"Straddling across boundaries"-thoracoabdominal lesions: spectrum and pattern approach.

The thoracoabdominal region consists of the inferior thorax and superior abdomen and is separated by the diaphragm. Although the diaphragm appears to act as a barrier in this region, various lesions can straddle across the diaphragm and lie contiguously in both the thorax and the abdomen. Thoracoabdominal lesions can extend across the diaphragm either through its various natural openings or through abnormal defects. The natural openings lie in the midline and include the hiatuses for the inferior vena cava, the esophagus, and the retrocrural space, which includes the aortic hiatus and the prevertebral and paravertebral spaces. Abnormal defects include congenital defects in fusion, that is, foramina of Morgagni and Bochdalek and acquired diaphragmatic rupture. Very large lesions can also displace the diaphragm, either inferiorly or superiorly, and thus appear to pseudoextend across this region. Using a pattern approach based on the location and route of extension, thoracoabdominal lesions can be classified as central and lateral lesions. Central lesions form a large group, and based on their location, they can be further classified as central anterior, central tendon, inferior vena cava, esophageal, and retrocrural pathologies. Both central and lateral thoracoabdominal lesions form a diverse spectrum and can be congenital, neoplastic, inflammatory, iatrogenic, or traumatic in etiology. Morphologically, these can consist of solid masses, cystic lesions, and ill-defined collections extending across the diaphragm. This article depicts the imaging appearance of the wide spectrum of lesions straddling across the diaphragm. Familiarity with these pathologies can help in better understanding the continuum formed by the thoracoabdominal region and the various routes of transdiaphragmatic extension.

Role of (99m)Tc-MDP bone scan in the diagnosis of Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare systemic non-Langerhans cell histiocytosis. It is a progressive disease of unknown etiology. The (99m)technetium-methylene diphosphonate ((99m)Tc-MDP) bone scan is useful in finding the sites of involvement in the skeleton and is helpful in excluding other causes of bony pain. Also a scintigraphic pattern consistent with ECD should alert the physician to evaluate the patient for visceral sites of involvement using fludeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), as this is known to be fatal at times.

Ophthalmic manifestations of systemic diseases--part 2: metabolic, infections, granulomatoses, demyelination, and skeletal dysplasias.

The orbit and globe can be secondarily involved in various systemic diseases. These range from tumor and tumorlike conditions, metabolic, infective, inflammatory, granulomatous demyelinating diseases, and skeletal dysplasias. In this article, we discuss the imaging appearances of the remaining systemic pathologies affecting the orbit such as (1) endocrine or metabolic, (2) infectious, (3) inflammatory or granulomatous, (4) demyelinating diseases, and (5) skeletal dysplasias. As the imaging appearances of various systemic diseases tend to overlap, we also introduce a list of pattern-based systemic differential diagnoses for commonly encountered orbital imaging findings. Awareness of the imaging appearances of the various ophthalmic manifestations of systemic diseases can help a radiologist to suggest the most appropriate differential diagnosis to guide further workup and facilitate correct treatment.

Ophthalmic manifestations of systemic diseases--part 1: phakomatoses, hematologic malignancies, metastases, and histiocytosis.

The orbit can be secondarily involved in various systemic conditions. The ophthalmic involvement is often the first clue to the presence of an underlying systemic condition. The ophthalmic involvement in systemic diseases can be either ocular or extraocular. The extent of involvement can be well delineated by imaging modalities like computed tomography and magnetic resonance imaging. In the first part of the article, we provide an overview of systemic diseases affecting the orbit, briefly discuss the modalities for orbital imaging, and discuss the imaging appearances of ophthalmic involvement in (1) phakomatoses, (2) hematologic malignancies, (3) metastases, and (4) histiocytosis. At the end of the 2-part article, we discuss a pattern-based approach and differential diagnosis of orbital lesions in systemic diseases.

Overview of airway involvement in tuberculosis.

Pulmonary tuberculosis is a ubiquitous infection and a re-emerging medical and socioeconomic problem resulting in increasing mortality and morbidity, especially in Asian countries. We aim to review the spectrum of imaging findings in airway involvement in tuberculosis through characteristic radiological images and to assess the role of computed tomography and image-guided interventions in the diagnosis and management of pulmonary tuberculosis.

