Reasoned approach to multiple osteosclerotic lesions. Combined diagnostic imaging in a case of osteopoikilosis.

The case of a female patient who had undergone mastectomy for infiltrating ductal carcinoma and come to the Orthopedics Division for lumbosacral pain unresponsive to conventional treatment is discussed. Pelvic X-ray, CT and scintigraphy were performed. The presence of multiple areas of selerosis of the pelvis and proximal femurs were documented. The differential range could be limited to osteoblastic metastasis and osteopoikilosis. The diagnosis of osteopoikilosis was established based on scintigraphy which proved the absence of uptake of the radiotracer.

Diagnostic approach to a rare case of osteoid osteoma of the astragalus.

A rare case of osteoid osteoma of the ankle of the left foot is discussed. Standard X-ray and MRI were negative. Triphasic bone scintigraphy followed by CT were performed. Combined clinical CT and scintigraphy findings were highly suggestive of osteoid osteoma. This diagnosis was confirmed on histology.

CT and functional respiratory tests. Evaluation of efficacy of bronchodilator therapy in chronic obstructive pulmonary disease (COPD).

PURPOSE: To evaluate changes in qualitative and quantitative parameters at high resolution CT (HRCT) and in respiratory function indexes (RFI) after bronchodilator administration in COPD patients. MATERIALS AND METHODS: Fifteen former smokers (9 male and 6 female, mean age 65 years), with COPD were studied. Patients with asthmatic or pulmonary diseases were excluded. After informed consent, the patients underwent blood gas analysis, baseline RFI (respiratory function index), inspiratory/expiratory HRCT, administration of salbutamol and bromide (by metered-dose inhaler), RFI after 45 minutes, and inspiratory/expiratory HRCT. First, we performed a visual qualitative analysis (by means of a preformed questionnaire), and then a quantitative analysis by "density mask" programme at three levels: aortic arch, carina, and supradiaphragmatic level. By using this diagnostic approach we were able to determined the global area of each lung, dependent and independent of density, bronchus-artery ratio, emphysema extension, air trapping, morphologic distortion of the airways. RESULTS: Data correlation analysed through linear regression statistical test. Outstanding correlations were found between the RFI (Raw, SVC, IC, RV, FEV1, VP70) and, respectively, density, global lung areas, and bronchus-artery ratio changes before and after bronchodilators administration. CONCLUSIONS: Our study confirmed the usefulness of bronchodilators and the need for a multiparametric and comparative (radiological and functional) approach to COPD, as well as the usefulness of HRCT in evaluating the response to visible airway physiologic stimulus and extension, and reversibility of air trapping.

Magnetic resonance imaging of cholangiocarcinoma.

Cholangiocarcinoma arises from the bile ducts and is the most common primary malignancy of the biliary tree. Cholangiocarcinoma is classified according to its growth pattern: mass-forming, periductal-infiltrating, or intraductal-growing type. The majority of cholangiocarcinomas occur at the common hepatic duct (CHD) and its bifurcation, also referred to as Klatskin's tumor, but they also can occur in more peripheral branches within the hepatic parenchyma. Microscopically, cholangiocarcinoma represents an adenocarcinoma with a glandular appearance arising from the epithelium of the bile ducts. On magnetic resonance (MR) images, cholangiocarcinomas appear hypointense on T1-weighted images, and hyperintense on T2-weighted images. Central hypointensity can be seen on T2-weighted images and correspond to fibrosis. On dynamic MR images, cholangiocarcinomas show moderate peripheral enhancement followed by progressive and concentric filling in the tumor with contrast material. Pooling of contrast within the tumor on delayed MR images is suggestive of peripheral cholangiocarcinoma. The role of MR imaging in hilar cholangiocarcinoma is to confirm/reach a diagnosis and to assess resectability. Hilar cholangiocarcinoma shows the same signal intensity pattern of peripheral tumors both on T1- and T2-weighted images. On magnetic resonance cholangiopancreatography (MRCP) images, hilar cholangiocarcinoma appears as a moderately irregular thickening of the bile duct wall (>/=5 mm) with symmetric upstream dilation of the intrahepatic bile ducts. The aim of preoperative investigation in Klatskin tumors typically requires the evaluation of the level of biliary obstruction, the intrahepatic tumor spread, and the vascular involvement; it also needs to show any atrophy-hypertrophy complex. Because of its intrinsic high tissue contrast and multiplanar capability, MR imaging and MRCP are able to detect and preoperatively assess patients with cholangiocarcinoma, investigating all involved structures such as bile ducts, vessels and hepatic parenchyma. The main reason for surgical/imaging discrepancy is represented by the microscopic diffusion along the mucosa and in the perineural space.

