nodes.

Conclusion: Histiocytic disorders encompass a group of rare diseases with a wide range of manifestations in which the abdominal involvement is quite infrequent. The role of the radiologist is to report the major imaging findings and the differential diagnosis; however, the imaging features are unspecific and biopsy usually is necessary to establish the definitive diagnosis.