By: Christopher Whaley PhD
Crux is the region on the pericardial cavity which is lined by mesothelial cells and posterior surface of the heart where all the four cardiac normally contains 10-30 ml of clear symptoms by dpo discount revia 50 mg on-line, watery serous fluid medicine rocks state park order line revia. These patterns are as under: the endocardium is the smooth shiny inner lining of the Right coronary artery preponderance is the most myocardium that covers all the cardiac chambers symptoms 8 days past ovulation order revia online now, the cardiac common pattern symptoms jaw cancer purchase revia 50 mg otc. In this treatment quadratus lumborum purchase revia overnight, right coronary artery supplies blood valves, the chordae tendineae and the papillary muscles. It to the whole of right ventricle, the posterior half of the is lined by endothelium with connective tissue and elastic interventricular septum and a part of the posterior wall of fibres in its deeper part. The valve cusps and semilunar leaflets are delicate and Balanced cardiac circulation is the next most frequent translucent structures. In this, the right and left ventricles receive blood collagen and elastic tissue and covered by a layer of supply entirely from right and left coronary arteries endothelium (valvular endocardium). The cardiac muscle, in is supplied by a branch of the right coronary while the order to function properly, must receive adequate supply of anterior part is supplied by a branch of the left coronary oxygen and nutrients. Most of blood flow to the In this, the left coronary artery supplies blood to the entire myocardium occurs during diastole. There are three major left ventricle, whole of interventricular septum and also coronary trunks, each supplying blood to specific segments supplies blood to a part of the posterior wall of the right of the heart (Fig. The anterior descending branch of the left coronary Coronary veins run parallel to the major coronary arteries artery supplies most of the apex of the heart, the anterior to collect blood after the cellular needs of the heart are met. For the purpose of pathologic discussion of heart diseases, they are categorised on the basis of anatomic region involved 3. The right coronary artery supplies the right atrium, the and the functional impairment. Accordingly, topics on heart remainder of the anterior surface of the right ventricle, the diseases are discussed in this chapter under the following headings: 1. It may be mentioned here that pattern of heart diseases in developing and developed countries is distinct due to difference in living standards. In children, valvular diseases are common all over the world, but in developing countries including India, infections, particularly rheumatic valvular disease, is the dominant cause compared to congenital etiology in affluent countries. On the other hand, ischaemic heart disease and hypertensive cardiomyopathy are the Figure 16. Heart failure is defined as the pathophysiologic state in which Acute heart failure. Sudden and rapid development of heart impaired cardiac function is unable to maintain an adequate failure occurs in the following conditions: circulation for the metabolic needs of the tissues of the body. In acute heart failure, there is sudden reduction in cardiac Etiology output resulting in systemic hypotension but oedema does not occur. Instead, a state of cardiogenic shock and cerebral Heart failure may be caused by one of the following factors, hypoxia develops. The most common and slowly as observed in the following states: most important cause of heart failure is weakening of the i) Myocardial ischaemia from atherosclerotic coronary ventricular muscle due to disease so that the heart fails to artery disease act as an efficient pump. The various diseases which may ii) Multivalvular heart disease culminate in pump failure by this mechanisms are as under: iii) Systemic arterial hypertension i) Ischaemic heart disease iv) Chronic lung diseases resulting in hypoxia and pulmo ii) Myocarditis nary arterial hypertension iii) Cardiomyopathies v) Progression of acute into chronic failure. This often results in well-maintained arterial pressure Increased mechanical load on the heart results in increased and there is accumulation of oedema. Though heart as an organ eventually fails as a whole, but i) Increased pressure load may occur in the following functionally, the left and right heart act as independent units. It is initiated by stress to the left ii) Increased volume load occurs when a ventricle is heart. The major causes are as follows: required to eject more than normal volume of the blood i) Systemic hypertension resulting in cardiac failure. This is seen in the following ii) Mitral or aortic valve disease (stenosis) conditions: iii) Ischaemic heart disease a) Valvular insufficiency iv) Myocardial diseases. Heart failure may be acute or chronic, right-sided or left Right-sided heart failure. However, some conditions affect the right ventricle primarily, failure can be explained on the basis of mutually inter producing right-sided heart failure. According to this concept, either of ii) Cor pulmonale in which right heart failure occurs due to the ventricles fails to eject blood normally, resulting in rise intrinsic lung diseases (Chapter 17). According to this hypothesis, clinical v) Myocardial disease affecting right heart. The Ultimately, however, dilatation decreases the force of mechanism of clinical manifestations resulting from heart contraction and leads to residual volume in the cardiac 421 Figure 16. These are as follows: Cardiac Hypertrophy i) Pulmonary stenosis and insufficiency ii) Tricuspid insufficiency Hypertrophy of the heart is defined as an increase in size iii) Mitral stenosis and/or insufficiency and weight of the myocardium. The basic factors that stimulate the hypertrophy of the Cardiac Dilatation