Cystic lung diseases: radiological aspects.

Cystic lung diseases (CLDs) are a heterogeneous group of pathophysiological entities comprising gas-filled lesions with imperceptible walls, which can occur throughout lung parenchyma. CLDs can arise from different mechanisms and may often have an unpredictable progression. As CLDs are infrequent and may be associated to many different processes, they pose a diagnostic challenge to the radiologist and referring physician. CLDs require a comprehensive diagnostic approach. An essential tool in the evaluation of CLDs is high-resolution computed tomography (HRCT). The first step is in distinction from true cysts, from other cysts mimicking entities, as emphysema, honeycombing, pneumatocoele, cavitate nodules, or bronchiectasis. Thereafter the identification of number, distribution, wall size, and other systemic manifestations provides an accurate characterisation of CLD, often avoiding further evaluation with lung biopsy. Features of pulmonary lucencies, classification of CLDs based on pathophysiological mechanisms, and radiological criteria, the less common aetiologies, and a multidisciplinary approach in pulmonary cysts are reported. Finally, a systematic diagnostic algorithm to guide radiologists in the evaluation of CLDs is discussed.

Role of contrast-enhanced ultrasound to define prognosis and predict response to biotherapy in pancreatic neuroendocrine tumors.

PURPOSE: The incidence of neuroendocrine tumors (NETs) is progressively increasing. Most cases arise from the digestive system, where ileum, rectum and pancreas represent the commonest site of origin. Liver metastases are frequently detected at diagnosis or during the follow-up. Contrast-enhanced ultrasound (CEUS) is used in patients with pancreatic NETs (P-NETs) and liver metastases from P-NET but its role has not been standardized. The aim of this retrospective study was to investigate CEUS in patients with P-NETs and liver metastases from P-NET both as prognostic factor and predictor of response to therapy with somatostatin analogues (SSAs). METHODS: CEUS was performed at the diagnosis of NET and 3, 6 and 12 months after the beginning of SSAs. CEUS pattern was compared with contrast-enhanced computed tomography (CT) pattern. RESULTS: There was a significant association between CEUS and CT pattern (X 2 = 79.0; p < 0.0001). A significant association was found between CEUS pattern and Ki-67 index (X 2 = 24.6; p < 0.0001). The hypervascular homogeneous CEUS typical pattern was associated with low tumor grading (G1 or G2) (X 2 = 24.0; p < 0.0001). CEUS pattern changed from hypervascular homogeneous in baseline to hypovascular/hypervascular inhomogeneous after SSA therapy, with a significant association between tumor response at CT scan and appearance of hypervascular inhomogeneous pattern at CEUS evaluation (6 months: X 2 = 57.0; p < 0.0001; 12 months: X 2 = 49.8; p < 0.0001). CONCLUSIONS: In patients with P-NET, CEUS pattern correlates with tumor grading, being homogeneous in G1-G2 but not in G3 tumors. After therapy with SSAs, CEUS is predictive of response to SSAs. These findings seem to support a role of CEUS as prognostic and predictive factor of response.

Unusual complications of endovascular repair of the thoracic aorta: MDCT findings.

With the development of minimally invasive surgical techniques, endovascular stent-graft placement has become an accepted and widely used alternative to the traditional surgical repair of aortic disease and is gaining acceptance as the treatment of choice. Many studies show that endovascular stent-graft therapy is safe and effective, although complications related to this treatment are also recognised. Although the incidence of major complication is low, neurological sequelae remain the major concern of endovascular repair. With growing experience, however, the spectrum of mid- and long-term complications has broadened to include potentially disastrous events, other than paraplegia or stroke, that require diligent surveillance. Three-dimensional data sets acquired quickly by multidetector computed tomography (MDCT) allow multiplanar reformations and 3D viewing, as well as quantitative assessment of vessel lumens, walls and surroundings. Although a large portion of radiologists will not be involved in the actual endograft deployment, many will be involved in the interpretation of postprocedural surveillance studies. Accordingly, the goal of this report is to summarise our experience with the presentation, diagnostic approach, management and outcomes of these unusual, but potentially catastrophic, postendovascular aortic repair complications to highlight their significance and increase familiarity with them among the imaging community. Increasing awareness of these complications may facilitate rapid diagnosis and/or triage and treatment.

