[The angiogram sign in lung consolidation: what is its diagnostic value?]

The angiogram sign in chest CT is the demonstration of normally enhanced pulmonary branches within hypoattenuating lung parenchyma consolidation. In a retrospective review of the chest CT exams performed in a 2-year period, we identified the angiogram sign in 10 patients with lung consolidation; the diagnosis was central lung tumor with obstructive pneumonia in 4 patients, bronchioloalveolar carcinoma in 2 patients, postirradiation fibrosis in 1 patient, tuberculous pneumonia in 1 patient, lung lymphoma in 1 patient and metastasis from pancreatic tumor in 1 patient. The diagnosis was made with cytology and/or surgical specimen in 9 patients and with clinical-radiologic follow-up in 1 patient. The density, air and mucous bronchogram and the volume loss in the consolidated lung were also considered. The consolidated lung density was < 30 HU in 5 patients-one bronchioloalveolar carcinoma, one metastasis from pancreatic carcinoma and 3 obstructive pneumonia cases-, while it was > 30 HU in the extant 5 patients. The air bronchogram sign was observed in 4 cases-one bronchioloalveolar carcinoma, one metastasis, one postirradiation fibrosis and one lung lymphoma-, while a mucous bronchogram was observed in 3 patients with obstructive pneumonia. Lung volume was reduced only in 2 patients-one obstructive pneumonia and one postirradiation fibrosis. In our opinion, the CT angiogram sign must be considered a poorly specific sign, because it can be found in many pathologic processes, both benign and malignant. If associated with the other features of lung consolidation, the CT angiogram sign can help diagnose, together with clinical findings and the patient's history, the pathologic condition. Particularly, the angiogram sign within a hypoattenuated lung consolidation area can be found in obstructive pneumonia, while the angiogram sign within a hypoattenuated consolidation with an air bronchogram probably indicates a mucinous carcinoma with lipidic growth.

Computed tomography visceral adipose tissue volume measurements of Italians. Predictive equations

OBJECTIVES

To evaluate total visceral adipose tissue (AT) volumes in relation to single slices of visceral AT area measured at different levels and to other simple anthropometric measurements.

DESIGN

Only outpatients examined in a metabolic unit were considered; subjects without conditions known to affect AT distribution who gave their informed consent were recruited.

SETTING

All subjects were hospitalized in the Department of Internal Medicine of the University of Messina.

SUBJECTS

90 adult subjects of which 18 men and 42 pre- and 30 post-menopausal women. Ages ranged from 18 to 69 years and body mass indexes ranged from 22 to 50.

INTERVENTIONS

The AT volume was calculated by computed tomography from the AT area of five scans and from the distances between these scans.

RESULTS

AT area at the level of the 2nd-3rd lumbar vertebra had by itself the highest predictive power in men (s.e. = 6.8%), in post-menopausal women (s.e. = 7.4%) and, together with age, in pre-menopausal women (s.e. = 14%). Of the non-radiological parameters it was waist circumference, together with age, which showed the highest predictive power in men (s.e. = 21%), pre-menopausal women (s.e. = 25%) and, together with height, in post-menopausal women (s.e. = 33%).

CONCLUSIONS

A single scan measurement at the lumbar level was confirmed to be representative of total visceral AT volume. Waist circumference was the non-radiological parameter that best correlated with volume.

Air-space pattern in lung metastasis from adenocarcinoma of the GI tract

PURPOSE

We retrospectively reviewed a series of proven lung metastasis to evaluate the frequency and CT features of metastases showing an air-space (lepidic) pattern of growth.

METHOD

CT examinations of 65 patients with proven lung metastasis from GI carcinomas were reviewed by three observers. Four CT features were used to classify lesions as air-space metastases: (a) air-space nodules; (b) parenchymal consolidation containing air bronchogram and/or showing angiogram sign; (c) focal or extensive ground-glass opacities; and (d) nodules(s) with a "halo" sign.

RESULTS

Six of 65 patients showed air-space metastases: three from pancreatic carcinoma, two from colonic carcinoma, and one from jejunal carcinoma. In one case, metastasis appeared as extensive parenchymal consolidation associated with ground-glass opacities; in one as an area of ground-glass opacity; in one as an extensive parenchymal consolidation with air bronchogram; in one as parenchymal consolidations with angiogram sign and multiple nodules, some of these with halo sign; in one as air-space nodules and patchy air-space consolidations; and in one as a solitary nodule with halo sign.

CONCLUSION

Our study shows that air-space lung metastasis from GI carcinomas is uncommon but not rare. On CT as well as microscopically, differential diagnosis between air-space metastasis and bronchioloalveolar carcinoma may be impossible.

Subcapsular renal spread of a pancreatic pseudocyst

In pancreatitis, the fluid collection may extend to unusual sites and organs and form a pseudocyst. We present US and CT findings of a pancreatic tail pseudocyst extending into the subcapsular space of the left kidney.