myocardial fibres are not known. It appears that stretching of myocardial fibres in response to stress induces the cells to Quite often, hypertrophy of the heart is accompanied by increase in length. Other factors which may volume of blood in a chamber of the heart causes increase in stimulate increase in size of myocardial fibres are anoxia. Hypertrophy with or without dilatation may the cardiac chambers from the following causes may result involve predominantly the left or the right heart, or both in dilatation of the respective ventricles or both: sides. The common causes are as in left ventricular dilatation, tricuspid and/or pulmonary under: insufficiency in right ventricular dilatation) i) Systemic hypertension ii) Left-to-right shunts. The weight of the heart is increased above sites for the formation of new sarcomeres. However, excessive epicar nucleic acid content determinations have shown increase dial fat is not indicative of true hypertrophy. It is the most common and important trabeculae carneae are rounded and enlarged, while in form of heart disease in the early years of life and is present hypertrophy with dilatation these are flattened. The incidence is higher Microscopically, there is increase in size of individual in premature infants. It is attributed to multi degenerative changes and necrosis in the hypertrophied factorial inheritance involving genetic and environmental myocardium (Fig. Other factors like rubella infection to the mother a result of relative hypoxia of the hypertrophied muscle during pregnancy, drugs taken by the mother and heavy as the blood supply is inadequate to meet the demands of alcohol drinking by the mother, have all been implicated in the increased fibre size. Ventricular hypertrophy renders causing in utero foetal injury resulting in congenital the inner part of the myocardium more liable to ischaemia. Congenital anomalies of the heart may myofilaments comprising myofibrils, mitochondrial be either shunts (left-to-right or right-to-left), or defects changes and multiple intercalated discs which are active causing obstructions to flow. The chambers opened up at the apex show concentric thickening of left ventricular wall (white arrow) with obliterated lumen (hypertrophy without dilatation). The free left ventricular wall is thickened (black arrow) while the lumen is dilated (white arrow) (hypertrophy with dilatation). Left-to-Right Shunts (Acyanotic or Late Cyanotic Group) In conditions where there is shunting of blood from left-to right side of the heart, there is volume overload on the right heart producing pulmonary hypertension and right ventricular hypertrophy. At a later stage, the pressure on the right side is higher than on the left side creating late cyanotic heart disease. The smaller defects often close spontaneously, while larger defects remain patent and produce significant effects. In 90% of cases, the defect involves membranous septum involving combinations of shunts and obstructions are also and is very close to the bundle of His (Fig. It may be accompanied by situs increased pulmonary flow and increased volume in the inversus so that all other organs of the body are also left side of the heart. These effects are as under: transposed in similar way and thus heart is in normal position i) Volume hypertrophy of the right ventricle. However, isolated dextrocardia is ii) Enlargement and haemodynamic changes in the associated with major anomalies of the heart such as tricuspid and pulmonary valves. Left-to-right shunts remains unnoticed in infancy and childhood till pulmonary (Acyanotic or late cyanotic group) hypertension is induced causing late cyanotic heart disease 1. Right-to-left shunts (Cyanotic group) i) Fossa ovalis type or ostium secundum type is the most 1. Transposition of great arteries (4-10%) defect is situated in the region of the fossa ovalis (Fig. Aortic stenosis and atresia (4-6%) the defect is located high in the interatrial septum near the 3. B, the opened up chambers of the heart show a communication in the inter-ventricular septum superiorly (white arrow). The ductus produced due to left-to-right shunt at the atrial level with arteriosus is a normal vascular connection between the aorta increased pulmonary flow. Normally, the i) Volume hypertrophy of the right atrium and right ductus closes functionally within the first or second day of ventricle. Its persistence after 3 months of age is considered ii) Enlargement and haemodynamic changes of tricuspid abnormal. These effects are as follows: i) Volume hypertrophy of the left atrium and left ventricle. Right-to-Left Shunts (Cyanotic Group) In conditions where there is shunting of blood from right side to the left side of the heart, there is entry of poorly Figure 16. The effects on the heart are as follows: i) Pressure hypertrophy of the right atrium and right ventricle. Tetralogy of Fallot is the most position of the aorta, pulmonary trunk, atrioventricular common cyanotic congenital heart disease, found in about orifices and the position of atria in relation to ventricles. There is complete transposition of the great arteries with aorta arising from the right ventricle and the pulmonary trunk from the left ventricle, as well as transposition of the great veins so that the pulmonary veins enter the right atrium and the systemic veins drain into the left atrium. This results in a single large common vessel receiving blood from the right as well as left ventricle. In tricuspid atresia, there is absence of tricuspid orifice and instead there is a dimple insufficiency such as claudication and coldness. In tricuspid stenosis, the there is development of collateral circulation between pre tricuspid ring is small and the valve cusps are malformed. Children are cyanotic since birth and live for a few weeks ii) Preductal or infantile type: the manifestations are or months. There is often associated