Imaging of paranasal sinuses today

CT is accepted as the gold standard for pathological-anatomical evaluation of paranasal sinus disease, CT is especially considered an obligatory part of planning surgical procedures. Indications for paranasal sinus CT include trauma, malignant disease, and chronic sinusitis, which accounts for the major part of examinations. Due to the benign character of the disease and the relatively moderate age of the patients involved, the radiation dose of paranasal sinus CT plays an important role. The use of a low-dose spiral CT technique and the reformation of coronal images out of the axial CT data instead of an additional direct coronal scan allow the effective dose of paranasal sinus CT to be reduced to the order of a chest radiogram. MRI is the preferred imaging modality in malignant disease or complications of inflammatory sinus disease that extend beyond the limits of the paranasal sinuses. The clinical value of other imaging modalities, including plain film radiography, ultrasound, or scintigraphy, is limited to special indications.     

Bildgebung der Nasennebenhöhlen (NNH) in der heutigen Zeit

CT is accepted as the gold standard for pathological-anatomical evaluation of paranasal sinus disease, CT is especially considered an obligatory part of planning surgical procedures. Indications for paranasal sinus CT include trauma, malignant disease, and chronic sinusitis, which accounts for the major part of examinations. Due to the benign character of the disease and the relatively moderate age of the patients involved, the radiation dose of paranasal sinus CT plays an important role. The use of a low-dose spiral CT technique and the reformation of coronal images out of the axial CT data instead of an additional direct coronal scan allow the effective dose of paranasal sinus CT to be reduced to the order of a chest radiogram. MRI is the preferred imaging modality in malignant disease or complications of inflammatory sinus disease that extend beyond the limits of the paranasal sinuses. The clinical value of other imaging modalities, including plain film radiography, ultrasound, or scintigraphy, is limited to special indications.     

Comparison of plain radiographs and coronal CT scans in infants and children with recurrent sinusitis

We performed a prospective study of 70 infants and children with recurrent sinusitis. We compared plain radiographs with coronal CT scans of the sinuses to determine if plain radiographs can be used to accurately diagnose and localize residual sinus disease amenable to endoscopic surgery. This residual disease is thought to be important in the pathogenesis of recurrences of sinusitis. The patients were taking antibiotics and were clinically well at the time of the two examinations (performed on the same day). Findings on slightly over 80% of the CT scans were abnormal. In about 75% of the patients, the findings on plain radiographs did not correlate with those on CT scans. About 45% of the patients had normal findings on plain radiographs of at least one sinus with an abnormality of that sinus shown on CT scans. Almost 35% of the patients had what was interpreted as an abnormality of at least one sinus on plain radiographs, but that sinus was normal on CT scans. Sinusitis in infants and children is often underdiagnosed or overdiagnosed on the basis of findings on plain radiographs of the sinuses. Plain radiographs cannot be used to determine the need for, or to guide, endoscopic surgery on the sinuses.     

Conventional sinus radiography compared with CT in the diagnosis of acute sinusitis

OBJECTIVES: To evaluate the value of plain film radiography in a prospective investigation of patients with clinical suspicion of acute sinusitis, using standard CT as a gold standard. METHODS: 47 consecutive patients were examined. Each patient underwent conventional X-ray and standard dose CT examinations on the same day. The sensitivity and specificity of the plain film examination were calculated. RESULTS: The specificity of the plain film examination was high, but the sensitivity was low except for the maxillary sinus (sensitivity 80%). Thus, for maxillary sinusitis, plain film examination was reasonably accurate. A negative finding in the other sinuses could not be relied upon. CONCLUSIONS: The sensitivity of plain film radiography for detecting sinus opacifications was unacceptably low for the ethmoid, frontal and sphenoid sinuses. The specificity was high.     

Prevalence of incidental paranasal sinuses opacification in pediatric patients: a CT study

A prospective evaluation of the paranasal sinuses was performed on a consecutive series of 137 pediatric patients referred for cranial CT. Approximately one-half of the patients less than 13 years of age had some degree of maxillary or ethmoid sinus opacification. The prevalence and severity of opacification was approximately the same for the maxillary and ethmoid sinuses. Sphenoid sinus abnormality was less common (16% of patients) and was usually minimal or mild. No incidental frontal sinus abnormalities were observed. This study confirms previous reports, based on plain film radiography, of the prevalence of incidental maxillary sinus opacification in children. However, contrary to some prior studies, we did not find a relatively higher rate of opacification in children less than 1 year of age. This may be due to overdiagnosis of maxillary sinus opacification on plain films, in small children. The diagnosis of sinusitis in childhood must take into account not only the radiographic findings but clinical signs and symptoms. Correlation is needed to avoid overdiagnosis in patients referred for sinus radiography for nonspecific indications or who have incidental opacification noted on radiographic or CT studies of the skull and brain.     

