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The volume of gas at which the tendency of the A lungs to collapse (elastic recoil pressure) and the B tendency of the chest wall to expand are equal safe phenytoin 100mg section 8 medications. The volume of gas remaining in the lungs at the end D of a normal tidal exhalation E C buy phenytoin 100mg without prescription symptoms emphysema. Diminished protein C level ited due to her fatigue discount phenytoin 100 mg without a prescription symptoms als, and there is significant orthopnea order phenytoin 100mg line medications and breastfeeding. Diminished protein S level During her evaluation, laboratory analysis reveals: So- E. A chest is hospitalized about three times yearly for infectious ex- x-ray is interpreted as “poor inspiratory effort. A ventilation-perfu- nosa and Staphylococcus aureus, but has never had sion scan has normal perfusion. He remains active and is in tests will most likely identify the cause of this patient’s college studying architecture. Forced vital capacity (supine and upright) indication for referral for lung transplantation? A 42-year-old woman presents to the emergency room with acute onset of shortness of breath. A 52-year-old man presents with crushing sub-ster- cently had been to visit her parents out of state and rode nal chest pain. The vital signs dial leads, and he is taken emergently to the catheteriza- are: blood pressure 98/60 mmHg, heart rate 114 beats/ tion laboratory. After angioplasty and stent placement he min, respiratory rate 28 breaths/min, SaO2 92% on room is transferred to the coronary care unit. An lessness and states that he has difficulty walking to and arterial blood gas measurement shows a pH of 7. It is not worse at night, and he can identify no trig- ing of the uterus and confirms a pulmonary embolus. He has had no fevers, chills, or of the following agents can be used alone as initial ther- weight loss. He is a former apy in this patient except smoker of about 50 pack-years, but quit 8 years previ- ously after being diagnosed with coronary artery disease. Which of the following contacts with a patient infected 86% after ambulating 300 ft (91 m). The child of a parent with smear-negative, culture- halfway through both lung fields. A 32-year-old male is brought to the emergency de- partment after developing sudden-onset shortness of breath and chest pain while coughing. He reports a 3- month history of increasing dyspnea on exertion, non- productive cough, and anorexia with 15 lb of weight loss. A chest radiogram shows a right 80% pneumo- thorax, and there are nodular infiltrates in the left base that spare the costophrenic angle. Intravenous α1 antitrypsin that stains positive with periodic acid–Schiff stain B. He states that he first noticed the symp- foci and honeycombing toms about 3 years ago. A 68-year-old woman has been receiving mechani- was still able to complete a full 18 holes. His symptoms began 2 years ago and are character- is appropriate for a spontaneous breathing trial. Which of ized by an episodic cough and wheezing that responded the following factors would indicate that the patient is initially to inhaled bronchodilators and inhaled cortico- not likely to be successfully extubated? Physical examination is notable tidal volume) >105 for mild diffuse polyphonic expiratory wheezing but no E. Exercise physiology testing recalls having an upper respiratory tract infection prior B. Skin testing for allergies solved, he states that “the cold moved to my chest” about E. A 46-year-old man is brought to your office by his but these are less frequent now. He is reluctant to admit that he has any health prob- been coughing that awakens him from sleep at night and lems. His wife, on the other hand, is adamant that some- ultimately has resulted in progressive fatigue. Specific triggers for his cough include eating frequently sleepy at work and falls asleep while watching cold foods, especially ice cream. He has no history of television at night, but he attributes this to stress on the asthma or prior history of prolonged cough. She describes loud snoring at night that begins almost symptoms of gastroesophageal reflux disease. He breathes immediately when he falls asleep, punctuated by long peri- easily through his nose and does not have seasonal rhi- ods of no breathing at all. He does not recall his vaccination history, normal oropharynx and has a short, squat neck. His lung but thinks he has not had any vaccinations since gradu- sounds are clear, and he has a protuberant, obese abdo- ating from high school. He is 190 cm amination, the patient’s wife demands to know what is tall and weighs 95. What are the piratory rate of 14 breaths/min, heart rate of 64 beats/ next steps in diagnosis and treatment? He and his wife should be reassured that his symp- nose, and throat examination reveals no enlargement of toms will improve as his work stress lessens. He should be prescribed a therapeutic trial of No forced expiratory wheezes are present. Which test is most likely to establish the diagno- plaint of cough and dyspnea on exertion that has gradu- sis correctly? Before 3 months ago the patient had no limita- systemic lupus erythematosus except tion of exercise tolerance, but now she reports that she A. A 68-year-old man presents to the emergency room has scattered rhonchi and faint expiratory wheezes bilat- with fever and productive cough. There is associated left-sided pleuritic chest chiectasis to explain his recurrent infections. Positive Gram stain or culture of the pleural fluid chiectasis in a patient with this history. A 45-year-old female is seen in the clinic for evalua- the following is the most common cause of mortality? She reports a cough that began in her early twenties that is occasionally productive of yel- A.