Congenital obstruction to blood flow may result from interatrial septal defect. Preductal coarctation results in obstruction in the aorta due to narrowing (coarctation of aorta), right ventricular hypertrophy while the left ventricle is obstruction to outflow from the left ventricle (aortic stenosis small. Cyanosis develops in the lower half of the body and atresia), and obstruction to outflow from the right while the upper half remains unaffected since it is supp ventricle (pulmonary stenosis and atresia). The most common localised narrowing in any part of aorta, but the constriction congenital anomaly of the aorta is bicuspid aortic valve which is more often just distal to ductus arteriosus (postductal or does not have much functional significance but predisposes adult), or occasionally proximal to the ductus arteriosus it to calcification (page 450). Congenital aortic atresia is rare (preductal or infantile type) in the region of transverse aorta: and incompatible with survival. Congenital aortic stenosis to the point of entry of ductus arteriosus which is often may be of three types: valvular, subvalvular and closed (Fig. The aorta i) Valvular stenosis: the aortic valve cusps are is dilated on either side of the constriction. The aortic valve is recognised in adulthood, characterised by hypertension may have one, two or three such maldeveloped cusps. In all these cases, there is pressure hypertrophy of the left ventricle and left atrium, and dilatation of the aortic root.
Duplex ultrasound imaging is highly operator dependent symptoms 8 days after iui purchase cheapest revia and revia, and these values vary widely among institutions 72210 treatment buy revia online from canada. It is less sensitive for detecting calf vein thrombi than those located more proximally medicine kidney stones buy revia without prescription. The procedure is not an ideal screening test because of cost and potential morbidity related to medications and mothers milk purchase revia visa the test symptoms zoloft order cheapest revia. The detection of pelvic thrombi is poor, unless direct femoral vein puncture is performed. It may be falsely positive in the thigh after total hip arthroplasty in which there is ﬁbrin present at the surgical site. It has a sensitivity of 100%, speciﬁcity of 49%, positive predictive value of 22%, and negative predictive value of 100%. Diamond S, Goldbweber R, Katz S: Use of D-dimer to aid in excluding deep venous thrombosis in ambulatory patients, Am J Surg 189:23-26, 2005. Haas S: Deep vein thrombosis: beyond the operating table, Orthopedics 6:629-632, 2000. It generally is felt in the distal part of the extremity in a nonsegmented distribution. As the symptoms continue, the pain becomes more diffuse and may spread gradually proximal to the involved limb and can spread to other parts of the body. Initially the dystrophic limb is cool, pale, and cyanotic with sweating changes that indicate sympathetic hyperactivity. Sensory abnormalities are not always dermatomal in distribution and can spread from distal to proximal or to the uninvolved limb. Osteopenia begins in the metacarpal or metatarsal joint but can spread more proximally. A more generalized osteoporosis of subchondral bone of the involved joints may be observed. On three-phase bone scans, changes usually result in increased periarticular uptake and blood flow on the affected side. Example: Initial tapping on the skin is not painful, but with repetition it becomes more painful. Acute Dystrophic Atrophic Pain Burning/neuralgia, Burning/throbbing, Burning/throbbing, ++ +++ +++ Dysesthesia ++ +++ + Function Minimal impairment Restricted Severely restricted Autonomic dysfunction Increased blood flow Decreased flow Decreased blood flow Temperature Increased Decreased Decreased Discoloration Erythematous Mottled, dusky Cyanotic Sudomotor dysfunction Minimal ++ +++ Edema ++ +++ + Trophic changes 0 ++ ++++ Three-phase bone scan Increased activity, Normal uptake, all Decreased activity all images phases except increased static phase Osteoporosis – + +++ 7. These 123 patients were of a general population of 1156 patients seen at a pain clinic and represented 10. The Reflex Sympathetic Dystrophy Syndrome Association estimates that 6 million adults and children suffer from the condition in the United States. Women seem to be more likely to suffer from this disorder than men (ratio, 2:1 to 3:1). All ages can develop this syndrome, but more commonly the distribution seems to be in women between the ages of 30 and 55. The most helpful guideline is early recognition and early treatment intervention, in which a multidisciplinary approach is used. Initial treatment should focus on locating and eliminating the initiating cause of pain. The treatment primarily is aimed toward interruption of the abnormal sympathetic response as well as interruption of the vicious cycle of dysfunction, including pain, swelling, immobility, and decreased weight-bearing. Interruption of the abnormal sympathetic reflex is by means of surgical decompression, nerve blocks, ganglion blocks, and axillary blocks in conjunction with physical, occupational, and psychological therapies. The delayed phase (3 to 4 hours after injection) must show diffusely increased activity in the involved joints with periarticular accentuation. Radiographic evidence of sympathetic hyperdysfunction includes patchy demineralization of the epiphyses and metacarpal and metatarsal bones of the hands and feet. Tunneling of the cortex may occur with subperiosteal reabsorption and striation formation. Patchy osteopenia usually is not seen on radiographs until the late stages of the disease. It has been shown to decrease the peptide substance P, which mediates pain transmission in the dorsal horn of the spinal cord. Clonidine stimulates α adrenoreceptors, leading to decreased sympathetic outflow. Both of these medications should be