Focal Parenchymal Abnormalities Research Articles

Results of quantitative chest-CT in chronic pulmonary graft-vs.-host disease (cGvHD) 3 years after allogeneic stem cell transplantation.

To quantify lung parenchymal changes in symptomatic patients with chronic pulmonary graft-versus-host disease 3 years after allogeneic stem cell transplantation (allo-SCT) by means of CT-densitometry (CTD) and to compare results with those of established pulmonary function tests (PFT). The study group consisted of 26 patients with pulmonary cGvHD (19 males, 7 females; mean age, 49.29±15.89; range, 19-72 years). The diagnosis was based on clinical symptoms, PFT and chest-CT findings. CTD and PFT were performed both in the pre- and post-transplantation setting and results compared with each other. CT scans were obtained during suspended deep inspiration including the whole lungs. The mean lung attenuation (MLD), low attenuation values (LAV) and distribution of focal parenchymal abnormalities compatible with emphysema (HU <-950) were quantitatively calculated with histograms and graphics. On PFT, total lung capacity (TLC), residual volume (RV), vital capacity (VC), forced expiratory volume in 1 s (FEV1s) and diffusion capacity for carbon monoxide (DLCOSB) were registered. Changes in end-inspiratory lung volume and density (MLD and LAV) in symptomatic cGvHD patients in mean three years after allo-SCT proved all not significant, but there was a clear trend towards an increase in lung volume and a decrease in lung attenuation. These results were similar throughout all classes of bronchiolitis obliterans (BO) by cGvHD. PFT showed a significant decrease in VC, FEV1s but only a minimal decrease in DLCOSB. Changes in FVC after stem cell transplantation correlated with changes in LAV (r=0.649, P=0.031). Predicted VC correlated with changes in LAV (r=0.771, P=0.005). There was a correlation between the absolute difference of FEV1 and DLCOSB (r=0.64, P=0.14) before and after stem cell transplantation. End-inspiratory phase CT lung parenchyma quantification in symptomatic patients with pulmonary cGvHD 3 years after allo-SCT shows discrete changes over the pre-transplantation setting representing airway obstruction, mirroring airflow limitation on PFT. Its use enables exclusion of relevant parenchymal destruction (emphysema-equivalent lung density) at this time.

The Aging Lung: Clinical and Imaging Findings and the Fringe of Physiological State.

Since aspects of demographic transition have become an essential part of socioeconomic, medical and health-care research in the last decades, it is vital for the radiologist to discriminate between normal ageing related effects and abnormal imaging findings in the elderly. This article reviews functional and structural aspects of the ageing lung and focuses on typical ageing related radiological patterns. • The physiological aging process of the thoracic organs shows typical structural and functional aspects.• Mild interstitial fibrosis and focal parenchymal abnormalities like septal thickening can be diagnosed frequently - whereas a clinical correlate is often lacking.• With increasing patient age, the influence by various intrinsic and extrinsic factors (including comorbidities of the patient, and drug inhalation toxicants) also increases.• A growing spectrum of imaging techniques (including functional cardiopulmonary MRI, MRI spectroscopy, hybrid-techniques) is confronted by rare empiric data in the very old people (aging 80 years and older).

Transient Pulmonary Eosinophilia Incidentally Found on Low-Dose Computed Tomography

To describe computed tomography (CT) findings of transient pulmonary eosinophilia (TPE) incidentally found on low-dose CT (LDCT) and to identify suggestive CT features helpful in initial diagnosis. We retrospectively reviewed LDCT scans in 40 individuals who met criteria for having TPE. There were 35 men and 5 women (age range, 32-62 years; mean, 48.5 +/- 9 years). Initial LDCT scans were assessed as either (a) nodules, further characterized as either solid, solid associated with a halo of ground-glass attenuation, or pure ground-glass lesions as well as by number, size, and location or (b) ill-defined foci of parenchymal consolidation. A range of focal parenchymal abnormalities (n = 78) were identified-both single (48%) and multiple (52%). Most of these proved to be either solid nodules with discrete ground-glass halos (72%), or poorly defined solid nodules exhibiting a variety of differing morphologies (24%). Ill-defined foci of consolidation were noted in 3 cases (4%). The lesions were predominantly located in the lower lung zone (73%) with peripheral distribution (92%). Transient pulmonary eosinophilia most often manifests as solid nodules with associated ground-glass halos. Awareness of TPE should serve to limit the number of mistaken diagnoses of early lung cancer.

