By N. Ur-Gosh. William Carey University.
Nguyen B 400mg levitra plus amex beta blocker causes erectile dysfunction, Brandser E discount 400 mg levitra plus with mastercard impotence nasal spray, Rubin DA (2000) Pains, strains, and nance imaging. Skeletal Radiol 22: 325-328 fasciculations: lower extremity muscle disorders. Disler DG, McCauley TR, Wirth CR et al (1995) Detection of Imaging Clin N Am 8:391-408 knee hyaline cartilage defects using fat-suppressed three-di- 83. Khan KM, Bonar F, Desmond PM et al (1996) Patellar tendi- mensional spoiled gradient-echo MR imaging: comparison nosis (jumper’s knee) : findings at histopathologic examina- with standard MR imaging and correlation with arthroscopy. Gagliardi JA, Chung EM, Chandnani VP et al (1994) nificance of magnetic resonance imaging findings. Am J Detection and staging of chondromalacia patellae: relative ef- Sports Med 27:345-349 ficacies of conventional MR imaging, MR arthrography, and 85. Zeiss J, Saddemi SR, Ebraheim NA (1992) MR imaging of the CT arthrography. Am J Roentgoenol 163:629-636 quadriceps tendon: normal layered configuration and its im- 66. Recht MP, Kramer J, Marcelis S et al (1993) Abnormalities of portance in cases of tendon rupture. Am J Roentgoenol articular cartilage in the knee: analysis of available MR tech- 159:1031-1034 niques. Sonin AH, Pensy RA, Mulligan ME et al (2002) Grading ar- sonography in the assessment of synovial tissue of the knee ticular cartilage of the knee using fast spin-echo proton densi- joint in rheumatoid arthritis: a preliminary experience. Kramer J, Recht MP, Imhof H et al (1994) Postcontrast MR arthritis of the knee: value of gadopentetate dimeglumine-en- arthrography in assessment of cartilage lesions. De Smet AA, Norris MA, Yandow DR et al (1993) MR diag- lonodular synovitis and related lesions: the spectrum of imag- nosis of meniscal tears of the knee: importance of high signal ing findings. Am J Roentgoenol 172:191-197 in the meniscus that extends to the surface. Hayes CW, Brigido MKI, Jamadar DA, Propeck T (2000) 161:101-107 Mechanism-based pattern approach to classification of com- 71. Kaplan PA, Nelson NL, Garvin KL et al (1991) MR of the knee: plex injuries of the knee depicted at MR imaging. Radio the significance of high signal in the meniscus that does not Graphics 20:S121-S134 clearly extend to the surface. Amis AA (1991) Functional anatomy of the anterior cruciate postoperative meniscus: potential MR imaging signs. Wascher DC, Markolf KL, Shapiro MS, Finerman GA (1993) MR and arthrographic findings after arthroscopic repair. Direct in vitro measurement of forces in the cruciate liga- Radiology 180:517-522 ments. JBJS 75-A:377-386 the postoperative meniscus of the knee: a study comparing 94. Kaplan PA, Walker CW, Kilcoyne RF et al (1992) Occult frac- conventional arthrography, conventional MR imaging, MR ture patterns of the knee associated with anterior cruciate lig- arthrography with iodinated contrast material, and MR ament tears: assessment with MR imaging. Applegate GR, Flannigan BD, Tolin BS et al (1993) MR diag- fractures: association of fracture detection and marrow edema on nosis of recurrent tears in the knee: value of intraarticular con- MR images with mechanism of injury. Tung GA, Davis LM, Wiggins ME et al (1993) Tears of the an- lizing structures of the knee: functional anatomy and injuries terior cruciate ligament: primary and secondary signs at MR assessed with MR imaging. Schweitzer ME, Tran D, Deely DM, Hume EL (1995) Medial rim (Segond) fractures: MR imaging characteristics.