prescribed by the physician, and the patient’s blood work should be monitored. They received an intensive exercise program of hydrotherapy, desensitization, aerobics, and functionally directed exercise. All had psychological evaluations, and 79% were referred for psychological counseling. Of the subjects followed for >2 years, 43 (88%) were symptom-free (15, or 31%, of these patients had a recurrence), 5 (10%) were fully functional but had some continued pain, and 1 (2%) had functional limitations. It is believed that the sympathetic nervous system can be stimulated by the products in cigarettes, causing an increase in the plasma levels of epinephrine and norepinephrine. It is also known that smoking decreases blood flow to the extremities, especially the distal portions, which leads to ischemia. Regional anesthesia instead of general anesthesia is preferred if surgery is warranted. Exercises are best performed during the analgesic periods following sympathetic blocks. Exercise also increases blood flow to the extremity and may cause central inhibition of the sympathetic nervous system. In this study, the patient had immediate or near complete resolution of symptoms. Poster presentation at the American Physical Therapy Association, Combined Sections Meeting, Seattle, 1999. In Orthopaedic home study course: the elbow, forearm, and wrist, Fairfax, Va, 1997, American Physical Therapy Association Orthopedic Section. At what depth have tissue temperature changes been recorded after treat ment with superﬁcial ice? Ice application is reported to lower tissue temperature in the skin, subcutaneous tissue, and muscle, depending on the amount of subcutaneous tissue (adipose), type of cold application, and length of time treated. Patients with little subcutaneous tissue showed more signiﬁcant cooling with a much shorter treatment time. Which method is more effective in lowering tissue temperature: ice massage or ice pack? A 5-minute ice massage treatment in the lower extremity decreased skin temperature by 20° C, subcutaneous tissue by 15° C, and muscle temperature at a depth of 2 cm by 5° C and a depth of 4 cm by 4° C. The extent of the temperature change seems to relate more to the length of application and the amount of subcutaneous adipose tissue. Clinical considerations include the size and location of the affected area, time allotted for ice application, and patient preference. Ice massage may produce its maximum effect sooner than an ice pack; however, if a large area is to be treated, an ice pack may be more efﬁcient. Lower tissue temperatures produce a decrease in metabolic rate and subsequently a decrease in demand for oxygen. This decreased need for oxygen serves to limit further injury, particularly in the case of acute tissue damage, when the blood supply and oxygen delivery are impaired, resulting in hypoxia. Cold-induced lower tissue temperature raises the threshold of activation of the muscle spindle, rendering it less excitable. How may the physiologic effect of cold application be successful in reducing muscle spasm or cramp? A decrease in muscle tension is produced by the less-excitable muscle spindle that is not altered by active or passive stretching exercises, which means that an ice pack can be employed successfully during a passive or active stretch of a muscle that is in spasm. The superﬁcial vasculature has a sympathetic innervation that produces vasoconstriction when stimulated. Norepinephrine secretion and epinephrine secretion are stimulated by exposure to ice and are secreted into the blood vessels, resulting in vasoconstriction. If the tissue temperature drops to below 15° C, vasodilation occurs as a result of a paralysis of the musculature, which provides the vasoconstriction or a conduction block of the sympathetic nervous system. Vaso constriction can lead to vasodilation if ice application is such that a tissue temperature <15° C is reached. If vasodilation results, there is no deﬁnite consensus regarding the overall effect on the blood flow. A decrease in the amount of blood lost was reported in patients who showed lower joint temperatures; this would seem to indicate that the overall blood flow remains decreased. Neither of these temperature ranges should bring the muscle tissue temperature to <15° C and should not produce vasodilation within the deeper or target tissues. Frostbite occurs when the extremities or face has been exposed to cold such that there is a drop in shell temperature, resulting in freezing of the tissue. Tissue freezing occurs as ice crystals form in the extracellular areas, causing fluids to be drawn out of the cells. The earliest or precursor stage of frostbite begins with tissue temperatures of 37° to 50° F (3° to 10° C). Cold-induced vasodilation occurs at temperatures <15° C, reaching a maximum at tissue temperatures of 0° C (32° F). What is the ideal tissue temperature to achieve the optimal physiologic effects of cryotherapy? Optimal physiologic effects from cryotherapy are achieved at tissue temperatures of 15° to 25° C. How long do tissue blood flow and tissue temperature remain decreased after application of an ice pack? Forearm blood flow has been shown to return to normal gradually over a 35-minute period after a 20-minute ice pack treatment. A 15-minute ice pack treatment has been shown to produce a maximum intramuscular cooling effect at 28. Which form of cold treatment is the most effective at relieving postoperative pain and swelling? Previous researchers reported a greater decrease in pain in those treated with a Cryocuff than in those treated with an ice pack. It is possible that, because of the postoperative Cryotherapy and Moist Heat 71 dressing, the tissue temperature is not decreased to an effective level to produce analgesia or to decrease swelling in some cases. Patients receiving continuous flow cold therapy demonstrated statistically signiﬁcant decreases in pain, decreased pain medication usage, and increases in range of motion 1 week after surgery when compared with the patients receiving crushed ice. There did not appear to be a correlation between the severity of the disease process and the length of recovery time required. Underlying pathology to explain the slow recovery is probably related to sympathetic nervous system involvement and associated peripheral vascular disease.