Diseases

• Reactive airway disease
• Restrictive cardiomyopathy
• Scott syndrome
• Chromosome 2, monosomy 2q24
• Young Hugues syndrome
• Thrombocytopenia cerebellar hypoplasia short stature
• Myofibrillar lysis
• Genital dwarfism
• Oculocutaneous albinism, tyrosinase positive

Digital Images Digital images are characterized by two quantities: matrix size and pixel depth purchase phenytoin 100mg otc medicine for bronchitis. The computer memory approximates the area of the detector in a gamma camera as a square matrix of a definite size that can range from 32 × 32 to 1024 × 1024 with 1024 (1K) to 1 buy phenytoin 100 mg low cost symptoms juvenile rheumatoid arthritis,048 buy phenytoin 100mg overnight delivery medicine river animal hospital,576 (1M) picture elements cheap 100mg phenytoin amex symptoms zoloft dose too high, called pixels, respectively. How many counts can be stored in a pixel depends on the depth of the pixel, which is represented by a byte or a word. Thus, a 1-byte pixel could record up to 28, or 256, events, whereas a 1-word pixel could store up to 216,or 65,536, events. The pixel size, which depends on the choice of the matrix size for a study, is an important factor that affects the spatial resolution of a digital image. Often, a zoom factor is applied during data acquisition to improve spatial resolution because it reduces the pixel size. The use of a zoom factor of, say, 2, reduces the pixel size by half, improving the spatial resolution, but counts per pixel are reduced thus increasing the noise on the image (see later). The choice of pixel size and zoom factor is limited by the spatial resolu- tion of the imaging device, particularly in tomographic systems. If the expected system resolution is 18mm, then the pixel size in the matrix should be less than 6mm. However, as mentioned before, the counts in each pixel would be reduced by 1/4, as the total counts are distributed over four times the pixels, compared to a 64 × 64 matrix. Thus the noise increases in the image and so the signal-to-noise ratio decreases causing degradation in image contrast. In both modes, a technique of magnification or zooming can be applied, whereby the pixel size is decreased by a zoom factor. Data acquisition in the frame mode is the most common practice in nuclear medicine and widely used in static, gated, dynamic, and single Application of Computers in Nuclear Medicine 145 A B Fig. In this mode, a matrix is chosen that approximates the entire area of the detector so that a position (X, Y) in the detector corresponds to a pixel position in the matrix. Digitized signals (X, Y) are stored in the corresponding (X, Y) posi- tions (pixel) of the matrix of choice in the computer. In this mode, one must specify the size and depth of the matrix, the number of frames per study, and the time of collection of data per frame or total counts to be collected. In the list mode, digitized X- and Y-signals are coded with “time marks” as they are received in sequence in time, and are stored as individual events in the order they occur (Fig. After the data acquisition is completed, the data can be sorted to form images in a variety of ways to suit a specific need. Data can be manipulated by changing the matrix size and the time of acquisition per frame. Since the data are listed sequentially without overlapping each other, the bad signals from an arrhythmic cardiac cycle can be discarded, as found appropriate, in the 146 11. Although the list mode acquisition provides wide flexibility, its major disadvantages are larger memory space and longer processing time required and unavailability of images during or immedi- ately after the completion of the study. Static Study A static study is the collection of data in one view of a region of interest in an object for a preset time or preset total counts. Data are acquired in the frame