[Computerized tomography in the assessment of obstructive jaundice caused by hepatic hydatid cysts]

This paper reports on the CT findings of obstructive jaundice caused by hydatid cysts of the liver, which are an unusual event occurring in 5-10% of cases. Thus, only a few reports can be found in the literature dealing with the CT features of this syndrome. Eight patients with obstructive jaundice were selected from 87 patients with hydatid disease of the liver and examined with CT. The CT diagnosis of rupture into the largest bile ducts is based upon the demonstration of hepatic hydatid cysts together with intrabiliary hydatid sand, membranes and scolices and/or the identification of parietal discontinuity with communication between the cyst and the biliary tree. Rupture into the largest bile ducts was demonstrated in 7 patients. The following CT patterns were observed: 1) intrahepatic biliary tract dilatation (all cases); 2) extrahepatic biliary tract dilatation (6 cases); 3) cyst wall interruption (5 cases--in 3 of them the communication between the cyst and the dilated bile duct was demonstrated); 4) daughter cysts, fragmented membranes or hydatid sand in the biliary tree (5 cases); 5) hydatid material in the gallbladder (1 case) and, finally, disappearance of the daughter cyst visible on a previous CT examination (1 case). In another patient, the diagnosis of compressive jaundice without biliary communication was suggested because a bulky hydatid cyst was found near the hilum of liver. CT findings were confirmed with ERCP or at surgery. CT failed to reveal small tears with minute biliary radicles, which are usually asymptomatic, whose diagnosis could be made only with preoperative cholangiography. Hydatid cysts of the liver can cause obstructive jaundice because of main bile duct compression or of large bile duct perforation with consequent passage of hydatid material into the biliary tree. This complication should be promptly managed surgically to avoid potentially fatal complications, which makes a preoperative diagnosis essential.

[Computerized tomography in the assessment of metastatic facial adenopathy]

The facial lymph nodes are classified in five groups: mandibular, buccinator, infraorbital, malar and retrozygomatic nodes. This paper reports the CT appearance of neoplastic involvement of these nodes, an unusual and not well documented event. The CT examinations of 62 patients with a history of primary or recurrent cancer of the epidermal structures of the face, oral cavity and sinonasal region were retrospectively reviewed to assess the presence of facial adenopathy. Nine cases of neoplastic involvement of facial nodes were found. Most commonly the buccinator nodes (4 cases) were involved, the infraorbital, mandibular (2 cases) and retrozygomatic nodes (1 case) being less commonly involved. No malar nodes were found. Neoplastic involvement of these nodes was caused by squamous cell carcinoma in 6 cases, by adenocarcinoma in 2 cases and by a lymphoma in 1 case. Normal nodes could not be confidently identified on CT studies. CT diagnosis of neoplastic involvement of facial nodes is based on the presence of a nodular lesion which lies along the lymphatic pathways of the primary neoplasm in an anatomically compatible location. CT diagnosis of facial nodes is very important for treatment planning if the nodes are deep or at a distance from primary cancer. This is especially true for retrozygomatic and buccinator nodes.

[Computerized tomography in gaseous hypotonic duodenography in the study of the pancreatico-duodenal area]

This study was aimed at assessing the role of CT-hypotonic gaseous duodenography in the study of the pancreatic-duodenal region. Forty-two patients with malignancies in this region were examined with CT of the upper abdomen followed by CT-hypotonic gaseous duodenography (30 pancreatic head cancers, 7 main bile duct and 5 ampullary lesions). In 20 of 28 cases of pancreatic head carcinoma, CT-hypotonic gaseous duodenography yielded more pieces of information than baseline abdominal CT and was also more useful in small pancreatic head cancers, < 4 cm diameter. In 4 of these patients, CT-hypotonic gaseous duodenography better demonstrated the pancreatic lesions which conventional CT had demonstrated poorly. In contrast, CT-hypotonic gaseous duodenography was less useful in main bile duct carcinomas, depicting focal duodenal infiltration in only 1 of 7 cases. In all ampullary tumor patients (5/5), CT-hypotonic gaseous duodenography demonstrated intraduodenal lesions. The authors conclude that CT-hypotonic gaseous duodenography is a useful technique to investigate small pancreatic head cancers and the method of choice to demonstrate ampullary lesions.

