Presence Of Low-attenuation Areas Research Articles

CT of invasive pulmonary aspergillosis (IPA) in cases with hematologic malignancy: Comparison of CT features in the group classified by the severity of neutropenia and underlying disease

PurposeTo identify differences in the radiological findings of invasive pulmonary aspergillosis (IPA) among patients classified by severity of neutropenia, and differences in underlying disease. Materials and MethodsWe retrospectively reviewed computed tomography (CT) scans from the time of the diagnosis of IPA in 83 hematological malignancy patients with probable or proven IPA according to the EORTC-MSG criteria. We evaluated CT findings (radiological pattern, number of lesions, distribution, and presence of low attenuation area [LAA]), and compared the radiological findings of patients classified by degree of neutropenia with two different indicators (neutrophil count at the onset, and c-d-index) and underlying disease. ResultsNeutropenia at the onset of IPA was associated with an increased frequency of LAA (p < 0.05), especially in FN (p < 0.01). Cases with a c-d-index of ≧5500 showed an increased incidence of the angio-invasive pattern. In contrast, cases with a c-d-index of 0 showed an increased incidence of the airway-invasive pattern (p < 0.05). The airway-invasive pattern was more frequent in cases with MM, while the angio-invasive pattern was more frequent in cases with AML (p < 0.01). Lower-predominant distribution was more frequent and random distribution was less frequent in cases with AML, random distribution was more frequent and lower-predominant distribution was less frequent in cases with ALL, and upper-predominant distribution was more frequent in cases with MDS (p < 0.05). ConclusionsCT features of IPA vary according to the degree of neutropenia and underlying disease.

Radiation pneumonitis in patients with lung and mediastinal tumours: a retrospective study of risk factors focused on pulmonary emphysema

To evaluate the impact of pulmonary emphysema (PE) on the incidence and severity of radiation pneumonitis (RP) in patients with lung and mediastinal tumours. 92 patients were enrolled. Involved-field radiation therapy (non-small cell carcinoma or mediastinal tumours in 69 patients; median 70 Gy) and accelerated hyperfractionation (limited disease small cell carcinoma in 23 patients; median 45 Gy) were performed. Common Terminology Criteria for Adverse Events v.3.0 was used to evaluate RP and the relationship with the percentage of pulmonary volume irradiated to >20 Gy (V20) and PE. PE was diagnosed by the presence of low-attenuation areas (LAAs) on CT scans and was classified into Grades 0-4 according to the extent of the LAAs. The median follow-up time was 16 months. The 6-month cumulative incidence of RP at Grade 3 or greater was 7.7% and 34.1% in patients with a V20 of <25% and ≥25%, respectively (p=0.017). In patients with PE Grades 0, 1, 2 and 3 or greater, the incidence of RP was 16.5%, 9.1%, 8.6% and 54.0%, respectively. As the PE Grade increased, the incidence of RP also increased significantly. The incidence and severity of RP are significantly higher in patients with a high V20 value as well as in those with severe PE.

CT assessment of subtypes of pulmonary emphysema in females.

We performed a retrospective study examining the prevalence and subtypes of pulmonary emphysema (PE) identified by computed tomography (CT) in females. We reviewed the records of 1,687 female subjects who had undergone CT. They were divided into the following 2 age groups:group A (＜50 years) and group B (≥50 years). PE was diagnosed by the presence of low-attenuation areas using visual assessment (grades 0-3) on CT images. Two subtypes of PE were observed:centrilobular emphysema (CLE) and paraseptal emphysema (PSE). PE was divided into the following 3 categories:I (CLE or CLE-predominant);II (CLE and PSE of equal extent);and III (PSE or PSE-predominant). PE was found in 64 of 274 smokers (23.3%) and 54 of 1,413 non-smokers (3.8%). In smoking subjects, when grades 1 and 2 were grouped together as mild PE, the mean age for CT grade 3 (severe PE) was significantly higher than that for mild PE. In group A, category III predominated, whereas category I was more prevalent in group B, in both smoking and non-smoking subjects. A high incidence of PE was found in smoking subjects as compared with non-smoking subjects. PSE predominated in younger subjects, whereas CLE predominated in older subjects.

