[Computerized tomography in the evaluation of the larynx after surgical treatment and irradiation].

The follow-up of the patients submitted to surgery for laryngeal carcinoma requires both clinical and CT examinations, particularly in the cases at high risk of recurrence. Our series consisted of 72 laryngeal carcinoma patients operated on and regularly followed-up with CT to distinguish relapse from normal or abnormal postoperative changes. Seventy-two laryngeal carcinoma patients were submitted to surgery: total laryngectomy was performed in 33 cases, supraglottic laryngectomy in 16 cases, Labayle subtotal laryngectomy in 18 cases and Mayer Piquet subtotal laryngectomy in 5 cases. The patients were followed-up postoperatively with CT and 94 examinations were performed in all; pathology was performed in all the cases with radiologic suspicion of recurrence (19 patients) and further clinical examinations were performed to exclude recurrence in the 14 cases where imaging findings were questionable. Local recurrences were confirmed in 16 of 19 patients with positive CT findings. Radiologically, the recurrence appeared as an irregular thickening of the pharyngo-laryngeal wall with inhomogeneous density after i.v. contrast agent infusion. The patients submitted to total or supraglottic laryngectomy recurred most often at the cranial site of resection (5/6 cases), those submitted to Labayle surgery at the mucosa adjacent to the cricoarytenoid unit (3/3 cases) and those submitted to Mayer Piquet surgery in the supraglottic region. Two more patients submitted to emergency tracheotomy recurred at this level. Lymph node recurrences were found in 6 total laryngectomy patients. Misinterpretations were most frequently due to postirradiation changes (5 of 14 cases) or to atypical postoperative images (4/14 cases). Three more patients presented a secondary lesion misinterpreted as a relapse. Our results confirm the role of CT in the follow-up of the patients operated on for laryngeal carcinoma when CT findings are closely correlated with clinical and endoscopic results, permitting to correctly assess the extent of relapse and possible nodal spread

[The solitary pulmonary nodule: the preliminary results in differential diagnosis by high-resolution computed tomography with a contrast medium].

High-resolution computed tomography (HRCT) with iodinated contrast material has been used by many authors to study solitary pulmonary nodules (SPNs). The degree of enhancement was correlated with the nodule malignancy.Forty adult patients were examined, before and after contrast agent administration, with incremental dynamic CT. We selected 22 patients with SPNs (3-30 mm phi, except one with 40 mm phi). The CT numbers of the inner nodule were calculated before and 1, 2 and 3 minutes after the i.v. administration of a weight-related dose (1.5 mL/kg/min) of nonionic iodinated contrast agent. A dose of 100 mL contrast agent was used in the first 6 patients. The difference in CT numbers between unenhanced images and the images with maximum enhancement (max. attenuation) was also calculated.Histologic diagnoses included 4 tuberculomas, 3 hamartomas and 15 malignant tumors (9 adenocarcinomas, 5 squamous cell carcinomas and 1 non-Hodgkin lymphoma). The CT numbers (in Hounsfield units, HU) of malignant nodules ranged 12-31 HU (mean: 21.5 HU) before contrast agent administration; the "long-standing" tuberculomas ranged 11-22 HU (mean: 16.5 HU) and the hamartomas had a mean density of 10.5 HU. We excluded for the study two "fresh" tuberculomas, one of which was surrounded by a low-attenuation infiltrate (the halo sign). We selected a threshold value of 20 HU on enhanced CT images to distinguish malignant (> or = 20 HU) from benign (< or = 20 HU) nodules. All lung cancers had complete enhancement (mean density: 35.5 HU). With 20 HU as the threshold value for a positive test, sensitivity was 100\%, specificity 85.7\%, positive predictive value 93.8\% and negative predictive value 100\%; test bias was 1.067.Positron emission tomography (PET) with 2-[fluorine-18] fluoro-2-deoxy-D glucose is reported to be as accurate as enhanced HRCT, but it does not provide accurate morphological information, is not widely available and it is quite expensive: therefore, in our opinion, CT should be preferred. After examining over 100 patients, we may use our results in the decision analysis comparing surgical risk with cancer risk

Radiological assessment of necrosis in glioblastoma: variability and prognostic value

In a previous study, we found that the extent of necrosis was the only radiological feature which correlated significantly with survival in patients with glioblastoma. The aim of this paper was to evaluate the variability and prognostic value of the extent of the necrotic area as seen on contrast-enhanced MRI and CT in a larger series. We studied 72 patients who underwent surgical removal of supratentorial glioblastomas and had CT and/or MRI with contrast medium before surgery; 38, all undergoing the same treatment (surgery plus radiotherapy), were followed clinically. Necrosis within the tumour varied greatly, ranging from none (only 1 case) to involvement of 76% of the tumour. Survival data in the subgroup suggested that only patients with a small area of necrosis (less than 35% of the tumour) had a significantly longer survival time. When necrosis involved more than 35% of the mass, patients had a shorter survival time, without any further correlation with the extent of necrosis