Abdominal Imaging最新文献

Magnetic resonance imaging is used to non-invasively stage and restage rectal adenocarcinomas. Accurate staging is important as the depth of tumor extension and the presence or absence of lymph node metastases determines if an individual will undergo preoperative neoadjuvant chemoradiation. Accurate description of tumor location is important for presurgical planning. The relationship of the tumor to the anal sphincter in addition to the depth of local invasion determines the surgical approach used for resection. High-resolution T2-weighted imaging is the primary sequence used for initial staging. The addition of diffusion-weighted imaging improves accuracy in the assessment of treatment response on restaging scans. Approximately 10%-30% of individuals will experience a complete pathologic response following chemoradiation with no residual viable tumor found in the resected specimen at histopathologic assessment. In some centers, individuals with no residual tumor visible on restaging MR who are thought to be at high operative risk are monitored with serial imaging and a "watch and wait" approach in lieu of resection. Normal rectal anatomy, MR technique utilized for staging and restaging scans, and TMN staging are reviewed. An overview of surgical techniques used for resection including newer, minimally invasive endoluminal techniques is included.

Purpose: Cesarean scar ectopic pregnancy (CSEP) is considered to be quite rare, but the frequency is increasing given the increasing number of cesarean sections being performed, along with increased detection due to widespread use of early endovaginal sonography. The normal sonographic and magnetic resonance findings of this phenomenon will be discussed, including the appearance of complications associated with abnormal placentation, such as the placenta accreta spectrum. Cases of CSEP at our institution will be illustrated, along with clinical presentations and treatment outcomes.

Methods: The study included women who were diagnosed with a CSEP in the first trimester, which was confirmed by ultrasound. The clinical presentations, imaging findings, and treatment outcomes of these pregnancies were recorded.

Results: In our series, treatment ranged from no intervention with fetal demise on short-term follow-up ultrasound to viable near-term deliveries requiring cesarean section, urgent blood products, and emergent surgery. The majority of our cases 75% (15 of 20) underwent successful early first trimester termination by a combination of systemic methotrexate administration, ultrasound-guided injection of embryocidal agents, and/or surgery.

Conclusion: Early imaging recognition and diagnosis of CSEP is critically important to minimize maternal complications, maintain treatment options, and potentially preserve future fertility.

Patients who have unenhanced abdominal CT scans are often critically ill. The unenhanced CT may reveal many unsuspected subtle abnormalities in the lower chest, abdomen, and pelvis and accordingly warrants careful attention. This article reviews unenhanced CT findings in the setting of pulmonary embolus, acute aortic syndromes, mesenteric and deep venous thrombosis, gastrointestinal hemorrhage, pancreatitis and its complications, as well as pyelonephritis.

Purpose: Computed tomographic (CT) fluoroscopy-guided percutaneous cryoablation is an effective therapeutic method used to treat focal renal masses. The purpose of this study is to quantify the radiation dose to the patient and interventional radiologist during percutaneous cryoablation of renal masses using CT fluoroscopic guidance.

Methods: Over a 1-year period, the CT fluoroscopy time during percutaneous cryoablation of renal masses was recorded in 41 patients. The level of complexity of each procedure was designated as simple, intermediate, or complex. Patient organ radiation doses were estimated using an anthropomorphic model. Dose to the interventional radiologist was estimated using ion chamber survey meters.

Results: The average CT fluoroscopy time for technically simple cases was 47 s, 126 s for intermediate cases, and 264 s for complex cases. The relative risk of hematologic stomach and liver malignancy in patients undergoing this procedure was 1.003-1.074. The lifetime attributable risk of cancer ranged from 2 to 58, with the highest risk in younger patients for developing leukemia. The estimated radiation dose to the interventionalist without lead shielding was 390 mR (3.9 mGy) per year of cases.

Conclusions: The radiation risk to the patient during CT fluoroscopy-guided percutaneous renal mass cryoablation is, as expected, related to procedure complexity. Quantification of patient organ radiation dose was estimated using an anthropomorphic model. This information, along with the associated relative risk of malignancy, may assist in evaluating risks of the procedure, particularly in younger patients. The radiation dose to the interventionist is low regardless of procedure complexity, but highlights the importance of lead shielding.

The female perineum, which is divided into the anterior urogenital triangle and the posterior anal triangle, is a surface structure often overlooked. Female perineal diseases may present with nonspecific clinical signs due to its close anatomical relationship between the different compartments. Diagnosis of the origin of a perineal disorder may also be a difficult problem encountered in pelvi-perineal imaging. Therefore, a precise knowledge of the female perineal anatomy and the associated disease processes is essential to radiologists, pathologists, and surgeons alike who are involved in the evaluation of the patient who presents with a perineal mass. Cross-sectional imaging plays a crucial role for proper management. Due to the robust contrast resolution of MR, MR imaging is the modality of choice for evaluation of the extent of a complex perineal lesion, its relationship to the adjacent structures. It has a greater sensitivity and specificity for the diagnosis than the other non-invasive imaging techniques and is helpful in guidance for surgical planning. The purpose of this article is to highlight the spectrum of imaging findings of female perineal diseases.

The retrorectal-presacral space is located posterior to the mesorectum and anterior to the sacrum, and can harbor a heterogeneous group of uncommon masses. Retrorectal-presacral tumors may be classified as congenital, neurogenic, osseous, and miscellaneous. Magnetic resonance imaging (MRI) plays a crucial role in directing appropriate management through accurate diagnosis, detection of complications and anatomic extent. MRI aids in the selection of optimal surgical approach such as anterior, posterior, or combined-based on the lesion extent and relationship to adjacent structures. This article reviews the anatomy of the retrorectal-presacral space and the related tumors, optimal MRI protocol, MRI-based approach to differential diagnosis, and finally pertinent reporting pointers and implications of MR imaging findings for surgical management.

Purpose: Time savings and clinical accuracy of a new miniature ultrasound device was investigated utilizing comparison with conventional high-end ultrasound instruments. Our objective was to determine appropriate usage and limitations of this diagnostic tool in internal medicine.

Methods: We investigated 28 patients from the internal-medicine department. Patients were examined with the Acuson P10 portable device and a Sonoline Antares instrument in a cross-over design. All investigations were carried out at the bedside; the results were entered on a standardized report form. The time for the ultrasound examination (transfer time, setting up and disassembly, switching on and off, and complete investigation time) was recorded separately.

Results: Mean time for overall examination per patient with the portable ultrasound device was shorter (25.0 ± 4.5 min) than with the high-end machine (29.4 ± 4.4 min; p < 0.001). When measuring the size of liver, spleen, and kidneys, the values obtained differed significantly between portable device and the high-end instrument. In our study, we identified 113 pathological ultrasound findings with the high-end ultrasound machine, while 82 pathological findings (73%) were concordantly detected with the portable ultrasound device. The main diagnostic strengths of the portable device were in the detection of ascites (sensitivity 80%), diagnosis of fatty liver, and identification of severe parenchymal liver damage.

Conclusions: The clinical utility of portable ultrasound machines is limited. There will be clinical roles for distinct clinical questions such as detection of ascites or pleural effusion when used by experienced examiners. However, sensitivity in detecting multiple pathologies is not comparable to high-end ultrasound machines.