Intrathoracic manifestations of collagen vascular diseases are very common. The frequency of intrathoracic manifestations and the pattern of abnormality are variable depending on the type of collagen vascular disease and may simultaneously involve one or more of the following: lung parenchyma, airways, pulmonary vessels, pericardium, and pleura. Most significant manifestations include diffuse interstitial pneumonia and pulmonary hypertension which together represent the main causes of morbidity and mortality of these patients. Pulmonary, airway and pleural involvement may also be secondary to the therapy adopted for management of the disease, or result from bacterial pneumonia or opportunistic infection. In the present review, the authors summarize the main intrathoracic manifestations of collagen vascular diseases and the differential diagnosis on high-resolution chest computed tomography.

Keywords: Lung, Collagen vascular disease, Interstitial pneumonia, Pulmonary hypertension, Computed tomography

OBJECTIVE: The present study was aimed at establishing the frequency of renal/perirenal and extrarenal computed tomography findings in patients with acute pyelonephritis, and evaluating the interobserver agreement. MATERIALS AND METHODS: Retrospective study based on the analysis of computed tomography images of 47 patients with clinical and laboratory findings of acute pyelonephritis. Two independent observers evaluated the main renal/perirenal and extrarenal alterations. The frequency of tomographic findings and interobserver agreement were analyzed by the kappa (k) test. RESULTS: The frequency of tomographic findings for the several parameters was the following: striated nephrogram, 100%; renal enlargement, 65%; perirenal fat heterogeneity, 62.5%; renal calculi, 16.6%; abscesses, 21%; pleural effusion, 36%; thickened gallbladder wall, 32.5%; periportal edema, 32.5%. The k test for interobserver agreement demonstrated reproducibility ranging between moderate (k = 0.511 for renal enlargement) to almost perfect (k = 0.87 for striated nephrogram) for all of the parameters analyzed, except for perirenal fat heterogeneity (k = 0.268). CONCLUSION: The frequency of findings of acute pyelonephritis on computed tomography is high. Overall, striated nephrogram was the most frequent finding. Peri- and extra-renal alterations were found in about 2/3 of the cases. Computed tomography demonstrated a good interobserver agreement.

Keywords: Acute pyelonephritis, Kidney, Computed tomography, Reproducibility

OBJECTIVE: The present study was aimed at describing the findings on high-resolution computed tomography in patients with exogenous lipoid pneumonia secondary to mineral oil aspiration MATERIALS AND METHODS: Eight adult patients - four men and four women - with mean age of 69.4 years were studied. All of the patients were users of mineral oil for treating intestinal constipation. High-resolution computed tomography studies of these patients were blindly evaluated by two radiologists. RESULTS: Air-space consolidation with areas of fat density and crazy paving pattern were the most frequent findings. The lesions were bilateral in six cases and unilateral in two CONCLUSION: Air-space consolidation with areas of fat density, associated with a clinical history of mineral oil ingestion virtually indicates a diagnosis of exogenous lipoid pneumonia.

Keywords: Exogenous lipoid pneumonia, High-resolution computed tomography, HRCT, Aspiration pneumonia, Lungs

Isolated renal lymphoma is rare due to the absence of lymphoid tissue in kidneys. Secondary involvement occurs more frequently and is reported in up to 1/3 of the autopsies of patients who died from lymphoma. Some authors believe this is actually the only existing form of renal lymphoma. The involvement of the kidney by lymphoma would occur through hematogenic metastasis or direct tumor invasion of the perirenal space. These different types of involvement determine the several forms of renal lymphoma presentation: multiple nodules, solitary mass, renal invasion from contiguous retroperitoneal disease, perirenal disease and diffuse infiltration. In this study the imaging findings features of the different forms of involvement are presented and discussed.

