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Plain radiographs are usually diagnostic of fecal impaction (soft-tissue density in the rectum containing multiple small purchase zithromax 100 mg amex virus killing kids, irregular lucent areas reflecting pockets of gas in the fecal mass) cheap zithromax 500 mg otc antibiotics yellow urine. May cause pleating of the adja- cent mucosa (secondary fibrosis) or present as a constricting lesion simulating annular carcinoma purchase cheapest zithromax and zithromax antibiotics for sinus infection list. Often the characteristic coiled-spring are ileocolic without a specific leading point proven 250mg zithromax how quickly do antibiotics work for sinus infection. Colitis cystica profunda Multiple, irregular filling defects in the rectosig- Large submucosal, mucous epithelium–lined cysts moid. Nodular lymphoid Multiple tiny nodular filling defects evenly dis- Aggregates of lymphoid tissue that can simulate fa- hyperplasia tributed throughout the involved bowel. Characteris- tic fleck of barium in the center of each “polyp” (um- bilication at the apices of the lymphoid nodules). Lymphoid follicular pattern Multiple tiny nodular filling defects evenly dis- Normal finding in children. Can also occur secondary to obstructing carcinoma, cecal volvulus, ischemia, colonic ileus, benign colonic obstruction, and herpes zoster in- fection. Single collection of amyloid usually involves the rectum and simulates a neoplasm. Multiple rectal filling de- acteristic flecks of barium in the centers of several of the fects (arrows) simulate polyps. Usually re- verts to a normal radiographic appearance if good collateral circulation is established. Ulcerative colitis and Multiple symmetric contour defects simulating Crohn’s colitis thumbprinting. Usually involves the rectum in ulcerative colitis (rectal involvement is infrequent in ischemic colitis). Transverse linear ulcers, skip areas, and terminal ileal disease suggest Crohn’s colitis. Infectious colitis Rare manifestation of amebiasis, schistosomiasis, strongyloidiasis, salmonellosis, anisakiasis, and cy- tomegalovirus. Develops after a course of antibiotic therapy, with the thumbprinting reflecting marked thicken- ing of the bowel wall. Diverticulosis Accordion-like effect simulating thumbprinting that reflects accentuated haustral markings due to extensive muscular hypertrophy of the bowel wall. There are usually multiple diverticula and evidence of muscular thickening and spasm. Hereditary angioneurotic Thumbprinting pattern develops during acute at- edema tacks and reverts to a normal radiographic appear- ance once the acute episode subsides. Submucosal cellular infiltrate produces the radio- graphic pattern of thumbprinting. Polypoid masses indenting the barium column are composed of air rather than soft-tissue density. Ulceration, edematous and dis- torted folds, and other sites of colon involvement suggest Crohn’s disease. Difficult to distinguish from diverticulitis unless there is clear radiographic evidence of bowel inflammation. There is a short extralumi- nal track (arrow) along the antimesocolic border of the sig- moid colon. The mucosal fold pattern appears granular and ulcerated and multiple diver- ticula are apparent. Rarely, retrorectal abscess from diverticulitis, perforated appendix, malignant perforation, or infected devel- opmental cyst. Benign retrorectal tumor Smooth, extrinsic impression on the posterior Most commonly due to a developmental cyst (es- wall. It may be diffi- cult to distinguish a widened retrorectal space caused by radiation effects from that due to recur- rent tumor. Neurogenic tumor Anterior displacement of the rectum without Chordomas often cause expansion and destruction bowel wall invasion. Characteristic smooth nar- cm, the patient had no abnormality by clinical history, digital rowing of the rectum with widening of the retrorectal space. Primary and secondary malignancies cause bone destruction; an anterior sacral meningocele is as- sociated with an anomalous sacrum; and sacrococ- cygeal teratomas frequently contain calcification. Pelvic lipomatosis/ Narrowed rectum with an excessively lucent Massive deposition of fat in the pelvis. Colitis cystica profunda Multiple intraluminal filling defects in the Filling defects represent cystic dilatation of colonic rectum. Marked widening of the retrorectal space with narrowing of a long segment of the rectosigmoid. Widening of the retrorec- tal space is due to operative trauma altering the normal anatomic relations in the pelvis. Size of the gallbladder in the resting state is approximately twice normal after a truncal vagotomy. Seen in 20% of patients with diabetes and proba- bly reflects an autonomic neuropathy. In 30% to 50% of patients with cystic fibrosis, the gallbladder has multiple web-like trabeculations, and is filled with thick, tenacious, colorless bile and mucus. Multiple intercommunicating septa divide the gallbladder lumen of the gallbladder. Huge gall- bladder (arrows) injected by error at per- cutaneous hepatic cholangiography. The incidence of gallstones der (the level depends on the relation of the increases in several disease states (hemolytic ane- specific gravity of the stone to that of the sur- mias, cirrhosis, diabetes, Crohn’s disease, hyper- rounding bile). Infrequently, a gallstone coated by tenacious mucus adheres to the gallblad- der wall. Multiple radiolucent gallstones, many of which contain a central nidus of calcifi- cation. Most commonly, melanoma (occurs in approxi- mately 15% of patients with the disease but is rarely detectable radiographically). Eggs of Ascaris lumbricoides or Paragonimus wester- mani deposited in the gallbladder wall incite an intense inflammatory cell infiltration. Very rare condition in which there is deposition leukodystrophy of metachromatic sulfatides due to an enzyme deficiency. The collections of intramu- ral contrast material appear to parallel the opacified gallbladder lumen (arrows), from which they are separated by a lucent space representing the thickness of the mucosa