Pulmonary reaction to radiation following mantle-field irradiation. Comparison of follow-up by conventional x-ray and by computed tomography

A group of 36 patients who received mantle field irradiation for Hodgkin's disease (35 pts) or non-Hodgkin lymphoma (1 pt) were prospectively examined by plain film radiography and computed tomography (CT) for evaluation of the pulmonary reaction at the beginning and the end of the course of irradiation, and at 12 weeks, 17 weeks, and 37 weeks after the start of the mantle field irradiation. A total of 173 plain chest radiographs (p.a. and lateral view), and 167 CTs were reviewed. As in chest radiography, the pulmonary reaction to radiation seen in CT took a characteristic course with different distinguishable stages. The radiation-induced changes typically seen on on CT were reducible to three basic patterns of opacification, which sometimes appeared in combination, and had a characteristic spatial distribution. Comparison of the two imaging modalities suggest that CT should be used in special cases, while conventional plain film radiography of the chest, with the possibility of short-term controls, is still the mainstay of follow-up for patients with Hodgkin's disease.     

Paraspinal interfaces in the lower thoracic area in children: evaluation by CT

Computed tomography was used to examine the three paraspinal interfaces (lines), consisting of the right and left paraspinal areas and the prespinal area in the lower thorax in 20 children. The abnormal CT findings were correlated with plain radiographic findings. The various disease contributing to paraspinal abnormality included malignant and benign neoplasm and inflammatory disease. Neuroblastoma was the most common entity. Fourteen of 20 patients had paraspinal masses representing either metastasis or lymphoma. Four had small pleural effusions and two had a combination of small pleural effusion and masses. Plain radiographs also showed the paraspinal masses, except in the prespinal area, where four of seven abnormalities seen with CT were not detected with plain radiographs. CT also better demonstrated the extent of involvement than did plain radiography.     

Comparison of plain radiographs and computed tomographic scanning in nasopharyngeal carcinoma

Plain radiographs, computed tomographic (CT) scans and clinical records of 100 patients with nasopharyngeal carcinoma were studied. CT scans and plain radiographs provided similar information in 46 patients. There were 54 cases in which the two techniques disagreed. In 45 cases CT demonstrated abnormalities not seen in plain radiographs and in nine cases plain radiographs demonstrated abnormalities not seen with CT scanning. Based on the total information gained from clinical examination, the imaging investigations, biopsies, and subsequent clinical course and investigations it appeared that none of the abnormalities predicted by plain radiographs alone could be substantiated. Conversely the CT abnormalities could be supported as being correct. We conclude that CT alone is the undoubted investigation of choice where this is available. Plain films provide less information, are unreliable and, where CT is available, superfluous.     

Orbital pneumosinus dilatans

Pneumosinus dilatans consists of an abnormal dilatation of the paranasal air sinuses which contain air only and are lined by normal epithelium. The condition is most commonly observed when it affects the sphenoid sinus as a response to a local meningioma of the tuberculum sellae or planum sphenoidale. Pneumosinus dilatans affecting the walls of the paranasal sinuses which form the boundaries of the orbit is less common; six patients reported here presented with either unilateral or bilateral exophthalmos. The frontal sinus and ethmoid cells were affected unilaterally in four patients and the maxillary antra bilaterally in two. The condition was associated with a meningioma in three patients and fibro-osseous disease in three patients. The importance of recognising this condition is in alerting the radiologist to the possible presence of an occult meningioma requiring soft-tissue imaging techniques (computed tomography or nuclear magnetic resonance imaging). The presence of fibro-osseous disease can usually be recognised by plain radiography.     

The ostiomeatal unit and endoscopic surgery: anatomy, variations, and imaging findings in inflammatory diseases.

Recent and ongoing advances made in endoscopic surgical techniques require the radiologist to understand the anatomy and pathophysiology of the paranasal sinuses and nasal passage. Endoscopy and CT are complementary procedures, and, as such, the normal anatomic relationships and their CT appearances need to be well understood in order for radiologists to offer continued support as consultants to their clinical colleagues. In this article, we review the pertinent anatomy of the lateral nasal wall and paranasal sinuses, discuss the most frequently encountered normal variations that may predispose a patient to inflammatory sinus disease, outline imaging protocols for evaluation of this region, and introduce the reader to current endoscopic surgical techniques. Last, the imaging findings in various inflammatory processes involving the sinuses, as well as the local and regional complications associated with paranasal sinus inflammatory diseases, are presented.     

