Ultrasonography of liver. Technique and focal and diffuse disease.

Because of its widespread use and availability, ultrasonography is frequently the first test used to assess patients with focal or diffuse hepatic disease. While ultrasonographic features of hepatic lesions often do not allow for a specific diagnosis, this article demonstrates typical ultrasonographic features of commonly encountered disease entities as an aid to differential diagnosis. Recent advances, including Doppler and intraoperative ultrasonography also are discussed.

Comparisons of dynamic infusion and delayed computed tomography, intraoperative ultrasound, and palpation in the diagnosis of liver metastases.

The purpose of this study was to determine whether delayed computed tomography (DCT) of the liver would more accurately detect hepatic malignancy when compared with bolus contrast-enhanced dynamic computed tomography (BCDCT). Fifty-one patients who required operation for intra-abdominal malignancy (92% with colorectal cancers) underwent preoperative BCDCT followed by DCT. At operation, palpation and intraoperative ultrasound (IOUS) examination of the liver were performed for localization and biopsy of tumor nodules. The standard for diagnosis was defined for this study as the combined results of IOUS, palpation, and biopsy. The sensitivities of BCDCT and DCT for hepatic metastases were 50% and 54%, respectively, with a corresponding specificity of 72% for each. DCT demonstrated no significant improvement over BCDCT in the detection of individual hepatic lesions. The sensitivity of palpation for the detection of metastases was 82%, equal to that of IOUS. Both palpation and IOUS were significantly superior to BCDCT or DCT in excluding false-positive and false-negative results (p < 0.001). IOUS failed to identify surface lesions less than 1.0 cm in diameter (sensitivity: 40%). Conversely, palpation was limited in the detection of subsurface tumors less than 1.0 cm in diameter (sensitivity: 33%). Combined IOUS and palpation were significantly more accurate in the detection of hepatic metastases than any single modality that was evaluated (p < 0.001).

Isolated portacaval adenopathy in Hodgkin lymphoma. CT and US findings.

We report a case of isolated portacaval adenopathy as the initial presenting feature in a patient with Hodgkin lymphoma. The differential diagnosis of masses located in the portacaval space is discussed and signs useful to localized tumors to this space are described.

CT of mullerian adenosarcoma arising in endometriosis.

Mullerian adenosarcoma is a rare tumor that usually arises in the uterus. Occasional cases arising in endometrial implants have been reported. We report the computed tomography (CT) findings of histologically proven mullerian adenosarcoma arising in perirectal endometriosis in a 46-year-old woman.

Inflammatory myofibrohistiocytic proliferation presenting as giant gastric pseudotumor.

A 5-year-old boy presented with refractory microcytic anemia, growth failure, and markedly elevated sedimentation rate. Computed tomographic (CT) and upper gastrointestinal study disclosed an ulcerated 9-cm large gastric mass, which proved to be an inflammatory myofibrohistiocytic proliferation (IMP). The characteristic clinical and radiologic features of this rare entity are herein reviewed.

Advances in pelvic ultrasound: endovaginal scanning for ectopic gestation and graded compression sonography for appendicitis.

Endovaginal sonography and graded compression sonography for appendicitis are two recent, significant advances in the imaging evaluation of the pelvis. Endovaginal sonography is performed by placing a dedicated high-frequency ultrasound probe within the vagina to evaluate the uterus and adnexa. Much early research with this technique has focused on the evaluation of early pregnancy, where changes related to intrauterine and ectopic gestation are evident at least one week earlier when compared with routine transabdominal ultrasound. Graded compression sonography for appendicitis is an ultrasound search for the inflamed, nonruptured appendix performed by compressing the right lower quadrant with a linear array transducer. Both techniques are fast, safe, and inexpensive evaluations that can be used to evaluate patients with nonspecific clinical findings and are particularly helpful in women of childbearing age.

CT of portal venous occlusion.

Thrombosis of a portion of the portal venous system can be directly imaged by contrast-enhanced CT as a low-attenuation lesion within the involved portal venous segment with or without expansion of the vessel or enhancement at the margin of the thrombus. Collateral venous pathways are often evident, which provide supporting evidence of the occlusion. Alterations in portal venous blood flow lead to metabolic disturbances in the liver and to abnormalities in parenchymal enhancement during dynamic CT scanning, and these changes are manifested as abnormalities in hepatic parenchymal density. The detection of portal venous thrombosis or occlusion, collateral veins, or abnormal liver enhancement should initiate a search for the diseases that cause these abnormalities.

The subcutaneous injection port: a new chest-wall artifact.

A totally implanted central venous catheter with a subcutaneous injection port is now in use in patients in whom long term venous access is required. This injection port creates a new artifact that can mimic a pulmonary lesion on chest radiographs.

CT diagnosis of splenic vein occlusion: imaging features, etiology and clinical manifestations.