Local-regional staging of endometrial carcinoma: role of MR imaging in surgical planning.

PURPOSE: To assess magnetic resonance (MR) imaging in depicting the depth of myometrial infiltration, cervical invasion, and presence of enlarged lymph nodes in patients with endometrial adenocarcinoma compared with surgicopathologic findings. MATERIALS AND METHODS: Thirty-seven consecutive patients with endometrial carcinoma were included in this prospective study. All patients underwent MR imaging and surgery. Qualitative image analysis included the depth of myometrial infiltration, infiltration of the uterine cervix, and presence of enlarged lymph nodes. Quantitative image analysis included tumor and myometrium contrast-to-noise ratios during different phases of dynamic imaging. MR imaging findings were compared with surgicopathologic findings. Sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values of MR imaging in depicting myometrial and cervical infiltration and in lymph node assessment were calculated. RESULTS: Respective sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values in assessing myometrial infiltration were 87%, 91%, 89%, 87%, and 91%; those for cervical infiltration, 80%, 96%, 92%, 89%, and 93%; and those for lymph node assessment, 50%, 95%, 90%, 50%, and 95%. There was significant agreement between MR imaging and surgicopathologic findings in assessment of myometrial invasion (P <.001). Myometrial and cervical invasion and lymph node enlargement were correctly assessed with MR imaging in 28 (76%) of 37 patients. Quantitative analysis showed a significant improvement in tumor and myometrium contrast-to-noise ratios during the equilibrium phase compared with the arterial and precontrast phases (P <.001). CONCLUSION: MR imaging coupled with contrast material-enhanced dynamic MR imaging is highly accurate in local-regional staging of endometrial carcinoma; more challenging is the assessment of pelvic and lumboaortic lymph nodes.

The evolution of digital radiography: from storage phosphors to flat-panel detectors.

At present, conventional radiology is being slowly but inexorably replaced by digital radiology. While storage phosphors introduced approximately twenty years ago are now routinely used, flat panel systems are increasingly popular. There are two types of flat panels: those with direct X-ray conversion to electric charge and those where there is initial X photon conversion to visible light from optical amorphous silicon photodiode coupling for conversion to electric charge. The charge is therefore amplified and digital signal conversion is obtained with an analog-to-digital converter. One of the main advantages of Computed Radiography is the separation of image acquisition processing and display. Acquisition systems of digital images with image processing techniques allow the operator to adapt the image characteristics to the clinical requirements. Contrast value and image brightness can be changed soon after acquisition to optimize visualization before printing or transfer to the workstation for postprocessing. Image processing can be interactive, directly on the system consolle. To digital data various processing algorithms can be applied as high spatial frequency enhancement through the construction of the shadow mask. The new digital systems have improved the quality of conventional radiological images as compared to the screen-film and storage phosphor systems with shorter times of procedures and lower exposure dose to patients, while the diagnostic potentialities of the acquired image are enhanced.

Evolution of digital angiography systems.

The innovations introduced by digital subtraction angiography in digital radiography are briefly illustrated with the description of its components and functioning. The pros and cons of digital subtraction angiography are analyzed in light of present and future imaging technologies. In particular, among advantages there are: automatic exposure, digital image subtraction, digital post-processing, high number of images per second, possible changes in density and contrast. Among disadvantages there are: small round field of view, geometric distortion at the image periphery, high sensitivity to patient movements, not very high spatial resolution. At present, flat panel detectors represent the most suitable substitutes for digital subtraction angiography, with the introduction of novel solutions for those artifacts which for years have hindered its diagnostic validity. The concept of temporal artifact, reset light and possible future evolutions of this technology that may afford both diagnostic and protectionist advantages, are analyzed.

Molecular imaging: state of the art.