Keywords: Kidney, Lymphoma, Computed tomography

Bone marrow transplantation has been the treatment of choice for many hematologic diseases. However, pulmonary complications, which may occur in up to 60% of the patients, are the main cause of treatment failure and may be divided in three phases according to the patient's immunity. In the first phase, up to 30 days after the procedure, there is a predominance of non-infectious complications and fungal pneumonia. Viral infections, mainly by cytomegalovirus, are common in the second phase (up to 100 days after bone marrow transplantation). Finally, in the late phase after bone marrow transplantation, non-infectious complications as bronchiolitis obliterans organizing pneumonia and graft-versus-host disease are most commonly seen. The authors present a pictorial essay of the high-resolution computed tomography findings in patients with pulmonary complications after bone marrow transplantation.

Keywords: High-resolution computed tomography, Bone marrow transplantation, Pulmonary infections

The authors report a case of lipoid pneumonia in an 80-year-old man with chronic constipation in regular use of mineral oil as a laxative. According to his family, he experienced coughing episodes when he took his medication. He also presented dyspnea at rest and diminished consciousness levels. Chest radiographs showed a consolidation area in the posterior segment of right upper lobe, which did not change on successive exams. High resolution computed tomography demonstrated low-density consolidation with negative Hounsfield units (-29 to -83 UH) and ground-glass opacities in the right upper lobe and inferior lobes. These opacities predominated in the posterior regions of the lungs. The diagnosis was confirmed by the presence of oil material on bronchoalveolar washing. The patient was advised to discontinue the ingestion of mineral oil and did not return for follow-up.

Keywords: Lipoid pneumonia, Computed tomography, Lungs

The purpose of this study is to report the main high-resolution computed tomography findings of two patients with lymphocytic interstitial pneumonia. High-resolution computed tomography findings were correlated with pathology findings of material obtained from open biopsies. One patient had diffuse ground glass opacities seen on high-resolution computed tomography whereas the other patient had peribroncovascular thickening. Anatomopathology studies showed that the main pattern was polyclonal lymphocyte interstitial infiltration, particularly along alveolar septa. The current study demonstrated a close correlation between high-resolution computed tomography and anatomopathology findings.

Keywords: Lymphocytic interstitial pneumonia, High-resolution computed tomography, Anatomopathology

Dynamic renal scintigraphy allows the diagnosis of complications in patients submitted to organ transplantation, such as perfusion abnormalities, acute tubular necrosis and rejection. In this study we employed 99mTc-DTPA scintigraphy to study patients submitted to kidney transplantation. The results obtained and the clinical findings were conjunctly analyzed in order to detect graft rejection or other complications. The type of immunosuppressive scheme used was also correlated with the observed complications. Fifty-five patients submitted to kidney transplantation from 1989 to 1999 were evaluated. All patients with nephrotoxicity received a 3-drug immunosuppressive scheme. In this study, acute rejection was the most frequent complication (40.4%) observed following transplantation. Thirteen of 15 recipients of cadaveric kidney grafts presented acute tubular necrosis. Only one false-positive case was observed when scintigraphy and clinical findings were not concordant. We suggest carrying out renal scintigraphy to follow-up post-transplantation patients.

Keywords: Dynamic renal scintigraphy, 99mTc-DTPA, Kidney transplantation, Immunosuppression

Our purpose was to evaluate the accuracy of unenhanced helical computed tomography in the diagnosis of ureteral lithiasis, to establish the frequency of the main computed tomography findings, and to assess and compare the interobserver agreement with the results of conventional intravenous urography. A prospective double-blind study was carried out in 25 patients referred for unenhanced helical computed tomography and conventional intravenous urography due to nephretic colic. Both methods were employed to evaluate the size of the kidneys, hydronephrosis and the size and location of ureteral stones. Perirenal hyperdensities, periureteral edema and the halo sign were also assessed by unenhanced helical computed tomography. In 23 of the 25 unenhanced helical computed tomography examinations (92%) and in 17 of the 25 conventional intravenous urography examinations (68%) there was agreement on the results of the two observers. In 21 of the 25 patients, there was agreement between the results of both methods. We concluded that unenhanced helical computed tomography is as efficient as conventional intravenous urography in the evaluation of patients with nephretic colic, is a reproducible method, and avoids the discomfort of the use of intravenous contrast.

