Finding the bubble: atypical and unusual extrapulmonary air in the chest

OBJECTIVE

To describe the radiologic findings of extrapulmonary air in the chest and to review atypical and unusual causes of extrapulmonary air, emphasizing the importance of the diagnosis in managing these patients.

CONCLUSION

In this article, we review a series of cases collected at our center that manifest with extrapulmonary air in the thorax, paying special attention to atypical and uncommon causes. We discuss the causes of extrapulmonary according to its location: mediastinum (spontaneous pneumomediastinum with pneumorrhachis, tracheal rupture, dehiscence of the bronchial anastomosis after lung transplantation, intramucosal esophageal dissection, Boerhaave syndrome, tracheoesophageal fistula in patients with esophageal tumors, bronchial perforation and esophagorespiratory fistula due to lymph-node rupture, and acute mediastinitis), pericardium (pneumopericardium in patients with lung tumors), cardiovascular (venous air embolism), pleura (bronchopleural fistulas, spontaneous pneumothorax in patients with malignant pleural mesotheliomas and primary lung tumors, and bilateral pneumothorax after unilateral lung biopsy), and thoracic wall (infections, transdiaphragmatic intercostal hernia, and subcutaneous emphysema after lung biopsy).

Diagnostic imaging in spontaneous rupture of a thoracic duct cyst in the mediastinum

Thoracic duct cysts in the mediastinum are extremely rare; they can give rise to chylothorax when they spontaneously rupture or after they are operated on. We present the case of an adult woman with a thoracic duct cyst in the mediastinum and chylothorax from its spontaneous rupture; to our knowledge, this phenomenon has not been specifically reported before. We describe the clinical and radiological findings, the therapeutic management, and the pathology findings, reviewing the literature for this entity.

Clinical features and therapeutic management of subglottic stenosis in patients with Wegener's granulomatosis

The objective of the study was to evaluate the clinical features, response to treatment, and long-term outcome of subglottic stenosis (SGS) in a series of patients diagnosed as having Wegener's granulomatosis (WG) at a single institution. Subglottic stenosis developed in 6 out of 51 (11.7%) patients, in four of them in the absence of other features of active disease, and was the symptom that leads to WG diagnosis in three cases. In two cases, SGS began while the patients were receiving systemic immunosuppressive therapy for disease activity involving other sites. PR3-ANCAs were positive in four cases. An urgent tracheostomy was needed in two patients. Four patients achieved SGS clinical remission on standard treatment with glucocorticoids and cyclophosphamide, but three of them experienced repeated local relapses and required additional immunosuppressive therapy and mechanical dilations. In one case, a local relapse was successfully managed with endotracheal dilation of the stenotic segment and intralesional injection of a long-acting corticosteroid plus mechanical dilation of the stenotic segment (ILCD) without adding supplemental immunosuppressant drugs. Two patients with isolated SGS were also successfully managed with ILCD alone and did not require the institution of systemic immunosuppressive therapy. One patient underwent open surgical repair when the disease was under control. Our data suggest that Subglottic stenosis often occurs or progresses independently of other features of active WG, and that ILCD may be a safe alternative to conventional immunosuppressive therapy in patients who develop SGS in the absence of other features of active disease, allowing reducing the treatment-related toxicity.

Septal thickening: HRCT findings and differential diagnosis

Thickening of the interlobular septa is a common and easily recognized high-resolution computed tomography feature of many diffuse lung diseases. In some cases, it is the predominant radiological finding. This article reviews the spectrum of entities that commonly present with thickening of the interlobular septa as the main radiological feature and establishes a practical approach for the differential diagnosis.

Radiological manifestations of pulmonary tuberculosis

Pulmonary tuberculosis (TB) is a common worldwide lung infection. The radiological features show considerable variation, but in most cases they are characteristic enough to suggest the diagnosis. Classically, tuberculosis is divided into primary, common in childhood, and postprimary, usually presenting in adults. The most characteristic radiological feature in primary tuberculosis is lymphadenopathy. On enhanced CT, hilar and mediastinal nodes with a central hypodense area suggest the diagnosis. Cavitation is the hallmark of postprimary tuberculosis and appears in around half of patients. Patchy, poorly defined consolidation in the apical and posterior segments of the upper lobes, and in the superior segment of the lower lobe is also commonly observed. Several complications are associated with tuberculous infection, such as hematogenous dissemination (miliary tuberculosis) or extension to the pleura, resulting in pleural effusion. Late complications of tuberculosis comprise a heterogeneous group of processes including tuberculoma, bronchial stenosis bronchiectasis, broncholithiasis, aspergilloma, bronchoesophageal fistula and fibrosing mediastinitis. Radiology provides essential information for the management and follow up of these patients and is extremely valuable for monitoring complications.

