Hepatic adenomatosis: MR imaging features.

Hepatocellular adenomas are rare benign liver neoplasms that commonly occur in women with a history of oral contraceptives intake for more than 2 years. Hepatic adenomatosis is characterized by the presence of multiple adenomas, arbitrarily > than 10, involving both lobes of the liver, without any history of steroid therapy or glycogen storage disease. Although the adenomas in liver adenomatosis are histologically similar to other adenomas, liver adenomatosis appears to be a separate clinical entity. Adenomas in hepatic adenomatosis may be of the inflammatory, hepatocyte nuclear factor 1alpha-mutated, or beta-catenin-mutated subtype, and accordingly show variable imaging appearances. Hepatic adenomatosis carries the risk of impaired liver function, hemorrhage and malignant degeneration. We report a case with the inflammatory subtype of hepatic adenomatosis in a 39-year-old woman with liver steatosis. The magnetic resonance imaging features using extracellular gadolinium chelates and hepatocyte-targeted contrast agents are described.

Acute intestinal anisakiasis: CT findings.

Small bowel anisakiasis is a relatively uncommon disease that results from consumption of raw or insufficiently pickled, salted, smoked, or cooked wild marine fish infected with Anisakis larvae. We report a case of intestinal anisakiasis in a 63-year-old woman presenting with acute onset of abdominal complaints one day after ingestion of raw wild-caught herring from the Northsea. Computed tomography (CT) scanning demonstrated thickening of the distal small bowel wall, mucosa with hyperenhancement, mural stratification, fluid accumulation within dilated small-bowel loops and hyperemia of mesenteric vessels. In patients with a recent history of eating raw marine fish presenting with acute onset of abdominal complaints and CT features of acute small bowel inflammation the possibility of anisakiasis should be considered in the differential diagnosis of acute abdominal syndromes.

Tuberculous adenitis: comparison of CT and MRI findings with histopathological features.

Our aim was to investigate the relationship between the various histopathological features and the CT and MRI findings in routinely submitted histopathological specimens for the diagnosis of tuberculous lymphadenopathy. Twelve formalin-fixed, paraffin-embedded tissue blocks from ten patients who were clinically suspected of having tuberculous lymphadenopathy were evaluated. We assessed the presence of histopathological features including granuloma formation, caseous necrosis, and presence of Langhans-type giant cells, calcifications, fibrosis or normal lymphoid tissue. We performed polymerase chain reaction (PCR)-based assay for mycobacterial DNA and Ziehl-Neelsen staining for acid-fast bacilli (AFB). Findings were compared with those of CT and MRI, including signal intensities on unenhanced MR images, lymph node homogeneity, attenuation values on contrast-enhanced CT and enhancement patterns on MRI. Based on CT and MRI findings, four lymph node types could be defined: (1) homogeneous nodes, visible on both pre- and post-contrast images and corresponding histopathologically to granulation tissue without or with minimal caseation necrosis (n = 2); (2) heterogeneous nodes, showing heterogeneous enhancement patterns with central non-enhancing areas and corresponding to minor or moderate intranodal caseation/liquefaction necrosis (n = 3); (3) nodes showing peripheral rim enhancement and corresponding to moderate or extensive intranodal caseation/liquefaction necrosis (n = 5); (4) heterogeneous nodes showing intranodal hyperdensities on CT and hypointense areas on T1- and T2-weighted images and corresponding to fibrosis and calcifications (n = 2). On CT and MRI, the findings reflect different stages of the tuberculous process. Imaging findings depend on the presence and the degree of granuloma formation, caseation/liquefaction necrosis, fibrosis and calcifications.

Tuberculosis: epidemiology, manifestations, and the value of medical imaging in diagnosis.

Mycobacterial infections have been shown to be increasing in number worldwide, mainly due a global increase in developing countries, the increased number of patients with HIV infection and AIDS disease worldwide, an increasing number of elderly patients and the emergence of multidrug resistant tuberculosis. Inhalation is the predominant pathway of Mycobacterium tuberculosis (M. tuberculosis) infection, making pulmonary tuberculosis the most common form of tuberculosis. Tuberculosis may arise either from a recent infection with M. tuberculosis, or from the reactivation of dormant bacilli, years or decades after initial infection. Extrapulmonary tuberculosis mainly results from reactivation of a tuberculous focus after hematogenous dissemination or lymphogenous spread from a primary, usually pulmonary focus. Tuberculosis may demonstrate a variety of radiological features depending on the organ site involved and may mimick other pathologies. The final diagnosis of tuberculous disease mainly depends on the detection of the causative organism on histopathological examination, culture and polymerase chain reaction-based assay for mycobacterial DNA on material obtained during bronchoscopic washings, fine needle aspiration cytology (FNAC) or biopsy.

CT and MR imaging of gastrointestinal tuberculosis.