MDCT in diagnosing acute aortic syndromes: reviewing common and less common CT findings.

Nontraumatic acute thoracic aortic syndromes (AAS) describe a spectrum of life-threatening aortic pathologies with significant implications on diagnosis, therapy and management. In this context, multidetector computed tomography (MDCT) is the gold standard due to its intrinsic diagnostic value; its performance approaches 100% sensitivity and specificity, and it is accepted as a first-line modality for suspected acute aortic disease. MDCT allows early recognition and characterisation of acute aortic syndromes as well as the presence of any associated complications - findings that are essential for optimising treatment and improving clinical outcomes. Although classic CT findings have long been known, other unusual signs are continually reported in the medical literature. We reviewed the classic and less common CT findings, correlating them with pathophysiology, timing and management options, to achieve a definite and timely diagnostic and therapeutic definition.

H1N1 pneumonia: our experience in 50 patients with a severe clinical course of novel swine-origin influenza A (H1N1) virus (S-OIV).

PURPOSE: The authors reviewed chest radiographs (CXR) and thin-section computed tomography (CT) findings of pulmonary complications in a selected population of 50 consecutive patients with severe novel swine-origin influenza A (H1N1) virus (S-OIV) pneumonia who were seen at the Subintensive Respiratory Unit (UTSIR) and at the Intensive Care Unit (ICU) at Monaldi Hospital, Naples, Italy. MATERIALS AND METHODS: CXR and CT findings of 50 patients who fulfilled the World Health Organisation (WHO) criteria for S-OIV infection were reviewed by four radiologists. The final study group of 50 patients was divided into two subgroups on the basis of clinical course: group 1 consisted of 42 patients requiring noninvasive mechanical ventilation and admitted to the UTSIR; group 2 consisted of eight patients who required ICU admission and extracorporeal membrane oxygenation or advanced mechanical ventilation from October 2009 to December 2009. All patients underwent CXR and thin-section multidetector CT (MDCT) scan; the initial and follow-up radiographs and CT scans were evaluated for the presentation and follow-up pattern (consolidation, ground-glass opacities, nodules, reticulation), distribution and extent of abnormality. RESULTS: All patients had radiological signs of pulmonary involvement. Ground-glass opacity and consolidation, which was mainly peripheral, was the most frequent finding. In three patients, we report for the first time in viral pneumonia the reversed halo sign. Lesion extent was related to aggressiveness of the illness. More often, both lungs were involved (82%). Thoracic comorbidity was present in 18% of patients; 22% of patients was obese, and in this group, the clinical course was more aggressive than in the others with the same lesion extent at imaging. Furthermore, superinfection led to worsening of the clinical conditions. CONCLUSIONS: The most common CXR and CT findings in patients with S-OIV infection were unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. On MDCT, ground-glass opacities and areas of consolidation had a predominant peribronchovascular and subpleural distribution, resembling organising pneumonia; they progressed to bilateral extensive airspace disease in severely ill patients.

Primary pleural haemangioendothelioma in an Italian female patient: a case report and review of the literature.

Primary epithelioid haemangioendothelioma (EHE) of the pleura is a rare vascular tumour that occurs mainly in men. Pleural effusion and thickening are the most common clinical presentations. A 58 year old female, nonsmoking patient presented to us with dry cough, dyspnoea and left chest pain for several weeks (no asbestos exposure). Standard chest X-ray and contrast enhanced multislice computed tomography revealed a large-size lobulated mass originating from the pleura which was diagnosed as primary pleural haemangioendothelioma (PHE) by histology and immunohistochemistry (reactivity for vimentin, CD31, CD34, Factor VIII and ulex europeaus). No metastases were detected. The patient refused treatment and died three months later due to the onset of acute and progressive respiratory failure. Despite the lack of high-grade malignancy, primary PHE displays a poor prognosis while curative therapies are actually not available. To our knowledge, this is the first case of primary PHE in a female patient occurring in Italy and the third one to have been reported in English literature. Difficulties in diagnosis and treatment management are discussed below.

Retrospective study of 23 cases of hepatic infarction: CT findings and pathological correlations.