and muscularis. May impact in the distal common duct and cause obstruction (smooth, sharply defined meniscus). Serial radiographs show the occurs after surgical manipulation or instrumenta- pseudocalculus disappearing as the sphincter tion of the common bile duct. If the patient is raised toward the upright position, the air bubbles rise (lighter than contrast-laden bile), while true calculi remain in a stationary position or fall with gravity. Typical linear filling defects and Fasciola hepatica (in pond water or watercress in when the worms are seen in profile. Hydatid cyst Round or irregular filling defect in a bile duct or If a liver cyst communicates with the biliary tree, (Echinococcus) a cyst cavity. Blood clot; right hepatic artery (extrinsic impres- sion); bile duct varices following extrahepatic obstruction of the portal vein. Multiple polypoid filling existing calculi, which are often seen in this defects in dilated intra- and extrahepatic bile condition. The filling defect in the left hepatic duct (curved arrow) prevents con- trast material filing of the left intrahepatic ducts. Note contrast material filling a large communicating cystic cavity in the liver parenchyma (white arrow). Klatskin tumors arising at the junction of the right and left hepatic ducts tend to grow slowly and metastasize late. Sclerosing cholangiocarcinomas aris- ing at the junction of the right and left hepatic ducts (arrow). Focal stricture in the distal common he- Extrinsic obstruction of the common bile duct (arrow) due to 53 patic duct (arrow). Almost always involves the extrahepatic sclerosing cholangitis is a rare condition that tends ducts; there may be progressive involvement to occur in patients with inflammatory bowel of the intrahepatic ducts. Acute pancreatitis Circumferential narrowing of the common bile Usually reversible when the acute inflammatory duct. Papillary stenosis Smooth narrowing of the terminal portion of the Controversial entity that is associated with chronic bile duct. Successfully treated by surgical relief of the obstruction at the choledochoduodenal junction. Parasitic infestation Relative obstruction usually due to an inflam- Clonorchis sinensis, Fasciola hepatica, Ascaris lumbri- matory stricture and stone formation. In Echinococcus infestation, daughter cysts shed into the bile ducts can cause obstruction at the ampullary level. Biliary atresia Obliteration of the ductal lumen (often segmen- Most common cause of persistent neonatal jaun- tal and irregular in distribution). Rather than a congenital defect, it probably develops postpartum as a complication of a chronic inflammatory process. Common duct that empties directly into a duodenal diverticulum may be obstructed by anatomic distortion, diverticulitis, or an enterolith in the sac.

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In essence buy discount zithromax 250 mg online virus scan for mac, the surgeon is simply excising a the subcuticular layer of the skin with interrupted sutures buy zithromax 100mg amex antimicrobial incise drape. At chronic granulomas surrounded by a fibrous capsule and cov- the conclusion of the procedure buy zithromax 500mg treatment for dogs eating poop, no subcutaneous fat is ered by a strip of skin containing the pits that constituted the visible in the wound buy zithromax 100 mg without prescription antimicrobial coatings. Healing of exposed subcutaneous fat original portal of entry of infection and hair into the abscess. Documentation Basics Coding for anorectal procedures is complex, and the com- plexity is multiplied when flap closure is elected. In general, it is important to document: • Findings • Primary closure or marsupialization? Operative Technique Although it is possible to excise the midline sinus pits and to evacuate the pus and hair through this incision under local anesthesia, often the abscess points in an area away from the Fig. Consequently, in most cases simply evac- uate the pus during the initial drainage procedure, and postpone subcuticular level of the skin to the lateral margin of the a definitive operation until the infection has subsided. Make a scalpel incision of Ideally, at the conclusion of this procedure, there is a sufficient size to evacuate the pus and necrotic material. In the rare situation where the pilonidal cyst wall is otherwise, simply insert loose gauze packing. We usually perform this operation Marsupialization with the patient in the prone position with the buttocks retracted laterally by adhesive straps under local anesthesia, First described by Buie in 1944, marsupialization begins by as Abramson advocated for his modification of the marsupi- inserting a probe or grooved director into the sinus. If the patient has a tract leading in a lateral direction, insert Pilonidal Excision with Primary Suture the probe into the lateral sinus and incise the skin over it. Now excise no more than 1–3 cm of the skin edges on each For pilonidal excision with primary suture, use regional, side to include the epithelium of all of the sinus pits along the general, or local field block anesthesia. This maneuver exposes a the prone position with a pillow under the hips and the legs narrow band of subcutaneous fat between the lateral margins slightly flexed. Achieve Apply adhesive strapping to each buttock and retract complete hemostasis by carefully electrocauterizing each each in a lateral direction by attaching the adhesive tape to bleeding point. Before scrubbing, in preparation for After unroofing the pilonidal cyst, remove all granula- the surgery, insert a sterile probe into the pilonidal sinus, tion tissue and hair, if present, using dry gauze, the back and gently explore the dimensions of the underlying cavity of a scalpel handle, or a large curet to wipe clean the pos- to confirm that it is not too large for excision and primary terior wall of the cyst (Fig. In properly selected patients, this requires excising a strip of skin no more than 1. Deepen the incision Excision of Sinus Pits with Lateral Drainage on each side of the pilonidal sinus (Fig. For