Lung cancer associated with cystic airspaces.

OBJECTIVE: The objectives of this study were to determine the frequency of lung cancers associated with a discrete cystic airspace and to characterize the morphologic and pathologic features of the cancer and the cystic airspace. MATERIALS AND METHODS: We reviewed all diagnosed cases of lung cancer resulting from baseline screening (n=595) and annual screening (n=111) in the International Early Lung Cancer Action Program to identify those abutting or in the wall of a cystic airspace. We also reviewed the pathologic specimens. RESULTS: A total of 26 lung cancers were identified abutting or in the wall of a cystic airspace. Of these, 13 were identified at baseline (13/595, 2%) and 13 at annual screening (13/111, 12%), which was significant (p<0.0001). The median circumferential portion of wall involved was less for the annual cancers than for the baseline ones, but this difference did not reach significance (90° vs 240°, p=0.07). The diagnosis was adenocarcinoma in all but three cases. Histologic analysis showed that the cystic space was a bulla, a fibrous walled cyst without a defined lining, or a pleural bleb and that in all but one case, the tumor was eccentric relative to the airspace and the wall of the airspace was unevenly thickened. CONCLUSION: At annual repeat CT screening, the finding of an isolated cystic airspace with increased wall thickness should raise the suspicion of lung cancer.

Periportal halo: a CT sign of liver disease.

Periportal halos are defined as circumferential zones of decreased attenuation identified around the peripheral or subsegmental portal venous branches on contrast-enhanced computed tomography (CT). These halos probably represent fluid or dilated lymphatics in the loose areolar zone around the portal triad structures. While this CT finding is nonspecific, it is abnormal and should prompt close scrutiny of the liver in search of an underlying etiology. Periportal halos which may be due to blood are commonly seen in patients with liver trauma. Periportal edema may cause this sign in patients with congestive heart failure and secondary liver congesion, hepatitis, or enlarged lymph nodes and tumors in the porta hepatis which obstruct lymphatic drainage. This CT sign has also been observed in liver transplants (probably secondary to disruption and engorgement of lymphatic channels) and in recipients of bone marrow transplants who might develop liver edema from microvenous occlusive disease. While the precise pathophysiologic basis of periportal tracking has not been proven, it represents a potentially important CT sign of occult liver disease.

Imaging of regional spread of breast cancer by internal mammary lymphoscintigraphy, CT, and MRI.

Forty women with breast cancer underwent imaging by internal mammary lymphoscintigraphy (IMLS), which was correlated with the results of CT and MRI of the chest. IMLS was performed and interpreted using the previously described methods of Ege. It identified 22 instances of ipsilateral internal mammary nodal involvement, none of which corresponded to cases of abnormally enlarged (diameter greater than 1.0 cm) internal mammary nodes on CT and/or MRI. Positive IMLS was associated with axillary nodal metastases in 15 out of 22 instances. The authors conclude that IMLS provides information on regional nodal spread of breast cancer that is not available with either CT/MRI imaging or axillary biopsy.

Prospective comparison of radionuclide, computed tomographic, sonographic, and magnetic resonance localization of parathyroid tumors.

The appropriate choice of imaging techniques to localize parathyroid tumors preoperatively remains controversial. We report the first prospective, blinded study to compare the efficacy of four imaging modalities in 100 patients with primary hyperparathyroidism (pHPT). Patients were examined by computer-assisted thallium 201/technetium 99m subtraction scintigraphy (TTS), computed tomography (CT), ultrasonography (US), and magnetic resonance (MR). Each study was performed and interpreted independently. Subsequent neck exploration and "curative" parathyroidectomy allowed correlation of surgical findings with imaging reports to score their accuracy. Overall sensitivities of the four imaging modalities were TTS, 73%, CT, 68%, US, 55%; and MR, 57%; with respective specificities of 94%, 92%, 95%, and 87%. Sensitivities for lesions located below the thyroid gland (thymic tongue and mediastinum) were TTS, 90%; CT, 46%; US, 44%; and MR, 50%; with respective specificities of 100%, 99%, 100%, and 94%. There was a significant increase in overall sensitivity when TTS and CT (90%, p less than 0.01) or TTS and US (85%, p less than 0.05) were used together; however, the combination of any three or even four imaging modalities did not increase sensitivity further. For small parathyroid tumors (less than or equal to 250 mg), no imaging technique had a sensitivity of more than 50%. None of the imaging studies accurately localized small hyperplastic parathyroid glands found in patients with multiple gland disease. Preoperative parathyroid imaging may not be indicated in pHPT patients undergoing first-time neck exploration because surgeons experienced in parathyroid surgery have a 93% to 96% cure rate.