The purpose of this study was to describe the CT and MR imaging findings of tuberculosis of the gastrointestinal tract. Abdominal and pelvic CT scans and MRI studies of 6 patients with histopathological and microbiological proven intestinal tuberculosis were reviewed by two radiologists in consensus. Location and pattern of bowel wall involvement, signal intensities in relation to the normal bowel wall, pattern of enhancement and associated abdominal abnormalities were evaluated. Gastrointestinal tract tuberculosis may be limited to one bowel segment, with the cecum and ileocecal valve as the predominant site of disease, or may involve multiple bowel segments. Asymmetric thickening of the bowel wall is a common finding. Associated findings include pericecal and mesenteric fat stranding, regional lymphadenopathy showing peripheral, heterogeneous and/or homogeneous enhancement patterns and less commonly, tuberculous 'dry plastic' peritonitis. On magnetic resonance (MR) imaging, tuberculous bowel involvement results in intermediate decreased signal intensities on T1-weighted images, and intermediate increased, slight heterogeneous signal intensities on T2-weighted images. On contrast-enhanced images, slight heterogeneous enhancement is seen.

Imaging of extraspinal musculoskeletal tuberculosis.

Tuberculosis (TB) is still a major cause of significant morbidity and mortality despite universal availability of effective chemotherapy. The emergence of multidrug-resistant mycobacteria along with a worldwide increase in HIV infection has led to a recent surge in the number of patients with TB. TB involves both pulmonary and extrapulmonary sites. Tuberculous spondylitis is the most common form of musculoskeletal TB and accounts for approximately 50% of cases. Extraspinal musculoskeletal TB is among the least common manifestations of TB. It shows a predilection for joints and para-articular areas while isolated soft tissue TB occurs extremely rare. A non-specific, often indolent clinical presentation in conjunction with its low prevalence constitutes obstacles for diagnosis. The differential diagnosis of extraspinal musculoskeletal TB consists of degenerative processes, inflammatory and infectious conditions, primary neoplasms, and metastatic lesions. Early diagnosis and treatment is of utmost importance to prevent serious joint and bone destruction. Radiological assessment of patients with musculoskeletal TB is often the key to adequate diagnosis and early treatment. The purpose of this manuscript is to review the imaging features of extraspinal musculoskeletal TB and to focus on the magnetic resonance imaging (MRI) characteristics of this pathology.

Vascular involvement secondary to tuberculosis of the abdomen.

Although involvement of the abdomen is a common site of extrapulmonary tuberculosis, involvement of abdominal vessels with complications is rare after infections with Mycobacterium tuberculosis (M. tuberculosis). Vascular complications may result from direct involvement by M. tuberculosis of the vascular wall or may occur as a consequence of local spreading from a tuberculous mass. We describe the imaging findings in two patients with proven tuberculosis of the abdomen and significant vascular complications. In one patient, "dry plastic" peritonitis and tuberculous lymphadenopathy at the level of the porta hepatis with subsequent encasement and compression of the portal vein resulted in prestenotic dilatation and varicose formation in the upper abdomen. In the other patient, bulky necrotic tuberculous lymphadenopathy, located at the splenic hilum, resulted in encasement with stenosis of the splenic vessels and subsequent splenic infarction.

Tuberculosis of the spine: CT and MR imaging features.

Tuberculosis (TB) remains endemic in most of the developing countries. However, a resurgence of tuberculosis has also been reported in the past decades in developed countries, not only in the lungs, but also in extrapulmonary sites, e.g. the vertebral column. Vertebral TB is most often found in the lower thoracic and upper lumbar regions. Diagnosis is often difficult; clinical findings are usually non-specific and radiologic features may mimic those of other bacterial, fungal, inflammatory and neoplastic diseases. However, recognition and understanding of the radiological findings may help in diagnosis. Two distinct patterns of vertebral tuberculosis may be seen: the classic finding of spondylodiscitis, characterized by destruction of two or more contiguous vertebrae and opposed end plates, disk infection, and commonly a paraspinal mass or collection. The second pattern, increasing in frequency, is a atypical form of spondylitis without disk involvement.The value of CT and MR imaging are discussed in the diagnostic workup of vertebral tuberculosis. A positive culture or histopathologic analysis of CT-guided needle aspiration or biopsy specimens is required in the absence of pulmonary manifestations of tuberculosis for definitive diagnosis and adequate treatment.

Abdominal tuberculous lymphadenopathy: MRI features.

