It can be diagnosed on the conventional radiograph by noting an indentation to and slight deviation of the right side of the trachea and displacement of the SVC shadow, as shown in Case 3-17 (Figure 3-47, arrows). Sagittal T2-weighted fat-saturated MR imaging of the knee shows a typical example of a tear of the posterior cruciate ligament (arrow). The middle mediastinum is the region between these two boundaries. LIVER, BILIARY TRACT, AND PANCREAS Figure 11-21. Large, bilateral subdural hematomas layer over the tentorium cerebelli in (A) (closed arrows) and within the interhemispheric fissure in (B) (arrow). Cystoscopy is also indicated when CT urography does not demonstrate a source for hematuria. In Figure 4-16 A,B, a sign of left lower lobe collapse in this patient is which of the following? Case 10-10. Figure 4-34. The supraspinatus tendon is easily seen on MR imaging as a low-signal-intensity structure, and tears of the supraspinatus tendon are well demonstrated on MR. After a 5-minute delay, the distal ureters (arrowheads) and bladder are easily identified. Detail of a mammogram (Figure 5-10 A) of the patient in Case 5-3. MR perfusion imaging is technically complex and requires advanced scanner and postprocessing software for image generation. The most common diseases causing these symptoms are esophageal and gastric malignancies, reflux esophagitis and peptic stricture, infectious esophagitis, lower esophageal mucosal ring, and peptic ulcers and erosions of the stomach and duodenum. They are 6 to 10 mm in diameter and always have ill-defined margins. Cecal volvulus is the cause of 1% to 2% of intestinal obstructions. These can overlap in appearance, as when an inflammatory mass simulates a neoplastic mass on imaging studies. The transverse aortic arch can usually be discerned on the normal lateral chest film as a smooth curving shadow originating anteriorly, crossing the mediastinum in a semilunar fashion, and then descending posteriorly as a linear shadow superimposed over the vertebral bodies. Paperback. Gas Pattern Gas has the lowest density (radiolucency) in the abdomen. Arthrogryposis multiplex congenita 3. Page size 526.3 x 673.2 pts See Spinal cord tumors Asymbolia, 189 Atelectasis, 87, 127 Atrial septal defect (ASD), 44 Azygoesophageal recess, 127 B Back pain, imaging for, 374 Barium enema, 3, 223, 262, 265, 266 Barium sulfate suspensions, 255 Barium suspension, 3 Barrett esophagus, 268 Basal ganglia hemorrhage, 347 Bat-wing edema, 91 Biliary inflammation, 310–316 Biliary tract calculi, 311 cholangitis, 316 choledocholithiasis, 313 cholelithiasis, 311–312 gallstones, 312 inflammation exercise, 310–316 MRCP of normal biliary ducts, 293 normal anatomy, 289–292 patient preparation for radiographic techniques, 294 technique selection, 292–294 Biological effects, x-rays, 22 Biopsy bones and joints, 162 breast, 130, 136–137 Bladder calculi, 219 Bleb, 127 Bleeding colonic, 280–284 small-bowel, 273–276 upper gastrointestinal, 269–273 Bones and joints. Close-up frontal (A) and lateral (B) chest radiographs of the left upper lobe demonstrate an air-fluid level (arrow). The case presented in this section demonstrates a focal nodular gray matter heterotopia involving the subependymal region BRAIN AND ITS COVERINGS CHAPTER 12 341 A Figure 12-13. Although plain films depict bone anatomy quite well, certain structures may be obscured by other structures in front of or behind them. It is very important to first decide whether a mass is within the brain parenchyma (intra-axial) or outside the brain (extra-axial). A. Benign duodenal ulcer (posterior wall) B. Malignant duodenal ulcer C. Benign duodenal polyp D. Benign duodenal ulcer (anterior wall) E. Ulcerated duodenal metastasis GASTROINTESTINAL TRACT Figure 10-21. Case 8-12. In recent years, the use of fat suppression has increased the utility of contrast-enhanced imaging of the spine, particularly in the evaluation of lesions within the spinal canal (Figure 13-8) and bone. Four major cell types account for almost 90% of all lung cancers. However, some important differences pertain. 