Distribution and contrast enhanced CT appearance of abdominal tuberculous lymphadenopathy

PURPOSE: To clarify the contrast enhanced CT features and anatomic distribution of the disseminated vs non-disseminated tuberculosis (TB) involving abdominal lymph nodes. MATERIALS AND METHODS: The contrast enhanced CT findings of abdominal lymphadenopathy in 25 patients, including disseminated TB associated with miliary TB of the lung (n = 5) and non-disseminated TB (n = 20), were retrospectively evaluated in a blind review to assess our criteria of morphology, density and location of the involved lymphadenopathy. RESULTS: The enhancement patterns of disseminated TB were not different from those of non-disseminated TB. Ninety-six percent of the patients had peripheral rim enhancement, and 60% showed a multilocular appearance. The enlarged lymph nodes of TB were less than 4 cm in diameter. Lymphadenopathy caused by hematogenous dissemination often accompanied splenic involvement showing multiple low-density foci in the spleen. The predominant sites of lymphadenopathy of disseminated TB were hepatoduodenal ligamentous, hepatogastric ligamentous, mesenteric, and both upper and lower portions of the retroperitoneal lymph nodes, whereas non-disseminated TB mainly involved hepatoduodenal ligamentous, hepatogastric ligamentous, mesenteric and upper retroperitoneal lymph nodes, excluding the lower retroperitoneal lymph nodes. By combining contrast enhancement patterns and the anatomic distribution of lymphadenopathy shown on the contrast enhanced CT images, reviewers made a correct diagnoses of tuberculosis in 94%, of cases, with a specificity of 95% and sensitivity of 92%. CONCLUSION: Contrast enhanced CT patterns correlate well with the pathologic features of tuberculous lymphadenopathy. A different anatomic distribution between disseminated and non-disseminated TB involving the lower retropentoneal lymph nodes was recognized in this study.     

US case of the day. Diffuse large B-cell lymphoma (posttransplant lymphoproliferative disorder [PTLD])

OBJECTIVE: We describe two new CT findings of congestive heart failure (CHF): enlarged mediastinal lymph nodes and hazy heterogeneous mediastinal fat. MATERIALS AND METHODS: Forty-six patients were retrospectively identified who had major and minor clinical signs of congestive heart failure and had undergone chest CT during their symptomatic period. Two radiologists reviewed the CT studies and by consensus documented the presence or absence of imaging findings of CHF, including interstitial abnormalities, vascular redistribution, axial thickening, pleural effusions, cardiac enlargement, and mediastinal abnormalities. RESULTS: Smooth septal thickening, bilateral pleural effusions, vascular redistribution, and cardiac enlargement were the most common CT findings in patients with CHF. Enlarged mediastinal lymph nodes and hazy mediastinal fat were seen in 55% and 33% of cases, respectively. In a cohort of 17 patients with elevated pressures in the pulmonary capillary wedge documented within 24 hr of CT, CT scans revealed lymphadenopathy in 14 patients (82%) and inhomogeneous fat in 10 patients (59%). CONCLUSION: Enlarged mediastinal lymph nodes and hazy mediastinal fat occur in patients with CHF and are revealed by CT. Lymphadenopathy in patients with CHF does not necessarily indicate malignancy or an infectious process.     

Acute graft-versus-host disease in children: abdominal CT findings

PURPOSE: To review the computed tomographic (CT) appearance of acute gastrointestinal graft-versus-host disease (GVHD) in children. MATERIALS AND METHODS: Sixteen abdominal CT scans obtained in 12 children with acute gastrointestinal GVHD who underwent allogeneic bone marrow transplantation (BMT) were compared with 16 CT scans obtained in autologous bone marrow recipients not at risk for GVHD (control group). Autopsy findings in six patients with GVHD were compared with CT findings. RESULTS: All CT scans in patients with GVHD showed an abnormally enhanced, thin mucosal layer of bowel wall involving fluid-filled, dilated, poorly opacified bowel loops from the duodenum to the rectum. This corresponded histologically to mucosal destruction and replacement by a thin layer of highly vascular granulation tissue. Bowel wall thickening was often absent. Infiltration of mesenteric fat was seen in 91% of patients The control group showed no similar abnormalities. CONCLUSION: Acute gastrointestinal GVHD characteristically appears on CT scans as multiple, diffuse, fluid-filled bowel loops with a thin, enhancing layer of bowel wall mucosa. Bowel wall thickening often is absent.     