Keywords: Lithiasis. Ureter. Kidney. Computed tomography.

OBJECTIVE: To describe the main anatomical variations of the celiac trunk and the hepatic artery at their origins. MATERIALS AND METHODS: This was a prospective analysis of 100 consecutive computed tomography angiography studies of the abdomen performed during a one-year period. The findings were stratified according to classification systems devised by Sureka et al. and Michels. RESULTS: The celiac trunk was “normal” (i.e., the hepatogastrosplenic trunk and superior mesenteric artery originating separately from the abdominal aorta) in 43 patients. In our sample, we identified four types of variations of the celiac trunk. Regarding the hepatic artery, a normal anatomical pattern (i.e., the proper hepatic artery being a continuation of the common hepatic artery and bifurcating into the right and left hepatic arteries) was seen in 82 patients. We observed six types of variations of the hepatic artery. CONCLUSION: We found rates of variations of the hepatic artery that are different from those reported in the literature. Our findings underscore the need for proper knowledge and awareness of these anatomical variations, which can facilitate their recognition and inform decisions regarding the planning of surgical procedures, in order to avoid iatrogenic intraoperative injuries, which could lead to complications.

Keywords: Anatomy; Computed tomography, Celiac artery; Hepatic artery; Liver transplantation.

OBJECTIVE: To evaluate the accuracy of steady-state free precession (SSFP) unenhanced magnetic resonance angiography (MRA) at 1.5 T for the identification of multiple renal arteries, using computed tomography angiography (CTA) as the reference standard. MATERIALS AND METHODS: This was a prospective study involving 39 patients (26 males; mean age, 62.6 years) who underwent CTA and unenhanced MRA to evaluate the proximal and middle segments of the renal arteries. The analysis was performed in two phases: the quality of unenhanced MRA images was classified as diagnostic or nondiagnostic for the presence of multiple renal arteries by two independent readers; two other independent readers then evaluated the images previously classified as being of diagnostic quality. The sensitivity, specificity, and overall accuracy of unenhanced MRA were calculated, CTA being used as the reference standard. The kappa statistic was used in order to calculate interobserver agreement. RESULTS: The image quality of unenhanced MRA was considered diagnostic in 70–90% of the extrarenal arterial segments. The CTA examination revealed 19 multiple renal arteries (8 on the right and 11 on the left). The accuracy of unenhanced MRA for the identification of multiple renal arteries was greater than 90%, with a sensitivity of 72.7–100% and a specificity of 96.3–100%. CONCLUSION: Unenhanced MRA provides high quality imaging of the extrarenal segments of renal arteries. This method may be used as an alternative for the evaluation of the renal arteries, given that it has an accuracy comparable to that of CTA.

Keywords: Computed tomography angiography; Magnetic resonance angiography; Kidney; Kidney transplantation; Diagnostic techniques, urological.

OBJECTIVE: To analyze the computed tomography (CT) findings of lymphocytic interstitial pneumonia (LIP). MATERIALS AND METHODS: We retrospectively reviewed the clinical and CT findings of 36 patients with LIP, including 25 women and 11 men, with a mean age of 52.5 years (age range, 22–78 years). RESULTS: The main associated diseases with LIP were Sjögren syndrome (42%), human immunodeficiency virus infection (17%), amyloidosis (17%), Sjögren syndrome associated with secondary amyloidosis (11%), idiopathic (8%), and systemic lupus erythematosus (5%). The predominant CT abnormalities were multiple cystic airspaces (n = 35), small nodules (n = 15), ground-glass opacities (n = 13), bronchiectasis and/or bronchiolectasis (n = 8), and thickening of the bronchovascular bundles (n = 8). Other CT findings included reticular opacities (n = 7), calcified nodules (n = 4), airspace consolidation (n = 4), emphysema (n = 3), honeycombing (n = 3), lymph node enlargement (n = 2), mosaic attenuation pattern (n = 1), and cavitated nodules (n = 1). CONCLUSION: The main CT findings of LIP were multiple cysts, small nodules, and ground-glass opacities.