Bascom’s (1980) modification of Lord and Millar’s Otherwise, the presence of blood prevents the accurate visu- (1965) operation, only the sinus pits (Fig. Remove the specimen and check for com- diameters as large as 5 mm, are simply cork borers whose plete hemostasis. If at some point during the opera- allel to the long axis of the pilonidal cavity. Make this inci- tion the pilonidal cyst has been opened inadvertently, irrigate sion about 1. Achieve complete hemostasis In the latter case, simply leave the wound open and insert with the electrocoagulator. In some cases it is possible to use a depilatory cream to achieve the same result. Following excision and primary suture, remove the gauze close together in the mid-gluteal cleft that individual exci- dressing on the second day and leave the wound exposed. In this case Bascom sim- Initiate daily showering especially after each bowel move- ply excised a narrow strip of skin encompassing all of the ment. In patients appears, open this area of the wound and administer appro- who have lateral extensions of their pilonidal disease, each priate antibiotics, treating the condition the same way you lateral sinus pit is excised. If the there was an ingrowth of dermal epithelium into the subcuta- infection is extensive, it is then necessary to lay open the neous fat, forming an epithelial tube resembling a thyroglos- entire incision. Also shave or apply a depilatory cream to the macaroni, and Bascom advised excising these epithelial area of the mid-gluteal cleft for the first two to three postop- tubes through the lateral incision. If the patient has undergone pit excision and lateral drain- age, postoperative care is limited to daily showers and Postoperative Care weekly observation by the surgeon to remove any hairs that may have invaded the wound. Bascom applied Monsel’s Following drainage of an acute pilonidal abscess, remove solution to granulation tissue. All of his patients have been the gauze packing the next day and have the patient shower operated in the ambulatory outpatient setting. Consequently, it appears that in most cases recurrence is caused by poor hygiene, permitting hair to drill its way into the skin of the mid-gluteal cleft, rather than by inadequate surgery. Some patients, especially those who have had a radical excision of pilonidal disease that leaves a large midline defect bounded by sacrococcygeal periosteum in its depths and subcutaneous fat around its perimeter, endure healing failure for a period as long as Fig. In some cases it is due to inadequate post- operative care in which the bridging of unhealed cavities has hair in the mid-gluteal cleft. Daily showering with special taken place or in which loose hair has found its way into the attention to cleaning this area should prevent recurrence. Occasionally, even when postoperative care is conscientious in these patients, there is protracted healing of the residual wound. Further Reading Hemorrhage is easily preventable by meticulous electro- coagulation of each bleeding point in the operating room. A simple marsupialization technique for treatment of pilonidal sinus; long-term follow-up. Comparison of Limberg results of the Karydakis flap versus the Limberg flap for treating flap and tension-free primary closure during pilonidal sinus surgery. Pilonidal disease: origin from follicles of hairs and results of Sinusectomy for primary pilonidal sinus: less is more. Leon Pachter The hepatobiliary system is a core component of general but this is not the dominant symptom. This chapter introduces the most common disorders that, while obstruction of the cystic duct is present, infection of the biliary tract and liver and provides the concepts is not. Bowel rest, intravenous fluids, and pain control are the treat- ment; cholecystectomy should be performed to prevent future symptoms. Biliary Surgery In cholecystitis, the offending gallstone is lodged in the cystic duct, and stasis of bile within the gallbladder allows Bile and associated products produced in the liver drain for bacterial proliferation and infection. These patients will through the biliary tree into the duodenum, with the gallblad- present with complaints similar to biliary colic; however der serving as a storage area off the main trunk. Disorders the pain of cholecystitis is persistent and lasts 1–2 days along this system are extremely common and can usually be if untreated. However, advanced management of present due to the infection and inflammation of the gall- the biliary system requires a clear understanding of the anat- bladder. A classic Murphy’s sign describes the focal gall- omy and physiology involved in order to have a successful bladder tenderness that is elicited when, upon taking a deep outcome. Importantly, liver function Cholelithiasis is extremely common, is most frequently tests should be entirely normal, except for in rare cases of asymptomatic, and is not in itself an indication for surgery Mirizzi syndrome where a large stone impacted in the gall- (Muhrbeck and Ahlberg 1995). The treatment of cholecystitis consists of should be evaluated for cholecystectomy since recurrent antibiotics, bowel rest with intravenous hydration, pain con- episodes tend to occur. In biliary colic, gallstones intermittently obstruct the cys- In the past, delayed cholecystectomy was advocated as tic duct, causing pain that lasts 4–6 h and is usually self- safer than cholecystectomy performed during the acute limited. Many times this finding is performed, they are not optimal for evaluating the gallblad- nonspecific and no cholecystitis is present, as previously der for two reasons. In a septic patient with multi- scans are often too sensitive for nonspecific findings such as ple comorbidities when the gallbladder cannot be definitively gallbladder wall thickening or pericholecystic fluid, which ruled out as a source of infection, ultrasound-guided percuta- are not necessarily indicative of acute cholecystitis. This both relieves Cholecystitis During Pregnancy cholecystitis if present, and spares the patient the physiologic