Dose to the cardiac vascular and conduction systems in primary breast irradiation.

Using computerized tomography (CT) in which cardiac anatomy was defined, doses delivered to the cardiac compartments, vascular and conduction systems were assessed for various standard techniques of primary breast irradiation. Included in the analysis were 6 MV photon tangents (T) alone, or in conjunction with a separate internal mammary field (IMF). Beams evaluated in the IMF were 6 MV photons, 12 MeV electron beam, and mixed photon/electron beam; Cobalt 60 was also analyzed as an alternate photon beam. Treatment of the IMF with photons, either alone or in combination with electron beam, delivered doses ranging between 30 Gy to 50 Gy to all chambers of the heart, coronary arteries and branches of the conduction system. Complete sparing of the posterior cardiac structures and volume is accomplished with treatment plans using tangents alone or in combination with 12 MeV electron beam irradiation to the IMF. Sparing of the anterior wall of the left ventricle, Bundle of His and left anterior descending coronary artery is also achieved in treatment with tangents and 12 MeV electron beam IMF. Doses to this region with tangents alone ranged from 20 Gy to 45 Gy compared to 0 to 30 Gy with tangents and 12 MeV electron beam IMF. Clinical significance of these findings will be discussed.

CT evaluation of parathyroid adenomas: diagnostic criteria and pitfalls.

Sixty-three patients with biochemically proven primary hyperparathyroidism underwent CT of the neck and upper chest prior to surgery. All examinations were prospectively evaluated. Parathyroid adenomas were correctly identified on CT in 81% of patients. Thyroid adenomas, tortuous vessels, the esophagus, and atypical parathyroid adenomas may be potential sources of error in the diagnosis of parathyroid adenomas.

Computed tomography examination of periampullary neoplasms.

The hospital records of 24 patients with periampullary neoplasms were reviewed. The clinical triad of jaundice, pain, and weight loss and the radiographic imaging triad of dilated biliary ducts, dilated pancreatic duct, and periampullary mass should suggest the diagnosis of periampullary neoplasm.

CT diagnosis of massive hemorrhage from hepatocellular carcinoma.

Massive hemorrhage from rupture of hepatocellular carcinoma is uncommon. We report our experience in two cases diagnosed by CT.

Pituitary and adrenal CT of Cushing syndrome.

Determination of the site of excessive hormone production in Cushing syndrome is possible with biochemical tests in 80% of cases. High-resolution CT of both the pituitary and adrenal glands was used to evaluate eight patients with surgically verified ACTH-secreting pituitary microadenomas and one patient with ectopic Cushing syndrome. Three ACTH-secreting microadenomas were demonstrated by CT. Adrenal CT was normal in six of the eight patients with pituitary tumors. The patient with ectopic ACTH production had mild unilateral adrenal gland enlargement and a normal pituitary CT scan. Normal adrenal or pituitary CT scans do not exclude Cushing syndrome.

Ascending aorta complications of cardiac surgery: CT evaluation.

Dissecting aortic aneurysms and pseudoaneurysms of the ascending aorta can occur secondary to clamping of the ascending aorta, incision of the great vessels, or secondary to aortic cannulation for cardiopulmonary bypass. Contrast-enhanced CT offers an excellent means of distinguishing between aortic pathology and other causes of mediastinal widening following cardiac surgery. Five cases are reported in which iatrogenic vascular lesions were identified on CT as the cause of postoperative mediastinal widening.

