The Role of cardiac MRI in congenital heart disease

Cardiac MRI is a valuable and an accurate modality used in the evaluation of structure and function of the heart. It is increasingly considered as a useful non invasive examination in management of cardiovascular conditions, a situation resulting from significant advances in MR technologies. Evaluation of congenital heart disease is an important application of Cardiac MRI since the morphological details of chambers, septum, defects and anomalous connections are depicted accurately. Additionally, flow information across valves, chambers, outflow tracts and shunts are also provided. Its utility is further increased especially during follow up of patients after corrective surgery. This article reviews current state-of-the-art MRI application in common congenital heart diseases.

Non Surgical Management of Pseudoaneurysms

BACKGROUND

The incidence of pseudoaneurysm has increased due to the large number of vascular procedures performed and the widespread use of anticoagulation therapy during procedures. Non-invasive methods for management of pseudoaneurysms comprise of ultrasound guided compression (USGC), thrombin therapy, arterial embolisation and endovascular stent graft insertion. We discuss our experience in the management of fourteen cases of pseudoaneurysms using non surgical techniques.

METHODS

During a two year period, fourteen patients presenting with pseudoaneurysms of different regions were treated.

RESULT

Of the fourteen patients, eleven were iatrogenic and three were attributable to trauma. There were six cases of pseudoaneurysms of the femoral artery following coronary angiography studies. One patient developed pseudoaneurysm of right popliteal artery after external fixation of fracture right tibia and fibula. Three cases of renal artery pseudoaneurysms occurred following percutaneous nephrolithotomy (PCNL). The cases were evaluated using a varying combination of color doppler, multidetector computerised tomography (CT) and angiography. These cases were treated with ultrasound guided compression (USGC), stent graft and coil embolisation. The selection of method was based on the location and size of pseudoaneurysms besides the efficacy of the technique. USGC was performed in seven, of which six were in the femoral artery and one supraorbital. The technique was unsuccessful in three of the seven, wherein stent graft was deployed in the femoral artery. Coil embolisation was utilised in three cases of renal artery pseudoaneurysms following PCNL.

CONCLUSION

Follow up with color doppler and CT angiography within a week, 6 and 12 months period showed successful regression of pseudoaneurysms in all cases.

Computer hardware for radiologists: Part 2

Computers are an integral part of modern radiology equipment. In the first half of this two-part article, we dwelt upon some fundamental concepts regarding computer hardware, covering components like motherboard, central processing unit (CPU), chipset, random access memory (RAM), and memory modules. In this article, we describe the remaining computer hardware components that are of relevance to radiology. “Storage drive” is a term describing a “memory” hardware used to store data for later retrieval. Commonly used storage drives are hard drives, floppy drives, optical drives, flash drives, and network drives. The capacity of a hard drive is dependent on many factors, including the number of disk sides, number of tracks per side, number of sectors on each track, and the amount of data that can be stored in each sector. “Drive interfaces” connect hard drives and optical drives to a computer. The connections of such drives require both a power cable and a data cable. The four most popular “input/output devices” used commonly with computers are the printer, monitor, mouse, and keyboard. The “bus” is a built-in electronic signal pathway in the motherboard to permit efficient and uninterrupted data transfer. A motherboard can have several buses, including the system bus, the PCI express bus, the PCI bus, the AGP bus, and the (outdated) ISA bus. “Ports” are the location at which external devices are connected to a computer motherboard. All commonly used peripheral devices, such as printers, scanners, and portable drives, need ports. A working knowledge of computers is necessary for the radiologist if the workflow is to realize its full potential and, besides, this knowledge will prepare the radiologist for the coming innovations in the ‘ever increasing’ digital future.

Objective structured clinical examination in radiology

There is a growing need for introducing objective structured clinical examination (OSCE) as a part of radiology practical examinations in India. OSCE is an established, reliable, and effective multistation test for the assessment of practical professional skills in an objective and a transparent manner. In India, it has been successfully initiated and implemented in specialties like pediatrics, ophthalmology, and otolaryngology. Each OSCE station needs to have a pre-agreed "key-list" that contains a list of objective steps prepared for uniformly assessing the tasks given to students. Broadly, OSCE stations are classified as "manned" or "unmanned" stations. These stations may include procedure or pictorial or theory stations with clinical oriented contents. This article is one of a series of measures to initiate OSCE in radiology; it analyzes the attributes of OSCE stations and outlines the steps for implementing OSCE. Furthermore, important issues like the advantages of OSCE, its limitations, a strengths, weaknesses, opportunities, and threats (SWOT) analysis, and the timing of introduction of OSCE in radiology are also covered. The OSCE format in radiology and its stations needs to be validated, certified, and finalized before its use in examinations. This will need active participation and contribution from the academic radiology fraternity and inputs from faculty members of leading teaching institutions. Many workshops/meetings need to be conducted. Indeed, these collaborative measures will effectively sensitize universities, examiners, organizers, faculty, and students across India to OSCE and help successfully usher in this new format in radiology practical examinations.