Adult cerebral malaria: prognostic importance of imaging findings and correlation with postmortem findings.

To correlate imaging abnormalities, clinical features, and postmortem findings in patients with proved cerebral malaria. Twenty-one patients aged 17-50 years with cerebral malaria consented to undergo transverse nonenhanced (10-mm sections) and contrast material-enhanced (8-mm sections in posterior fossa and 10-mm sections in supratentorial region) CT on admission (n = 21) and on day 10 (n = 6), with thin sections (5 mm) obtained in the area of abnormality. All CT scans were evaluated for diffuse cerebral edema, focal parenchymal abnormalities, and hemorrhage. CT findings were categorized as normal, diffuse cerebral edema, and edema with thalamic hypoattenuation without or with cerebellar hypoattenuation. Spearman rank correlation test was performed. Initial scans were normal in seven patients with mild disease (median Acute Physiology and Chronic Health Evaluation [APACHE] II score of 7, median Glasgow Coma Scale [GCS] score of 10), and all survived. Of eight patients with diffuse cerebral edema (GCS > or = 8; median APACHE II, 21), six survived. Cerebral edema with thalamic and cerebellar white matter hypoattenuation was seen in five patients. All had GCS score of 6 or less, median APACHE II score of 26, and multiorgan failure; none survived. One patient (GCS = 6) had thalamic hypoattenuation without cerebellar lesions. He survived with mild residual hemiparesis. Diffuse petechial hemorrhages were seen in the cerebrum and cerebellum at autopsy in all seven patients who died. These petechial hemorrhages were not visualized on CT scans. CT findings did not correlate with degree of parasitemia. CT findings correlate well with level of consciousness and severity of disease but underestimate the extent of disease at pathologic examination. A normal CT scan indicates a favorable outcome, whereas cerebellar hypoattenuation portends a poor outcome.

ACCURACY AND EFFICACY OF CHEST RADIOGRAPHY IN THE INTENSIVE CARE UNIT

In summary, the chest radiograph has only moderate accuracy in visualizing opacification caused by cardiopulmonary abnormalities and may be quite nonspecific as to etiology, whereas it has high diagnostic accuracy for detecting malpositioning of tubes and lines. While focal parenchymal abnormalities are usually visualized on chest radiographs, identification of concomitant abnormalities when ARDS or PE already exist is more difficult. Atelectasis, aspiration, pneumonia, pulmonary hemorrhage, pulmonary thromboembolism, atypical cardiogenic edema, asymmetric ARDS, and neoplasms may be indistinguishable. Repeat chest radiographs and different views may be helpful, as the progression and time course of various etiologies can be quite different. On the other hand, Winer-Muram et al found that review of prior radiographs and clinical data did not improve the diagnostic accuracy for either ARDS or pneumonia. Pleural effusions may even be difficult to distinguish from parenchymal processes, particularly when the patient is in the supine position. Additional views with the patient in a different position--semi-erect, decubitus, or cross-table lateral--may be of assistance. In most cases, pneumothorax is readily detected. Additional studies such as the decubitus view occasionally may be necessary for further evaluation when there is uncertainty about the findings. Subcutaneous air is readily visualized radiographically. Pneumomediastinum and interstitial pulmonary emphysema may be more difficult to see. It is well known that CT allows visualization of much smaller abnormal air collections than radiography. Despite this lack of sensitivity and specificity of chest films, studies have shown that up to 65% of daily films in the ICU reveal significant and/or unsuspected abnormalities that may change the patient's diagnosis or management. Based on these results, the consensus opinion of the ACR Expert Panel found that daily chest radiographs are indicated on patients with acute cardiopulmonary problems and those receiving mechanical ventilation. Patients who require cardiac monitoring but are otherwise stable require only an initial admission film. Additional radiographs are indicated only when a new device is placed or when there is a specific question regarding cardiopulmonary status. It is also noteworthy that despite the chest film being the most commonly ordered radiologic examination for inpatients, there are no comprehensive studies evaluating its cost-effectiveness. Although several studies have done a very limited cost accounting of the potential savings by eliminating routine films in the evaluation of specific subsets of patients, overall impact on patient outcome has not been investigated. Thus, a true assessment of cost-effectiveness has yet to be determined.