Cystic teratoma is the most common acute treatment cheap revia 50 mg fast delivery, benign tumor of the ovary treatment 6th february order revia 50 mg visa, and is not associated with abnormal sexual development medicine 513 buy revia paypal. Dysgerminoma is a malignant germ cell tumor symptoms 1 week after conception order revia online, which are not associated with abnormal sexual development medicine universities purchase revia 50mg on line. Granulosa cell tumors are the most common malignant neoplasm of sex cord origin and are often hormonally active, presenting with precocious puberty or with menstrual irregularities after puberty. Endodermal sinus tumors, or yolk sac tumors, are germ cell neoplasms which are not associated with abnormal sexual development. A contrast enema is performed on a one-day-old infant presenting with bilious emesis and abdominal distension. Rationale: Findings: the examination shows a microcolon, which is a term applied to an unused colon; this happens in infants with congenital distal bowel obstruction. Patients with Hirschsprung disease should demonstrate a zone of transition between normal caliber colon distally, and dilated colon proximally. The colon is normal in caliber, and demonstrates a large filling defect representing the meconium plug. In patients with small left colon syndrome, the left colon and often portions of the sigmoid are small, similar to a microcolon; however, unlike the findings in the test case, the remainder of the colon, including the rectum, is normal in caliber. Shwachman Diamond Syndrome – a review of the clinical presentation, molecular pathogenesis, diagnosis and treatment. Metaphyseal dysostoses have been reported, but epiphyseal dysplasia is not part of this syndrome. You are shown an extremity radiograph on a 4-month-old with irritability and altered mental status. Rationale: Findings: the radiograph shows bucket-handle lesions in the distal femur and proximal tibia with extensive periosteal reaction, characteristic of non-accidental trauma. In patients with rickets there is widening of the physes, loss of the zones of provisional calcification, and irregular metaphyses. However, the findings of child abuse described and seen on this image are not present. Although patients with congenital syphilis may show periosteal reaction, the bucket handle lesions are not seen. Although there could be periosteal reaction due to subperiosteal hemorrhage, the bucket handle lesion is not seen. A 6-year-old girl presents with a 3-year history of recurrent shortness of breath. Young patient with generalized lymphangiomatosis: differentiating the differential. Although lymphoma can present with splenic involvement and pleural effusion, the diffuse lytic bone lesions in multiple bones are not characteristic. Infantile myofibromatosis occurs mainly in infancy and is characterized by solitary or multiple soft tissue nodules; bone lesions are not common, but when they occur they resemble those seen in histiocytosis, with focal lytic areas and sclerotic rims, rather than the diffuse, expansile lesions seen here. Typical findings as noted, include pleural effusions, lytic lesions involving multiple bones, and cystic lesions in the spleen. Infantile subglottic hemangioma: a review and presentation of two cases of surgical excision. Unilateral impression upon the subglottic airway is the classic appearance for a subglottic hemangioma. Croup typically causes symmetric tapering of the subglottic airway leading to a "steeple" sign. A retropharyngeal abscess typically causes mass effect posterior to the oropharyngeal airway rather than effacement of the subglottic airway. Subglottic stenosis may resemble croup with generalized symmetric tapering of the subglottic airway or may cause a more focal constriction of the subglottic airway. Physics Radiology In-Training Test Questions for Diagnostic Radiology Residents May, 2018 Sponsored by: Commission on Publications and Lifelong Learning Committee on Residency Training in Diagnostic Radiology © 2018 by American College of Radiology. Boone, the Essential Physics of Medical Imaging, 3nd edition, Lippincott Williams Wilkins (2012). The average energy of the filtered spectrum is typically 1/3 to1/2 the maximum energy, which is 100 keV for a 100 kVp x-ray beam. The average energy of the filtered spectrum is typically 1/3 to 1/2 the maximum energy, which is 100 keV for a 100 kVp x-ray beam. Increasing the mAs increases the number of x rays striking the patient, but does not affect the energy of the beam and therefore does not affect the percentage of the beam that is transmitted through the patient. Increasing the kVp increases the average beam energy, making the beam more penetrating. Increasing the tube-patient distance does not affect the energy of the beam or penetrability of the beam. Decreasing the tube-patient distance does not affect the energy of the beam or penetrability of the beam. Compared to standard contact imaging, which of the following may compromise image quality of magnification views in mammography? Quantum noise is decreased compared to standard contact imaging because there are more photons per object area creating the image. The air gap between the breast support surface and image receptor reduces scattered radiation. The dose went up by a factor of 4 from 100 mAs to 400 mAs, so the standard deviation goes down by a factor of 2. Key: D References: Bushberg, Seibert, Leidholdt, Boone, Essential