mode, and normally the matrix size is specified prior to starting the study. The choice of a matrix size depends on the field of view of the imaging system and the pixel size to give desired image resolution. For all practical purposes, a pixel size of 2 to 3mm is considered appropriate for good image resolution. Because of the high count densities in static views, data acquisition in byte mode may overflow in individual pixels and, therefore, the word mode is usually employed. Digital images essentially represent the count density in regions of inter- est in an object. It depends on how small a region in an image is to be identified and its appar- ent contrast with the surrounding background. Large and high-contrast objects are easily detectable at low count densities, whereas small and low- contrast objects are difficult to delineate from the statistical noise. Dynamic Study In dynamic studies, a series of images are collected and each image (frame) is acquired over a certain period of time selected by the operator. While the patient’s position cannot be changed during the image acquisition, the matrix size and the frame rate (time of acquisition) can be changed. The acquisition of image data is buffered such that while one frame is being collected, the previous frame is stored in the external storage device (e. The choice of frame rate for a given study depends on the kinetics of the radiotracer through the organ of interest. The common matrix size used in dynamic studies is 64 × 64 or 128 × 128, although some loss of spatial resolution is expected with these matrices. Since counts collected per frame are low in number, the data are collected in byte mode, which obviates the need for a large memory space, and normally does not allow pixel counts to exceed 255 with little chance of counts overflow. Application of Computers in Nuclear Medicine 147 Gated Study The gated study was introduced in the mid-1970s to determine the ejection fraction of the heart by acquiring two images, one at end diastole and the other at end systole. The normal heart beat is about 1 beat/second, and the R-R interval is therefore about 1 second, i. First, the R-R interval is divided into several segments or frames (16–32 segments) depending on the number of frames one chooses to obtain. For example, with a choice of 20 frames in the R-R interval, each frame will be 50msec long. In actual data collection, first the counts are acquired in frame 1 for 50msec, followed by the collection of counts in frame 2 for another 50msec, and so on. After completion of counting in all 20 frames, a new R-wave is detected, and the above sequence of counting continues until sufficient counts have been accumulated in each frame. Assuming a count rate of 10,000 to 20,000 counts/s in a typical cardiac study, each 50msec frame would accumulate counts of the order of 500 to 1000. If the heart beat is irregular such as in cardiac arrhythmia, the R-R interval is suf- ficiently altered and the data become corrupted from R-wave to R-wave. Using the list mode acquisition, bad heart beat data can be sorted out and rejected in postacquisition reformatting. Reconstruction of Images In planar imaging, the acquired data are displayed in a two-dimensional images without further processing. In tomographic imaging, data are acquired in different angular projections around the patient. The data of each projection are processed further using the methods described in Chapter 12 to reconstruct the images at different depths of the patient’s organ in 3-D directions. Superimposition and Subtraction of Images It has been a common practice to superimpose image data from one modal- ity onto another for better interpretation of the images. Another important utility of the computer is the subtraction of back- ground activity from an image or one set of images from another set.