Usefulness of CT in patients with intestinal obstruction who have undergone abdominal surgery for malignancy

OBJECTIVE: The purpose of this study was to evaluate the usefulness of CT in determining the causes of intestinal obstruction in patients who have undergone abdominal surgery for malignancy. MATERIALS AND METHODS: We analyzed the CT scans of 55 patients with benign (n = 26) or malignant (n = 29) intestinal obstruction that developed after abdominal surgery for malignancy. After calculating the diagnostic accuracy of interpretations by three radiologists, we compared CT findings for benign and malignant intestinal obstructions with respect to peritoneal involvement patterns and other ancillary findings. Multivariate logistic regression analysis was used to determine the diagnostic performance of CT in revealing causes of obstruction. RESULTS: Diagnostic accuracies of the three radiologists were 67%, 75%, and 78%. CT findings indicating malignant obstruction were a mass at the site of obstruction or prior surgery, lymphadenopathy, or an abrupt transition zone and irregular bowel wall thickening at obstructed sites (p < .05). Conversely, the chance for benign obstruction increased when CT revealed mesenteric vascular changes, a large amount of ascites, or a smooth transition zone and smooth bowel wall thickening at the obstructed site (p < .05). With multivariate logistic regression analysis using two variables (a mass at the site of obstruction or prior surgery and lymphadenopathy), we calculated the overall accuracy of CT as 84% (46/55 patients). CONCLUSION: CT is useful in differentiating benign from malignant intestinal obstructions in patients who have undergone abdominal surgery for malignancy. However, CT has limitations in patients not having a demonstrable peritoneal mass.     

Differential effects of sunscreens on UVB-induced immunomodulation in humans

Ischemic bowel disease is a rare disorder whose incidence is increasing as the mean age of the population increases. Diagnosis by clinical, laboratory and radiologic means is often difficult, and delay in definitive therapy results in substantial morbidity and mortality. A series of 26 consecutive patients, with proved acute superior mesenteric ischemia, was retrospectively reviewed: the authors report the diagnostic methods performed preoperatively, the site and the cause of infarction and the time passed between the first radiograph ans surgery. Plain abdominal radiographs were performed in 25 of 26 patients, screening abdominal US in 23 cases and CT in 19 cases. All radiological examinations were retrospectively reviewed by three authors, independently, to recognize the different signs of infarction. On plain abdominal films, the findings warranting a presumptive diagnosis of bowel infarction were air-fluid levels (84% of cases), dilated bowel loops (48%), thickened and unchanging loops (20%), gastric distension and gasless abdomen (12%), small bowel pseudo-obstruction (8%). Screening abdominal US demonstrated intraperitoneal free fluid (26%) and dilated bowel loops (22%). Abdominal CT showed air-fluid levels (79%), dilated loops and free intraperitoneal fluid (47%), intramural gas and thickened bowel loops (36.8%), engorgement of the mesenteric vessels (31%), mesenteric-portal gas, mesenteric thrombus and marked reduction in the volume of gas in the small bowel (10.5%) and paper-thin bowel loops (5%). The authors conclude that air-fluid levels, dilated loops and intraperitoneal free fluid are the most frequent findings, even though they are not specific. While abdominal plain film and screening ultrasonography can be negative, CT detects at least one abnormal finding and at least three abnormal findings in 73% of cases.     