3. CT scan without contrast at the level of the adrenal glands in a 47-year-old patient with newly diagnosed lung cancer who presented to the emergency department for right flank pain. Although they can be seen in an infectious or inflammatory process, semisolid nodules are more concerning for neoplasm. When questions arise concerning whether a particular appearance is normal or abnormal, several solutions are possible. They also characteristically have an elevated ESR. Thoracic Imaging: Pulmonary and Cardiovascular Radiology. This patient (Figure 3-27) has cardiomegaly, increased pulmonary vascularity, and prominent pulmonary Figure 3-29. (A–H) Normal CT anatomy. Instead it will slowly remodel by resorption of endosteal bone and deposition of periosteal new bone. D. pericardial effusion. Most commonly, no important findings except hepatomegaly occur on CT in hepatitis. Other readers will always be interested in your opinion of the books you've read. (B) Preinfusion T1weighted MR imaging showing background of cirrhosis and the high signal intensity of the periphery of the lesion (arrow) before contrast administration. (A–N) Normal CT anatomy. Sagittal (A) and coronal (B) T1-weighted MR imaging of the brain in a 2-day-old male infant who presents with multiple craniofacial deformities, including microcephaly and a fleshy mass on the bridge of the nose. These reactions are categorized as mild, moderate, or severe based on degree of symptoms. Therefore, ground-glass nodules require more extended monitoring than solid nodules do. The horizontal and ascending portions of the duodenum terminate at the duodenojejunal junction (L), which is attached to the ligament of Treitz. The patient in Figures 4-47 A,B has two large opacities projecting over the upper lung zones bilaterally. For example, sarcomas have been reported to grow along the surgical or needle tracks after diagnostic biopsies. On T2-weighted images, a long-T2 substance (fluid) will appear bright. The yield of plain radiographs is higher in patients with moderate or severe abdominal symptoms and signs than in those with minor symptoms. C. aortic stenosis. 88 PART 2 CHEST A B Figure 4-20. Additionally, CT angiography (CTA) of the chest is particularly useful for the evaluation of vascular pathology as well as pulmonary embolus (Table 4-3). In cases of acute complete rupture of the tendon, the MR images show discontinuity of the normally low-signalintensity fibers of the Achilles tendon, which are replaced by edema and hemorrhage. Free delivery on qualified orders. A 65-year-old male with midepigastric pain over a long period of time. Although SPECT provides critical information regarding regional cerebral perfusion, particularly in the setting of stroke, this information can be more readily obtained during CTA/CT perfusion or MR perfusion acquisitions. Importantly, imaging techniques are not necessarily exclusive and in some circumstances are complementary— taken alone, they may not provide enough information, but together they allow a correct clinical diagnosis. 13-9. Typical Effective Doses and Resulting Increased Risk of Fatal Cancer for Various X-ray Examinations X-ray examination Chest (PA and lateral) Typical effective dose, mrem (1 mrem 0.01 mSv) Lifetime risk of fatal cancer per million persons Time period for equivalent effective dose from natural background radiation 8 3 10 d Lumbar spine 127 51 155 d Upper gastrointestinal tract 244 98 297 d Barium enema 870 348 2.9 y Abdomen (KUB) 56 22 68 d Pelvis 44 18 54 d Head CT 180 72 219 d Abdominal CT 760 304 2.53 y THE PHYSICAL BASIS OF DIAGNOSTIC IMAGING The National Council on Radiation Protection (NCRP) in its report NCRP No. demonstrates increased signal within the infarcted territory due to the presence of cytotoxic edema (Figure 12-19 D). 13-6. Reston, Va: American College of Radiology; 2008:23-37. In addition, a chest radiograph is indicated for patients with systemic diseases that have a high likelihood of secondary involvement of those structures. In both methods, large and small compression images of all segments of the colon are obtained. If the infarct is not obvious on the initial CT scan, an MR scan is usually obtained to verify high clinical suspicion. 1. The technique for performing myelography is simple. 