Aortoesophageal fistula in a child.

Aortoesophageal fistulae (AEF) are rare and are associated with very high mortality. Foreign body ingestions remain the commonest cause of AEF seen in children. However in a clinical setting of tuberculosis and massive upper GI bleed, an AEF secondary to tuberculosis should be kept in mind. An early strong clinical suspicion with good quality imaging and endoscopic evaluation and timely aggressive surgical intervention helps offer the best possible management for this life threatening disorder. Our case is a 10-year-old boy who presented to the pediatric emergency with massive bouts of haemetemesis and was investigated and managed by multidisciplinary team effort in the emergency setting.

Sonographic diagnosis of subungual intraosseous epidermoid cyst.

Intraosseous epidermoid cyst is an uncommon subungual mass. We report the sonographic findings in a case of intraosseous epidermoid cyst, which showed the characteristic whorled pattern of layers, previously described in other locations and unequivocally clinched the diagnosis in favor of this benign etiology and guided the management to phalangeal-sparing surgery.

Internal jugular vein: Peripheral vein adrenocorticotropic hormone ratio in patients with adrenocorticotropic hormone-dependent Cushing's syndrome: Ratio calculated from one adrenocorticotropic hormone sample each from right and left internal jugular vein during corticotrophin releasing hormone stimulation test.

BACKGROUND: DEMONSTRATION OF CENTRAL: Peripheral adrenocorticotropic hormone (ACTH) gradient is important for diagnosis of Cushing's disease. AIM: THE AIM WAS TO ASSESS THE UTILITY OF INTERNAL JUGULAR VEIN (IJV): Peripheral vein ACTH ratio for diagnosis of Cushing's disease. MATERIALS AND METHODS: Patients with ACTH-dependent Cushing's syndrome (CS) patients were the subjects for this study. One blood sample each was collected from right and left IJV following intravenous hCRH at 3 and 5 min, respectively. A simultaneous peripheral vein sample was also collected with each IJV sample for calculation of IJV: Peripheral vein ACTH ratio. IJV sample collection was done under ultrasound guidance. ACTH was assayed using electrochemiluminescence immunoassay (ECLIA). RESULTS: Thirty-two patients participated in this study. The IJV: Peripheral vein ACTH ratio ranged from 1.07 to 6.99 (n = 32). It was more than 1.6 in 23 patients. Cushing's disease could be confirmed in 20 of the 23 cases with IJV: Peripheral vein ratio more than 1.6. Four patients with Cushing's disease and 2 patients with ectopic ACTH syndrome had IJV: Peripheral vein ACTH ratio less than 1.6. Six cases with unknown ACTH source were excluded for calculation of sensitivity and specificity of the test. CONCLUSION: IJV: Peripheral vein ACTH ratio calculated from a single sample from each IJV obtained after hCRH had 83% sensitivity and 100% specificity for diagnosis of CD.

Unusual retrovesical cystic mass in a male patient.

Primary tumors of the seminal vesicles are very rare, with most reported cases being malignant. Benign tumors of the seminal vesicles are even rarer. A spectrum of tumors is derived from both epithelium and stroma and constitutes a distinct subset termed "epithelial-stromal tumors." We present the classic imaging findings of a cystadenoma of the seminal vesicles in a 23-year-old man, who presented with lower abdominal pain and obstructive urinary symptoms.

Congenital portosystemic venous shunt in a preterm Rh-isoimmunized infant.

The authors report a preterm infant with Rh-isoimmunization, who had persistent hepato-splenomegaly with conjugated hyperbilirubinemia, transaminitis, and hyperammonemia. Ultrasound abdomen revealed an intrahepatic portosystemic venous shunt (PSVS). The child was managed conservatively. On follow up at 2.4 y of age, the child is having normal growth and development, but with persisting shunt. Severe Rh-isoimmunisation in a neonate can sometimes share some of the features of congenital PSVS and delay the diagnosis of the latter. The index case had shunt ratio >80 % during the neonatal period but did not require any intervention.

Persistent primitive trigeminal artery: an unusual cause of vascular tinnitus.