Meckel’s diverticulum is the most common anomaly of Also of clinical concern and treatable are the various problems the small intestine levitra plus 400 mg sale erectile dysfunction doctors in nj. It is the result of failure of the embryonic that may occur during descent of the testes into the scrotum discount levitra plus 400mg amex erectile dysfunction when cheating. Present in about 3% of the popu- the normal development of the male fetus, the testes will be in lation, a Meckel’s diverticulum consists of a pouch, approxi- scrotal position by the twenty-eighth week of gestation. Like the appendix, a Meckel’s diverticulum is prone to infec- tions; it may become inflamed, producing symptoms similar to Trauma to the Abdomen appendicitis. For this reason, it is usually removed as a precau- The rib cage, the omentum (see fig. The connection from the ileum of the small intestine to the However, puncture wounds, compression, and severe blows to outside sometimes is patent at the time of birth; this condition is the abdomen may result in serious abdominal injury. It permits the passage of fecal material through The large and dense liver, located in the upper right quad- the umbilicus and must be surgically corrected in a newborn. In pyloric stenosis, there is a narrowing of the liver is extremely serious because of the possibility of internal pyloric orifice of the stomach resulting from hypertrophy of the hemorrhage from such a vascular organ. This condition is more The spleen is another highly vascular organ that is fre- common in males than in females, and the symptoms usually ap- quently injured,especially from blunt abdominal trauma. The constricted opening interferes with the tured spleen causes severe internal hemorrhage and shock. Its Meckel’s diverticulum: from Johann Friedrich Meckel,German anatomist,1724–74 Hirschsprung’s disease: from Harold Hirschsprung, Danish physician, 1830–1916 Van De Graaff: Human IV. Surface and Regional © The McGraw−Hill Anatomy, Sixth Edition Anatomy Companies, 2001 Chapter 10 Surface and Regional Anatomy 337 prompt removal (splenectomy) is necessary to keep the patient in gastric juice. The spleen may also rupture sponta- stomach, including alcohol and aspirin, and hypersecretion of neously because of infectious diseases that cause it to hypertrophy. The danger of a ruptured pancreas is the flow of pancre- Enteritis, or inflammation of the intestinal mucosa, is atic juice into the peritoneal cavity, the subsequent digestive ac- frequently referred to as intestinal flu. Diarrhea is symptomatic of inflamma- blow to one side propagates through the kidney and may possibly tion, stress, and other body dysfunctions. In children, it is of rupture the renal pelvis or the proximal portion of the ureter. Trauma to the external genitalia of both males and females is a relatively common occurrence. The pendant position of the Shoulder and Upper Extremity penis and scrotum makes them vulnerable to compression forces. For example, if a construction worker were to slip and land astride a steel beam, his external genitalia would be compressed Developmental Conditions between the beam and his pubic bone. In this type of accident, Twenty-eight days after conception, a limb bud appears on the the penis (including the urethra) might split open, and one or upper lateral side of the embryo, which eventually becomes a both testes might be crushed. Three weeks later (7 weeks Trauma to the female genitalia usually results from sexual after conception) the shoulder and upper extremity are present abuse. Vaginal tearing and a displaced uterus are common in in the form of mesenchymal primordium of bone and muscle. The physical and mental consequences are gener- is during this crucial 3 weeks of development that malformations ally severe.
Shifting all of them to cell d falsely inflates both sensitivity and specificity discount levitra plus 400 mg free shipping medicare approved erectile dysfunction pump. If this potential problem is recognised before the study begins discount levitra plus 400 mg online erectile dysfunction pills review, investigators can design their reference standard to prevent such patients from falling into cell z. This is accomplished by moving to a more pragmatic study and adding another, prognostic dimension to the reference standard, namely the clinical course of patients with negative test results who receive no intervention for the target disorder. If patients who otherwise would end up in cell z develop the target disorder during this treatment-free follow up, they belong in cell c. The result is an unbiased and pragmatic estimate of sensitivity and specificity. Second, the reference standard may be lost; and third, it may generate an uninterpretable or indeterminate result. As before, arbitrarily analysing such patients as if they really did or did not have the target disorder will distort measures of diagnostic test accuracy. Once again, if these potential biases are identified in the planning stages they can be minimised, a pragmatic solution such as that proposed above for cell z considered, and clinically sensible rules established for shifting them to the definitive columns in a manner that confers the greatest benefit (in terms of treatment) and the least harm (in terms of labelling) to later patients. Fourth, fifth, and sixth, the diagnostic test result may be lost, never performed, or indeterminate, so that the patient winds up in cells w, x,or y. Here the only unforgivable action is to exclude such patients from the analysis of accuracy. As before, anticipation of these problems before the study begins should minimise tests that are lost or never performed to the point where they would not affect the study conclusion regardless of how they were classified. If indeterminate results are likely to be frequent, a decision can be made before the study begins as to whether they will be classified as positive or negative. Alternatively, if multilevel likelihood ratios are to be used, these patients can form their own stratum. In addition to the 6 threats to validity related to cells v–z, there are two more. The seventh threat to validity noted in the above critical appraisal guide arises when a patient’s reference standard is applied or interpreted by someone who already knows that patient’s diagnostic test result (and vice versa). This is a risk whenever there is any degree of interpretation (even in reading off a scale) involved in generating the result of the diagnostic test or reference standard. We know that these situations lead to biased inflations of sensitivity and specificity. When they can place the cut-point wherever they want, it is natural for them to select the point where it maximises sensitivity (for use as a SnNout), specificity (for use as a SpPin), or the total number of patients correctly classified in that particular “training” set. If the study were repeated in a second, independent “test” set of patients, employing that same cut-point, the diagnostic test would be found to function a little or a lot worse. Thus, the true accuracy of a promising diagnostic test is not known until it has been evaluated in one or more independent studies. The foregoing threats apply whether the diagnostic test comprises a single measurement of a single phenomenon or a multivariate combination of several phenomena. For example, Philip Wells and his colleagues determined the diagnostic accuracy of the combination of several items from the medical history, physical examination, and non-invasive testing in the diagnosis of deep vein thrombosis. Limits to the applicability of Phase III studies Introductory courses in epidemiology introduce the concept that predictive values change as we move back and forth between screening or primary care settings (with their low prevalence or pretest probability of the target disorder) to secondary and tertiary care (with their higher probability of the target disorder). This point is usually made by assuming that sensitivity and specificity remain constant across all settings. However, the mix (or spectrum) of patients also varies between these locations; for example, screening is applied to asymptomatic individuals with early disease, whereas tertiary care settings deal with patients with advanced or florid disease. No wonder, then, that sensitivity and specificity often vary between these settings.