96 PART 2 CHEST Note that the margins of the lesion, whether smooth or spiculated, are of no value in determining the benignity or malignant potential of a lesion. The findings are characteristic of the late changes in LeggCalvé-Perthes disease (C is the correct answer to Question 7-20). D. CT of the hips. Lateral chest radiographs. Malignant microcalcifications are usually less than 0.5 mm in size, and the very coarse calcifications are classically benign. Regarding Case 9-2 (Figure 9-17), the diagnosis or exclusion of metastatic adrenal disease is one of the most important issues facing the radiologist in daily practice. The spinal cord is intact, but spread of tumor or retropulsion of fractured bone could result in cord compression. The irregular, angulated mass narrowing is likely due to a small-bowel malignancy; a carcinoid tumor was found at surgery. Note the stent in the renal pelvis (arrowhead) of the left kidney, placed to relieve urinary obstruction. B Figure 4-51. Ultrasonography Ultrasonography is the diagnostic application of ultrasound to the human body. CT of liver laceration shows an illdefined low-density defect in the liver extending to the capsule (arrow) with high-attenuation fluid (∗) consistent with blood surrounding the liver. The left adrenal has the characteristic inverted Y shape (arrow) while the right, located immediately behind the inferior vena cava, is somewhat more linear in appearance (open arrow) in this case. 3-18. No further imaging is needed. CT scan with contrast of the abdomen in a 39-year-old male patient who presented with refractory hypertension and episodes of headaches and palpitations. Gallbladder stones are usually present, and there is a higher incidence (approximately 10% to 20%) of gallbladder carcinoma. Based on the MR images for Case 9-4 (Figure 9-21), what is the most likely diagnosis? In fact, as many as one-third of all patients originally felt to have ureteral stones are shown by 252 PART 4 ABDOMEN Figure 9-28. A. Functional ileus of the bowel B. Ultrasound of the carotid bifurcation is another modality that provides both anatomic and functional information. Image is oriented slightly oblique with the superior calvarium cut away. A Figure CHAPTER 3 51 EXERCISE 3-3. At angiography, normal organs enhance to variable extents. B. cyst. Perhaps most importantly, however, if the clinician consults with the radiologist and conveys to him or her the clinical information, imaging often can be tailored to hone in on the most likely site or type of abnormality. What is the most likely diagnosis in Case 8-22 (Figure 8-47)? Incidentally noted is the tip of an internal jugular triple-lumen catheter in the superior vena cava (arrow). See Joints exercises computed tomography, 182 conventional tomography, 181–182 joint disease and, 185–186 magnetic resonance imaging, 183 radiography, 181 radionuclide imaging, 184–185 technique selection, 186 acute trauma, 186 congenital diseases, 186 nontraumatic cases, 186 subacute and remote trauma, 186 ultrasonography, 184 Joint trauma, 189–196 K Kerley line. Intravascular enhancement extending into the cortical sulci may be seen in the acute to early subacute phase of infarct, generally related to prolonged intravascular opacification from slow vascular flow (Figure 12-19 E). Additionally, the parenchyma near the renal hila may appear prominent as well, occasionally mimicking a mass. These malignancies, along with metastatic neoplasms of the small bowel, show a wide spectrum of appearances varying from polypoid and ulcerated masses to multifocal and infiltrative processes (Figure 10-37). Detail of a mammogram of the patient. This quantity is called exposure, and 1 R of exposure results in 2 109 ionizations per cubic centimeter of air. Screening mammography B. Excisional biopsy C. Ultrasonography D. Diagnostic mammography E. Needle aspiration 5-2. In this case, the CT scan (Figure 12-34 A) shows extensive subarachnoid hemorrhage filling the basal cisterns, more pronounced on the right (black arrows), with extension of hemorrhage into the interhemispheric and Sylvian fissures. Normal 99mTc-MAG3 renogram. D. foreign body. TCC of the bladder spreads by local invasion and by lymphatic and hematogenous spread. The TV image can be recorded using a videotape recorder or a videodisc recorder, the latter having the advantage of being able to view one frame at a time as well as providing random access rather than the sequential viewing required by videotape. The major advantages of CT are that it is inexpensive, is widely available, can be used in patients with MR-incompatible hardware, and allows a relatively quick assessment of intracranial contents in the setting of a neurological deficit. After an anterior dislocation, there is frequently associated injury of the anterior glenoid labrum. These relative risks are considered to be related to radiation dose and effective dose, which is essentially the exposure to various critical organs multiplied by an organ-weighing factor (the units of radiation dose or exposure: a rem, a rad, and a