Prevalence of Emphysema in Individuals Who Underwent Screening CT for Lung Cancer in Nagano Prefecture of Japan

Background: Screening for lung cancer with low-dose spiral computed tomography (CT) was carried out in Nagano prefecture in Japan. Objective: To study the prevalence of emphysema in 7,847 individuals based on the Nagano spiral CT screening and to correlate the prevalence and severity of emphysema with various factors. Methods: Spiral CT images with scan parameters of 120 kV, 50 mA, 10-mm collimation and a pitch of 2 obtained at full inspiration were retrospectively evaluated in 7,847 individuals. Emphysema was defined as the presence of low-attenuation areas in the lung parenchyma. Extent of emphysema was graded on a four-level scale and correlated with gender, age and smoking habits. Results: There were 4,288 males and 3,559 females. Mean age of the subjects was 61 years; 45.8% of the participants were smokers. Overall prevalence of emphysema was 2.9%; the prevalence was significantly higher in males (5.0%) than in females (0.5%); it was also significantly higher in smokers, and increased with age. Emphysema was positively correlated with age, but there was no correlation with smoking indices. Emphysema was mostly mild and localized in the upper lung. The logistic model revealed that gender, age and smoking indices were significant factors for developing emphysema. Conclusions: Overall prevalence of emphysema was 2.9%. The prevalence was higher in males and in older people. Smoking was also related to a higher prevalence of emphysema but not to its severity.

Computed tomography of superior mesenteric vein thrombosis following appendectomy.

During a 5-year period, superior mesenteric vein (SMV) thrombosis was detected with computed tomography (CT) in six patients shortly after an appendectomy. No sign of SMV was present at appendectomy, and a period of more than 2 weeks free of clinical symptoms had elapsed between the appendectomy and the onset of the SMV thrombosis. In four cases, the appendicitis was complicated. These patients had nonspecific signs and symptoms, although two of them had elevation of blood hepatic enzyme levels. In all cases, postcontrast CT demonstrated enlargement of the SMV, with well-defined enhancement of the vascular wall and an intraluminal clot. In one case, CT showed extension of the thrombus to the portal vein with the presence of low-attenuation areas in the liver, consistent with hepatic infarcts. Two patients had predisposing diseases: idiopathic hypersplenism in one case and chronic hepatic disease in the other. SMV thrombosis is a possible complication of appendicitis, and early appendectomy in appendicitis can prevent this complication. Moreover, as in any abdominal surgery, early appendectomy may be complicated by thrombosis of the SMV, thus creating problems of postoperative diagnosis. The complication is more frequent when the initial operation is performed under difficult conditions (peritonitis), or when the patient presents with a coagulopathy. CT is useful in the diagnosis of SMV thrombosis, thus leading to early management with anticoagulant therapy, with a view to avoiding complications such as intestinal ischemia, portal vein thrombosis, and hepatic infarction.

Neutrophil elastase associated with alveolar macrophages from older volunteers.

We focused on the role of neutrophil elastase (NE) in alveolar macrophages (AMs), and evaluated the esterolytic activity using an NE-sensitive substrate, methoxysuccinyl-alanyl-alanyl-prolyl-valyl paranitroanilide (MEOSAAPVNA) in AMs from 36 older healthy volunteers (61 +/- 2 yr mean age +/- standard error) and examined the relationship to chronic effects of cigarette smoking and also to the presence of low attenuation areas (LAAs) on the computed tomographic (CT) scans. The AMs from the subjects with LAAs showed significantly higher activity than those from the current smokers without LAA (1.16 +/- 0.40 versus 0.34 +/- 0.07 nM, respectively, p < 0.05). Although the study of inhibitory profile revealed that the esterolytic activity could not be attributed to NE alone, the NE activity seemed to dominate in AMs at least from some who had higher esterolytic activity. We then examined the releasability of NE from cultured AMs in 10 subjects. The immunologic NE complex with alpha 1-protease inhibitor (alpha 1-PI) was released significantly higher in the LAA(+) group than in the LAA(-) group (17.4 +/- 6.5 versus 1.8 +/- 0.6 micrograms/L, respectively, p < 0.05). These data suggest that NE in AMs may play a role in the development of emphysematous changes in susceptible smokers.

A case of Leigh's disease with initial manifestation of dystonia

A case of Leigh's disease (subacute necrotizing encephalomyelopathy) is reported with such noteworthy features as early onset, dystonia, paraparesis the presence of low attenuation areas in both basal ganglias on computerized tomography of the brain and the presence of a high signal intensity in both basal ganglias in T2 weighted image by MR. The electron microscopic findings of muscle biopsy are suggestive of pleoconial mitochondrial myopathy.

Complicated appendiceal inflammatory disease in children: pylephlebitis and liver abscess.

Five children with complicated appendiceal inflammatory disease are reported. They presented with nonspecific signs and symptoms, but three had liver abscess and two had inflammation of the portal vein. The inflamed portal vein may act as a conduit to the liver for bacteria, or it may become thrombosed and cause portal hypertension and hypersplenism. In one child, symptomatic portal hypertension developed 10 years after the initial disease. In children, an ultrasonic finding of a focal liver mass of low-to-mixed echogenicity or the presence of low-attenuation areas on computed tomographic scans should suggest the possibility of a hepatic abscess, and the radiologist has a major role in suggesting complicated inflammatory disease of the appendix as the cause. Similarly, when portal vein thrombosis or portal hypertension are found, the radiologist should consider complicated inflammatory disease of the appendix as the cause.