Complications of pneumoconiosis: Radiologic overview

A wide spectrum of pulmonary complications occurs in patients with pneumoconiosis. Those complications include chronic obstructive pulmonary disease, hemoptysis, pneumothorax, pleural disease, tuberculosis, autoimmune disease, anthracofibrosis, chronic interstitial pneumonia, and malignancy. Generally, imaging workup starts with plain chest radiography. However, sometimes, plain radiography has limited role in the diagnosis of pulmonary complications of pneumoconiosis because of overlapping pneumoconiotic infiltration. Computed tomography (CT), ultrasonography (US), and magnetic resonance imaging (MRI) are potentially helpful for the detection of pulmonary complications in patients with pneumoconiosis. CT, with its excellent contrast resolution, is more sensitive and specific method than plain radiograph in the evaluation of pulmonary abnormalities. CT is useful in detecting lung parenchymal abnormalities caused by infection, anthracofibrosis, and chronic interstitial pneumonia. Also, CT is valuable in distinguishing localized pneumothorax from bullae and aiding the identification of multiloculated effusions. US can be used in detection of complicated pleural effusions and guidance of the thoracentesis procedure. MRI is useful for differentiating between progressive massive fibrosis and lung cancer.     

Low-dose CT and inflammatory disease of the paranasal sinuses

Summary Computed tomography (CT) is the gold standard for exact delineation of inflammatory sinus disease, especially before endoscopic surgical treatment, and in cases of postoperative recurrences. In routine CT studies, the radiation dose to the patient is not negligible. Therefore, the authors evaluated prospectively the CT scans of 44 patients with inflammatory disease of the paranasal sinuses, to define the imaging ability of low-dose CT (i.e. 60 mA-3 s, 30 mA-3 s, and 30 mA-2 s), comparatively with the standard mAs settings (130 mA-3 s). In all cases, the exact extent of the disease was correctly assessed on each of the low-dose settings, with no false negative study. The increasing graininess of low mAs sections did not induce errors of interpretation, despite a less pleasant appearance to the eyes. In cases of extensive sinus disease, the thickness and integrity of the ethmoid septa were sometimes more difficult to evaluate on lowdose CT sections. The authors recommend the use of low mAs settings in the evaluation of inflammatory disease of the sinuses, complemented, if necessary, in cases of extensive abnormalities, by one or two sections obtained with standard mAs settings, focused on questionably abnormal bone septa.     

Complex fractures of the proximal humerus: role of CT in treatment

The authors reviewed the computed tomography (CT) scans, plain radiographs, and subsequent treatment of 17 patients with complex proximal humeral fractures. CT scans and radiographs were compared in the demonstration of fracture lines, displacement of fracture fragments, rotation of fragments relative to their normal positions, and status of the head and articular surface of the humerus. The impact of CT findings on the decision to treat with surgery versus closed reduction and on the choice of surgical procedure was assessed. Surgery was not performed in nine patients because CT scans showed no significant displacement of fragments previously judged displaced or "indeterminate" on radiographs. Surgery was performed in eight patients; CT demonstrated significant abnormalities not definitely shown with radiography. In six of these eight patients, CT scans demonstrated unsuspected abnormalities that directed the choice of surgical procedure. CT scans provide clinically useful information for the treatment of complex proximal humeral fractures when radiographs provide inadequate or indefinite information.     

Detection of hepatic portal venous gas: its clinical impact and outcome

The clinical impact and outcome of a rare radiographic finding of hepatic portal venous gas (HPVG) as well as the effectiveness of computed tomography (CT), CT scanogram, and conventional radiography in the detection of HPVG were retrospectively analyzed. CT scans, CT scanogram, and plain film radiographs of 11 patients with HPVG were reviewed and compared with their medical records and surgical and pathology reports. Eight of the 11 patients underwent plain film radiographs 1 day before or after the CT scan. HPVG was detected at CT in all 11 patients, on CT scanogram in three (3 of 11, 27.3%), and on plain films in one (one of eight, 12.5%). In nine of 11 patients (81.8%), CT revealed an associated pneumatosis intestinalis. In six of the 11 patients (54.6%), acute mesenteric ischemia was the underlying disease for HPVG. Seven patients (63.6%) underwent emergency exploratory laparotomy. The mortality rate for HPVG alone was 27.3% (3 of 11) and for HPVG related to mesenteric bowel disease 50% (three of six). Acute mesenteric ischemia is the most common cause of HPVG, which continues to have a predictably higher mortality. CT is superior to CT scanograms and radiographs in the detection of HPVG and its underlying diseases and, therefore, should be used as the primary diagnostic tool.     

