[Lateral chest X-rays. Radiographic anatomy]. / Radiografía lateral de tórax. Anatomía radiográfica.

Lateral chest views constitute an essential part of chest X-ray examinations, so it is fundamental to know the anatomy on these images and to be able to detect the variations manifested on these images in different diseases. The aim of this article is to review the normal anatomy and main normal variants seen on lateral chest views. For teaching purposes, we divide the thorax into different spaces and analyze each in an orderly way, especially emphasizing the anatomic details that are most helpful for locating lesions that have already been detected in the posteroanterior view or for detecting lesions that can be missed in the posteroanterior view.

Hydatid disease: radiologic and pathologic features and complications.

Hydatid disease primarily affects the liver and typically demonstrates characteristic imaging findings. However, there are many potential local complications (eg, intrahepatic complications, exophytic growth, transdiaphragmatic thoracic involvement, perforation into hollow viscera, peritoneal seeding, biliary communication, portal vein involvement, abdominal wall invasion). Furthermore, secondary involvement due to hematogenous dissemination may be seen in almost any anatomic location (eg, lung, kidney, spleen, bone, brain). Ultrasonography (US) is particularly useful for the detection of cystic membranes, septa, and hydatid sand. Computed tomography (CT) best demonstrates cyst wall calcification and cyst infection. CT and magnetic resonance (MR) imaging may demonstrate cyst wall defects as well as the passage of contents through a defect. Chest radiography, US, CT, and MR imaging are all useful in depicting transdiaphragmatic migration of hydatid disease. CT is the modality of choice in peritoneal seeding. US and CT demonstrate rupture in most cases that involve wide communication. Indirect signs of biliary communication include increased echogenicity at US and fluid levels and signal intensity changes at MR imaging. CT allows precise assessment of osseous lesions, whereas MR imaging is superior in demonstrating neural involvement. Familiarity with atypical manifestations of hydatid disease may be helpful in making a prompt, accurate diagnosis.

Using gadolinium-enhanced three-dimensional MR angiography to assess arterial inflow stenosis after kidney transplantation.

OBJECTIVE: Our objective was to evaluate use of gadolinium-enhanced three-dimensional (3D) MR angiography in the assessment of suspected arterial inflow stenosis after kidney transplantation. SUBJECTS AND METHODS: Twenty-eight consecutive patients receiving kidney transplants (26 single-kidney transplants and two en block transplants) with suspected arterial inflow stenosis were examined with two MR angiography sequences: gadolinium-enhanced 3D fast spoiled gradient-recalled (SPGR) imaging and 3D phase-contrast imaging. Twenty-four of these patients then were examined using the gold standards: either digital subtraction angiography (DSA) (n = 23) or surgery (n = 1). MR angiography and DSA studies were independently and prospectively analyzed for the presence of arterial stenoses (mild [<50%], severe [50-90%], or critical [>90%]) in the iliac, anastomotic, and renal artery segments. Two independent observers retrospectively evaluated the MR angiography sequences for ability to detect or exclude significant (> or = 50%) arterial stenoses. RESULTS: In 22 single-kidney transplants, DSA showed eight significant stenoses in 66 arterial segments. MR angiograms adequately showed 66 of 66 segments (prospective observers) and 64 of 66 segments (each retrospective observer), which were subsequently evaluated. The sensitivity and specificity of MR angiography in revealing significant stenoses were 100% and 98% (prospective analysis), 88% and 98% (retrospective observer 1), and 86% and 100% (retrospective observer 2). Concordance between observers showed kappa values exceeding .85 for all comparisons except the analysis of phase-contrast series (kappa = .62). In one en block transplant, DSA showed that stenosis was greater than 90%, although it had been graded at less than 50% with MR angiography. CONCLUSION: Gadolinium-enhanced 3D MR angiography accurately evaluated arterial inflow in single-kidney transplants.

Evaluation of the European image quality criteria for chest examinations.

The European Commission has published guidelines for image quality, radiographic technique and patient dose. These could be easily checked by staff either during the examination or when reporting the resulting radiographs. The objective was to achieve comparable image quality throughout Europe using optimum techniques. This paper presents an application of the image criteria for chest examinations. The application of criteria to a large number of films helps to correlate scoring films using this method with other alternatives such as the evaluation of physical parameters using phantoms or test objects. The advantages and limitations of the image quality list of criteria are discussed. As a result of its application, some modifications of image quality criteria, based upon simple essential indicators (minimizing the number of criteria) are formulated and presented.

Evolution of diagnostic radiology in a big hospital during a 5 year period, and the derived collective dose.

An analysis is presented of the trends in the annual number of radiological examinations and in the average effective dose equivalent for each type of examination in a big Spanish hospital. Annual frequencies for each type of examination, annual average effective dose equivalent values for each study group, and the contribution of each examination group to the collective dose are presented. Also, sex and age distributions for several important examinations are given, and their impact on the collective dose is reviewed.

Computed tomography in abdominal Castleman's disease.