Smith’s translation is ambiguous on this point: ‘Rather buy 100 mg phenytoin mastercard symptoms 7dpo, one must consider that the whole nature (physis) is responsible (aitios) [for what usually occurs for each] discount phenytoin 100 mg with mastercard treatment research institute. A second possible interpretation is that ‘the whole nature’ refers to the sum of natural factors that play a part in the production by a certain substance of a certain dietetic effect with a certain patient buy phenytoin 100 mg amex medicine to stop runny nose. Indeed order phenytoin 100mg fast delivery symptoms 0f parkinsons disease, a number of such factors are mentioned by Galen in the pages following on the Diocles fragment: not only the ‘peculiar essence’ (o«ke©a oÉs©a) of the substance itself, but also climate, geographical area, season, a patient’s natural constitution, his way of life (t‡ –pithdeÅmata), his age, particular characteristics of the stomach and the intestines determine the effect a foodstuff produces in a particular case. A third interpretation of ‘the whole nature’ has been proposed by Jaeger, who argued that the nature of the consuming organism is meant, that is, the constitution of its body, its age, and so on. It therefore seems best to interpret the words ‘the whole nature’ as referring to the nature of the foodstuff. In section 8 Diocles criticises a third claim, which is, like the first, pre- sented as a view which is actually being held by a certain group (‘those who believe... The claim seems to be that in every par- ticular case, one should state the cause why a thing (again we may think of a foodstuff) has a certain dietetic power. At first sight, this claim looks rather different from the ones discussed earlier, for what is at issue is not the identity or the kind of causes sought for but the search for causes itself. Moreover, there is a shift of attention from the universal (‘all’, p†nta in section 5) to the particular (‘each’, –fì —k†stou in section 8). His first argument seems rather obvious: for practical purposes, causal explanation is not often ‘necessary’. For instance, when we know that a certain foodstuff is profitable for people 16 Galen, De alim. His second objection is that a causal explanation of a substance’s having a certain power is in many cases not possible. As for the words ‘many of the things that are’, poll‡ tän Àntwn, it seems that we have to think not only of things or separate entities (e. It is not clear from the text whether by ‘starting-points’ Diocles means fundamental physical states of affairs or logical postulates that should be accepted as valid without further demonstration, comparable to the logical postulates discussed by Aristotle in Metaphysics ,19 but perhaps this is not relevant to the point he wants to make: ‘honey is laxative’ (to mention just an imaginary example) is similar to a postulate like ‘a statement p and its negation not-p cannot both be true at the same time under the same conditions’ in that it does not admit of demonstration. Whereas a real principle like a logical postulate is undemonstrable without qualification (‰pläv, one is tempted to say), foodstuffs and their effects are so only ‘in some way’ (tr»pon tin†). These are usually translated in an Aristotelian-like way by ‘naturally’, ‘by nature’, or ‘normally’, suggesting as Diocles’ intention that it is in the 18 Cf. Diocles of Carystus on the method of dietetics 83 nature of things that many things look like, or are taken as, principles. Yet if we connect the use of the word phusis here with that in section 7 above, a more comprehensible view emerges: phusis again refers to the nature of the substance in question, for example the foodstuff, and kat‡ fÅsin means ‘according to their nature’, ‘in virtue of their nature’. In section 7 the ‘whole nature’ was said to be the cause of the effect the foodstuff normally produces; thus it is relatively easy to understand the statement that in virtue of their nature these foodstuffs and their producing such-and-such an effect are like principles. For the purpose of clarity, let me paraphrase what I think Diocles’ line of thought in this whole fragment amounts to. A foodstuff has its effect due not to one of its particular qualities but to its nature as a whole; as soon as we descend to a level that is lower (e. To be sure, we might be able to explain why honey is sweet (which is, after 21 Jaeger: ‘von Natur’; Torraca: ‘secondo natura’. Kullmann takes kat‡ fÅsin as belonging to ˆrca±v: ‘Viele Gegebenheiten gleichen in gewisser Weise bestimmten naturgemaßen Prinzipien, so daß sie¨ keine Darlegung uber die Ursache zulassen’ (¨ 1974, 351) and he comments on p. Smith’stranslation(‘manythingsareinsomefashionlikefirstprinciplesinnature’) is not explicit on this point, like Frede’s paraphrase: ‘He also maintained that we should treat many facts of nature as primitive, rather than try to explain them in terms of some questionable theory which would serve no further purpose’ (‘Introduction’, 1985, xxii). Bertier’s paraphrase goes too far beyond what is in the text: ‘Apport insignifiant des theories explicatives, dans la mesure ou les realites´ ` ´ ´ contiennent en elles-memes le reflet de leurs principes, et oulˆ ` atheorie n’est qu’une repetition de´ ´ ´ la description du fait’ (1972, 32). Gottschalk (private correspondence) understands the whole sentence as