Monitor displays in radiology: Part 2

Monitor displays play an important role in modern radiology practice. Practicing radiologists need to be familiar with the various performance parameters of medical-grade displays. A certain amount of technical knowledge is useful when making purchasing decisions since the right choice of equipment can have a great impact on the accuracy, efficiency, and speed in the radiology department.

Monitor displays in radiology: Part 1

Monitor displays are an integral part of today's radiology work environment, attached to workstations, USG, CT/MRI consoles and PACS terminals. For each modality and method of use, the correct display monitor needs to be deployed. It helps to have a basic understanding of how monitors work and what are the issues involved in their selection.

Multidetector CT Evaluation in Arterial Stenting

BACKGROUND

Multidetector CT (MDCT) represents breakthrough in CT technology, significantly improving CT Angiography applications.

METHODS

Twenty one patients with aortoiliac & branch aneurysms or stenosis were evaluated by Digital Subtraction Angiography (DSA) and Multidetector CT (MDCT) before and after endovascular repair.

RESULTS

There were eight cases of aortic & branch aneurysms and 13 with stenosis. Four cases had aortic aneurysms, while one case had left subclavian artery aneurysm, thoracic aneurysm, femoral and popliteal artery pseudoaneurysms. Of the 13 cases with stenotic lesions, iliac stenosis was seen in eight patients. The others included carotid, vertebral, aortic, renal and aortic bifurcation stenotic. MDCT offered accurate information on shape and size of aneurysm, shape and patency of graft, the presence or absence of perigraft thrombosis or endoleaks, while in stenotic lesions it provided useful information on shape of graft, its location, its patency and the presence and quantity of distal flow.

CONCLUSION

MDCT was found to be a potentially useful modality during initial evaluation and follow up of patient undergoing endovascular repair.

Radiology Image Management in a Teaching Hospital Network Scenario: Initial Experience

INHS Asvini has the distinction of emerging as the first Armed Forces Hospital with networked radiology images, sourced principally from a recently installed Digital Substraction Angiography (DSA) machine (Siemens Polystar Top 1000 MA). In recent times, newer imaging machines offer digital images that are in DICOM format. DICOM denotes 'Digital Imaging and Communications in Medicine". Image management at INHS Asvini, involves transfer of DSA images in DICOM format, their conversion into Joint Photographic Experts Group (JPG) format and subsequent transmission of JPG images through a robust networking system that connects all departments/OPD/Wards, facilitating direct access of images to a variety of specialists and specialities. Clearly, this encouraging outcome is a small but useful step heralding the concept of 'anytime anywhere' images, and has the scalable expansibility of including CT and MRI images in future.

MAGNETIC RESONANCE IMAGING IN INTRACRANIAL TUBERCULOSIS

Tuberculosis (TB) is still a major cause of serious illness in many parts of the world. Intracranially, TB manifests itself variably as meningitis, tuberculoma and tubercular abscess [1]. Although its appearance on MR is not absolutely specific, it is important in the proper clinical setting to recognize the range of possible patterns that can be observed on images [2]. Magnetic Resonance Imaging (MRI) has emerged as a quality imaging tool aiding in the diagnostic evaluation of intracranial TB variably displaying meningeal, parenchymal, osseous and craniovertebral lesions. The MRI characteristics of 18 cases of intracranial TB were reviewed.

RESULTS

Multiple lesions occured with a slightly higher incidence at 61%. In all, 11 patients (61%) presented with meningitis. Meningeal lesions without parenchymal or vascular involvement were seen in 16% of cases. 2 patients had extension of enhancing exudates into the spinal subarachnoid spaces. While 6 patients had focal intra-axial tuberculomas, representing 33% cases, 3 patients presented with infarcts. 1 patient presented with haemorrhagic infarct at right middle cerebral artery territory while two other showed multiple small infarcts. Hydrocephalus was identified in 4 patients and epidural lesions were noted in 2 cases. MRI should be considered as the imaging modality of choice for patients with suspected intracranial TB.