Cholecystitis is common during pregnancy and is the second insult of surgery if the source of infection lies elsewhere. The natural hesitancy of cli- tion typically seen in severely ill patients on vasopressor sup- nicians to image and treat a pregnant patient can lead to a port. This condition is thought to develop from hypotension delay in diagnosis and intervention. This delay can be more and ischemic end-organ injury and can result in necrosis of harmful to the mother and fetus than the cholecystitis itself. Once tissue necrosis has set If possible, patients should be treated with bowel rest and in, simple cholecystostomy tube placement will not amelio- intravenous antibiotics so that the pregnancy can be brought rate the condition; cholecystectomy is needed to debride the to term. However if cholecystectomy is necessary during necrotic infected tissue (Fagan et al. The vast majority of cholecystectomies can be performed Cholecystitis in the Hospitalized Patient laparoscopically. As surgeons have become more facile at The surgeon is often asked to consult on the possibility of managing difficult cholecystectomies laparoscopically, the cholecystitis as the source of infection in hospitalized patients only absolute indications that remain for conversion to open with a fever of unknown origin. This suspicion may be cholecystectomy are brisk hemorrhage and an inability to 76 Concepts in Hepatobiliary Surgery 693 clarify biliary anatomy. In these cases, prompt conversion to open cholecystectomy should not be considered a techni- cal failure, but a demonstration of sound clinical judgment. Any surgeon operating on the biliary tract must be confident with the technique for open cholecystectomy, as described in subsequent chapters. During cholecystectomy some surgeons use intraoperative cholangiography on a selective basis and others advocate for its routine use. Preoperative indications for cholangiography include jaundice or hyperbilirubinemia, gallstone pancreati- tis, or the presence of biliary dilatation. If these indications are not present, and the intraoperative anatomy is straightfor- ward, no cholangiogram is performed. Routine The most feared complication of cholecystectomy is that cholangiography adds only 10 min to the procedure in expe- of iatrogenic injury to the common bile duct (Fig.

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Low-attenuation nidus within an area of thickened cortical bone in the lesser trochanter of the right femur zithromax 500 mg on-line bacterial 16s sequencing. In this aggressive form generic zithromax 100mg amex antibiotics for uti cefdinir, focal areas of bone formation within the lesion and invasion of the cortex simulate a malignant process purchase zithromax with amex antibiotics for acne rash. Chondromyxoid fibroma Eccentric metaphyseal lesion with well-defined Most commonly involves the knee and distal tibia order zithromax 250 mg without prescription antibiotic resistance patterns. There is continuity of the cor- tex, which extends without interruption from the osteochondroma into the tibia. The central area of lucency, devoid of calcifications, was worrisome for malignancy, but a biopsy demonstrated the benign nature of the lesion. Well-defined lesion in the distal has well-defined sclerotic margins with no tibial epiphysis with calcifications. Aneursymal bone cyst Well-defined expansile, eccentric lesion of fluid More than half occur in the long bones; up to 30% (Fig B 35-8) attenuation. Single lesion (monostotic) generally involve the (Fig B 35-9) Lesions with greater fibrous content may show femur, tibia, ribs, and skull base. Multiple lesions a low-attenuation matrix with an amorphous (polyostotic) usually affect one side of the skeleton. Giant cell tumor Metaphyseal lesion of low attenuation with no Typically occurs around the knee (distal femur or (Fig B 35-10) calcified matrix. Coronal image of metaphyseal lesion with scalloped sclerotic the anterior portion of the talus demonstrates margins. Coronal image shows a lytic lesion without sclerotic margins in the subchondral region of the proximal tibia. Image through the shoulder joint shows high-attenuation areas of sclerosis in the humeral head and scapula (arrows). Adamantinoma Eccentric, expansile lesion that occurs primarily The cortical and soft-tissue involvement are best in the tibia. Bone infarct Central coarse calcifications in medullary le- Unlike enchondroma, there is no evidence of endo- (Fig B 35-12) sions, typically about the knee. Intraosseous ganglion Area of low attenuation rimmed by a zone of Common finding with a predilection for the articu- (Fig B 35-13) reactive sclerosis. The appearance is similar to that of a degenerative cyst, but in most cases there are no degenerative changes in the adjacent joint. Distal femur lesion with central coarse calcification but no endosteal scallop- ing of the cortex. Eccentric oval lesion in the proximal tibia that has low attenuation and ramifications. Area of low attenuation that contains a central sequestrum (arrowhead) and has a sinus tract extending through the thickening cortex. Typically bleeding within the cyst produces heteroge- has an oval configuration with its long axis parallel neous signal intensities on both sequences. Coronal T1-weighted image shows the low signal intensity lesion (curved arrow) in the lateral aspect of the neck of the left femur. Osteochondroma Cartilaginous cap has low signal intensity on Common process that appears on plain radio- (Fig B 36-4) T1-weighted images and high signal intensity graphs as a bony projection with contiguous mar- on T2-weighted sequences. Enchondroma Lobulated lesion with low signal intensity on Most commonly an asymptomatic lesion involving (Fig B 36-5) T1-weighted images and high intensity on the fingers. Chondroblastoma Well-defined epiphyseal lesion with low signal Generally presents as chronic local pain in a patient (Fig B 36-6) intensity on T1-weighted images and variable under age 25. Extensive sharp margins and a sclerotic rim, with calcification surrounding edema is usually