Keywords: Lymphocytic interstitial pneumonia; Lung cysts; Computed tomography.

OBJECTIVE: To define diagnostic criteria for coronavirus disease 2019 (COVID-19) on computed tomography (CT); to study the correlation between CT and polymerase chain reaction (PCR) testing for infection with severe acute respiratory syndrome coronavirus 2; and to determine whether the extent of parenchymal involvement and the need for mechanical ventilation are associated with the CT findings and clinical characteristics of patients with COVID-19. MATERIALS AND METHODS: This was a retrospective study of 155 patients with COVID-19 treated between March and May 2020. We attempted to determine whether the CT findings correlated with age and clinical variables, as well as whether the need for mechanical ventilation correlated with the extent of the pulmonary involvement. RESULTS: On average, the patients with COVID-19 were older than were those without (mean age, 54.8 years vs. 45.5 years; p = 0.031). The most common CT finding (seen in 88.6%) was ground-glass opacity, which correlated significantly with a diagnosis of COVID-19 (p = 0.0001). The CT findings that correlated most strongly with the need for mechanical ventilation were parenchymal bands (p = 0.013), bronchial ectasia (p = 0.046), and peribronchovascular consolidations (p = 0.012). The presence of one or more comorbidities correlated significantly with more extensive parenchymal involvement (p = 0.023). For the diagnosis of COVID-19, CT had a sensitivity of 84.3%, a specificity of 36.7%, and an accuracy of 73.5% (p = 0.012 vs. PCR). CONCLUSION: The patterns of CT findings are useful for the diagnosis of COVID-19 and the evaluation of disease severity criteria. The presence of any comorbidity is associated with greater severity of COVID-19.

Keywords: Coronavirus infections/diagnostic imaging; Tomography, X-ray computed; Pneumonia, viral.

Pancreas transplantation is a well-established treatment for patients with complicated diabetes mellitus and advanced renal failure. The most common procedure is simultaneous pancreas-kidney transplantation, in which the pancreas graft is positioned in the right pelvic region and the kidney graft is positioned in the left iliac fossa. Various imaging methods are used for the post-transplantation evaluation of the graft parenchyma and vascular anatomy, as well as for the identification of possible complications. As the number of cases increases, it is fundamental that radiologists understand the surgical procedure and the postoperative anatomy, as well as to recognize the possible postoperative complications and their imaging aspects, with the aim of providing the best guidance in the postoperative management of transplant recipients.

Keywords: Pancreas transplantation; Kidney transplantation; Organ transplantation; Diabetes mellitus; Postoperative complications.

OBJECTIVE: To evaluate the performance of 1.5 T true fast imaging with steady state precession (TrueFISP) magnetic resonance imaging (MRI) sequences for the detection and characterization of pulmonary abnormalities caused by coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: In this retrospective single-center study, computed tomography (CT) and MRI scans of 20 patients with COVID-19 pneumonia were evaluated with regard to the distribution, opacity, and appearance of pulmonary lesions, as well as bronchial changes, pleural effusion, and thoracic lymphadenopathy. McNemar’s test was used in order to compare the COVID-19-associated alterations seen on CT with those seen on MRI. RESULTS: Ground-glass opacities were better visualized on CT than on MRI (p = 0.031). We found no statistically significant differences between CT and MRI regarding the visualization/characterization of the following: consolidations; interlobular/intralobular septal thickening; the distribution or appearance of pulmonary abnormalities; bronchial pathologies; pleural effusion; and thoracic lymphadenopathy. CONCLUSION: Pulmonary abnormalities caused by COVID-19 pneumonia can be detected on TrueFISP MRI sequences and correspond to the patterns known from CT. Especially during the current pandemic, the portions of the lungs imaged on cardiac or abdominal MRI should be carefully evaluated to promote the identification and isolation of unexpected cases of COVID-19, thereby curbing further spread of the disease.

Keywords: Thorax; Tomography, spiral computed; Magnetic resonance imaging; Pneumonia; Coronavirus infections.