roentgen are essentially equivalent for x- and -ray irradiation). It is helpful to remember the normal positions of the hemidiaphragms, trachea, mediastinum, and hila so that displacement of these structures can be readily noted. The typical breast cancer has been present for several years by the time it is 1 cm in size. On radiographs, the normal joint has a separation between the adjacent bones representing the region occupied by the hyaline or articular cartilage, menisci, and joint fluid (the so-called articular space) depending on which joint is imaged. (B) The corresponding PET image in the same patient reveals increased activity of the band heterotopia relative to the adjacent normal cortex (arrows), of unclear significance. These deposits cause episodic joint inflammation and are associated with pain and disability. angiocardiography (heart), coronary arteriography (coronary arteries) (Figure 3-12), aortography (aorta) (Figure 3-13), and pulmonary angiography (pulmonary arteries and lungs). 7. Case 10-3. Axial scans of the chest, contiguous slices at approximately 1 cm collimation, lung window settings. Also, with the use of luminal distention and intravenous agents of various types, assessment of obstructive and inflammatory bowel disease has shown dramatic results. 7-7. the glenoid. (B) T2-weighted sagittal cervical spine. In the severest form, colonic infarction and perforation may occur; however, the most common appearances relate to submucosal hemorrhage, which causes narrowing of the affected colon associated with irregular, smooth margins often called “thumbprinting”; complete healing and return to normal may occur (Figure 10-53), or progression to a smooth, tapered stricture can result. Nephrolithiasis (better known as “kidney stones”) is much more common than nephrocalcinosis. US assessment is often specific in identifying simple or mildly complicated cysts and differentiating these lesions from a solid mass. John Leyendecker, Michael Oliphant, and James Perumpillichira, for providing me with nearly all of the CT, MR, and CTC images used in this chapter. Malposition of central venous catheter. 158 pages. Note the increased size of the cardiac silhouette, the ill-defined reticular perihilar air-space opacities, the enlargement of the vascular pedicle, and the redistribution of blood flow to the upper lung zones. B Figure 10-37. Figure 4-69. Biopsy is indicated, but needle aspiration without imaging would have been inappropriate (Statement C is false). Orthopantograms are one of the few remaining vestiges of this imaging technique. Other sites of increased activity represent bowel loop (arrowhead) and bladder (open arrow) activity. There is often dorsal tilting of the dens, which may indent the brainstem. The strengths and weaknesses of these techniques are discussed. The kidneys should be evaluated in a similar fashion to that of other modalities. Note the homogeneous density of the noncontrast portion (A), the distinction of cortex and medulla of the corticomedullary phase (B), and the once again homogeneous enhancement during the nephrographic phase (C). Therefore, Option E is true, because these ringlike calcifications have a better-than-average chance of being benign. E. calcified plaques in a patient with asbestos exposure. More severe injuries that involve complete disruption of the tissue into fracture planes, perhaps involving the hepatic veins, inferior vena cava, or portal veins, are called lacerations. Radiolucent structures that exhibit a branching pattern are noted to arborize through both opacities (B is the correct answer to Question 4-8.). Case 10-13. Figure 3-24. This Website!! IMAGING OF THE SPINE CHAPTER 13 385 Radiologic Findings Discussion 13-8. The kidneys are typically located at the level of the upper lumbar spine with the right kidney slightly lower than the left. Tsai IC, Chen MC, Lee WL, et al. These injuries can result in massive intraperitoneal bleeding from disruption of mesenteric vessels, or peritonitis from bowel perforation. In a patient with suspected Pancoast’s (superior sulcus) tumor (Figure 4-9), MR imaging is preferred to CT because of the ability to obtain images in coronal and sagittal planes. Figure 8-46. 