seen. Chondromyxoid fibroma Well-defined lesion with uniform low intensity Most commonly involves the metaphyses of the (Fig B 36-7) on T1-weighted images and high or interme- knee and distal tibia. T2-weighted image show- the low signal intensity of this proximal humeral ing the thin cartilaginous cap as a band of high lesion, indicating the bony matrix. The rim of high signal intensity (arrows), covered by a linear signal intensity adjacent to the posterolateral margin area of low signal representing perichondrium of the tumor reflects peritumoral edema. On plain radiographs, it appears as an eccentric metaphyseal lytic defect with scalloped sclerotic margins. Aneursymal bone cyst Well-defined lesion with high signal intensity on Plain radiographs show an eccentric lytic lesion (Fig B 36-8) T2-weighted sequences. An axial T2-weighted image shows a sharply marginated lesion of the left Fig B 36-7 humeral head that has a sclerotic border and central Chondromyxoid fibroma. Note the small amount of joint image, the lesion has uniform high signal intensity. Single lesion (monostotic) generally involves the (Fig B 36-9) The mass has low signal intensity on T1- femur, tibia, ribs, and skull base. Multiple lesions weighted images and intermediate signal inten- (polyostotic) usually affect one side of the skeleton. Giant cell tumor Low intensity lesion on T1-weighted images Typically occurs around the knee (distal femur or (Fig B 36-10) that has intermediate signal on T2-weighted proximal tibia) in a subchondral location following sequences. On plain radiographs, the lytic weighted images reflects hemosiderin deposi- lesion has nonsclerotic margins. Langerhans cell Well-defined lesion with low signal intensity on Increased signal intensity on T1-weighted images histiocystosis T1-weighted images and high signal intensity is due to xanthomatous histiocytes. Coronal T1-weighted shows a lesion of the left inferior pubic ramus that image demonstrates expansion of the has high signal intensity. Note the multiple fluid-fluid 45 left femoral neck and abnormal signal levels characteristic of an aneurysmal bone cyst. On plain radiographs, an eccentric lytic area with (Fig B 36-12) sclerosis that generally involves the tibia. Brodie’s abscess Low intensity rim about a well-defined lesion This localized osseous infection demonstrates prom- (Fig B 36-13) that has low-to-intermediate signal on T1- inent contrast enhancement. Bone island Low signal intensity on both T1- and T2- Homogeneously dense, sclerotic focus in cancellous (Fig B 36-14) weighted images. This expansile lesion of the tibia has the signal intensity of muscle on a sagittal T1-weighted image (A) and high signal intensity on an axial T2-weighted sequence (B). This coronal contrast T1- weighted image shows marked enhancement of an expansile lesion of the right femur. Axial T2-weighted image shows a low- T1-weighted image demonstrates rim intensity lesion with irregular margins (arrow) in the enhancement about this lesion in the right femoral head. Chondrosarcoma Irregular mass with low signal intensity on May arise de novo in bone or develop secondarily (Fig B 37-2) T1-weighted images and intermediate-to-high in an osteochondroma or enchondroma. Ewing’s sarcoma In lytic permeative lesions, low signal intensity Primarily affects children under age 20. In addition (Fig B 37-3) on T1-weighted images and high signal inten- to local pain and swelling, there may be fever and sity on T2-weighted scans. Fibrosarcoma/Malignant Low signal intensity on T1-weighted images Uncommon malignancies that in almost a third of fibrous histiocytoma and high signal intensity on T2-weighted scans. Best modality for demonstrating extent of marrow involvement and soft-tissue extension. Patients (Fig B 37-5) intensity of T1-weighted images and high signal may present with local bone pain and constitu- intensity on T2-weighted scans. Characteristic multiple small lytic foci on plain radiographs, though a single expansile process with soft-tissue mass may occur. Axial contrast T1-weighted, fat-saturated image de- Malignant fibrous histiocytoma. Coronal T1- monstrates an enhancing mass that arises from the left iliac bone and weighted image shows the large humeral lesion produces extensive bone destruction and a large soft-tissue mass. Paget’s sarcoma Low signal intensity on T1-weighted images in Malignant degeneration (half osteosarcomas) (Fig B 37-7) areas of lucency on plain radiographs suggests occurs in up to 6% of patients and presents as in- malignant degeneration. Metastases Variable pattern depending on the characteris- Diffusion or chemical shift imaging may be of value (Fig B 37-8) tics of the lesion. Sclerotic metastases have in determining whether a compression fracture in decreased signal intensity on all sequences. Lytic lesions have decreased signal intensity on T1-weighted images and increased signal in- tensity on T2-weighted sequences. Axial T1-weighted image shows diffuse marrow changes and a large associated soft-tissue mass. Coronal T1-weighted image demonstrates both the bone destruction and the large soft-tissue mass. May have This most common soft-tissue mass consists of (Fig B 38-1) fibrous septa but no contrast enhancement. Ganglion cyst Well-defined mass with characteristics of a cyst This juxta-articular lesion most commonly occurs (Fig B 38-2) (uniform low signal intensity on T1-weighted in the wrist and hand. The appearance varies if there is hemorrhage or thick proteinaceous debris within the lesion, and the wall shows contrast enhancement. Hemangioma High signal intensity in characteristic serpigi- Cavernous hemangiomas are larger than capillary (Fig B 38-3) nous vessels on T2-weighted images. Coronal T1-weighted image shows a well-defined mass of fat signal intensity along the flexor tendons of the hand. Coronal fat-suppressed T2-weighted image demonstrates a lobulated lesion of the wrist. Coronal T2-weighted image shows deep and superficial hemangiomas in the distal thigh with markedly increased signal intensity in serpiginous vascular structures.