Physics of Medical Imaging. Although the ability to distinguish small low contrast objects is affected by image noise, the spatial resolution of the system is not directly affected by the mAs. Which of the following digital detectors directly converts x-ray signals into an electrical charge? When photostimulable storage phosphers absorb x rays, some of the energy is trapped and stored, and is read out later using laser light. When x rays are absorbed the energy is converted directly into charge, producing electron hole pairs in proportion to incident x ray energy. Which of the following occurs when the x-ray field is collimated to the smallest possible size to cover the specific anatomic region? Geometric magnification is increased Key: B References: nd Bushberg, Seibert, Leidholdt, Boone, Essential Physics of Medical Imaging. Geometric unsharpness depends on geometric factors such as focal spot size and magnification. Collimation to a smaller field of view reduces scatter, which improves image contrast. Incorrect Higher grid ratios will reduce scatter, but reducing the field of view by collimating to the smallest possible size already reduces scatter, so making that change would not make a higher grid ratio needed. Magnification is determined by distances from x ray source to image receptor and x ray source to object. The chemical shift phenomenon arises as a result of the slightly shielded magnetic environment experienced by protons in fat, causing a lower frequency (about 3 parts per million) compared to protons in water. Because of this frequency shift, the major chemical shift artifact occurs in the frequency encode gradient direction (answer A). Note; the “slice encode” gradient is a gradient that is applied for volumetric ordering of the proton locations in a 3D acquisition. Higher tube voltage decreases image noise, with all other factors the same, since more x rays are used to form the image (more x rays are produced and a greater percentage are transmitted through the patient). Increasing slice thickness actually decreases image noise, since more photons are used to form the image. The lower tube current results in fewer x ray photons, thereby increasing image noise. Ultrasound Radiology In-Training Test Questions for Diagnostic Radiology Residents May, 2018 Sponsored by: Commission on Publications and Lifelong Learning Committee on Residency Training in Diagnostic Radiology © 2018 by American College of Radiology. You are shown color and spectral Doppler evaluation of the right hepatic artery of a 34-year-old woman, 72 hours status post liver transplant (Figure 6). The upstroke in this waveform is also abnormal, both delayed and lower than expected compatible with a “tardus parvus” waveform, which is also suspicious for proximal narrowing. Pseudoaneurysm is a rare complication of liver transplant that typically occurs at the arterial anastomosis. On greyscale imaging a pseudo aneurysm appears as a cystic structure with turbulent flow shown on color and spectral Doppler imaging. You are shown longitudinal gray scale image of the testis in an asymptomatic 57 year old man (Figure 2). Tubular ectasia of the rete testis typically occurs as a result of inflammatory of traumatic obstruction of the epididymis. Sonographic findings of cystic or tubular structures along the mediastinum testis with no internal flow on color Doppler imaging is characteristic of this diagnosis. Intratesticular varicoceles appear as dilated, tubular structures coursing through the testis. Most lesions are solid and hypoechoic compared to the normal testicular parenchyma. Sonographic features of intra-testicular abscess include enlarged testis with a focal fluid-filled or hypoechoic mass. Gas may be identified within an abscess as bright echogenic foci with posterior acoustic shadowing. Benign tumors and tumorlike lesions of the gallbladder and extrahepatic bile ducts: radiologic-pathologic correlation. Gas within the gallbladder in patient s with emphysematous cholecystitis appear as liniear, echogenic foci with posterior "dirty" shadowing. In porcelain gallbladder, the gallbladder wall is calcified and appears diffusely echogenic with posterior acoustic shadowing. Impacted gallstones are located in the neck of the gallbladder and are echogenic, shadowing and non-mobile. The grey scale image shows focal thickening of the gallbladder wall with echogenic foci that show posterior comet tail artifact. The color Doppler image shows twinkle artifact associated with the echogenic foci. Stein-Leventhal syndrome, also called poly cystic ovary syndrome is associated with an abnormal appearance of the ovaries on ultrasound including ovaries with increased volume and numerous, small, typically peripherally oriented cysts. Theca lutein cysts are not seen in association with elevated serum progesterone levels. Theca Lutein cysts are not an expected finding in the setting of a normal singleton pregnancy. You are shown a transverse image of the uterus from a 24-year-old woman with a positive urine pregnancy test (Figure 3). Failed intrauterine pregnancy is diagnosed with no embryo is seen on transvaginal ultrasound with a mean sac diameter of greater than or equal to 25mm. This image shows an enlarged uterus with an intrauterine mass that is echogenic with cystic spaces of varying size.