follows: ‘(a) archai, because they are archai, cannot be explained or demonstrated, and (b) any train of reasoning, even if it does not start from the most universal and ultimate archai, must start from something accepted as true for the purpose of that argument, a quasi-arche not subjected to further analysis or demonstration’, and he takes the words kat‡ fÅsin as expressing that ‘Our using such propositions [e. Peck in his 1928 Cambridge PhD thesis ‘Pseudo-Hippocrates Philosophus; or the development of philosophical and other theories as illustrated by the Hippocratic writings, with special reference to De victu and De prisca medicina’, pp. On the level of its nature and with regard to the effect it produces, a foodstuff ‘resembles’ (›oike) a genuine undemonstrable starting- point – although it is not a starting-point in the absolute sense: the words ‘in some way’ serve the purpose of qualifying the resemblance that exists between a genuine starting-point and a foodstuff which, from a certain point of view, behaves like a starting-point. To say it with some exaggeration (which goes beyond what is in the text): there is a causal ‘gap’ between the nature of a foodstuff as being causally responsible for certain dietetic effects on the one hand, and the nature of the foodstuff as being the result of a certain sum of elements or qualities. Since no subject of ‘make mistakes’ (diamart†nousin) is specified, it seems that he is still referring to the same group as in section 8 (but see below). These people, he says, miss the truth (note the similarity to the wording at the end of section 7), because their explanations are ill-founded. The third objection of ‘implausibility’ introduces the notion of persuasiveness of the doctor’s statements – an element which is also reflected in section 11 in the words ‘more reliable’ (pist»teron) and which is familiar from the Hippocratic writings. It is important to note the use of ‘rather’ (mŽllon), and to see to what exactly the habit of putting more trust in the results of long-term experience is said to be preferable: the ill-founded and undue 22 Cf. Diocles of Carystus on the method of dietetics 85 causal explanations of the groups mentioned in the above. While ‘those who believe that one should state a cause for all [things]’ (to±v p†ntwn o«om”noiv de±n l”gein a«t©an) clearly refers to the group criticised in section 8, it is less clear who are meant by the words ‘those who state causes in this way’ (to±v m•n oÔn oÌtwv a«tiologoÓsi). The most likely possibility is that it refers to those who are criticised in the sentence immediately preceding it, that is those who make mistakes because their causal explanations are ill-founded; but this is not quite compatible with section 9, where the lack of a change of subject suggests that Diocles’ additional criticism (‘in addition’, pr¼v d• toÅtoiv) still applies to the same group. Another possibility is that ‘those who state causes in this way’ are the ones criticised in the first part of the fragment (the champions of claims one and two), although it is a bit awkward to take the phrase ‘in this way’ (oÌtwv) as referring not to the ill-founded ‘stating the cause’ (l”gein tŸn a«t©an) mentioned just before but to what was discussed in section 7. Perhaps this difficulty becomes less urgent when we consider how the three claims Diocles criticises are interrelated. As I said, at first sight it seems that in his refutation of claim three in section 8, Diocles is arguing against a rather different group from the one which is his target in the earlier part of the fragment (claims one and two). Yet after reading the whole fragment, it is easy to see why he discusses these claims in the same context and in this order. The first claim is the weakest, in that it does not commit itself to the assumption of a causal nexus between quality and power; consequently, its empirical refutation is likewise easy. Subsequently, this empirical refutation is used by Diocles as an argument against the second claim, which is one of the possible implications of the first claim. Finally, this second claim can in its turn be seen as a possible instance of the third 26 See Smith (1979) 184. Bertier rightly concedes that Diocles does not reject causal explanation altogether (1972, 32). I cannot endorse Smith’s translation ‘But we must seek a cause for what we accept. It seems that Diocles is criticising views he believes to be erroneous rather than addressing distinct groups, each of which held one of the views in question. Thus we may understand why Diocles in section 10 syntactically presents the two groups as different, while at the same time marking a close connection between them (‘those who state causes in this way’, to±v m•n oÌtwv a«tiologoÓsi). Both claim one and claim two can easily be understood as manifestations or consequences of too strict an application of the quest for causes, which is what claim three amounts to. As for Diocles’ own position, if the above explanation of the words ‘the whole nature’ and ‘by nature’ is acceptable, both sections of the fragment are closely interrelated and rooted in a consistent conviction. The history of medicine was regarded as an ongoing process of exchange of ideas between members of the same ‘school’, of indiscriminate acceptance of the views of greater authorities (‘influence’) or of vigorous polemics against them.