Digital Mammography Revolution

SenoBright is an exciting innovation from GE Healthcare  to help doctors in the diagnosis of breast diseases. Two images are provided in the same orientation for each of the standard CC and MLO views. The first image exposure uses standard mammography parameters, while the second image shows contrast-enhanced areas with the background tissue signal suppressed.

Thanks to the combination of two types of images, generated by the system, one obtained at low-energy spectrum and one at high-energy spectrum, the radiologist has one clear final image where signal from the normal tissue is removed and where contrast appears very distinctly.

SenoBright could be interesting alternative when additional tests are required to clarify an equivocal lesion, being a very fast imaging technique with immediate availability in the mammography suite without the waiting often associated with scheduling other types of tests and waiting for the results.

Knee Joint

The knee joint is complicated anatomically and consists of three articulations: two between the condyles of the femur and the tibia, and the third between the femur and the patella. The synovial cavity is common to all three joints, but is indented by the two menisci between the femur and the tibia. These menisci are best seen on the MRI.

Fractures of all three bones can occur and can be visualized on these views. A fracture of the patella may only be visible on the skyline view. It should not be confused with a congenital bipartite patella, which is often present bilaterally. To assess whether there is free fat within the joint space, an x-ray with a horizontal beam should be performed and, if positive, is a fair indication of bone damage. A tunnel view has not been included, but is of use when looking for a loose body or evidence of osteochondritis dissecans. Note also on the skyline view that the lateral femoral condyle projects higher than the medial condyle to resist lateral dislocation of the patella.

The tibia and fibula are connected by an interosseous membrane similar to that of the forearm. Again, with paired long bones, fracture of one bone is often accompanied by a fracture of the other. As mentioned before with the forearm radiograph, if one bone is fractured with considerable displacement, then both proximal and distal joints should be checked for dislocation of the other bone. Note that the head of the fibula does not form part of the knee joint, but has a separate synovial joint with the tibia. Fractures of the tibia and fibula are often compound because of the lack of soft tissues anteriorly. Fractures of the mid-tibial shaft are prone to non-union because of the apparent poor vascularity. Paget's disease and syphilis are causes of 'sabre tibia'.



Hand and Wrist (Brief Note)

Fractures and dislocations are particularly important in the wrist, as considerable incapacitation with osteoarthritis can result from delayed treatment. Note that fractures of the scaphoid may not show for 10 days following the injury. If a fracture of the waist of the scaphoid is mistreated, ischaemic necrosis of the distal fragment may result. It is important to learn the normal appearance of the positions of the carpal bones so that dislocations are not overlooked. Common fracture sites include the following: fracture of the distal radius and ulna with backward displacement (Colles' fracture); forward displacement of this fracture may occur which is relatively rare (Smith's fracture); fracture of the base of the first metacarpal (Bennett's fracture). Spiral fractures of the metacarpals and distal shaft fractures of the fourth and fifth metacarpal bones may follow a punch! Note that many systemic diseases have bony and soft tissue abnormalities which can be seen on a hand x-ray, e.g. hyperparathyroidism, scleroderma and rheumatoid arthritis.

Wrist PA View

Hysterosalpingogram

The two main indications for this examination are infertility and recurrent abortion. Watertight cannulation of the cervix is performed and aqueous contrast medium is injected to outline the uterus and uterine tubes. Some authorities use oil-based contrast, but granuloma formation and a flare-up of any pelvic infection may result. The narrowest point of the Fallopian or uterine tube is at the entrance to the uterine cavity. The widest point is at the abdominal end, the infundibulum, before it opens into the peritoneal cavity.

Free spillage of contrast into the pelvic cavity is an important sign and should be distinguished from loculated spill due to pelvic inflammatory disease. When possible, this examination should be performed 7-10 days following menstruation as earlier in the cycle, venous intravasation may result, and later on in the cycle, accidental fetal irradiation may occur.

sacrum and coccyx

The sacrum is formed by the fusion of five sacral vertebrae. It has a natural kyphosis. The median sacral crest is seen to bear the spinous tubercles and this crest is the fused spines of the sacral vertebrae. Below the spine of S4 is the sacral hiatus which is due to failure of fusion of the S5 laminae. It is through this hiatus that caudal epidural anaesthesia is performed. Note the four coccygeal segments which, in this case, are existing as separate entities, but are often fused together. The sacral spinal canal contains the cauda equina and the spinal meninges. These are best seen, however, on a lateral lumbosacral myelogram. The filum terminale from the pia mater emerges below the sacral hiatus and passes downwards to insert into the coccyx. Babies of mothers suffering from diabetes mellitus may occasionally have sacral agenesis.