Role and limitations of plain radiography in chest radiology]

Despite the recent development of diagnostic modalities such as CT and MRI, plain radiography continues to play an important role in chest radiology. Chest radiography remains the imaging modality of choice for initial examinations because it offers simplicity, low cost, and a large amount of information. It is important for radiologists to understand normal anatomy and variants simulating disease to avoid false-positive interpretations of chest radiographs and unnecessary CT examinations. It should be noted that many cases can be diagnosed correctly by chest radiographs alone. Only after careful evaluation of an abnormality on chest radiograph should CT examination be performed. We should also be aware that some serious chest diseases, including miliary tuberculosis, can present normal chest radiographs in the early stage. In such patients with respiratory symptoms, even when the chest radiograph is negative, CT examination should be performed promptly to avoid disease progression.     

Imaging of the elbow

The imaging needs for diagnosis of abnormalities in and about the elbow are presently satisfied in most instances by plain film radiography. Arthrography with tomography and CT has enabled us to delineate the joint space and articular surfaces better. The sensitivity of radionuclide imaging allows early detection of disease processes but lacks specificity. The advantages of MR imaging in the musculoskeletal system should allow improved diagnostic imaging capability about the elbow as it has for other joints.     

Radiographic manifestations of congenital heart disease in the adult patient

Improvements in the preoperative evaluation, surgical treatment, and postoperative care of patients with congenital cardiac disease have allowed a large patient population with congenital cardiac abnormalities to reach adolescence and adulthood. Noninvasive diagnostic imaging procedures (e.g., plain film radiography, echocardiography, computed tomography, and magnetic resonance imaging) are playing an increasingly important role in the evaluation and management of adults with both treated and untreated congenital cardiac disease. The role of plain film radiology is emphasized.     

Pulmonary lymphangiomyomatosis and tuberous sclerosis: comparison of radiographic and thin-section CT findings

Chest radiographs, thin-section computed tomographic (CT) scans, and results of pulmonary function tests in nine women with pulmonary lymphangiomyomatosis and two women with pulmonary tuberous sclerosis were retrospectively evaluated. In all patients, CT demonstrated thin-walled cysts less than 20 mm in diameter scattered at random in all parts of the lungs. In eight patients, cysts larger than 20 mm in diameter were also present. Lung tissue between cysts appeared normal in all 11 patients, except one with septal lines and dependent alveolar areas of attenuation. CT showed cysts in three patients whose radiographs were normal, and it demonstrated that many lesions that appeared reticular on plain radiographs were actually cysts. CT findings correlated better with the diffusion capacity of the lungs for carbon monoxide than did the plain radiographic findings. CT was more sensitive and more precise than radiography at showing the presence and morphology of lung abnormalities.     

Seronegative spondyloarthropathies: what radiologists should know

Inflammatory involvement of the spine and sacroiliac joints is the most peculiar feature of seronegative spondyloarthropathies (SpA), which include ankylosing spondylitis, psoriatic arthritis, reactive arthritis (Reiter’s syndrome), enteropathic spondylitis (related to inflammatory bowel diseases) and undifferentiated spondyloarthropathies. SAPHO syndrome may also be considered a SpA, but there is no clear agreement in this respect. Imaging, along with clinical and laboratory evaluation, is an important tool to reach a correct diagnosis and to provide a precise grading of disease progression, influencing both clinical management and therapy. Conventional radiography, which is often the first-step imaging modality in SpA, does not allow an early diagnosis. Computed tomography (CT) demonstrates with a very high spatial resolution the tiny structural alterations of cortical and spongy bone before they become evident on plain film radiographs. Magnetic resonance imaging (MRI) is the only modality that provides demonstration of bone marrow oedema, which reflects vasodilatation and inflammatory hyperaemia. The primary aim of this review article was to examine the involvement of the spine and sacroiliac joints in SpA using a multimodal radiological approach (radiography, CT, MRI), providing a practical guide for the differential diagnosis of these conditions.     

Magnification radiography in osteomyelitis

Osteomyelitis often eludes early diagnosis because plain film radiography is too insensitive and radionuclide bone scanning is nonspecific. In this study, 90 diabetic patients were studied with plain film and magnification radiographs of their feet. Among the 24 patients with osteomyelitis, plain radiographs suggested the diagnosis in 14 patients and magnification radiography was diagnostic in 18 of these patients. Thus, magnification radiography offers some diagnostic advantage in patients suspected of having osteomyelitis.