BACKGROUND: Previous reports have described the computed tomographic (CT) appearance of collateral veins following splenic vein occlusion (SVO). This retrospective study was performed to determine the etiology, clinical manifestations, and accuracy of CT diagnosis in patients with this entity. METHODS: A computer search of radiology reports for a 1-year period found 52 patients with SVO diagnosed by absence of visualization of the splenic vein accompanied by the formation of the expected perigastric collateral veins. Clinical data were reviewed for sequela of SVO and clinical impact of the diagnosis. RESULTS: In 12 cases, other studies confirmed the CT diagnosis of SVO. In no case was the CT diagnosis proved to be incorrect by other imaging studies. Angiographic records found five additional cases with SVO not diagnosed by CT, but two of five had convincing CT evidence of SVO noted upon reevaluation by the authors. Review of clinical data showed heme-positive stool in six, of which three had significant gastrointestinal hemorrhage. Splenic infarction occurred in two cases. CONCLUSIONS: Our data indicate that SVO is more common than previously suspected and usually remains clinically silent, but CT appears to be highly specific and fairly sensitive for its diagnosis.

Duodenal manifestations of nontropical sprue.

Barium studies of the upper gastrointestinal tract and small bowel were performed in 16 adult patients with biopsy-proven nontropical sprue. Commercially available contrast media containing micropulverized barium sulfate, suspending agents, and various other additives were used. Radiographs were analyzed for the incidence and pattern of duodenal vs. small-bowel changes associated with celiac disease. Thirteen of 16 patients (81%) demonstrated abnormalities of the duodenum which ranged from focal erosions to diffusely thickened and nodular folds. A nonspecific, mild dilatation pattern was present on the small-bowel series of 11 patients (69%). The classic radiographic signs of malabsorption, such as flocculation and segmentation, however, occurred in less than 20% of cases, apparently because of the stability of new barium suspensions. The pathogenesis of duodenal changes in sprue and its diagnostic implications are emphasized.

Positron emission tomography in the evaluation of stage III and IV head and neck cancer.

BACKGROUND: Detection of metastatic disease in head and neck cancer patients is critical to preoperative planning, because patients with distant metastasis will not benefit from surgical therapy. Conventional radiographic modalities, such as CT and MR, give excellent anatomic detail but poorly identify unenlarged lymph nodes harboring metastatic disease. OBJECTIVE: A pilot study was conducted to evaluate the usefulness of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) detection of metastatic disease in patients with advanced-stage head and neck cancer. METHODS: Total body FDG-PET imaging was performed in a prospective manner on 12 consecutive patients with a new diagnosis of stage III or IV mucosal squamous cell carcinoma of the head and neck. Chest CT was also performed on all 12 patients. Patients found to have metastatic disease on either CT or PET imaging underwent procedures to obtain histopathologic confirmation of disease. RESULTS: Three patients (25%) had FDG-PET scans demonstrating metastatic disease. Two of these patients had no evidence of disease on chest radiograph or chest CT but were noted to have positive FDG-PET imaging within the mediastinal lymphatics. Mediastinoscopy was performed confirming metastatic disease in these patients. The third patient had a peripheral lung lesion detected on chest radiograph, CT, and FDG-PET. This nodule was diagnosed by CT-guided biopsy as squamous cell carcinoma. CONCLUSION: FDG-PET scanning detected mediastinal disease in two patients (17%) with advanced-stage head and neck squamous cell carcinoma that was not identified with conventional imaging techniques. PET imaging seems to have significant potential in the detection of occult metastatic disease, particularly in the mediastinal lymphatics.

The inability to detect kidney disease on the basis of echogenicity.

With the use of new sonographic technology, we have observed that the echogenicity of kidneys is often equal to that of the liver in patients in whom there is no evidence of renal disease; this observation conflicts with the generally accepted notion that a normal kidney is always less echogenic than the liver. In order to reassess renal echogenicity as an indicator of disease, three experienced radiologists blindly reviewed the sonograms of the right kidney and liver in 153 patients. The prevalence of renal disease was 26% (40/153). Accepted sonographic criteria for abnormal renal echogenicity (kidney echogenicity greater than or equal to liver) were neither sensitive (62%) nor specific (58%) for renal disease, with a positive predictive value of 35%. Most of these inaccuracies occurred because 43 (72%) of 60 patients in whom renal echogenicity was equal to that of liver had normal renal function. If stricter criteria for abnormality were adopted (kidney echogenicity greater than liver), specificity (96%) and positive predictive value (67%) rose; however, sensitivity was only 20%. We conclude that renal echogenicity equal to the echogenicity of liver is not a good indicator of disease. Use of stricter criteria (kidney echogenicity greater than liver) provides a specific but insensitive test.

Septic thrombosis of the portal vein: CT and clinical observations.

The CT and clinical findings were reviewed in seven patients with septic thrombosis of the portal vein (STPV). Of the seven patients, five had associated pyogenic liver abscesses. Five of seven patients presented de novo with STPV without a clinically obvious extrahepatic source of intraabdominal infection. All seven patients were successfully managed nonsurgically with intravenous antibiotics and in two patients percutaneous drainage of hepatic abscesses. Serial follow-up examinations in five patients demonstrated complete resolution of portal venous thrombus in three patients and progression to cavernous transformation in two. When diagnosed early by CT or sonography, STVP may have a more benign clinical course following appropriate antibiotic therapy.