Colles’ fracture

Radiological features:

• Dorsal angulation with loss of the normal (5–10 degrees) volar tilt of the articular surface of the radius.
• Dorsal displacement of the distal fracture fragment.
• Impaction at the fracture site.
• Radial displacement of the distal fragment.
• Radial tilt of the distal fragment.

Appendicitis

Radiological features:

• Abdominal X-Ray: Look for a calcified appendicolith in the right lower quadrant (RLQ). Other indicators include free air; small bowel ileus; extra-luminal  gas; caecal wall thickening; loss of pelvis fat planes around the bladder suggests pelvic free fluid; loss of the properitoneal fat line; psoas line distortion and abrupt cut-off of the normal gaseous pattern at the hepatic flexure due to colonic spasm.



Large calcified appendicolith (arrowhead)

•  Ultrasonography: Suggestive features include an obstructing appendicolith – a blind ending non-peristaltic, non-compressible tubular structure and prominent vasculature within the meso-appendix; wall thickness should be 2mm in a normal appendix or 6mm in total diameter.

Inflammed appendix displaying thick wall

• CT: Sensitive and specific investigation. Not routine due to radiation dose. Luminal distension with a thickened enhancing wall (+/-) an appendicolith. Local inflammation shows as linear streaking in the adjacent fat. Abscesses may be present.



Inflammed appendix with multiple appendicoliths

• Contrast investigations: Occasionally picked up coincidently. Suggested by non-filling or localised mucosal oedema within the caecal pole.

Normal appendix; barium enema radiographic examination

Le Fort Classification

• Le Fort I involves tooth bearing maxilla.
• Le Fort II involves maxilla, nasal bones and medial aspects of orbits.
• Le Fort III involves maxilla, nasal bones, vomer, ethmoids and small bones of skull base (The face is separated from the skull base).

Radiofrequency Ablation of Lung Tumours

The lung malignancy is the second most common malignancy among both males and females ,yet it comes first in the reported mortality rates. Primary lung cancer is considered an aggressive tumor ,with high recurrence rate after successful resection, and with the chemotherapy and external beam radiation resulting in unsatisfactory survival outcomes . On the other hand, the lung is a common site for metastases as 30% of patients dying of malignancy have lung metastases on autopsy. Tissue ablation provides an adequate treatment with minimal complications.

 RF ablation is a viable alternate or complementary treatment method for patients with Non Small Cell lung carcinoma or lung metastases of favourable histotypes who are not candidates for surgical resection. Indications of RFA for NSCLC include: non-surgical candidates with operable tumors (local recurrence, refusal of surgery), conjoint RT ,while RFA applications in lung metastases depends on the number, size and site allowing for complete ablation, whether the extrathoracic disease is under control. RFA can be also used for palliation in case of Pain, hemoptysis, cough not otherwise controllable.

MSCT In Congenital Heart Disease

Congenital heart disease is a common health problem. To plan for effective management of congenital heart disease, one needs the clearest understanding of the anatomy and the complex cardiovascular abnormalities; especially the extra-cardiac morphology.

 Echocardiography and cardiac catheterization are the traditional imaging modalities used to diagnose congenital heart disease. Echocardiography is limited by the small field of view and difficulty in delineating extra-cardiac vascular structures. Cardiac catheterization is an invasive modality.

 Multislice computed tomography (MSCT) allows volume acquisition in seconds and provides unlimited 3D and 2D vascular images, even for neonates and infants. Today MSCT could take a place prior to cardiac catheterization as complementary modality for echocardiography in the diagnosis and surgical planning of congenital heart disease.

Digital Mammography and Tomosynthesis

One of the most recent advances in mammography, is digital mammography. In digital mammography, radiation transmitted through the breast is absorbed by an electronic detector, the response of which is faithful over a wide range of intensities. Once this information is recorded, it can be displayed by using computer image-processing techniques to allow arbitrary settings of image brightness and contrast, without the need for further exposure to the patient.

 With digital mammography, the magnification, orientation, brightness, and contrast of the mammogram image may also be altered after the exam is completed to help the radiologist more clearly see certain areas of the breast. The limitations of mammography are well known. Mainly, they include a low positive predictive value and a low sensitivity.These deficits stem largely from the superimposition of normal breast structures in the path of the X-ray beam.