Miliary lung disease revisited

This article reviews the high-resolution computed tomography imaging features of miliary pattern, a characteristic radiologic manifestation of diffuse micronodular lung disease. The most common entities with this pattern are miliary tuberculosis, pneumoconiosis, sarcoidosis, metastases, and hypersensitivity pneumonia. According to the distribution of the nodules in relation to the secondary lobule, high-resolution computed tomography findings divide miliary patterns into 3 groups: centrilobular, perilymphatic, and random presentation. The radiologic features that help in the differential diagnosis are discussed.

Ventilatory insufficiency due to asbestos-related diffuse pleural fibrosis successfully treated with noninvasive home mechanical ventilation

A 54-year-old man with diffuse pleural fibrosis due to previous asbestos exposure developed hypercapnic respiratory failure. Noninvasive mechanical ventilation (NIMV) was started at the hospital and maintained at the patient's home, achieving reversal of the respiratory failure. During a 2-year follow-up, NIMV has been well tolerated by the patient and no relapse in ventilatory failure has occurred. Home NIMV can be considered as an alternative to pleural decortication in asbestos-related diffuse pleural fibrosis with ventilatory insufficiency.

Improved diagnosis of hepatic perfusion disorders: value of hepatic arterial phase imaging during helical CT

The liver has a unique dual blood supply, which makes helical computed tomography (CT) a highly suitable technique for hepatic imaging. Helical CT allows single breath-hold scanning without motion artifacts. Because of rapid image acquisition, two-phase (hepatic arterial phase and portal venous phase) evaluation of the hepatic parenchyma is possible, improving tumor detection and tumor characterization in a single CT study. The arterial and portal venous supplies to the liver are not independent systems. There are several communications between the vessels, including transsinusoidal, transvasal, and transplexal routes. When vascular compromise occurs, there are often changes in the volume of blood flow in individual vessels and even in the direction of blood flow. These perfusion disorders can be detected with helical CT and are generally seen as an area of high attenuation on hepatic arterial phase images that returns to normal on portal venous phase images; this finding reflects increased arterial blood flow and arterioportal shunting in most cases. Familiarity with the helical CT appearances of these perfusion disorders will result in more accurate diagnosis. By recognizing these perfusion disorders, false-positive diagnosis (hypervascular tumors) or overestimation of the size of liver tumors (eg, hepatocellular carcinoma) can be avoided.

[Lymphangioleiomyomatosis: study of 15 patients]

BACKGROUND

Lymphangioleiomyomatosis (LAM) is an uncommon disease of not well-known evolution. We describe the clinical features and follow-up of a group of patients diagnosed of LAM in a hospital pulmonary transplantation programme.

PATIENTS AND METHODS

15 women (mean age: 43, range: 36-52) diagnosed of LAM, 9 at the Hospital Vall d'Hebron and 6 referred from other hospitals, for preoperative evolution of lung transplantation, were retrospectively studied.

RESULTS

Dyspnea appeared in all cases and it was the main symptom. Pleural problems in the early evolution of the disease were also very frequent (12 out of 15 patients). For this reason, pleurodesis was performed in 7 patients and pleurectomy in 2 (one of them bilateral). Thoracic CT scan showed very characteristic cystic images and abdominal CT proved the presence of extrathoracic associated angiomyolipomas in one case. In two patients, LAM was diagnosed after studying the explanted lung. These two patients had been previously misdiagnosed of emphysema and pulmonary haemosiderosis. Survival since the beginning of symptoms was 82 and 49%, 5 and 10 years later, respectively. Six out of eight patients who underwent lung transplantation had a long postoperative survival.

CONCLUSIONS

LAM seems to be as infrequent in Catalunya as in other countries, even if some cases could be misdiagnosed. Lung transplantation is useful in the advanced stages of the disease and, in our experience, it has improved respiratory insufficiency in half of the patients.

Arteriovenous fistula secondary to iliac mycotic aneurysm: helical CT findings

We describe the case of a 59-year-old man who presented a mycotic aneurysm of the common right iliac artery due to Streptococcus agalactiae and developed an arteriovenous fistula within the inferior vena cava secondary to spontaneous rupture of the aneurysm. The clinical syndrome, helical computed tomographic, and angiographic findings are described and discussed.

Intrahepatic arterioportal shunt: helical CT findings

The purpose of this study was to characterize the appearance of intrahepatic arterioportal shunts (APS) on two-phase helical CT, with emphasis on the importance of the hepatic arterial-dominant phase (HAP) to demonstrate perfusion disorders. We review eight cases of APS diagnosed by helical CT in our institution from January 1996 to March 1997 and describe the CT findings that established diagnosis. Five of them were confirmed by angiography. In seven (87. 5 %) cases of APS we found early enhancement of the peripheral portal branches during the HAP of helical CT, whereas the superior mesenteric and splenic veins remained unenhanced. In five (62.5 %) cases of APS, transient, peripheral, triangular parenchymal enhancement was depicted during the HAP of helical CT; in four of these cases there was associated early enhancement of the portal branches. Helical CT can show perfusion alterations that might remain undiagnosed with conventional CT. An understanding of the hemodynamic changes that occur in APS can help in the interpretation of focal transient hepatic parenchymal enhancement and to differentiate APS from hypervascular tumors. We believe that the helical CT findings described herein are characteristic enough to suggest the diagnosis of APS.