Menstrual cycle and age: influence on parenchymal contrast medium enhancement in MR imaging of the breast

PURPOSE: To quantify how frequently mesenteric adenitis clinically mimics appendicitis and to determine its appearance at computed tomography (CT). MATERIALS AND METHODS: The medical records of 651 consecutive patients with an admission diagnosis of appendicitis were reviewed to determine how often mesenteric adenitis was the discharge diagnosis. The CT scans of a separate group of 18 patients with a discharge diagnosis of mesenteric adenitis were reviewed. These patients were part of a group of 100 consecutive patients prospectively evaluated with CT of the appendix for clinically suspected appendicitis. RESULTS: Fifty of 651 patients (7.7%) with an admission diagnosis of appendicitis had a discharge diagnosis of mesenteric adenitis. Mesenteric adenitis constituted 50 of the 252 (19.8%) discharge diagnoses other than appendicitis. All 18 CT scans of mesenteric adenitis showed three or more nodes that measured at least 5 mm in shortest axis clustered in the right lower quadrant, with a normal appendix identified. Eight patients had associated ileal or ileocecal wall thickening. CONCLUSION: Mesenteric adenitis is an important clinical mimic of appendicitis. It appears at CT as clustered, enlarged mesenteric lymph nodes with a normal appendix, and there may be associated ileitis or ileocolitis noted.     

Retropsoas positioned bowel: incidence and clinical relevance

PURPOSE: Our goal was to assess the incidence of retropsoas positioned large or small bowel in the population and to examine factors predisposing to its formation. METHOD: The presence of retropsoas positioned bowel was retrospectively studied in 1,852 abdominal CT examinations of 1,055 men and 797 women, 648 younger and 1,204 older than 50 years. All examinations were considered normal or demonstrated findings that were unrelated to the position of the bowel. RESULTS: Retropsoas positioned colon (RPC) was observed in 51 (2.8%) cases for the ascending and 45 (2.3%) for the descending colon. RPC appeared more frequently in younger (< 50 years) than older patients and in individuals with decreased amount of retroperitoneal fat. Retropsoas position of small bowel loops was observed in 11 (0.6%) patients, all exhibiting paucity of retroperitoneal fat. CONCLUSION: Because of its prevalence, retropsoas positioned bowel should be considered when performing percutaneous diskectomy or other interventional procedures in the posterior retroperitoneum.     

Small lymph nodes of the abdomen, pelvis, and retroperitoneum: usefulness of sonographically guided biopsy

PURPOSE: To evaluate the usefulness of sonographically guided percutaneous biopsy of small lymph nodes in the abdomen, retroperitoneum, and pelvis. MATERIALS AND METHODS: From May 1995 through January 1997, 35 sonographically guided lymph node biopsies were performed in 34 patients. All biopsies were performed with a 20- (n = 18) or 22-gauge (n = 10) self-aspirating needle alone or in combination (n = 7). To determine the amount of compression achieved with the transducer, the skin-to-lesion distance on reference computed tomographic (CT) scans was compared with that on sonograms. A biopsy was considered successful if a specific benign or malignant diagnosis was rendered by the pathologist. RESULTS: Of 35 sonographically guided biopsies, 30 (86%) were successful. Diagnoses included 26 (74%) cases of carcinoma, three (9%) cases of benign reactive lymphocytosis confirmed at open biopsy, and one (3%) case of a lymph node with a positive acid-fast bacilli stain. The average lymph node diameter was 2.1 cm (range, 0.9-4.3 cm). With sonography, a mean of 2.5 needle passes (range, 1-5) were made per biopsy. Transducer compression reduced the skin-to-lesion distance from an average of 8.8 cm (at CT) to 4.5 cm. CONCLUSION: Sonographic guidance seems to provide a reasonable alternative to CT in biopsy of small abdominal, pelvic and retroperitoneal lymph nodes.     

IgG response to pneumococcal polysaccharide-protein conjugate appears similar to IgG response to polysaccharide in bone marrow transplant recipients and healthy adults