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This is probably the most important prophylactic measure as it eliminates all favourable conditions for growth and survival of tetanus bacilli zithromax 500mg with amex antibiotic 500g. Moreover it also acts on pyogenic organisms particularly gram-positive ones generic zithromax 100 mg mastercard antibiotics without food, whose presence helps germination and multiplication of Cl order 500mg zithromax fast delivery antibiotics for uti staph infection. Whenever one suspects that there is a chance of tetanus generic zithromax 250 mg overnight delivery bacteria with flagella list, injection penicillin should be given in large dose (10 lacs I. A single dose of long-acting depot penicillin like Penidural- 12 is sometimes used in different centres. Passive immunization with 4000 units of Humotet should be administered alongwith tetanus toxoid injection. It can be supplemented with Metronidazole to protect the lungs against respiratory infections. The most important features of surgical care are thorough cleansing and debridement. The wound should be left open till the patient has recovered from convulsing stage. Further treatment depends upon the severity of the case — In mild cases, where there is only tonic rigidity without any dysphagia or reflex spasm, the patient should be sedated with promazin (200 mg I. Suction through tracheostomy tube should be done now and then alongwith humidification. In very severe cases, who are having cyanotic convulsions, more care should be taken to maintain respiration, (a) A muscle relaxant should be given in the dose of 40 mg Tubocurarine I. Anaemia and exhaution which may be so severe due to repeated convulsions that the patient passes into coma and expires. Previously, anaphylactic reactions due to use of equine or bovine tetanus antitoxin led to death. Compression fracture of the vertebra, specially the thoracic vertebrae is more of a complication rather than cause of death. So two factors should play simultaneously — (i) entry of Clostridial organisms particularly Clostridium perfringens or Cl. Welchii and (ii) the conditions within the wound should be such that these organisms produce toxins and are able to multiply to cause gas gangrene. Production of gas gangrene is only possible when these organisms are able to multiply with a layer of toxin sufficiently concentrated to overcome the local defence of the tissue, (a) Injury to the tissue causes tissue breakdown with lowering of tissue resistance, (b) Presence of calcium is one of the determining factor and is derived from soil, blood clots etc. So the predisposing factors for producing gas gangrene are — (i) Haemorrhage and blood clot help infection especially by supplying calcium. As Clostridial organisms are present in human and animal faecal flora, contamination with manured soil provide enough Clostridium organisms to produce gas gangrene. Dirty splinters or fragments if contaminate the wound, chance of forming gas gangrene increases. Presence of aerobic bacilli in the wound utilise the oxygen in the tissues and create an atmosphere for growth of the anaerobes. These organisms are found in the stools and therefore buttock, perineum and thigh wounds are more often complicated by gas gangrene. Welchii are as follows — (a) Alpha toxin (lecithinase) is a haemolytic and also a lecithinase which splits lecithin to phosphocholine and diglyceride. The anaerobic Clostridium organisms can be divided into two groups — namely Saccharolytic and Proteolytic. The saccharolytic group of organisms grows on the sarcolemma and breaks down the muscle glycogen into carbondioxide, hydrogen and lactic acid. Excessive production of acid may stop the growth of the saccharolytic organism for the time being. At this stage the proteolytic group of organisms multiplies with liberation of proteinase and formation of aminoacid in the tissues. The aminoacid further breaks down into ammonia, sulphurated hydrogen (H S) and other2 noxious gases. The earliest pathological change is a rapidly spreading oedema of the subcutaneous tissue and muscle with accumulation of gas. The blood vessels are damaged with destruction of their endothelial cells, which helps the necrotic process to proceed further. The muscle gradually loses its striation and nuclei and passes through various stages of degeneration. It loses contractility and its normal healthy colour with crepitation due to presence of gas bubbles. Ultimately