PURPOSE: The aim of this study was to retrospectively review the cases of hepatic infarction diagnosed at our institute using conventional, spiral and multislice computed tomography (CT) over the last decade in order to describe its morphological and density characteristics and define its possible etiopathogenesis. MATERIALS AND METHODS: Twenty-three consecutive patients aged 27-65 years with hepatic infarction were studied by CT at our institute over a period of about 10 years. A conventional CT unit was used in seven patients, a helical CT scanner in ten and a multislice CT in six. CT was performed before and after the administration of 130-150 cc of contrast material infused at a rate of 3-3.5 ml/s. RESULTS: CT showed hepatic infarction due to arterial causes in 19 cases, 11 of which were in liver transplant patients. The infarction was related to right hepatic artery embolisation to control haemorrhage (one case), chemoembolisation of a multifocal hepatocarcinoma in a cirrhotic liver (one case), arterial mesenteric infarction due to thromboembolism (two cases), necrotising pancreatitis (one case), surgery in pancreatic cancer invading the hepatic artery (one case), pancreaticoduodenectomy (two cases), portal thrombosis in a young woman with pregnancy-related clotting disorder (one case), haemolytic anaemia, elevated liver enzymes, low platelet count (HELLP) syndrome (one case); eclampsia and disseminated intravascular coagulation (DIC) (one case) and acute exacerbation of Budd-Chiari syndrome (one case). At CT scans, hepatic infarction was depicted as a hypodense parenchymal area, at times triangular in shape, with sharp peripheral contours (12 cases) or as a rounded central or marginal area (four cases) with irregular appearance (three cases), with lobar extension (two cases) and ill-defined shape (two cases). Moreover, CT showed intralesional gas not correlated to bacterial infection (two cases). In all surgical cases, the results were confirmed by pathology. CONCLUSIONS: CT is the method of choice in the diagnosis of hepatic infarction, providing useful information regarding site, morphology, and extent of the lesion. Furthermore, in most cases, CT is able to suggest the possible aetiology and guide appropriate management.

[Small bowell volvulus - combined radiological findings]. / Volvolo dell'intestino tenue - diagnostica radiologica integrata.

PURPOSE: We retrospectively evaluated the radiological findings observed at plain abdominal film, abdominal sonography and abdominal CT performed in 66 patients with surgically proven small bowel volvulus. MATERIAL AND METHODS: Sixty-six patients (35 women and 31 men, ranging in age 38-77 years) with surgically proven small bowel volvulus were submitted to plain film, sonography and CT of the abdomen. Abdominal plain film was performed in the upright position (postero-anterior view) in 46 cases, and in the supine position in 20 cases. On plain abdominal film we evaluated the following findings: bowel loops dilatation, air-fluid levels and site of obstruction. At abdominal US, performed with 3.5 e 7.5 MHz probes, we retrospectively searched for: bowel loop dilatation, bowel wall thickening, peristalsis alteration, extraluminal fluid. CT was performed with a helical unit (thickness 4 mm, reconstruction interval 4 mm, pitch 1.5), after intravenous contrast agent (120 ml) infusion (3 ml/s, 55 s acquisition delay from bolus starting) and using a power injector. The following CT findings were searched for: whirl sign, beak sign, extraluminal fluid, bowel loop dilatation, bowel wall thickening, bowel wall or mesenteric alterations. RESULTS: Plain abdominal film showed the following findings: air-fluid levels (92.4% of cases), bowel loops dilatation (71.2%), site of obstruction (42.4%). Abdominal sonography demonstrated bowel loop dilatation (48.5%), extraluminal fluid (48.5%), peristalsis alteration (27.3%), bowel wall thickening (27.3%). The most frequent CT findings were: bowel loop dilatation (95.5%), bowel wall thickening (78.8%), beak sign (69.7%), mesenteric alterations (66.7%), extraluminal fluid (54.5%), whirl sign (13.6%). CONCLUSIONS: Air-fluid levels and bowel loop dilatation were the most frequent radiological findings in our series. Plain abdominal film allowed us to identify signs of obstruction, whereas signs of bowel wall necrosis were accurately shown by abdominal CT.

[Nine consecutive patients with gallstone ileus. Personal experience]. / Nove pazienti consecutivi con ileo biliare. Esperienza personale.