OBJECTIVE: This study was done to determine if the detection of pericolic lymph nodes on CT scans could be used to differentiate cancer of the colon from diverticulitis. MATERIALS AND METHODS: We retrospectively evaluated 58 CT scans from 57 patients with proven diverticulitis or cancer of the colon. The CT scans were evaluated by five board-certified radiologists who were unaware of the proven diagnosis. Consensus opinions regarding the presence and size of pericolic lymph nodes were recorded. These data were correlated with the proven diagnoses to determine the correlation between the observed findings and the type of colonic abnormality. Fisher's exact test was used to determine statistical significance. RESULTS: Lymph nodes were seen in 22 (71%) of 31 cases of colonic cancer and in four (15%) of 27 cases of diverticulitis. The lymph nodes were 0.5-2.5 cm in short-axis diameter. We saw no difference in node size for patients with colonic cancer versus patients with diverticulitis. The nodes were most commonly located along the blood vessels in the mesenteric fat. Statistical analysis showed a significant difference (p < .001) in the frequency but not in the size of nodes between the two groups of patients. The detection of nodes resulted in a diagnostic sensitivity and specificity for colonic cancer of 71% and 85%, respectively. CONCLUSION: Pericolic lymph nodes are seen much more frequently in patients with colonic cancer than in patients with diverticulitis. The detection of pericolic lymph nodes in patients suspected of having diverticulitis should raise the suspicion of underlying colonic cancer that should, in turn, prompt additional evaluation.     

Identification of the tumor antigen 90K domains recognized by monoclonal antibodies SP2 and L3 and preparation and characterization of novel anti-90K monoclonal antibodies

PURPOSE: To study the imaging findings in patients with systemic mastocytosis and to correlate the findings with the severity of disease on the basis of an established classification system. Pathologic findings, when available, were correlated with imaging findings. MATERIALS AND METHODS: Computed tomographic (CT) and ultrasound (US) scans and corresponding pathologic findings, when available, were retrospectively reviewed in 27 patients with systemic mastocytosis. RESULTS: Only five (19%) of the patients in our series had normal abdominal CT and/or US examination results. Common abdominal imaging findings associated with systemic mastocytosis were hepatosplenomegaly, retroperitoneal adenopathy, periportal adenopathy, mesenteric adenopathy, thickening of the omentum and the mesentery, and ascites. Less common findings included hepatofugal portal venous flow, Budd-Chiari syndrome, cavernous transformation of the portal vein, ovarian mass, and complications such as chloroma. The findings were more common in patients with category II and those with category III disease. CONCLUSION: Abdominal findings at CT and US are common in patients with systemic mastocytosis. Although the findings in patients with systemic mastocytosis are not specific to the disease, they are useful in directing further studies for diagnostic confirmation and in estimating the extent of systemic involvement.     

Giant cell tumour of the retropharynx

INTRODUCTION: Few pancreatic carcinomas (5-22%) are resectable at the time of diagnosis because this lesion is seldom diagnosed in an early stage. Unresectability is mainly due to the presence of metastases to the liver, peritoneum and lymph nodes and to tumor spread especially to the portal mesenteric trunk where it can invade, compress, reduce, or occlude the vessels. We investigated the diagnostic yield of multiplanar and 3D spiral CT in the assessment of pancreatic carcinoma resectability. MATERIAL AND METHODS: Twenty-seven patients with histologically confirmed pancreatic head cancer were submitted to spiral CT and color Doppler US in the Surgical Clinic I of the Bologna University. The examination results were correlated with the intraoperative findings of careful inspection and palpation and of US studies of the pancreatic mass and adjacent structures. The tumors were classified in relation to some CT parameters: tumor size (T), infiltration of the stomach (S) and/or duodenum, lymph nodes (N) or distant (M) metastases, involvement of vascular structures (V), particularly of portal or superior mesenteric vein, or superior mesenteric artery. Five grades of vascular involvement were considered. The results of these techniques were correlated with intraoperative findings from careful inspection and palpation and with US studies of the pancreatic mass and adjacent structures. RESULTS: Spiral CT revealed vascular involvement in 19 of 27 cases (70.4%): involvement of portal and superior mesenteric vein was found in 14 (73.6%), superior mesenteric vein was involved in 2 (10.6%), the portal vein in one (2%) and, finally the portal, superior mesenteric vein and superior mesenteric artery in 2 cases (10.6%). The spiral CT results were confirmed intraoperatively in 26 of 27 cases (96.3%); spiral CT did not reveal hepatic metastasis only in one case. Spiral CT with multiplanar reconstructions had very high specificity and sensitivity (100%) in the assessment of vascular involvement, while color Doppler US had the same specificity but lower sensitivity (84.2%). Spiral CT was less sensitive (80%) in the detection of liver metastases. CONCLUSIONS: We believe that spiral CT is currently the best technique for pancreatic carcinoma staging, providing useful information for correct surgical planning.     