the muscle becomes soft, friable and green to black in colour due to the action of sulphurated hydrogen on iron liberated from broken down muscle haemoglobin. The gas is chiefly hydrogen and odourless in the beginning, but soon it becomes foetid due to the production of sulphurated hydrogen (H2S), ammonia and volatile gases by the action of proteolytic group of organisms. There may be local extension along fascial planes, but involvement of muscle is absent. Clostridium perfringens may be present but the predominant organisms are proteolytic and non-toxigenic Clostridia e. The spread of cellulitis may rarely be rapid and extensive requiring immediate radical surgical drainage. There may be rise of temperature which never becomes hectic, on the contrary in severe cases the temperature may be subnormal. The pulse is rapid and there is fall of blood pressure due to liberation of toxins which suppress the suprarenal gland. There is gradual swelling and gross oedema of the part, so much so that the stitches may give way. The most characteristic feature is profuse discharge of brownish and foul smelling fluid between the sutures. Crepitus is always present due to presence of gas in the muscle and subcutaneous tissue. The causative organisms will be shown as thick rectangular bacilli suggesting one of the organisms — Cl. Exudate is directly applied and anaerobic organisms show their growth in anaerobic cultures. Welchii are rapidly detected by direct plate culture of the exudate by Nagler reaction method. Welchii splits soluble lipoprotein complex of the human serum with the formation of an insoluble precipitate of lipoids and protein, producing an opacity in the culture medium. As this condition carries a considerable mortality rate, prophylaxis should be followed very rigidly. The margins of the wounds should be excised, (i) All devitalized tissues and blood clots should be removed, (ii) All dead and damaged muscles should be removed. Administration of high dose of penicillin about 2 grams 4 hourly is always necessary whenever a patient is admitted with a badly lacerated wound. Whenever the wound is in tension, it is better to leave open than to apply primary sutures under tension. This polyvalent serum is administered every 4 to 6 hours, if the disease becomes established. This should be followed by a booster dose 3 to 9 months after the previous immunization or at the time of the injury sustained by the person. Due to rapid spread of infection, a 24-hour delay in the treatment may prove fatal. Surgery : (a) As soon as the diagnosis is established multiple longitudinal incisions for decompression and drainage are urgently required. In case of group type, all the affected portions of the muscle should be removed, till the healthy muscles are reached, which is identified by their colour, contractility and bleeding capability. The principles of amputation are — (i) The tourniquet should always be avoided to minimise further circulatory damage to the living muscles and at the same time bleeding from the muscle can be seen to judge the viability of the various muscles. That means in case of affection of calf muscles, a mid thigh amputation should be performed. This should be supplemented by tetracycline 2 g daily or chloramphenicol 2 g daily or streptomycin 1 to 2 g daily. The limb is placed in the chamber of hyperbaric oxygen after the operation has been performed. In surgical practice extensive raw wound can result from many conditions, of which trauma and bum deserve special mention. If this raw wound is not grafted it scars easily with the blemishes and deformities. Then diluted cetavlon solution is used to clean the area with sponge-holding forceps. If present, they should be scraped off to expose a flat healthy granulation tissue as the bed for skin graft. The area is now dressed with sterile gauze and bandage, which will be opened only in the operation theatre. In this case as the distance is too much the flap from the abdominal wall is first transferred to the forearm and then from the forearm to the face. Now the wound is closed in such a manner that the V-shaped incision is turned into a Y-form. Smallest side of the triangle is extended by an incision, undermined and the skin flaps can be brought over the defect. It can be used where a linear scar has been excised leading to a linear skin loss. Two types can be used — thin grafts through the tips of the papillae (Thiersch graft) or thick grafts (Split-skin grafts).