CT appearance of hemangiopericytoma.

Hemangiopericytoma is an uncommon tumor that may occur anywhere in the body but is most often found in the retroperitoneum, extremities, and nasopharynx. The CT evaluation of five malignant hemangiopericytomas (two retroperitoneal, two nasopharyngeal, one thigh) revealed speckled calcifications in all cases. The lesions in the retroperitoneum and thigh were large and lobular, with areas of cystic-degeneration or hemorrhage. Computed tomography of a rare, benign osseous hemangiopericytoma demonstrated characteristics of a slow-growing bone tumor with a cortical break in the proximal femur. The homogeneously enhancing, noncalcified mass found in the posterior fossa appeared similar to the typical benign hemangiopericytoma reported in this location by other authors.

Magnetic resonance imaging of discrete and conglomerate retroperitoneal lymph node masses.

In the identification of discrete and conglomerate retroperitoneal lymph node masses, MRI and CT performed equally well. No specific MRI characteristics were identified.

Differential diagnosis of low-attenuation splenic lesions on computed tomography.

A retrospective computed tomography evaluation of proved low-attenuation splenic lesions in nontraumatic cases was done. Computed tomography was able to distinguish cystic from solid lesions. Although computed tomography examination is sensitive in the detection of low-attenuation lesions, the computed tomography findings alone are not helpful in differentiation of different low-attenuation lesions. Associated computed tomography findings in other organs and clinical findings are more helpful than the size, shape, and computed tomography attenuation of the lesions. Splenic lesions may be the only metastatic manifestation in some cancer patients. A thin needle aspiration may be done to document the nature of the pathologic lesion in problematic cases.

Evaluation and treatment of intraabdominal bilomas.

In a 3-year period, 21 intraabdominal bilomas developed in 18 patients. Fifteen of the patients had a solitary biloma, and the other three patients each had two separate concurrent bilomas. The major cause of biloma formation was postoperative bile leakage from a bile duct after laparotomy done primarily for surgery on the gallbladder or liver. Maximal diameter of the bilomas in the transaxial plane ranged from 2 to 19 cm. Sixteen of the bilomas were in the right upper quadrant, and five were in the left upper quadrant. Two large right-sided collections extended caudally into the lower abdomen. The contours of the bilomas were configured by the diaphragm, mesenteries, liver, and other abdominal organs. On CT and sonography, the bilomas were invariably well demarcated, but most did not have an identifiable capsule. CT did demonstrate a thin rim on four bilomas and a thick rim on one. In 19 bile collections, the CT numbers were less than 20 H. The combination of the clinical history, the location, and the CT appearance of the lesion led to the correct diagnosis in each case. Percutaneous drainage was an effective form of therapy that often eliminated the need for surgical drainage.

Primary biliary carcinoma: CT evaluation.

Fifty-three patients with documented primary biliary carcinoma were studied with computed tomography. Twenty-six patients had gallbladder carcinoma and 27 patients had carcinoma of the biliary ductal system. Ninety percent of patients with gallbladder cancer had an intraluminal mass. Local invasion into the liver was common. The majority of patients with biliary ductal carcinoma had dilated bile ducts, while only 50% of patients with gallbladder cancer had biliary ductal dilatation. The most common location of tumor involving the extrahepatic biliary ductal system was the distal common bile duct. This occurred in eight patients out of 27, or 30% of the cases.

Contrast enhancement technique for dynamic hepatic computed tomographic scanning.

A study comparing precontrast and survey postcontrast dynamic computed tomographic (CT) scanning was performed on 60 patients who had suspected hepatic metastases. An incremental dynamic technique was used during and following a 50-g iodine load administered over two minutes. The survey postcontrast dynamic technique was superior in both sensitivity and contrast differentiation and yielded no known false-negative examinations. No postprocedure renal dysfunction was observed. High-dose contrast-material delivery in conjunction with incremental dynamic CT scanning appears to be the most suitable technique for performing postcontrast hepatic CT examinations.