Ultrasound guided fine needle aspiration cytology in abdominal tuberculosis

Although barium studies and CT are useful in assessing abdominal pathology in tuberculosis, imaging findings are not always specific and a histopathological or bacteriological confirmation is often required. The aim of the present study was to evaluate the role of ultrasound (US) guided fine needle aspiration cytology (FNAC) in the diagnosis of abdominal tuberculosis in patients with non-palpable lesions detected on US/CT. FNAC was performed on 31 sites in 30 patients. The sites included enlarged lymph nodes (n = 14), focal lesions in liver (n = 2) and spleen (n = 8), and thickened bowel in the ileocaecal region (n = 7). The results were classified cytomorphologically into four groups: (1) definite evidence of tuberculosis; (2) presumptive evidence of tuberculosis; (3) suggestive of tuberculosis; and (4) negative for tuberculosis. 18 of the 31 FNACs (58%) revealed a positive diagnosis of tuberculosis (definite evidence in nine patients and presumptive evidence in nine patients). 13 of the 31 FNACs (42%) showed either necrosis alone (n = 4) or negative results (n = 9). Zeihl-Neelson staining for acid-fast bacilli on direct smear was positive in only nine patients (29%). Splenic and lymph nodal FNAC had a high sensitivity (87.5% and 78.6%, respectively) in the diagnosis of tuberculosis. None of the bowel and liver FNACs was diagnostic. No complications were encountered. US guided FNAC offers a safe and accurate method of achieving a diagnosis in patients with suspected abdominal tuberculosis who present with radiologically demonstrable but non-palpable lesions, especially those involving lymph nodes and spleen.     

Variability in the detection of enlarged mediastinal lymph nodes in staging lung cancer: a comparison of contrast-enhanced and unenhanced CT

OBJECTIVE: Because CT protocols for staging lung cancer vary and little information exists regarding the diagnostic importance of using i.v. contrast material, our intent was to evaluate intra- and interobserver agreement in the detection of enlarged mediastinal lymph nodes, comparing i.v. contrast-enhanced and unenhanced CT. SUBJECTS AND METHODS: Fifty patients with known or suspected bronchogenic carcinoma underwent unenhanced thoracic CT followed by contrast-enhanced CT. Three observers noted enlarged lymph nodes (> 10 mm in the short axis) and assigned the enlarged nodes to American Thoracic Society nodal station designations. Enlarged lymph nodes were grouped two ways: by assigning the exact number of enlarged lymph nodes found (zero, one, two, three, four or more), and by assigning whether at least one, or no, enlarged mediastinal lymph nodes were found at a station ("one or none"). Agreement levels were determined for inter- and intraobserver interpretations using weighted kappa statistics and the McNemar test. RESULTS: The number of enlarged lymph nodes with enhanced CT was 11% higher than on unenhanced studies (418 versus 377; p = .044). Numbers of enlarged lymph nodes were different for five stations; however, the numbers were small except for the right upper paratracheal station (2R) (contrast-enhanced, 68 enlarged lymph nodes; unenhanced, 44 enlarged lymph nodes; p = .014). With regard to all stations together, intraobserver agreement between contrast-enhanced and unenhanced studies was almost perfect (kappa range, .85-.94), and no difference was found for any observer in the proportion of patients with at least one enlarged lymph node. Interobserver agreement was substantial or almost perfect for the total number of enlarged lymph nodes. For specific stations, the lowest kappa value was .48 at 2R. One observer reported more patients with at least one enlarged lymph node with contrast enhancement at station 2R (p = .031). Greater agreement existed between two observers at station 2R with contrast enhancement versus no enhancement (kappa = .85 versus .48; p = .02). Conclusions matched, and calculations of estimated kappa values gave similar results for determination of the specific number of enlarged lymph nodes at a station and the "one or none" category. CONCLUSION: We found high agreement for intra- and interobserver interpretations for contrast-enhanced and unenhanced CT, although contrast-enhanced CT revealed more enlarged lymph nodes, especially at station 2R.     