INTRODUCTION: Gallstone ileus is a mechanical obstruction of the gastrointestinal tract caused by the impaction of one or more gallstones within the bowel lumen. The insidious clinical presentation and the lack of specific signs of biliary disease are responsible for the delayed preoperative diagnosis which leads to an overall mortality rate of 15%. MATERIAL AND METHODS: A series of 9 consecutive patients (7 women and 2 men, age ranging from 17 to 83 years), with surgically proved gallstone ileus, was retrospectively reviewed: the authors report the radiologic procedures performed preoperatively and the diagnostic findings. Plain abdominal radiographs were performed in 4 of 9 patients, abdominal US in 4 and CT in 7 patients. All radiologic examinations were retrospectively reviewed by all authors independently, to recognize the different signs of gallstone ileus. RESULTS: The signs of Rigler's triad (small bowel obstruction, ectopic gallstones and air in the biliary tree) were observed on plain abdominal films in two cases, and ectopic gallstones and pneumobilia in two cases. The ectopic gallstones and the small bowel obstruction were demonstrated on abdominal US images in three cases. Rigler's triad was identified on abdominal CT images in 4 cases, while two findings (small bowel obstruction and ectopic gallstones) were observed in three cases. CONCLUSIONS: When the bowel is obstructed by a radiopaque calcified stone, plain radiographs and US of the abdomen are usually enough to diagnose gallstone ileus and no further studies are required.

The role of dityrosine formation in the crosslinking of CUT-2, the product of a second cuticlin gene of Caenorhabditis elegans.

A second cuticlin gene, cut-2, of the nematode Caenorhabditis elegans, has been isolated and its genomic and cDNA sequences determined. The gene codes for a component of cuticlin, the insoluble residue of nematode cuticles. Conceptual translation of cut-2 reveals a 231-amino acid secreted protein which, like CUT-1, begins with a putative signal peptide of 16 residues. The central part of the protein consists of 13 repetitions of a short hydrophobic motif, which is often degenerated with substitutions and deletions. Parts of this motif are present also in CUT-1 (Caenorhabditis elegans) as well as in several protein components of the larval cuticle and of the eggshell layers of various insects (Locusta migratoria, Ceratitis capitata and Drosophila species). These sequence similarities are related to the similar functions of these proteins: they are all components of extracellular insoluble protective layers. Immunolocalisation and transcription analysis suggest that CUT-2 contributes to the cuticles of all larval stages and that it is not stage-specific. Analysis by reverse transcriptase-PCR suggests that it is not stage-specific. Analysis by reverse transcriptase-PCR suggests that transcription is not continuous throughout larval development but occurs in peaks which precede the moults. Dityrosine has been detected in the cuticle of nematodes and of insects; formation of dityrosine bridges may be one of the cross-linking mechanisms contributing to the insolubility of cuticlins. Recombinant, soluble CUT-2 is shown to be an excellent substrate for an in vitro cross-linking reaction, catalysed by horseradish peroxidase in the presence of H2O2, which results in the formation of insoluble, high-molecular weight CUT-2 and of dityrosine.

cut-1 a Caenorhabditis elegans gene coding for a dauer-specific noncollagenous component of the cuticle.

We have molecularly identified a new gene of Caenorhabditis elegans that codes for a component of the cuticle. The gene has been physically mapped on LGII near the locus sqt-1. The structure and the sequence of the gene have been determined and antisera have been raised against parts of the protein produced as fusions in Escherichia coli. By transcription analysis, and by the use of specific antisera, we have determined that this gene is expressed specifically during dauer larva formation. In extracts of worms completing the dauer transformation the product of this gene migrates in sodium dodecyl sulfate acrylamide gels with an apparent molecular mass of 40 kDa. By immunofluorescence we have determined that it is a component of the cuticles of dauer larvae. It forms a ribbon approximately 2 microns wide running along the lateral lines underneath the alae. Once it is assembled in the cuticle the protein becomes insoluble even in the presence of strong detergents and reducing agents in a manner that is similar to that described for the noncollagenous, insoluble residue of nematode cuticles called cuticlins; therefore, we have named the gene cut-1 for cuticlin 1. cut-1 represents the first gene for a noncollagenous component of C. elegans cuticle that has been characterized molecularly.