[Bronchiolo-alveolar carcinoma. The computed tomographic picture and histological correlations]

Twenty-one CT examinations of 18 patients with a known bronchioloalveolar carcinoma in the lung were retrospectively reviewed to describe the CT features of bronchioloalveolar carcinomas. Surgical specimens were available in 13 cases in which CT-histologic correlation was also obtained. In 5 patients the diagnosis was made with cytology and confirmed with radiologic-clinical follow-up. Three patients were reexamined for relapses 6-20 months after the resection of a localized carcinoma. Carcinomas exhibited 3 radiologic patterns: a) solitary pulmonary nodule (11 cases), b) mass or pulmonary consolidation (3 cases) and c) multicentric or diffuse disease (7 cases). Solitary nodular bronchioloalveolar carcinomas were associated with irregular or spiculated margins in 9 of 11 patients. In some cases internal inhomogeneity due to bubble-like radiolucencies was demonstrated. At pathology, bubble-like radiolucencies correlated with air-containing cystic spaces lined by neoplastic epithelium or patent and dilated bronchi. Some nodules exhibited linear and serpentine internal radiolucencies. Pathology demonstrated them to be consistent with patent intratumoral bronchioles (air bronchiologram) and air-containing neoplastic glandular spaces, respectively. In two cases a perinodular ground-glass halo was demonstrated surrounding the nodule (CT halo sign), due to perinodular lepidic tumor growth. Massive or ground-glass opacity involving a pulmonary segment or a lobe was another CT pattern of bronchioloalveolar carcinoma. An air bronchogram was usually demonstrated within the lesion. In the mucinous type of bronchioloalveolar carcinoma, pulmonary consolidations had a low CT value because of the large amount of intratumoral mucus. The diffuse type of tumor presented as multiple pulmonary nodules or multiple pulmonary consolidations, or both. In two cases multiple nodules were associated with carcinomatous lymphangitis. In conclusion, bronchioloalveolar carcinoma should be considered in the differential diagnosis of solitary pulmonary nodules, multiple pulmonary nodules and chronic alveolar opacities. The diagnosis of a bronchioloalveolar carcinoma is of great value since surgery can help nearly 70% of the patients at this stage recover.

CT-pathologic correlation in nodular bronchioloalveolar carcinoma

OBJECTIVE

We retrospectively reviewed CT and pathologic examinations in resected nodular bronchioloalveolar carcinomas (BACs) to correlate the histology with the appearance of the nodules on preoperative thin section CT images.

MATERIALS AND METHODS

Thin section CT scans of 11 patients with nodular BAC were reviewed by two observers. In each case, size, tumor-lung interface, and internal characteristics of the nodule were recorded and correlated with histopathologic examinations.

RESULTS

Computed tomography showed a large bronchus leading to or contained within the nodule in 36%; spiculated, lobulated, or irregular borders in 82%; pleural retraction in 36%; internal inhomogeneity in 45%; and a zone of intermediate attenuation surrounding a higher attenuation nodule and separating it from the surrounding lung parenchyma (the CT halo sign) in 18% of the 11 BACs. In two lesions internal serpentine radiolucencies could be seen. Histopathologic studies showed this correlated with the air-containing glandular spaces of the tumor.

CONCLUSION

The CT halo sign and serpentine radiolucencies should be added to the list of the CT findings of nodular BAC. However histologic examination is required to confirm the diagnosis of BAC.

Small bronchogenic carcinomas presenting as solitary pulmonary nodules. Bioptic approach guided by CT-positive bronchus sign

To evaluate the utility of the CT bronchus sign in making a choice between transbronchial biopsy (TBB) and transthoracic needle aspiration (TTNA) as the first diagnostic procedure in a patient with a solitary pulmonary nodule (SPN), we reviewed the results of TBB and TTNA in 26 patients who had a bronchogenic carcinoma less than 3 cm, studied with thin-section CT. The patients were divided into two groups. Group 1 included ten cases with a third- to fifth-order bronchus sign. Group 2 included two cases with a sixth-order bronchus sign and 14 cases with absence of a bronchus sign. TBB was performed in all the patients; conversely, TTNA was carried out in 22 patients. In group 1, TBB gave a diagnostic yield in eight (80 percent) of ten patients, while TTNA was positive in three (42 percent) of seven patients (p > 0.05). Conversely, in group 2, results of TBB were normal in all the patients, while TTNA gave a diagnosis in 10 (66 percent) of 15 patients (p < 0.05). We think that TBB should be considered the method of choice in diagnosing SPNs associated with a third- to fifth-order bronchus sign; conversely, TTNA is more useful than TBB in diagnosing SPNs in the presence of a more peripheral bronchus sign or with the absence of a bronchus sign. In conclusion, we suggest routine evaluation with thin-section CT of each SPN to optimize diagnostic management.

CT "halo sign" in pulmonary tuberculoma

The CT halo sign has been described as the CT finding of a low-attenuation zone surrounding a pulmonary nodule. It is an early clue to the diagnosis of invasive pulmonary aspergillosis. We describe a case of CT halo sign associated with a pulmonary tuberculoma. Therefore, we think that a diagnosis other than invasive pulmonary aspergillosis should be considered in the presence of the CT halo sign in immunocompetent patients.