(18)F-FDG Uptake at the Surgical Margin after Hepatic Resection: Patterns of Uptake and Differential Diagnosis.

OBJECTIVE: To evaluate the patterns of (18)F-FDG uptake at the surgical margin after hepatectomy to identify features that may differentiate benign and malignant uptake. METHODS: Patients who had undergone a PET/CT after hepatectomy were identified. Delay between resection and PET/CT, presence of uptake at the surgical margin, pattern of uptake, and maximal standardized value were recorded. The PET/CT findings were correlated with contrast-enhanced CT or MRI. RESULTS: There were 26 patients with increased 18F-FDG uptake; uptake was diffuse in seven and focal in 19. Diffuse uptake was due to inflammation in all cases. Focal uptake was due to recurrence in 12 and inflammation in seven cases. Defining a focal pattern only as a positive for malignancy yielded 100 % sensitivity, 87 % specificity, 37 % false positive rate. As expected, SUVmax was significantly higher for recurrence than inflammation, but did overlap. Contrast-enhanced CT allowed differentiation between malignant and benign uptake in all cases. CONCLUSION: F-FDG uptake after hepatectomy does not equate to recurrence and yields a high false positive rate. Diffuse uptake did not require additional evaluation in our sample. Focal uptake, however, may be due to recurrence; differentiating benign and malignant nodular uptake relies on optimal contrast-enhanced CT or MRI. KEY POINTS: • Marginal uptake exposes patients to the risk of false positive diagnosis of recurrence. • Benign and malignant patterns of marginal uptake overlap. • Diffuse marginal uptake in our experience, has a high chance to be inflammatory. • Focal marginal uptake can be due to recurrent tumour or inflammation. • Contrast-enhanced CT or MR allows the differentiation between benign and malignant uptake.

Intrabiliary growth of colorectal liver metastasis: spectrum of imaging findings and implications for surgical management.

OBJECTIVE: The propensity for colorectal liver metastasis to invade the biliary tree is increasingly recognized, placing particular emphasis on the risk of postoperative recurrence. This article illustrates the spectrum of imaging findings when colorectal metastasis invades the biliary tree. CONCLUSION: Knowledge of the imaging features of intrabiliary invasion by colorectal liver metastasis improves the quality of preoperative staging and is crucial in an era in which nonanatomic wedge resection and radiofrequency ablation are routinely performed.

Gastric cancer: Patterns of disease spread via the perigastric ligaments shown by CT.

OBJECTIVE: The stomach is suspended in the abdominal cavity by perigastric ligaments, which are derived from the dorsal and ventral mesogastrium. These ligaments provide a direct contiguous pathway for the peritoneal spread of gastric cancer. In this article, we discuss the embryology and anatomy of the stomach and describe the specific ligamentous routes along which gastric cancers may spread by direct invasion. CONCLUSION: Extragastric disease alters the prognosis and treatment options available to patients with gastric cancer. Familiarity with the stomach's embryology will help the radiologist understand its anatomy and, therefore, the patterns of regional spread of gastric cancer. The location of the primary tumor can predict involvement of specific perigastric ligaments because locoregional spread of gastric cancer occurs along the arteries, veins, nerves, and lymphatic channels within those ligaments. Thus, identifying the location of the primary tumor can potentially improve patient outcomes.

Clinical utility of positron emission tomography/computed tomography in the evaluation of suspected recurrent ovarian cancer in the setting of normal CA-125 levels.