 Digital mammographic systems have made breast tomosynthesis possible. Digital tomosynthesis, creates a 3-dimensional picture of the breast using x-rays. In Tomosynthesis, low-radiation-dose images were acquired as the x-ray source is moved in an arc above the stationary breast and digital detector. The resulting digital data set is reconstructed into tomographic sections through the breast in the orientation of acquisition—that is, craniocaudal, oblique, or 90° lateral.

 Tomosynthesis improves the specificity of mammography with improved lesion margin visibility and may improve early breast cancer detection, especially in women with radiographically dense breasts. Tomosynthesis may have great potential in screening and diagnostic breast imaging practices and other procedures, and initial results are certainly encouraging.

CT Enterography

Computed tomographic (CT) enterography combines the improved spatial and temporal resolution of multi–detector row CT with large volumes of ingested enteric contrast material to permit visualization of the small bowel wall and lumen.

 In both CT and MR enterography adequate luminal distention can usually be achieved with oral hyperhydration, thereby obviating naso-enteric intubation and making CT and MR enterography useful, well tolerated study for the evaluation of diseases affecting the mucosa and bowel wall.

 Unlike routine CT, which has been used to detect the extra-enteric complications of Crohn’s disease such as fistula and abscess, CT and MR enterography clearly depict the small bowel inflammation associated with Crohn’s disease by displaying mural hyperenhancement, stratification, and thickening; engorged vasa recta; and peri-enteric inflammatory changes. As a result, CT and MR enterography are becoming the first line techniques for the evaluation of suspected inflammatory bowel disease.

18 FDG PET/CT Role In Inflammatory Conditions

Early diagnosis or exclusion of infection and inflammation is critical for the optimal management of patients with such common disorders. Currently, the integration of molecular imaging using PET with other structural imaging modalities including CT and MRI provides a unique tool combining both functional data with precise anatomic details of the body. Greatest utility of PET imaging has been reported in osteomyelitis, complicated lower-limb prostheses, complicated diabetic foot, arthritis, fever of unknown origin, acquired immunodeficiency syndrome, inflammatory bowel disease, lung and pleural diseases, atherosclerosis, vasculitis, clots, vascular graft infection and fistula. Fused molecular and structural imaging has been recognized and increasingly employed for detecting, characterizing, and monitoring patients with suspected and proven infections, and inflammatory disorders of known and unknown etiologies.

Does MRI Solve Liver Problems?

MR imaging is considered the most accurate modality to the image the liver for the detection and characterization of focal and diffuse liver diseases.The superiority of MR imaging compared with other imaging modalities for liver evaluation has become more even apparent because of substantial improvements in 1.5 T magnets with faster image acquisition and better quality. Advancements in MR imaging hardware ,software and contrast agents have made a major impact on imaging of the liver, phased array surface coil technology significantly improved SNR and conventional spin echo pulse sequences have been replaced by faster sequences .Gradients-echo (GRE) sequences generally are used for T1–weighted sequences and echo-train sequences are used for T2–weighted sequences. Introduction of parallel imaging techniques has enabled further reduction of acquisition time and improved spatial resolution.

MDCT of the Urinary Tract: Free Hand Techniques

Technologic advances in computed tomography (CT) imaging have resulted in the ability to image the urinary tract in ways that surpass the prior mainstay of urinary tract maging, the intravenous urogram. In adults, for most, if not all, historical indications for intravenous urography, CT urography is now the preferred examination. Although a variety of techniques for CT urography examination have been described, the test provides more diagnostic information than does intravenous urography.

 With the introduction of multidetector technology, CT urography, to date, has emerged as the initial heir apparent to intravenous urography; many years of experience have now clearly demonstrated that CT is the test of choice for many urologic problems, including urolithiasis, renal masses, urinary tract infection, trauma, and obstructive uropathy.

 CT urography provides a detailed anatomic depiction of each of the major portions of the urinary tract—the kidneys, intrarenal collecting systems, ureters, and bladder—and thus allows patients with urinary problems to be evaluated comprehensively. Several issues create debate between radiologists and include reaching a consensus on the optimal protocols and appropriate utilization in an era of cost containment and heightened concerns about radiation exposure.

Radiology

Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies such as x-ray radiography, ultrasound, computed tomography (CT), nuclear medicine, positron emission tomography (PET) and magnetic resonance imaging (MRI) to diagnose or treat diseases. Interventional radiology is the performance of (usually minimally invasive medical procedures with the guidance of imaging technologies. The acquisition of medical imaging is usually carried out by the radiographer or radiologic technologist.