Pulsatile tinnitus is generally of vascular origin and can be due to arterial, venous, or systemic causes. While certain congenital anatomical variants and arterial vascular loops have been commonly found in symptomatic patients undergoing imaging, persistent primitive trigeminal artery in association with isolated tinnitus is unusual. Thus we report a patient with unilateral isolated pulsatile tinnitus who was evaluated with magnetic resonance angiography and was found to have a persistent primitive trigeminal artery. We also briefly discuss vascular tinnitus as well as the embryology, imaging, and classification of persistent primitive trigeminal artery with the clinical implications.

Imaging evaluation of hemoptysis in children.

Hemoptysis is an uncommon but distressing symptom in children. It poses a diagnostic challenge as it is difficult to elicit a clear history and perform thorough physical examination in a child. The cause of hemoptysis in children can vary with the child's age. It can range from infection, milk protein allergy and congenital heart disease in early childhood, to vasculitis, bronchial tumor and bronchiectasis in older children. Acute lower respiratory tract infections are the most common cause of pediatric hemoptysis. The objective of imaging is to identify the source of bleeding, underlying primary cause, and serve as a roadmap for invasive procedures. Hemoptysis originates primarily from the bronchial arteries. The imaging modalities available for the diagnostic evaluation of hemoptysis include chest radiography, multi-detector computed tomography (MDCT), magnetic resonance imaging (MRI) and catheter angiography. Chest radiography is the initial screening tool. It can help in lateralizing the bleeding with high degree of accuracy and can detect several parenchymal and pleural abnormalities. However, it may be normal in up to 30% cases. MDCT is a rapid, non-invasive multiplanar imaging modality. It aids in evaluation of hemoptysis by depiction of underlying disease, assessment of consequences of hemorrhage and provides panoramic view of the thoracic vasculature. The various structures which need to be assessed carefully include the pulmonary parenchyma, tracheobronchial tree, pulmonary arteries, bronchial arteries and non-bronchial systemic arteries. Since the use of MDCT entails radiation exposure, optimal low dose protocols should be used so as to keep radiation dose as low as reasonably achievable. MRI and catheter angiography have limited application.

Pediatric vs adult pulmonary tuberculosis: A retrospective computed tomography study.

AIM: To compare the manifestations of chest tuberculosis (TB) in pediatric and adult patients based on contrast enhanced computed tomography of chest. METHODS: This was a retrospective study consisting of 152 patients of chest TB including 48 children and 104 adults who had undergone contrast enhanced computed tomography of chest prior to treatment. The patterns and severity of parenchymal, mediastinal and pleural manifestations were analyzed and compared among different age groups. RESULTS: Parenchymal changes observed include consolidation, air space nodules, miliary TB, cavitation, bronchiectasis and fibrosis and these were noted in 60% of children, 71% of adolescents and 76.9% of adults. These changes were more common in right upper lobe in all age groups. There was no significant difference in the frequency of these changes (except nodules) in different age groups. Centrilobular nodules were seen less commonly in children less than 10 years (P = 0.028). Pleural effusion was noted in 28 (18.42%) patients and pericardial effusion in 8 (5.3%) patients. No significant difference in the serosal involvement is seen among children and adults. Mediastinal adenopathy was seen 70% of children, 76.3% adolescents and 76.9% of adults and paratracheal nodes were seen most frequently. Nodes had similar features (except matting) among all age groups. Matting of nodes was seen more commonly in children (P = 0.014). CONCLUSION: Pediatric chest tuberculosis can have severe parenchymal lesions and nodal involvement similar to adults. The destructive lung changes observed in children needs immediate attention in view of the longer life span they have and hence in formulating optimal treatment strategies.

Unusual orbital involvement in Erdheim Chester disease: a radiological diagnosis.

Erdheim-Chester disease (ECD) is an exceedingly rare, disseminated non-Langerhan cell histiocytosis with multisystem involvement, having characteristic sclerotic skeletal lesions. We present an unusual case primarily manifesting as an extensive orbital disease, with low-grade systemic involvement. Owing to its rarity and therefore lack of general awareness it remains a difficult clinical and pathologic diagnosis. Immuno-histochemistry of the biopsy specimen is diagnostic.