Molecular imaging includes all imaging methods applied in the identification, characterization and assessment "in vivo" of biological processes which occur at the cellular and molecular level. Molecular imaging parallels the remarkable advances achieved in the medical field, culminated in the sequencing of human DNA, the genome project. The understanding of the genetic basis of diseases and of human biology in general, together with the development of new drugs, led to a growing need for novel, sensitive and safe imaging technology to be rapidly translated from animal models into patients. The present evaluation of presence/absence of disease is based on anatomic and morphologic changes, the result of underlying molecular alterations. Direct "in vivo" visualization of these alterations allows early diagnosis before the onset of typical pathologic manifestations. Similarly, short-term effects of therapy can be directly visualized. In a near future, "evidence-based" medicine will become "presymptomatic" medicine. Histopathology will be replaced by "molecular pathology" with genomic implications in disease classification. In the near future the conventional morphologic methods should be supported and then replaced by the new functional and molecular methods with additional information proved useful for the diagnostic approach. In this article, the potentialities and applications of Nuclear Medicine, Magnetic Resonance Imaging, Optical Imaging and Contrast-enhanced Ultrasound are reviewed.

Picture archiving and communication in radiology.

After over 80 years of exclusive archiving of radiologic films, at present, in Radiology, digital archiving is increasingly gaining ground. Digital archiving allows a considerable reduction in costs and space saving, but most importantly, immediate or remote consultation of all examinations and reports in the hospital clinical wards, is feasible. The RIS system, in this case, is the starting point of the process of electronic archiving which however is the task of PACS. The latter can be used as radiologic archive in accordance with the law provided that it is in conformance with some specifications as the use of optical long-term storage media or with electronic track of change. PACS archives, in a hierarchical system, all digital images produced by each diagnostic imaging modality. Images and patient data can be retrieved and used for consultation or remote consultation by the reporting radiologist who requires images and reports of previous radiologic examinations or by the referring physician of the ward. Modern PACS owing to the WEB server allow remote access to extremely simplified images and data however ensuring the due regulations and access protections. Since the PACS enables a simpler data communication within the hospital, security and patient privacy should be protected. A secure and reliable PACS should be able to minimize the risk of accidental data destruction, and should prevent non authorized access to the archive with adequate security measures in relation to the acquired knowledge and based on the technological advances. Archiving of data produced by modern digital imaging is a problem now present also in small Radiology services. The technology is able to readily solve problems which were extremely complex up to some years ago as the connection between equipment and archiving system owing also to the universalization of the DICOM 3.0 standard. The evolution of communication networks and the use of standard protocols as TCP/IP can minimize problems of data and image remote transmission within the healthcare enterprise as well as over the territory. However, new problems are appearing as that of digital data security profiles and of the different systems which should ensure it. Among these, algorithms of electronic signature should be mentioned. In Italy they are validated by law and therefore can be used in digital archives in accordance with the law.

Multirow CT angiography of coronary arteries.

The introduction of spiral multislice or multidetector CT (MSCT) has led to significant results in coronary diagnostic imaging. In fact with MSCT, isotropic (cubic voxel) three-dimensional imaging of large volumes (e.g. the entire cardiac volume) was possible in a single breath-hold. Moreover, with dedicated reconstruction algorithms, temporal resolution and scannable volume could be optimized, limiting the artifacts associated with the spiral technique. The quantification of calcium deposits in the coronary walls and, in particular, the morphologic study of these vessels represent an important challenge to this technique. Multislice CT with retrospective gating is now a relevant diagnostic instrument in coronary heart disease; however only most recent CT devices with 16 rows of detectors enable a real solution of problems of spatial (isotropic, submillimetric imaging) and temporal (< 0.5 s rotation time) required for correct identification of stenosis and plaque characterization, which are the two main goals of noninvasive coronary imaging.

Information systems in the management of the radiology department.

