Maria Luigia Storto

Malignant pleural disease

The vast majority of pleural neoplasms invade the pleura secondarily and can be seen in patients with bronchogenic carcinoma, breast cancer, lymphoma, and ovarian or gastric carcinoma. Primary pleural neoplasms are less common, although they have developed notoriety since the up-surge of malignant mesothelioma and the knowledge of its connection to asbestos exposure. Other malignant primary tumors include localized fibrous tumor and pleural liposarcoma. In most patients with diffuse malignant pleural disease the chest radiograph shows pleural effusion with or without pleural thickening. Computed tomography (CT) usually provides precise localization and extent of the disease and may be of value in assessing chest wall and mediastinal involvement. In specific situations, magnetic resonance (MR) may be useful as a problem-solving tool when CT findings of chest wall or diaphragmatic invasion are equivocal or in patients with contraindication to intravenous administration of ionic contrast material.

Lung cancer staging: the role of computed tomography and magnetic resonance imaging

Because complete resection remains the only reliable method of cure of lung cancer, one important aim of preoperative staging is to select patients with localised disease who may benefit from surgery, while avoiding unnecessary thoracotomies in patients with unresectable neoplasm. Computed tomography (CT) of the chest is a valuable method for staging local and regional spread of lung neoplasms, although limitations in its accuracy are well-known. While gross invasion of the mediastinum and major structures as well as the presence of metastatic disease can be easily demonstrated with CT, differentiation between tumour contiguity and subtle invasion of mediastinum or chest wall often remains a problem. Although magnetic resonance imaging (MRI) may have the same limitations as CT, in specific situations it may be superior in diagnosing minimal chest wall or mediastinal invasion. Moreover, MRI is useful in the assessment of patients with superior sulcus tumours as well as in patients with contraindication to intravenous administration of ionic contrast material. Since nodal size is the only useful criterion for evaluating lymph node metastases, CT and MRI show similar, poor accuracies in lymph node staging resulting from both low sensitivity (normal-sized nodes may contain microscopic metastases) and low specificity (enlarged lymph nodes may be reactive). For this reason, if enlarged lymph nodes are detected, further evaluation is recommended before excluding the patient from a potentially curative resection. Advantages and limitations of CT and MRI in the preoperative staging of non-small-cell carcinoma are reviewed in this article. The imaging of small-cell carcinoma is not included because most patients with this cell type do not benefit from surgical resection. Similarly we do not discuss imaging of distant metastases.

Bronchioloalveolar carcinoma of the lung.

Abstract. Bronchioloalveolar carcinoma is a histologically distinct form of pulmonary adenocarcinoma representing an estimated 2–10 % of all primary lung cancers. Its varied appearances include focal masses, nodular patterns, and pneumonic and diffuse forms so that bronchioloalveolar carcinoma should be considered in the differential diagnosis of solitary or multiple pulmonary nodules and acute or chronic alveolar diseases. In this article we describe the different radiographic manifestations of bronchioloalveolar carcinoma with particular emphasis on CT findings and those signs that may help in identifying the lesion as bronchioloalveolar carcinoma.

Multislice Spiral Computed Tomography for In-Stent Restenosis

A 72-year-old man was admitted for recurrent episodes of chest pain 3 months after stent deployment in the left anterior descending (LAD) artery. The patient underwent a computerized tomographic (CT) examination of the thorax with a multislice spiral CT scanner (MSCT) (Somatom Volume Zoom, Siemens). A dynamic study was performed with acquisition of 20 scans at the level of the LAD distal to the stented segment during injection of 20 mL of nonionic contrast medium (370 mgI/mL); the resultant time-density curves were suggestive of high-grade stenosis (Figure 1A). Thereafter, a …

Low-dose multidetector-row CT-angiography of abdominal aortic aneurysm after endovascular repair

PURPOSE To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm. MATERIALS AND METHODS In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement. RESULTS Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p<0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p=0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63±6.97 vs. 11.48±8.13; p=0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol. CONCLUSION In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.

Coronary artery bypass grafts and MDCT imaging: what to know and what to look for

Multi-detector row CT (MDCT) scanners with high spatial and temporal resolutions are now available and are increasingly used for non-invasive assessment of vascular disease, including coronary arteries and coronary artery bypass grafts (CABG). Follow-up of patients who have previously undergone surgical revascularization for coronary artery disease is nowadays one of the main applications of MDCT. Thanks to the continuous technical evolution of the CT scanners, it is now possible to scan the heart and the full anatomic extent of grafts with sub-millimeter slice-thickness within a single breath-hold. In the evaluation of these patients, it is important for the radiologist to be familiar with the different types of grafts and surgical techniques to know the main characteristics of each graft type and what to look for in the assessment of a patient who has undergone coronary artery surgical revascularization. This review summarizes some surgical aspects, the biological characteristics of conduits, and the main technical MDCT features, and describes the CABG anatomy together with some typical CT findings.