The aim of this study was to describe the MRI features of abdominal tuberculous lymphadenopathy. MRI studies of 13 patients with abdominal tuberculous lymphadenopathy were reviewed with regard to anatomic distribution and size. Signal intensities, in relation to abdominal wall muscle, on unenhanced T1- and T2-weighted images and patterns of contrast enhancement of lymphadenopathy were evaluated in each patient. In each patient, the largest lymph node with the same imaging characteristic was evaluated. The upper paraaortic region was the most common site of involvement (n=12 patients), followed by the lesser omentum (n=10 patients), the anterior pararenal space (n=9 patients), the lower paraaortic area (n=8 patients), the small bowel mesentery (n=6 patients), the greater omentum (n=2 patients) and the originating site of the inferior mesenteric artery (n=2 patients). The mean lymph node size was 1.8 cm (range 0.5-5 cm). The overall mean lymph node number per patient was 16 (range 2-50). A total of 41 lymph nodes were evaluated in 13 patients. On T2-weighted images, 40 lesions were hyperintense and one lesion was isointense. Nine hyperintense lesions showed a hypointense peripheral rim and seven internal heterogeneïty. Perinodal T2-hyperintensity was present in 23 lesions. The latter finding was valid for all patients. On T1-weighted images, 30 lesions were hypointense and 11 isointense. Nine hypointense lesions demonstrated a hyperintense peripheral rim, and six were heterogeneous. Contrast-enhanced fat-suppressed T1-weighted images demonstrated predominant peripheral enhancement in 28 lesions: (1) peripheral uniform, thin (n=19); (2) thick irregular, complete (n=3); and (3) conglomerate group of nodes showing peripheral and central areas of rim enhancement (n=6). Heterogeneous and homogeneous enhancement was present in ten and three lesions, respectively. Combinations of enhancing patterns in the same nodal group and different nodal groups were seen in eight and nine patients, respectively. Abdominal tuberculous lymphadenopathy may show a variety of signal intensities and patterns of contrast enhancement on MRI. Lymphadenopathy, hypointense on T1-weighted, hyperintense on T2-weighted images with perinodal hyperintensity, and predominant peripheral rimlike enhancement may suggest the diagnosis of tuberculosis.

Clinical and radiological deterioration in a patient with AIDS.

Paradoxical clinical deterioration of miliary tuberculosis, characterized by pulmonary and abdominal manifestations, is reported in a patient with the acquired immunodeficiency syndrome, after initiation of treatment with highly active antiretroviral therapy. Paradoxical reaction was attributed to partial restoration of cell-mediated immunity related to highly effective antiretroviral therapy. Because tuberculosis has a high prevalence in HIV patients and tuberculosis is often characterized by miliary spreading of disease in these patients, it is important to recognize this phenomenon.

Percutaneus translumbar inferior vena cava venous access in an intensive care patient.

We report the case of a critically ill 30-year-old chronic haemodialysis patient with a history of intravenous substance abuse whose intravenous access sites had become exhausted. She subsequently underwent elective insertion of a percutaneous translumbar inferior vena caval paired Tesio catheter and peripherally inserted central catheter (PICC line). This technique has been used successfully in patients who require longstanding central venous access (hyperalimentation, chemotherapy, chronic renal hemodialysis patients). This approach could be an alternative where the standard access routes have become non-viable.

Tuberculosis of the pancreas: MRI features.

OBJECTIVE: The purpose of this study was to describe the MRI features of tuberculosis of the pancreas. CONCLUSION: Pancreatic tuberculosis can be focal or diffuse. If focal, it presents as a sharply delineated mass located in the pancreatic head, showing heterogeneous enhancement. Lesions are hypointense on fat-suppressed T1-weighted images and a mixture of hypo- and hyperintense on T2-weighted images. The appearances of common bile duct and main pancreatic duct are normal. Diffuse involvement is characterized by pancreatic enlargement with narrowing of the main pancreatic duct and heterogeneous enhancement. Signal intensity abnormalities indicating diffuse involvement include hypointensity on fat-suppressed T1-weighted images and hyperintensity on T2-weighted images.

Considerations for planning and implementation.

Installing Picture Archiving and Communication System (PACS) has very wide implications on the radiology department and the hospital as a whole. PACS is an entire hospital investment, which will change many professionals' working practices. Its selection and implementation must involve all the groups it will affect and this demands an appropriate approach. Developing processes that establish the needs of the users, support strategic initiatives, and address risk management is not a minor undertaking. The development of a plan that provides PACS selection committees with a step-by-step roadmap to seek and procure PACS best suited to their workflow is a valuable tool. This review considers the process of planning and implementation for PACS.

Picture archiving and communication system--Part one: Filmless radiology and distance radiology.

Picture archiving and communication system (PACS) is a collection of technologies used to carry out digital medical imaging. PACS is used to digitally acquire medical images from the various modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and digital projection radiography. The image data and pertinent information are transmitted to other and possibly remote locations over networks, where they may be displayed on computer workstations for soft copy viewing in multiple locations, thus permitting simultaneous consultations and almost instant reporting from radiologists at a distance. Data are secured and archived on digital media such as optical disks or tape, and may be automatically retrieved as necessary. Close integration with the hospital information system (HIS)--radiology information system (RIS) is critical for system functionality. Medical image management systems are maturing, providing access outside of the radiology department to images throughout the hospital via the Ethernet, at different hospitals, or from a home workstation if teleradiology has been implemented.