Groups at increased risk of infection in industrialized countries include immigrants from or long-term visi tors to medications ending in lol buy revia in india areas with endemic infection treatment dry macular degeneration revia 50 mg otc, institutionalized people treatment of hyperkalemia order revia uk, and men who have sex with men symptoms pinched nerve neck order cheap revia on-line. Ingested cysts treatment x time interaction cheap revia express, which are unaffected by gastric acid, undergo excystation in the alkaline small intestine and produce trophozoites that infect the colon. Cysts that develop subsequently are the source of transmission, especially from asymptomatic cyst excreters. Fecal-oral transmission also can occur in the set ting of anal sexual practices or direct rectal inoculation through colonic irrigation devices. The incubation period is variable, ranging from a few days to months or years but commonly is 2 to 4 weeks. Specimens of stool may be examined microscopically by wet mount within 30 minutes of collection or may be fxed in formalin or polyvinyl alcohol (available in kits) for concentration, permanent staining, and subsequent microscopic examination. Biopsy specimens and endoscopy scrapings (not swabs) may be examined using similar methods. Polymerase chain reaction, isoenzyme analysis, and monoclonal antibody-based antigen detection assays can differentiate E histolytica from E dispar and E moshkovskii. Patients may continue to have positive serologic test results even after adequate therapy. Diagnosis of an E histolytica liver abscess is aided by serologic testing, because stool tests and abscess aspirate frequently are not revealing. Ultrasonography, computed tomography, and magnetic resonance imaging can identify liver abscesses and other extraintestinal sites of infection. E dispar and E moshkovskii infections are considered to be nonpathogenic and do not require treatment. Corticosteroids and antimotility drugs administered to people with amebiasis can worsen symptoms and the disease process. In settings where tests to distinguish species are not available, treatment should be given to symptomatic people on the basis of positive results of microscopic examination. Asymptomatic cyst excreters (intraluminal infections): treat with a luminal amebicide, such as iodoquinol, paromomycin, or diloxanide. An alternate treatment for liver abscess is chloroquine phosphate administered concomitantly with metronida zole or tinidazole, followed by a therapeutic course of a luminal amebicide. Dehydroemetine followed by a therapeutic course of a luminal amebicide may be considered for patients for whom treatment of invasive disease has failed or cannot be tolerated. Chloroquine or dehydroemetine have been added to metronidazole for rare cases of amebic liver abscesses not responding to metronidazole alone. Percutaneous or surgical aspiration of large liver abscesses occasionally may be required when response of the abscess to medical therapy is unsatisfactory. In most cases of liver abscess, though, drainage is not required and does not speed recovery. Follow-up stool examination is recommended after completion of therapy, because no pharmacologic regimen is effective in eradicating intestinal tract infection completely. Household members and other suspected contacts also should have adequate stool exami nations performed and be treated if results are positive for E histolytica. Sexual trans mission may be controlled by use of condoms and avoidance of sexual practices that may permit fecal-oral transmission. Because of the risk of shedding infectious cysts, people diagnosed with amebiasis should refrain from using recreational water venues (eg, swim ming pools, water parks) until after their course of luminal chemotherapy has completed and any diarrhea they might have been experiencing has stopped. Early symptoms include fever, head ache, vomiting, and sometimes disturbances of smell and taste. The illness progresses rapidly to signs of meningoencephalitis, including nuchal rigidity, lethargy, confusion, personality changes, and altered level of consciousness. Seizures are common, and death generally occurs within a week of onset of symptoms. No distinct clinical features differ entiate this disease from fulminant bacterial meningitis. Signs and symptoms may include personality changes, seizures, headaches, nuchal rigidity, ataxia, cranial nerve palsies, hemiparesis, and other focal defcits. The most common symptoms of amebic keratitis, usually attributable to Acanthamoeba species, are pain (often out of proportion to clinical signs), photophobia, tearing, and foreign body sensation. Characteristic clinical fndings include radial keratoneuritis and stromal ring infltrate. Acanthamoeba keratitis generally follows an indolent course and initially may resemble herpes simplex or bacterial keratitis; delay in diagnosis is associated with worse outcomes. Most infections with N fowleri have been associated with swimming in natural bodies of warm fresh water, such as ponds, lakes, and hot springs, but other sources have included tap water from geothermal sources and contaminated and poorly chlorinated swimming pools. In the United States, infection occurs primarily in the summer and usually affects children and young adults. The trophozoites of the parasite invade the brain directly from the nose along the olfactory nerves via the cribriform plate. Acanthamoeba species are distributed worldwide and are found in soil; dust; cooling towers of electric and nuclear power plants; heating, ventilating, and air conditioning units; fresh and brackish water; whirlpool baths; and physiotherapy pools. The environ mental niche of B mandrillaris is not delineated clearly, although it has been isolated from soil. However, some patients infected with B mandrillaris have had no demonstrable underlying disease or defect. Central nervous system infection by both amebae probably occurs by inhalation or direct contact with contaminated soil or water. The primary foci of these infections most likely are skin or respiratory tract, followed by hematogenous spread to the brain. Acanthamoeba keratitis occurs primarily in people who wear contact lenses, although it also has been associated with corneal trauma. Poor con tact lens hygiene and/or disinfection practices as well as swimming with contact lenses are risk factors. The incubation period for Acanthamoeba keratitis also is unknown