Three patients with abdominal Castleman disease studied by CT are presented. Two cases corresponded to localized mesenteric disease and the third to a systemic form of the process. The CT findings are nonspecific, although a dense enhancement of the lesions can be demonstrated sometimes on dynamic CT.

CT findings in gastrointestinal perforation by ingested fish bones.

Preoperative diagnosis of complications due to foreign bodies in the gastrointestinal tract is uncommon by conventional radiographic methods. We present two cases of gastric and duodenal perforation secondary to fish bone ingestion, diagnosed preoperatively by CT.

The value of computed tomography in the localization of undescended testes.

Eight patients with unilateral and four with bilateral (4) unpalpable testes were evaluated with CT for localization. All patients were later submitted to laparascopy and/or surgery and 13 cryptorchid testes and 3 atrophic or agenesic testes were found. CT detected correctly 11 of the cryptorchid testes - (85%) with one false positive and one false negative finding. In the three atrophic or agenesic testes, CT did not identify any image suspicious of being a testis, so there three were no false positive studies here. It is concluded that CT is an accurate noninvasive method for the preoperative detection of cryptorchid testes.

Giant fibrous polyp of a calyx.

A case of a giant fibrous polyp of the pyelocaliceal system producing hydronephrosis is described. The presentation of the findings in this case as well as brief review of the literature are included.

CT findings in Mirizzi syndrome.

Six cases of Mirizzi syndrome have been studied by computed tomography (CT). Although not specific, CT frequently reveals an irregular cavity near the gallbladder neck and calculi outside the viscus. Emphasis is placed on the possibility of recognizing this entity by CT prior to surgery.

CT cholangiography: multiplanar reconstruction in obstructive jaundice.

The value of multiplanar reconstruction (MR) in coronal and sagittal planes from axial transverse computed tomography (CT) slices was investigated in cases of obstructive jaundice. The clinical application for this technique lies in its potential to depict the dilated bile duct to the point of obstruction providing a "map" of the biliary tree. We call the technique "CT cholangiography." The images obtained were of good quality in 77.5% of the cases. Coronal planes proved better than sagittal in demonstrating the bile duct. Furthermore, MR added information concerning the cause of obstruction in 27% of the cases. Improvements in technique will refine the method and likely eliminate the need for invasive cholangiography in many cases of obstructive jaundice.

Computed tomography in obstructive jaundice. Part I: The level of obstruction.

Computed tomographic (CT) scans of 67 cases of obstructive jaundice were analyzed to determine the value of CT in detecting the level of obstruction. The cases were divided into four groups by anatomical segments, according to the number of visualized hypodense ringlike structures produced by the dilated bile duct, as seen in axial sections made 1 cm apart. Gallbladder size, dilatation of intrahepatic biliary radicals and the pancreatic duct, visualization of tumor masses, and condition of the bile duct below the obstruction were other variables used to determine the level of obstruction. The overall accuracy of CT in determining the exact level has been 97%. The most reliable indicator is the number of rings, which has excellent correlation with the results of direct cholangiography. The diagnostic value of all other variables is limited to specific cases.

Computed tomography in obstructive jaundice. Part II: The cause of obstruction.

The value of computed tomography (CT) in determining the cause of obstructive jaundice in 67 proved cases is described. The presence of stones, the level of obstruction, the relative size of the ringlike structures produced by the dilated bile duct, and the shape of the distal visualized ring have proved to be the most important variables. The retrospective analysis determined the correct cause in 94% of the cases. CT fulfills all goals considered important in obstructive jaundice and eliminates the need for invasive procedures in many cases.

CT findings in subacute perforation of the gallbladder: report on 5 cases.

Perforation of the gallbladder is a serious complication of acute and subacute cholecystitis which is rarely recognized before operation, either by clinical or radiological methods. Five cases of walled-off perforation of the gallbladder have been diagnosed by computed tomographic (CT) studies, within a period of less than one year. The studies were routinely made in the supine projection, with or without an intravenous injection of contrast medium. Scanning time was 4.7 seconds. The patients did not receive any pre-medication. CT demonstrated direct signs of the perforations: calculi outside the gallbladder; the ruptured segment of the wall. Indirect signs were also readily detected: localized abscesses, occasionally multiple or situated distant from the gallbladder; gallstones; thickening of the wall of the gallbladder. CT may have an important role in preoperative diagnosis of complicated acute cholecystitis and in the surgical management of patients with this condition, if ultrasound examination fails to establish the diagnosis or cannot be done for technical reasons.

Mycotic tuberculous aneurysm of the thoracic aorta.

Tuberculous mycotic aneurysm has been reported with surprising frequency, especially in the aorta. Because the diagnosis can often be made on clinical and roentgenologic grounds, and because of the very poor prognosis if untreated and surgical curability if recognized, experience with three cases is reported. The aneurysm is generally of the false variety, representing a walled-off perforation of the aorta. Contiguous tuberculosis in the form of lymphadenitis or Pott abscess is generally responsible for the aortic involvement that results in the aneurysm. Miliary tuberculosis, which is often present, is probably a result rather than the cause.