CT of blunt trauma to the bowel and mesentery

Injuries to the bowel and mesentery are found in approximately 5% of all patients undergoing laparotomy after blunt abdominal trauma. Bowel and mesenteric injuries are often subtle and difficult to diagnose, and a delay in the diagnosis is associated with increased mortality and morbidity. CT is the best imaging method for diagnosing injuries to the bowel and mesentery. With meticulous scanning techniques, most significant bowel and mesenteric injuries can be reliably identified with CT preoperatively, and associated injuries to other abdominal viscera can be confirmed.     

Developing a patient self-medication program for the rehabilitation setting

Imaging methods provide an important diagnostic basis to clarify mesenteric ischemia. Angiography is the definitive method of investigation in such cases. Other noninvasive methods such as ultrasonography, computed tomography, and magnetic resonance imaging must still prove their importance. We describe three cases of unspecific abdominal pain where the CT shows a mesenteric venous thrombosis with an infarcted bowel. The venous infarcted bowel is clearly demonstrated by CT when other signs for MTV such as ascites, bowel wall thickening, bowel dilatation, and pneumatosis intestinalis are present. CT seems to be a good procedure in order to identify unspecific abdominal pain as being caused by a vascular insufficiency.     

Structure of the glycosylphosphatidylinositol membrane anchor glycan of a class-2 variant surface glycoprotein from Trypanosoma brucei

Neoplasms of the small bowel are rare lesions that account for less than 5% of all gastrointestinal tumors. Although the differential diagnosis for a small bowel tumor is extensive, various small bowel neoplasms have characteristic features at computed tomography (CT) that may aid in making a diagnosis. Small bowel adenocarcinoma may appear at CT as an annular lesion, a discrete nodular mass, or an ulcerative lesion. Non-Hodgkin lymphoma may appear as a segmental bulky mass that gradually merges into the normal bowel wall. Lymphoma is characteristically associated with marked luminal dilatation. Carcinoid tumor may appear as an ill-defined homogeneous mass that displaces bowel loops. Calcification and desmoplastic reaction in a mesenteric mass suggest the diagnosis of carcinoid tumor. Gastrointestinal stromal tumors (GISTs), both benign and malignant, may be submucosal, subserosal, or intraluminal. The CT appearance of a GIST may include a sharply defined mass with homogeneous attenuation, sometimes with calcification. Lipoma appears at CT as a well-circumscribed, intraluminal homogeneous mass with fat attenuation. Most malignant small bowel tumors are actually metastases that have spread intraperitoneally, hematogenously, or by local extension. Intraperitoneal seeding usually manifests at CT as multiple small nodular metastases along the small bowel serosa, mesentery, and omentum. In patients with Peutz-Jeghers syndrome, nonneoplastic lesions may mimic small bowel neoplasms.     

Tuberculous mesenteric lymphadenitis mimicking pancreatic carcinoma

Tuberculous mesenteric lymphadenitis is a rare clinical entity and non-surgical diagnosis of this condition remains a challenge. A 38-year-old Indian woman presented with a six-week history of epigastric pain, low-grade fever and anorexia. Upper endoscopy showed a gastric ulcer of the posterior wall of the stomach. On CT scan there was a 8 cm abdominal mass involving the pancreatic body and tail and the endoscopic ultrasonography was also compatible with a cystic pancreatic tumor which had eroded into the stomach. An exploratory laparotomy was performed and the diagnosis of tuberculous mesenteric lymphadenitis was confirmed by bacteriological and histological examinations. Medical therapy was started after surgery. At 18 months she is asymptomatic and abdominal CT scan is normal. Tuberculosis of mesenteric lymph nodes usually raises serious diagnostic problems. A high grade of suspicion is necessary in order to perform a pre-operative diagnosis.     

