Staging and current treatment of hepatocellular carcinoma.

Early-stage hepatocellular carcinoma (HCC) is typically clinically silent, and HCC is often advanced at first manifestation. Without treatment, the 5-year survival rate is less than 5%. The selected treatment depends on the presence of comorbidity; tumor size, location, and morphology; and the presence of metastatic disease. Complete surgical resection followed by hepatic transplantation offers the best long-term survival, but few patients are eligible for this therapy. All other therapies are palliative. Radiofrequency ablation is the preferred method for managing unresectable small HCCs that are few in number. More widespread disease is treated with percutaneous therapies such as chemoembolization and selective internal radiation therapy. Systemic administration of biologic and chemotherapeutic agents is minimally successful in slowing the growth of HCC and typically is used to control symptoms in patients with overwhelming disease. A multidisciplinary approach that includes surgery, systemic therapy, and radiation therapy and that is based on the cooperation of radiation oncologists, interventional and diagnostic radiologists, hepatologists, and pathologists may offer the best chance of a cure or at least a longer and more normal life. To participate effectively in this effort, radiologists must be familiar with staging and treatment options for HCC and with the factors that affect the choice of management method.

Evaluation of liver metastases after radiofrequency ablation: utility of 18F-FDG PET and PET/CT.

OBJECTIVE: Our objective was to review the CT appearance of liver metastases after radiofrequency ablation and to describe the imaging findings of and utility of (18)F-FDG PET and PET/CT in assessing tumor recurrence after ablation. CONCLUSION: (18)F-FDG PET and PET/CT can provide added diagnostic information compared with conventional imaging in patients after radiofrequency ablation of liver metastases and can be useful in guiding repeat ablation procedures.

The trend of using computed tomography in the detection of acute thoracic aortic and branch vessel injury after blunt thoracic trauma: single-center experience over 13 years.

BACKGROUND: The purpose of this study was to review the trend of using chest computed tomography (CT) and aortography in evaluating patients with blunt thoracic trauma. METHODS: A total of 85 patients who had blunt aortic injury diagnosed by chest CT, aortography, or both were included in this study. RESULTS: Aortography was the dominant modality before 1998, and the use of chest CT has increased to 50% of patients with aortic injuries as of 2001. Isolated aortic, branch vessel, or combined injuries were found in 71 (84%), 11 (13%), and 3 (4%) patients, respectively. All 14 patients with branch vessel injuries were diagnosed by aortography. Ninety-eight percent of patients with aortography were true-positives, and 20% of patients with chest CT had indirect signs of aortic injury. CONCLUSION: Our institution has increased the use of chest CT to evaluate blunt thoracic trauma. Patients with indirect signs of aortic injuries shown on chest CT require further evaluation. In our experience, angiography remains the optimal diagnostic modality for evaluating aortic branch vessel injuries.

Complications of ureteral stent placement.

The recent increase in usage of ureteral stents in the management of a variety of urinary tract disease processes mandates familiarity with these devices, their consequences, and their potential complications, which at times can be devastating. Radiology plays an important role in the routine monitoring of stents and in the evaluation of these consequences and complications. It may also offer solutions for their correction. Stents should be monitored while in place, promptly removed when no longer needed, and changed periodically if chronically indwelling. Risk factors for complications should be minimized with high fluid intake, timely evaluation of clinical complaints, and aggressive treatment of documented infection. Certain patients may not be best served by indwelling stent placement, and urinary diversion by means of other mechanisms may be indicated. The implanting physician is responsible for informing the patient of the requirements, consequences, and complications associated with stent placement. Failure to do so has obvious management and potential medicolegal implications.

Percutaneous nephrostomy with extensions of the technique: step by step.

Minimally invasive therapy in the urinary tract begins with renal access by means of percutaneous nephrostomy. Indications for percutaneous nephrostomy include urinary diversion, treatment of nephrolithiasis and complex urinary tract infections, ureteral intervention, and nephroscopy and ureteroscopy. Bleeding complications can be minimized by entering the kidney in a relatively avascular zone created by branching of the renal artery. The specific site of renal entry is dictated by the indication for access with consideration of the anatomic constraints. Successful percutaneous nephrostomy requires visualization of the collecting system for selection of an appropriate entry site. The definitive entry site is then selected; ideally, the entry site should be subcostal and lateral to the paraspinous musculature. Small-bore nephrostomy tracks can be created over a guide wire coiled in the renal pelvis. A large-diameter track may be necessary for percutaneous stone therapy, nephroscopy, or antegrade ureteroscopy. The most common extension of percutaneous nephrostomy is placement of a ureteral stent for treatment of obstruction. Transient hematuria occurs in virtually every patient after percutaneous nephrostomy, but severe bleeding that requires transfusion or intervention is uncommon. In patients with an obstructed urinary tract complicated by infection, extensive manipulations pose a risk of septic complications.

Mesenteric venous thrombosis: diagnosis and noninvasive imaging.

Mesenteric venous thrombosis is an uncommon but potentially lethal cause of bowel ischemia. Several imaging methods are available for diagnosis, each of which has advantages and disadvantages. Doppler ultrasonography allows direct evaluation of the mesenteric and portal veins, provides semiquantitative flow information, and allows Doppler waveform analysis of the visceral vessels; however, it is operator dependent and is often limited by overlying bowel gas. Conventional contrast material-enhanced computed tomography (CT) allows sensitive detection of venous thrombosis within the central large vessels of the portomesenteric circulation and any associated secondary findings; however, it is limited by respiratory misregistration, motion artifact, and substantially decreased longitudinal spatial resolution. Helical CT and CT angiography, especially when performed with multi-detector row scanners, and magnetic resonance (MR) imaging, particularly gadolinium-enhanced MR angiography, enable volumetric acquisitions in a single breath hold, eliminating motion artifact and suppressing respiratory misregistration. Helical CT angiography and three-dimensional gadolinium-enhanced MR angiography should be considered the primary diagnostic modalities for patients with a high clinical suspicion of mesenteric ischemia. Conventional angiography is reserved for equivocal cases at noninvasive imaging and is also used in conjunction with transcatheter therapeutic techniques in management of symptomatic portal and mesenteric venous thrombosis.

Noninvasive assessment of portomesenteric venous thrombosis: current concepts and imaging strategies.

Rapid, noninvasive imaging strategies, especially multidetector spiral CT and CT angiography (CTA) as well as gadolinium-enhanced MR angiography (MRA), have facilitated early diagnosis of splanchnic venous thrombosis, a potentially lethal cause of intestinal ischemia. Single breath-hold volumetric acquisitions permit superior temporal and contrast resolution while eliminating motion artifact and suppressing respiratory misregistration. Increased spatial resolution is aided by thinner slice collimation. These cross-sectional imaging techniques are becoming a preferred noninvasive alternative to conventional selective mesenteric angiography with delayed imaging for venous evaluation and should be considered the primary diagnostic modalities for evaluating patients with high clinical suspicion of nonsurgical mesenteric ischemia.