6-11. Third, how big is the lump? What is the most likely diagnosis in Case 11-16 (Figure 11-60)? In addition, the close spatial coupling between brain activity and CBF permits the application of perfusion MR techniques to imaging brain function. The curved arrow in Figure 3-41A identifies the enlarged right descending pulmonary artery (C is the correct answer to Question 3-12). LIVER, BILIARY TRACT, AND PANCREAS A C CHAPTER 11 303 B D Figure 11-31. (A,B) Case 13-10. Discussion Congenital joint disorders are uncommonly encountered, but they should be diagnosed as early as possible after birth because delayed diagnosis complicates management. Although attenuation of the ultrasound beam occurs with air, such as might occur with emphysematous pyelonephritis, the shadowing in those cases is often “dirty” in appearance, being somewhat inhomogeneous (D is incorrect). Indirect information about intracranial abnormalities can sometimes be obtained from the skull plain radiograph, although this information can be quite subtle, even in the setting of advanced disease. The terminal ileum (l) has refluxed from the colon. However, this finding may be overlooked if the left and right designations on the film are marked incorrectly or are misinterpreted. The anterior border of the cardiac shadow is composed primarily of the anterior wall of the right ventricle. 2. Intracranial brain herniation may also be a prominent feature in this condition. The patient lies in supine position while the discharging duct is cannulated with a blunt-tipped needle or catheter under visual inspection and with the aid of a magnifying glass. Ultrasonography Ultrasonography, first developed for use in World War II for detection of submarines, was adopted after the war for use in medical imaging. Azygoesophageal recess: On the frontal chest radiograph, a vertically oriented interface between air in the right lower lobe, and the adjacent mediastinum containing the azygos vein and esophagus. In Case 13-3, Figure 13-11 shows marked narrowing and osteophyte formation at C5-6 and C6-7. This 5-year-old girl has been limping off and on for 2 months. The thalami are fused, a central monoventricle is present, and there is no corpus callosum. The choice of imaging tests should ideally be made in consultation with the radiologist, taking into consideration potential morbidity, cost, availability of the technology, and the interest and expertise of the radiologist. 2009;192: 1481-1487. (A) Axial CT bone window shows different components of the fracture (arrows). There is no history of trauma. Overall measurements of wall thickness and biliary duct caliber are the same as for US. The obstruction to flow due to the coarctation results in elevated upper-extremity blood pressure and decreased lower-extremity blood pressure. the heart. Characteristic appearance of heavily calcified involuting fibroadenoma. B. left ventricular hypertrophy. Digital images generated from PPCR are capable of being transmitted through a picture archiving and communications system (PACS), similar to other digital images acquired from CT or MR facilities. The origins of the right and left pulmonary arteries are generally well demarcated on the normal PA film as they emerge from the mediastinum. On ultrasound, shadowing echogenic foci are noted within the renal medulla. Reticular pattern: A collection of innumerable small, linear opacities that together produce the appearance of a net. Mediastinal masses may occur in a location or a distribution that makes the heart appear enlarged on the chest radiograph. In Case 12-16, what is the most likely diagnosis (Figure 12-36 A, B)? Fat is distributed in the subcutaneous layer, in among the parenchymal elements centrally, and in the retromammary layer anterior to the pectoral muscle (Figure 5-4). B. Septic Arthritis Septic arthritis is usually blood-borne (hematogenous) and is most commonly monoarticular (that is, involving only one joint at any time). After the introduction of a catheter into a peripheral vessel (usually, the femoral or axillary vein or artery), the angiographer, under fluoroscopic visualization, positions the catheter in the region of interest, injects contrast material to confirm the location of the catheter, and then injects larger amounts of contrast material for diagnostic purposes. If clinical information is insufficient or if radiographic confirmation is necessary, plain films and contrast studies may be performed. 5. Warnes CA: Adult Congenital Heart Disease. LANGE Clinical Science Gopal B. Saha This book is an ideal text on PET imaging technology that focuses on the basics, such as physics, instrumentation, production of PET radionuclides and radiopharmaceuticals, and regulations affecting PET.