Clinical, organizational and administrative service improvement has always been the primary aim of a radiology information system. Studies carried out at Massachusets General Hospital in the late sixties identified two "bottlenecks" in the Departments of Diagnostic Imaging: the planning of examinations and the management of picture archiving. Therefore, the information system started to be viewed as a potential tool for the solution of these problems. In time, the concept of Radiology Information System (RIS) was conceived. With its developments it is now considered an effective support for the daily activity of the Radiology department, to tackle and solve the operational problems posed by the various healthcare professionals. A radiology information system essentially concerns three functional areas: the patient management, the procedure management, the department management. Another major task of RIS is represented by its integration with the other information systems of Radiology and hospital to enable to share information in real time with the hospital information system (HIS) and the other information systems (system of first-aid management, intensive therapy units etc). A modern RIS must be in conformance with DICOM 3 for the service class of the working list to be able to transmit to the diagnostic imaging equipment the patient correct names and demographics and the type of procedure to be performed.

Post-processing of digital images.

Post-processing of bi- and three-dimensional images plays a major role for clinicians and surgeons in both diagnosis and therapy. The new spiral (single and multislice) CT and MRI machines have allowed better quality of images. With the associated development of hardware and software, post-processing has become indispensable in many radiologic applications in order to address precise clinical questions. In particular, in CT the acquisition technique is fundamental and should be targeted and optimized to obtain good image reconstruction. Multiplanar reconstructions ensure simple, immediate display of sections along different planes. Three-dimensional reconstructions include numerous procedures: multiplanar techniques as maximum intensity projections (MIP); surface rendering techniques as the Shaded Surface Display (SSD); volume techniques as the Volume Rendering Technique; techniques of virtual endoscopy. In surgery computer-aided techniques as the neuronavigator, which with information provided by neuroimaging helps the neurosurgeon in simulating and performing the operation, are extremely interesting.

IHE: integrating the healthcare enterprise, towards complete integration of healthcare information systems.

Information systems of a modern hospital govern extremely important functions as patient management, control of work flows, administration etc. However a great variety of recommended standards are used while in most cases no effective coordination and intercommunication is possible. Some years ago to simplify and resolve this problem IHE was created; it is a technical framework which identifies a number of components of the healthcare enterprise (the "actors") whose interactions are defined in terms of "transactions", that should be implemented according to HL7 and DICOM standards. Attempting an in-depth understanding of IHE structure and its principles of function, those transactions that can occur among the various actors, which of these are supported and which require specific actors, are analyzed. IHE is continuously evolving, therefore open to the factual contribution of all health professionals who can point out the main instances that emerge daily from their activity in the field. While its origin was specific for the field of radiology, the true soul and driving force of the project lay on the type of approach used: to get together medical specialists and information technology professionals in order to identify and solve the difficulties which hindered an effective and functional integration of healthcare information systems.

Diffusion and perfusion MR imaging.

Diffusion (DWI) and perfusion weighted (PWI) MR imaging, have come to have an increasingly important clinical role, especially in neurovascular imaging. Diffusion MR imaging does not evaluate hemodynamic parameters, but can be considered a functional technique because it provides information about the tissue functional structure at a microscopic level. In this technique, image contrast to a large extent depends on the diffusion coefficient, a parameter indicative of the characteristics of the stochastic thermic translational motion of water molecules (Brownian motion). Clinical perfusion measurement has been performed in almost all organs with different techniques. Over the last ten years, with the use of contrast media, considerable experience has been gained in the measurement of hemodynamics with MRI. At present, perfusion-MR imaging is one of the clinically most relevant procedures of functional MRI, whose application is gaining ground, owing to the increasing availability of necessary hardware and software. Physical and hemodynamic principles of the two techniques, pulse sequences necessary for their implementation and main applications in the imaging of CNS disorders are illustrated. While DWI and PWI alone can address numerous questions, their information is for the most part complementary to that provided by conventional MRI and their combination seems extremely promising.

Computer-aided diagnosis.

The evolution of logic thought in relation to the predominant recent advances in technology is analyzed. In fact, the computer was the prime mover of this major change. At present the use of sophisticated software has allowed to attain increasingly accurate levels of simulation of human reasoning. The computer has determined profound transformations in many sectors of work, study and research. Among these, it is extremely relevant how the computer has completely transformed medicine and the medical role, especially in the field of radiology. Expert systems are the most interesting and futuristic applications of artificial intelligence. These systems are able to reproduce on a computer the behavior of an expert human being. Some of the recent innovations introduced in the field of breast, thoracic and mainly neural pathology are illustrated.