Mediastinal tuberculous lymphadenitis: CT findings of active and inactive disease

OBJECTIVE: The purpose of this study was to analyze CT findings of active and inactive disease in patients with mediastinal tuberculous lymphadenitis. MATERIALS AND METHODS: Using biopsy and culture results, we categorized 49 consecutive patients with mediastinal tuberculous lymphadenitis studied with CT scans as patients with active disease (n = 37) or patients with inactive disease (n = 12). Follow-up CT scans were obtained after antituberculous therapy in 25 patients with active disease and three patients with inactive disease. In 10 patients (seven with active disease and three with inactive disease), CT findings were analyzed and correlated with pathologic findings. RESULTS: In all 37 patients with active disease, the nodes (n = 151) varied in size (1.5-6.7 cm; mean, 2.8 +/- 1.0 cm) and had central low attenuation and peripheral rim enhancement. Calcifications within the nodes were seen in seven patients (19%). In the 12 patients with inactive disease, the nodes (n = 34) varied in size (1.0-4.7 cm; mean, 2.1 +/- 1.0 cm) but were usually smaller than nodes in patients with active disease. In the patients with inactive disease, the diseased nodes were homogeneous and without low-attenuation areas. Calcifications within the nodes were seen in 10 (83%) of the 12 patients with inactive disease. Low-attenuation areas within the nodes corresponded pathologically to areas of caseation necrosis in seven patients with active disease and in no patients with inactive disease. After treatment, enlarged mediastinal nodes in patients with active disease shrunk and low-attenuation areas within the nodes disappeared in all 25 patients. However, the findings of calcified nodes in the three patients with inactive disease did not change after 6 months of follow-up. CONCLUSION: In these 49 patients with mediastinal tuberculous lymphadenitis, CT findings of nodes with central low attenuation and peripheral rim enhancement suggested active disease, and findings of homogeneous and calcified nodes suggested inactive disease. Low-attenuation areas within the nodes had pathologic correspondence to areas of caseation necrosis and may be a reliable indicator for disease activity.     

Abdominal CT findings when the superior vena cava, brachiocephalic vein, or subclavian vein is obstructed

OBJECTIVE: We evaluated findings on contrast-enhanced abdominal CT scans that suggest obstruction of the superior vena cava, brachiocephalic vein, or subclavian vein. SUBJECTS AND METHODS: We conducted a retrospective review of 22 patients with superior vena caval, brachiocephalic vein, or subclavian vein obstruction and analyzed the upper abdominal images on a chest CT scan or an abdominal CT scan. We assessed collateral vessels in the upper abdomen to answer the following question: Did enhancement approach undiluted IV contrast or were there other findings? In the second part of our study, we conducted a prospective review of abdominal CT scans of 200 patients without known mediastinal disease or known upper extremity venous occlusion to determine the frequency of abnormal enhancement of these vessels in a healthy population. RESULTS: The groups of collateral vessels revealed on abdominal CT scans were azygos or hemiazygos veins, internal mammary veins, lateral thoracic and superficial thoracoabdominal veins, vertebral venous plexus veins, and small mediastinal collateral veins. In the retrospective series, one patient had focal enhancement of the liver and early inferior vena caval enhancement due to collateral vessels. In the prospective series, abdominal CT scans of two patients (1%) revealed dense undiluted enhancement of one or more groups of collateral vessels: One patient had an ipsilateral pacemaker, and the other patient had an anterior neck phlegmon to the upper mediastinum. Both conditions may have been factors in the revealing of the collateral vessels. Two other patients (1%) in the prospective series had mild to moderate vessel enhancement that was less than that from undiluted contrast material. In one of these patients, the enhancement was related to abdominal wall hyperemia after surgery. In the other patient, enhancement may have been the result of ipsilateral axillary nodes. CONCLUSION: On upper abdominal CT scans, dense undiluted contrast material in the collateral vessel groups that we studied suggests possible obstruction of the superior vena cava, brachiocephalic vein, or subclavian vein.     

Abdominal pain, weight loss, tarry stools

A 65-year-old man had abdominal pain and night sweat for several weeks. He had lost weight and also reported black stools. Anemia of iron deficiency was found in laboratory tests. Further investigation revealed a stenosing process in the small intestine as source of bleeding. High grade non-Hodgkins' lymphoma was diagnosed histologically in the resected bowel segment and the mesenteric lymph nodes. Further staging did not reveal further manifestations of lymphoma. Polychemotherapy and subsequent irradiation were administered.