but thought to range from several days to several weeks. The organism also can be cultured on nonnutrient agar plates layered with Escherichia coli or on monolayers of E6 and human lung fbroblast cells. In infection with Acanthamoeba species and B mandrillaris, trophozoites and cysts can be visualized in sections of brain, lungs, and skin; in cases of Acanthamoeba keratitis, they also can be visualized in corneal scrapings and by confocal microscopy in vivo in the cornea. Computed tomography and magnetic resonance imaging scans of the head show single or multiple space-occupying, ring-enhancing lesions that can mimic brain abscesses, tumors, cerebro vascular accidents, or other diseases. Acanthamoeba species, but not Balamuthia species, can be cultured by the same method used for N fowleri. Although an effective treatment regimen for primary amebic meningoencephalitis has not been identifed, amphotericin B is the drug of choice, although treatment usually is unsuccessful, with only a few cases of com plete recovery having been documented. Two survivors recovered after treatment with amphotericin B in combination with an azole drug (either miconazole or fuconazole) plus rifampin, although rifampin probably had no additional effect; these patients also received dexamethasone to control cerebral edema. Although these 2 patients did not receive azithromycin, this drug has both in vitro and in vivo effcacy against Naegleria species and also may be tried as an adjunct to amphotericin B. Early diagnosis and insti tution of high-dose drug therapy is thought to be important for optimizing outcome. Effective treatment for infections caused by Acanthamoeba species and B mandrillaris has not been established. Voriconazole, miltefosine, and azithromycin also might be of some value in treating Acanthamoeba infections. Unlike with Acanthamoeba, voriconazole has virtually no effect on Balamuthia species in vitro. Early diagnosis and therapy are important for a good outcome (see Drugs for Parasitic Infections, p 848). Only avoidance of such water-related activities can prevent Naegleria infection, although the risk might be reduced by taking measures to limit water exposure through known routes of entry, such as getting water up the nose. To prevent Acanthamoeba keratitis, steps should be taken to avoid corneal trauma, such as the use of protective eyewear during high-risk activities, and contact lens users should maintain good contact lens hygiene and disinfection practices, use only sterile solutions as applicable, change lens cases frequently, and avoid swimming and showering while wearing contact lenses. Cutaneous anthrax begins as a pruritic papule or vesicle that enlarges and ulcerates in 1 to 2 days, with subsequent for mation of a central black eschar. The lesion itself characteristically is painless, with sur rounding edema, hyperemia, and painful regional lymphadenopathy. Inhalation anthrax is a frequently lethal form of the disease and is a medical emergency. A nonspecifc prodrome of fever, sweats, nonproductive cough, chest pain, headache, myalgia, malaise, and nausea and vomiting may occur initially, but illness progresses to the fulminant phase 2 to 5 days later. In some cases, the illness is biphasic with a period of improvement between prodromal symptoms and overwhelming illness. Fulminant manifestations include hypotension, dyspnea, hypoxia, cyanosis, and shock occurring as a result of hemorrhagic mediastinal lymphadenitis, hemorrhagic pneumonia, and hemorrhagic pleural effusions, bacteremia, and toxemia. Chest radiography also may show pleural effusions and/or infltrates, both of which may be hemorrhagic in nature. Gastrointestinal tract disease can present as 2 clinical syndromes—intestinal or oropharyngeal. Patients with the intestinal form have symptoms of nausea, anorexia, vomiting, and fever progressing to severe abdominal pain, massive ascites, hemateme sis, bloody diarrhea, and submucosal intestinal hemorrhage. Oropharyngeal anthrax also may have dysphagia with posterior oropharyngeal necrotic ulcers, which may be associated with marked, often unilateral neck swelling, regional adenopathy, fever, and sepsis. Hemorrhagic meningitis can result from hematogenous spread of the organism after acquiring any form of disease and may develop without any other apparent clini cal presentation. The case-fatality rate for patients with appropriately treated cutaneous anthrax usually is less than 1%, but for inhalation or gastrointestinal tract disease, mortal ity often exceeds 50% and approaches 100% for meningitis in the absence of antimicro bial therapy. B anthracis has 3 major virulence factors: an antiphagocytic capsule and 2 exotoxins, called lethal and edema toxins. The toxins are responsible for the signifcant morbidity and clinical manifestations of hemorrhage, edema, and necrosis. B anthracis spores can remain viable in the soil for decades, representing a potential source of infection for live stock or wildlife through ingestion. Natural infection of humans occurs through contact with infected ani mals or contaminated animal products, including carcasses, hides, hair, wool, meat, and bone meal. Outbreaks of gastrointestinal tract anthrax have occurred after ingestion of undercooked or raw meat from infected animals. Historically, the vast majority (more 1 Center for Infectious Disease Research and Policy, University of Minnesota. Anthrax: Current, comprehensive information on pathogenesis, microbiology, epidemiology, diagnosis, treatment, and prophylaxis. Severe disseminated anthrax following soft tissue infec tion among heroin users has been reported. The incidence of naturally occurring human anthrax decreased in the United States from an estimated 130 cases annually in the early 1900s to 0 to 2 cases per year by the end of the frst decade of the 21st century.
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