Renal trauma in occult ureteropelvic junction obstruction: CT findings

The aim of this study was to present CT findings of occult ureteropelvic junction obstruction in patients with renal trauma and to describe the clinical signs and singular CT features that are characteristically observed with trauma and are relevant to management of these patients. We retrospectively reviewed 82 helical CT studies in patients with renal trauma referred to our institution. We found 13 cases of occult preexisting renal pathology, six of which were occult ureteropelvic junction obstructions. The clinical presentation, radiologic findings of trauma according to the Federle classification, and CT findings of obstructed ureteropelvic junction are presented. We found three category-I lesions (one in horseshoe kidney), two of them treated with nephrostomy because of increased ureteropelvic junction obstruction due to pelvic clots; two category-II lesions (parenchymal and renal pelvis lacerations) that had presented only with microhematuria; and one category-IV lesion (pelvic laceration alone). Pelvic extension was demonstrated in all the cases with perirenal collections. The CT studies in all the cases with suspected ureteropelvic junction obstruction showed decreased parenchymal thickness and enhancement, and dilatation of the renal pelvis and calyx, with a normal ureter. Computed tomography can provide information to confidently diagnose underlying ureteropelvic junction obstruction in renal trauma, categorize the traumatic injury (at times clinically silent) and facilitate proper management according to the singularities observed, such us rupture of the renal pelvis alone (Federle category IV) and increasing ureteropelvic obstruction due to clots which can be decompressed by nephrostomy.

Aortic dissection: diagnosis and follow-up with helical CT

Acute aortic dissection is a cardiovascular emergency that requires prompt diagnosis and treatment. Helical computed tomography (CT) allows diagnosis of acute aortic dissection with a sensitivity and specificity of nearly 100%. With helical CT, a dissection involving the ascending aorta (type A in the Stanford classification) can be differentiated from one distal to the left subclavian artery (type B). Helical CT can also be used to identify atypical forms of aortic dissection such as intramural hematoma, penetrating atherosclerotic ulcer, ruptured type B dissection, and atypical configurations of the intimal flap. Helical CT is useful in follow-up of aortic dissection by allowing assessment of early and late changes after surgery or medical treatment. Such changes include postoperative complications of type A dissection, healing of intramural hematoma, progression of intramural hematoma, and aneurysms of the true or false lumen. Helical CT can also be used to monitor potentially life-threatening ischemic complications of abdominal branch vessels.

Small bowel obstruction secondary to bezoar: CT diagnosis

Two cases of small bowel obstruction secondary to phytobezoar diagnosed by computed tomography (CT) and confirmed at surgery are presented. CT findings were dilated intestinal loops and an intraluminal mass with air bubbles retained in its interstices, resulting in a mottled appearance. We propose that definite diagnosis of small bowel bezoar can be made on the basis of these CT findings.

Duodenal schwannoma causing gastrointestinal bleeding: helical CT findings

Neurogenic tumors of the small intestine are extremely rare and represent an unusual cause of gastrointestinal hemorrhage. We present a case of schwannoma of the fourth portion of the duodenum demonstrated by helical computed tomography. Multiplanar reconstructions showed a hypervascular tumor arising from the inferior wall of the duodenum. The use of water as oral contrast agent instead of iodinated contrast permitted a better visualization of the intact mucosa and differentiated a hypervascular tumor from hypodense gastrointestinal content.

CT evaluation of underlying cause in spontaneous subcapsular and perirenal hemorrhage

We evaluated the CT scans of 13 patients with spontaneous subcapsular or perinephric hemorrhage (SPH) associated with these underlying causes: 4 angiomyolipomas, 2 renal cell carcinomas, 1 renal metastatic malignant melanoma, 1 ruptured renal artery aneurysm, 1 adrenal myelolipoma, 1 ruptured renal abscess, 2 ruptured hemorrhagic cysts, and 1 patient with undiagnosed coagulation disorder. Our objective was to ascertain whether an underlying cause of SPH was identifiable by CT, and to determine the extension of the hematomas. Computed tomography identified the hematoma in all 13 cases (sensitivity 100 %). In all 12 cases in which there was a renal or adrenal anatomic lesion, the underlying cause was identified with CT (100 %), with correct diagnosis in 11 cases (91.6 %). The case in which no lesion was identified was the undiagnosed coagulation disorder. We conclude that CT is a useful technique for the initial evaluation of SPH, permitting diagnosis of hemorrhage and identification of the underlying cause.