This situation can be found in tumor infiltration of to reactive bone marrow stimulation discount 400 mg levitra plus with mastercard vascular erectile dysfunction treatment. The subtraction placed by non-neoplastic stimulated cheap levitra plus 400 mg with mastercard erectile dysfunction pills from india, bone marrow cells, of fat and water signal on opposed GRE sequences pro- which are necessary for the production of white blood vides a perfect background with low signal intensity to cells in chronic infection. Stäbler Imaging Diffuse Bone Marrow Abnormalities When there are diffuse abnormalities of the bone marrow signal in hematologic neoplasias and myeloproliferative diseases but no focal disease is present, a pathologic sig- nal intensity of the bone marrow can be overlooked. In this situation, a homogenous diffuse decrease of signal intensity over all vertebral bodies on T1-weighted spin- echo images results from a homogenous replacement of fat cells by cellular marrow or an accumulation of iron in the bone marrow in hemolytic disorders. In the presence of diffuse neoplastic bone marrow in- filtration or bone marrow stimulation, low homogenous SI on T1-weighted images is seen, in addition to increased SI on STIR-images. The percentage enhancement following Gadolinium injection is increased (Fig. On the STIR-image multiple metastasis are outlined with high signal intensity. The lo- cation of the metastasis, which is of risk for a neuro- logic complication by com- pressing the spinal cord, is easily recognized a b Fig. Diffuse neoplastic bone marrow infitration in a patient enhanced T1-weighted image (a). On unenhanced T1-weighted image a diffuse quency selective fat suppression creates a low intensity back- low SI is present in all vertebrae (a). Gadolinium enhancement is ground to highlight the enhancing metastasis (b) heavily increased indicating the diffuse tumor infiltration (b) Bone Marrow Disorders 79 Multiple Myeloma The “salt-and-pepper” pattern is characterized by an irregular bone marrow structure with irregular areas of Multiple myeloma is characterized by bone marrow infil- high and low signal intensity on T1-weighted spin-echo tration with neoplastic plasma cells. Hyperintense areas cretory and Bence Jones plasmacytoma, these cells pro- on T1-weighted spin-echo images represent focal fat de- duce monoclonal immunglobulins, recognizable in serum posits, whereas hypointense areas correlate with electrophoresis. The “salt-and-pepper” pattern correlates up to ten years in cases of smoldering myeloma. Bone marrow biopsy is essential for diagnosis of mul- When minimal plasma cell infiltration is present, this tiple myeloma and gives direct proof for atypical plasma is usually accompanied by a normal or even increased cells. Because of the small size of the biopsy sample, amount of marrow fat cells. In malignant tumors with dif- however, the result is not always representative of the en- fuse bone marrow infiltration, there is rapid displacement tire bone marrow, especially in cases of nodular involve- of fat cells by tumor cells. At the beginning of interstitial ment, in which the correlation of bone marrow biopsy tumor infiltration in multiple myeloma, monoclonal plas- and MRI is low. Laboratory parameters, such as serum- ma cells arrange themselves in such a way as to not dis- paraprotein, β2-microglobulin and the labeling index, are place the fat cells. Apparently, these cells produce factors indirect criteria, but correlate well with tumor mass and which inhibit normal hematopoesis, thus increasing the survival times. Therefore, despite tumor cell in- plasmacytoma, these parameters may be negative. When filtration and replacement of hematopoetic cells, bone “solitary” plasmacytoma is present, MR imaging can de- marrow fat may be normal or even increased without sig- tect or exclude additional marrow abnormalities. As long as there is no crit- ical shift in the water to fat ratio of the bone marrow, myeloma remains undetected in MR imaging. Differentiation of acute osteoporotic In diffuse plasma cell infiltration, no contrast to unin- and tumor-related vertebral fractures volved bone marrow is present. Patients with a diffuse infiltration pattern in multiple myeloma are generally in On T1- and T2-weighted spin echo as well as STIR im- stage II or III disease which is prognostically unfavor- ages and following contrast enhancement, acute benign able. Bone marrow edema as well as normal bone marrow by neoplastic plasma cells with or tumor infiltration exhibit hypointense signal on non-en- without trabecular destruction. Myelomatous foci in gen- hanced T1-weighted spin echo-images and increased eral show low signal intensity on T1-weighted spin-echo signal intensity on T2-weighted spin echo or STIR-im- images, but they can be isointense or hyperintense com- ages.