OBJECTIVES: This study was conducted to estimate the accuracy of [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) as compared with contrast-enhanced CT (CECT) in detecting cancer in patients who have normal cancer antigen (CA)-125 (<35 U/dL) but are suspected of having a recurrent disease based on clinical symptoms. METHODS: We retrospectively reviewed the records of patients who had undergone primary cytoreductive surgery and subsequently underwent CECT and FDG-PET/CT for suspected recurrence. [18F]-fluorodeoxyglucose positron emission tomography/computed tomography and CECT interpretation to evaluate a recurrent disease was carried out independently by 2 experienced radiologists who were blinded to the final diagnosis for the suspected recurrence. Long-term follow-up imaging (12 months) and biopsy reports were used to assess the true status of the suspected recurrence seen on FDG-PET/CT or CECT. Sensitivity and specificity of all modalities were estimated. McNemar test was used to compare pairs of modalities. All tests were 2-sided, and P < or = 0.05 was considered statistically significant. RESULTS: Sixty-six patients met the eligibility criteria for inclusion in our analysis. Fifty-eight percent (18/31) and 54% (17/31) of the patients with normal CA-125 levels had evidence of a recurrent disease on FDG-PET/CT and CECT, respectively. Thirty-one percent (6/19) of the patients with no indication of cancer on CECT had evidence of disease on FDG-PET/CT images, which was supported by pathological proof. CONCLUSION: [18F]-Fluorodeoxyglucose positron emission tomography/computed tomography is capable of detecting ovarian cancer recurrence in symptomatic patients with normal CA-125 levels and, in this setting, has slightly better sensitivity than CECT and can be considered as the frontline modality for all such patients.

Role of magnetic resonance imaging as an adjunct to clinical staging in cervical carcinoma.

Magnetic resonance imaging depicts the morphological details of the female pelvis and is useful for evaluating both benign and malignant cervical masses. Clinical assessment of the extent of cervical cancer is crucial in determining the optimal treatment strategy, but clinical staging by itself has limitations. Clinical staging, as defined by FIGO (International Federation of Gynecologic Oncology), is based on the findings of physical examination, lesion biopsies, chest radiography, cystoscopy, and renal sonography and can be erroneous, depending on the stage of the disease, by 16% to 65%. The prognosis of cervical cancer is determined not only by stage, but also by nodal status, tumor volume, and depth of invasion, none of which are included in the FIGO guidelines. Magnetic resonance imaging has been described as the most accurate, noninvasive imaging modality in staging cervical carcinoma. This review outlines the magnetic resonance features of normal cervix, primary disease (by stage), and recurrent disease and discusses the role of magnetic resonance imaging in staging and clinical decision making.

Magnetic resonance imaging of endometrial carcinoma.

Endometrial carcinoma is the most common female pelvic malignancy and the seventh most common neoplasm worldwide, with the highest incidence in North America and Europe. Endometrial cancer is staged according to the International Federation of Gynecology and Obstetrics surgical system. Clinical estimation of stage, however, can be inaccurate in more than 20%, and therefore, preoperative imaging of the disease may assist in planning the optimal course of treatment. For example, cross-sectional imaging, especially magnetic resonance imaging (MRI), may detect gross myometrial extension or extension of tumor to the cervical stroma, which can alter management and therefore help in preoperative surgical planning. This issue is increasingly relevant as less invasive surgical techniques, such as laparoscopic surgeries, are becoming more commonplace for lower stage cancers. Several imaging techniques such as MRI, computed tomography, and transvaginal ultrasound have been used as tools for preoperative staging of endometrial cancer. Currently, MRI is the most widely used modality for preoperative planning. This article discusses the use of MRI in diagnosis, staging, and detection of endometrial cancer and treatment of recurrent disease.

Evaluation of cancer treatment in the abdomen: Trends and advances.

Response evaluation in Oncology has relied primarily on change in tumor size. Inconsistent results in the prediction of clinical outcome when size based criteria are used and the increasing role of targeted and loco-regional therapies have led to the development of new methods of response evaluation that are unrelated to change in tumor size. The goals of this review are to expose briefly the size based criteria and to present the non-size based approaches that are currently applicable in the clinical setting. Other paths that are still being explored are not discussed in details.

Thoracolithiasis: a case report.

We present a rare case of incidentally found mobile thoracolithiasis in a 76-year-old cirrhotic patient on serial computed tomography scans performed before and after transarterial chemoembolization for hepatocellular carcinoma. Mobility and calcification are the important clue to diagnosing this benign condition and avoiding unnecessary surgery.

Littoral cell angioma of spleen: an uncommon presentation of a rare neoplasm.

Littoral cell angioma (LCA) is a rare primary splenic tumor that is difficult to differentiate preoperatively from other benign and malignant splenic lesions. Most of the cases present as multiple nodules in the spleen. We report a case of large solitary LCA of the spleen, an uncommon presentation. LCA should be considered in the differential diagnosis of multiple and solitary splenic lesions.