Applications of Duplex Ultrasonography in the Liver Transplant Patient

Duplex ultrasonography plays an important role in the preoperative and postoperative assessment of liver transplant patients. Before surgical intervention, the principal use of sonography is to assess the patency of the extrahepatic portal vein because a narrowed or thrombosed portal vein may preclude transplantation. Postoperatively, several potential complications can lead to allograft dysfunction (rejection, infection, vascular thromboses, and biliary tract complications). Because these complications often manifest with variable and nonspecific symptoms, diagnosing them can be difficult. Sonography is a valuable noninvasive means of evaluating postoperative complications in liver transplant patients. When vascular complications are suspected, duplex sonography is the optimal screening procedure for assessment of the vascular anastomoses. Focal parenchymal abnormalities (hematomas, infarcts, and bilomas) and localized collections of abdominal fluid are readily detected by ultrasonography and can be safely aspirated and, when infected, percutaneously drained under sonographic guidance. Sonography is less useful in the detection of biliary tract complications early after transplantation.

Renal Allograft Rejection: US Evaluation

Real-time ultrasonography (US) was performed on the allografts of 100 consecutive renal transplant recipients at the time of allograft biopsy. Evaluation of the sonograms included the grading of parameters previously demonstrated to be indicative of allograft rejection. The appearance of the renal sinus fat, allograft size, corticomedullary ratio, sharpness of the corticomedullary junction, medullary conspicuity, presence of focal parenchymal abnormalities, and thickening of the pelvic or infundibular wall were individually evaluated. The authors correlated the US and the histopathologic findings. While the accuracy of a positive prediction of rejection was relatively high (83%-90%), this result is influenced by the relatively high prevalence of rejection in the biopsy group (83%). Accuracy of a negative prediction was uniformly low (17%-30%). Mild rejection was difficult to differentiate ultrasonographically from no rejection, although severe rejection could usually be differentiated from mild or no rejection, particularly in patients with the interstitial type of rejection.

Abdominal sonography after hepatic transplantation: results in 36 patients.

Hepatic transplantation was performed in 46 patients over a 2-year period at the University of Minnesota. Thirty-six of these patients subsequently underwent 166 sonographic examinations of the upper abdomen. Forty-three examinations were performed within 2 weeks of transplantation, 47 between 2 and 8 weeks after transplantation, and 76 more than 8 weeks after transplantation. The sonograms were reviewed retrospectively and correlated with the available clinical and histopathologic data. Diffuse, nonspecific parenchymal abnormalities were seen in 27 patients. Focal regions of parenchymal abnormality seen in four patients were associated with abscess and infarction. Moderate to severe biliary dilatation was seen in seven patients with biliary obstruction diagnosed by percutaneous or T-tube cholangiography. Obstruction was seen most commonly in children who had undergone cholecystojejunostomy biliary reconstruction, and it required radiologic or surgical intervention. Routine sonographic assessment of the upper abdominal vasculature showed thrombosis of the portal vein in two cases, thrombosis of the inferior vena cava in one case, thrombosis of the donor aorta in three cases. Focal intraabdominal fluid collections were identified in 14 patients and represented hematomas in all but one. Free peritoneal fluid was detected in 19 patients. Sonography was used to guide percutaneous aspiration of abdominal fluid and to guide fine-needle puncture for percutaneous transhepatic cholangiography. Upper abdominal sonography provides a noninvasive means of evaluating and confirming a wide spectrum of complications that can follow hepatic transplantation. Because clinical and laboratory findings often are nonspecific in these patients, sonographic detection of focal parenchymal abnormalities, biliary dilatation, and vascular compromise is especially valuable.

Renal allograft rejection: US evaluation.

Real-time ultrasonography (US) was performed on the allografts of 100 consecutive renal transplant recipients at the time of allograft biopsy. Evaluation of the sonograms included the grading of parameters previously demonstrated to be indicative of allograft rejection. The appearance of the renal sinus fat, allograft size, corticomedullary ratio, sharpness of the corticomedullary junction, medullary conspicuity, presence of focal parenchymal abnormalities, and thickening of the pelvic or infundibular wall were individually evaluated. The authors correlated the US and the histopathologic findings. While the accuracy of a positive prediction of rejection was relatively high (83%-90%), this result is influenced by the relatively high prevalence of rejection in the biopsy group (83%). Accuracy of a negative prediction was uniformly low (17%-30%). Mild rejection was difficult to differentiate ultrasonographically from no rejection, although severe rejection could usually be differentiated from mild or no rejection, particularly in patients with the interstitial type of rejection.