Evaluation of ectopic bone by CT.

The CT appearance of ectopic bone and its maturation in 25 patients were correlated with the findings on radiographs and bone scans. Ossification progressed from an early appearance of soft-tissue density of lower attenuation than muscle to a calcific density paralleling radiographic and scintigraphic evidence of bone formation. Persistent unossified, low-density soft tissue was detected adjacent to mineralized areas of ectopic bone in 14 patients up to 16 years after neurologic injury, often with bone-scan evidence of maturity of the ectopic bone. This soft tissue most likely corresponds to immature, unossified connective tissue, which may have a potential for ossification. Detection of areas of soft-tissue density by CT and their avoidance during surgical resection of an ankylosing mass of ectopic bone may reduce intraoperative hemorrhage and postoperative ectopic bone recurrence.

CT-angiographic correlation of collateral venous pathways in isolated splenic vein occlusion: new observations.

The computed tomographic (CT) findings in 18 patients with angiographically proved, isolated splenic vein occlusion (SVO) were retrospectively analyzed. The distribution of venous collateral vessels and the frequency of their occurrence in these patients were then compared with CT findings in 17 patients with proved portal hypertension and normal CT findings in 20 patients. Short gastric and coronary collateral vessels were seen in 61% and 83%, respectively, of patients with SVO and in 71% each in patients with portal hypertension. However, a large gastroepiploic vein was seen only in patients with SVO (11 of 18 patients [61%]). Recanalization of umbilical/paraumbilical veins was seen only in patients with portal hypertension (seven of 17 patients [41%]). Results suggest that collateral vessels in SVO often have a characteristic and distinctive appearance on abdominal CT scans.

Ischemic colitis associated with systemic lupus erythematosus.

A case of colonic ischemia, infarction, and perforation secondary to systemic lupus erythematosus (SLE) is described in a 37-year-old woman. The incidence and significance of gastrointestinal complications in SLE are discussed.

Hepatic parenchymal changes after intraarterial Y-90 therapy: CT findings.

The serial contrast material-enhanced computed tomographic scans of 23 patients treated with intraarterial yttrium-90 microspheres as therapy for hepatic metastatic disease were reviewed for evidence of parenchymal changes in the liver in areas not involved with tumor. Irregular low-attenuation geographic areas that developed in the hepatic parenchyma after therapy were graded as mild, moderate, or severe and were evident in 12 of 23 patients. In nine cases of mild to moderate changes in the hepatic parenchyma, the abnormality was either focal or asymmetric. In all three patients receiving the highest dose (15,000 cGy), severe diffuse parenchymal changes were seen in all hepatic segments. In the remaining 11 patients, no parenchymal changes were seen. The most pronounced changes were seen at 8 weeks after therapy and were partially or completely reversible at 16-24 weeks. All patients had minimal or no change in liver function and no clinical sequelae attributable to liver injury.

CT findings in ulcerative, granulomatous, and indeterminate colitis.

Eight patients with ulcerative colitis, three with colitis indeterminate, and 15 patients with Crohn disease were studied by computed tomography (CT) to establish CT criteria for each disorder in hopes of providing a new diagnostic perspective useful in the radiographic evaluation of inflammatory colitis. The CT findings in ulcerative colitis included thickening of the colon wall (mean, 7.8 mm), which was characterized by inhomogeneous attenuation and a "target" appearance of the rectum, and proliferation of perirectal fat. Bowel wall thickening (mean, 13 mm) with homogeneous attenuation, fistula and abscess formation, and mesenteric abnormalities were observed in patients with Crohn colitis. Patients with colitis indeterminate showed colonic changes on CT observed in both disorders. Initial experience suggests that CT can differentiate patients with well established ulcerative and Crohn colitis.

Acquired malposition of the colon and gallbladder in patients with cirrhosis: CT findings and clinical implications.

Topographic relationships among the gallbladder, liver, hepatic flexure of the colon, right hemidiaphragm, and anterolateral peritoneal reflection were evaluated with computed tomography in 75 patients with biopsy-proved cirrhosis and in 200 control subjects to determine the effect of cirrhotic liver morphology on the anatomy of the right upper quadrant of the abdomen. Interposition of the colon between the liver and anterolateral abdominal wall and/or diaphragm was seen in 18 of the 75 (24%) cirrhotic patients and in six of the 200 (3%) control subjects. There was a strong correlation among gallbladder malposition, colonic interposition, and a ratio of transverse caudate lobe width to right lobe width (C/RL) exceeding 0.60. Patients with cirrhosis, colonic interposition, and gallbladder malposition had a mean C/RL of 0.62, compared with a mean of 0.50 for cirrhotic patients without interposition (P less than .0001). The mean C/RL for control subjects without interposition was 0.43, as compared with 0.69 for control subjects with interposition (P less than .01). These acquired malpositions of the colon and gallbladder may pose a diagnostic dilemma and increase the risk of inadvertent injury during percutaneous liver biopsy, interventional biliary tract procedures, and laparotomy.