Staging of thoracic lymphoma by radiological imaging

Abstract Thoracic lymphomas, which are very common especially in Hodgkins disease patients, are characterised by enlargement of mediastinal lymph nodes, parenchymal abnormalities, and pleural, pericardial and chest wall involvement. The use of several imaging techniques has been proposed in order to assess the extent of the disease correctly and to plan therapy. The most relevant results in this field, especially those using computed tomography (CT), magnetic resonance imaging (MRI) and gallium scanning, are summarised in this review. Presently CT is widely and successfully used in staging patients, whereas MRI seems to be preferable, as a second-step technique, if pericardial, pleural and chest wall involvement are suspected. The role of gallium scanning is limited in the staging, although it could be relevant in the follow-up of treated patients.

Neoplastic extension across pulmonary fissures: value of spiral computed tomography and multiplanar reformations.

To assess the value of spiral computed tomography (CT) with multiplanar reformations for detection of neoplastic extension across pulmonary fissures, 51 patients with a lung neoplasm near a fissure underwent spiral CT, followed by multiplanar reformations, and spaced thin-section CT scans through the area of contact between tumor and fissure. The CT studies were evaluated for visibility of fissures and their relationship to the tumor. Imaging findings were compared with surgical results in 31 patients who underwent thoracotomy. Visibility of fissures on multiplanar reformations was either good or acceptable in 47 (92.2%) patients, and poor in four. Surgical findings of neoplastic extension across the major or the minor fissure were present in seven and eight patients, respectively. Thin-section CT scans were 83.3% sensitive in assessing neoplastic involvement of the major fissure, axial CT scans were 57.1% sensitive, and spiral CT multiplanar images were 100% sensitive. In the evaluation of the minor fissure, thin-section CT and axial spiral CT scans were considered inconclusive in six patients whereas multiplanar reformations enabled correct assessment of the fissure/neoplasm relationship in all but one patient. Spiral CT multiplanar images are accurate for detection of transfissural neoplastic extension, and are superior to axial CT scans for evaluation of tumors near the minor fissure.

MDCT angiography for detection of pulmonary emboli: Comparison between equi-iodine doses of iomeprol 400 mgI/mL and iodixanol 320 mgI/mL

OBJECTIVES To compare iomeprol 400 and iodixanol 320 in pulmonary artery MDCTA in subjects with suspected pulmonary embolism. METHODS Eighty randomized subjects received equi-iodine intravenous doses (48 g) of iomeprol 400 (n=40) or iodixanol 320 (n=40), via power injector at 4 mL/s. Four-row (35 subjects) and 64-row (45 subjects) scanners were used. Lumen attenuation was determined on-site and by two off-site blinded readers in the main, lobar, segmental and subsegmental pulmonary arteries. Statistical comparison between groups was performed for demographics and lumen attenuation. RESULTS There were no between-group differences (p>0.05) in demographics. Pulmonary artery attenuation was significantly (p<or=0.03) higher with iomeprol 400 for all readers. Attenuation quality was excellent in more patients after iomeprol 400 than after iodixanol-320 (80% vs. 62.5%; 82.5% vs. 77.5%; off-site readers 1 and 2, respectively). No safety concerns were noted. CONCLUSION The greater iodine delivery rate achievable with iomeprol 400 compared to iodixanol-320 at equi-iodine dose and injection rate permits consistently greater attenuation at all levels of the pulmonary arterial tree.

Spiral CT of the mediastinum: optimization of contrast medium use

Spiral computed tomography (CT) allows very satisfactory temporal resolution for the detection and analysis of changes in contrast medium density, so that volumes of contrast material smaller than those recommended for conventional CT can be used. The present double-blind, parallel group study was designed to compare image quality and diagnostic efficacy obtained with two different iodine strengths (200 and 300 mgI/ml) and two different flow rates (2 and 3 ml/s) of a fixed volume (70 ml) of iomeprol in adult consenting patients requiring spiral CT of the mediastinum. Imaging was performed during suspended respiration and, a 15-s delay to scan. Spiral CT was initiated 1 cm above the aortic arch and continued inferiorly for 24 cm in all patients. Two independent readers blindly graded image quality, opacification of the superior vena cava, thoracic aorta and pulmonary arteries, and overall diagnostic quality of the CT examination. CT density measurements were performed over the level of the aortic arch, left and right pulmonary arteries, left atrium, and descending aorta. Opacification of the mediastinal vessels was better in the patients injected at 3 ml/s flow rate and was independent of the iodine strength used, except in the case of the thoracic aorta, which was better opacified by injecting iomeprol 300 mgI/ml at 3 ml/s. The highest diagnostic efficacy of the spiral CT examination was obtained with iomeprol 300 mgI/ml at 3 ml/s infusion rate, which seems to represent the administration scheme of choice.