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Viral infection Cytomegalovirus infection order generic zithromax from india virus 68 ny, which typically occurs (Figs C 48-8 and C 48-9) in immunocompromised individuals cheap 100mg zithromax with amex antibiotic qt prolongation, can cause thickening of the bronchovascular bundles and the “tree-in-bud” pattern cheap zithromax 100mg with mastercard antibiotics for uti without penicillin. In infants and young children order 500 mg zithromax with visa antimicrobial properties of garlic, this appearance may be due to bronchial wall thickening and dilatation related to respiratory syncytial virus. Thin-walled cavity in the left upper lobe (large ripheral centrilobular nodules and branching linear arrow) and “tree-in-bud” pattern in the right upper lobe (small opacities in a patient with acquired human immunod- arrows). Peripheral poorly defined glass opacities in addition to nodules and “tree-in-bud” centrilobular nodules and “tree-in-bud” opacities bilaterally in opacities in a patient with chronic myelogenous leuke- a patient with leukemia. Indirect signs of small airway disease include a mosaic pattern of lung attenuation and air trapping on expiratory scanning. Cystic fibrosis Abnormally low water content of airway mucus is (Fig C 48-11) at least partially responsible for decreased clearance of mucus, mucous plugging of small and large airways, and an increased incidence of bacterial airway infection. This woman with a history of asthma shows impaction of dilated large airways, producing the “finger-in-glove” sign (large arrows). There is also impaction of dilated small airways, producing the “tree-in-bud” pattern (small arrows). Airway damage can extend to the smaller airways, resulting in bronchiolectasis, centrilobular opacities (“tree-in-bud” pattern), and air trapping. Juvenile Bronchiolar involvement by neoplasms is un- laryngotracheobronchial common, but has been described with juvenile papillomatosis laryngotracheobronchial papillomatosis. Most frequently seen in adults, this condition is thought to be related to infection with the human papillo- mavirus. Papillomas may spread from the larynx to the bronchi and bronchioles and result in centrilo- bular nodules and the “tree-in-bud” appearance. Aspiration Aspiration of infected oral secretions or other (Fig C 48-13) irritant material can cause bronchiolar disease. In acute cases, extensive exudative bronchiolar disease may develop and result in a “tree-in-bud” pattern. Predisposing factors include structural abnormalities of the pharynx, esophageal disorders (achalasia, Zenker’s diverticulum, hiatal hernia and reflux, esophageal carcinoma), neuorologic defects, and chronic illness. Recurrent aspiration of foreign chiolar thickening with mucoid impaction and the “tree-in-bud” particles in a patient with achalasia. Note the air trapping in the left lower areas of increased attenuation with a characteristic “tree- lobe. The "tree-in-bud" pattern due to tumor emboli may be caused either by filling of the centrilobular arteries with tumor cells or by a rare thrombotic microangiopathy, in which widespread fibrocellular intimal hyperplasia of small pulmonary arteries (carcinomatous arteritis) is initiated by tumor microemboli. Patients with pulmonary tumor emboli present with progressive dyspnea, cough, and signs of hypoxia and pulmonary hypertension. Idiopathic Inflammatory lung disease of unclear etiology that Diffuse panbronchiolitis is prevalent in Asia and represents a transmural (Fig C 48-17) infiltration of lymphocytes and plasma cells, with mucus and neutrophils filling the lumen of affected bronchioles. In addition to the “tree-in-bud” pattern appearance, there may be nodules, bronchiectasis, or large cystic opacities accompanied by dilated proximal bronchi. Note the bron- nodules and branching lines with the “tree-in-bud” appearance (arrows), chial dilatation, bronchial wall thickening, and con- caused by tumor emboli from gastric adenocarcinoma. A common (Fig C 48-18) sequela of lung transplantation (representing chronic rejection) and bone marrow trans- plantation (in which it reflects chronic graft versus host disease), it also can result from collagen vascular disorders, inhalation of toxic fumes, and infection. Coned view at level of the left basal trunk bronchioles (large arrow) and the “tree-in-bud” pattern (small arrows). Atelectasis, lung scarring, and calcifi- abnormalities on plain radiographs, in whom it can cation often develop. Endobronchial dissemi- detect cavities, identify areas of bronchiectasis, and nation of infection from rupture of a tuberculous distinguish pleural from adjacent parenchymal cavity into the airway produces scattered ill- disease. Pneumocystis carinii Bilateral patchy consolidation or ground-glass Approximately 20% of patients have a more pneumonia (Fig C 49-4) pattern that often has a sharp demarcation reticular pattern of disease. Air bronchograms and accompa- formation anteriorly (arrow), and accompanying pleural effu- nying hilar lymphadenopathy. Initially, there may be a ground-glass pattern (homogeneous slight increase in lung attenuation without obscuration of underlying vessels) as a small amount of fluid tends to layer against the alveolar walls and is indistinguishable from alveolar wall thickening in interstitial disease. Char- More common in patients who are immuno- aspergillosis acteristic “halo sign” in which a zone of compromised as a result of chemotherapy for (Fig C 49-5) intermediate attenuation (hemorrhage and lymphoma or leukemia or undergoing immuno- coagulative necrosis) surrounds a central dense suppressive therapy for organ transplantation than fungal nodule. An “air-crescent” sign may develop late in the course of infection when the host’s immune function begins to recover. Other fungal infections Various patterns of cavitary pneumonia or Most frequently, Cryptococcus neoformans, which nodular disease. Diffuse, bilat- peribronchial and peribronchiolar distribution of the nodular eral ground-glass opacities with minimal peripheral sparing. Scan performed at the time of bone marrow recovery in a neutropenic chemotherapy patient shows a low-attenuation center that probably reflects early necrosis. The air-filled spaces near the lower border represent unin- volved emphysematous air spaces. Pulmonary Classically, a wedge-shaped peripheral opacifi- May produce multiple peripheral nodules. A thromboembolism cation abutting the pleura with its apex directed common and important finding is the presence of a (Fig C 49-7) toward the hilum. Although this indicates the vascular origin of the process, a similar appearance can be seen with septic emboli and metastases. Septic emboli Multiple peripheral nodules, often with an Result from infectious particles reaching the lung (Fig C 49-8) evident feeding vessel. Persons at risk include drug abusers, immunocompromised patients, and those with indwelling venous catheters or prosthetic heart valves. Two months after radiation ther- apy for tracheal carcinoma, localized air-space consolidation has developed in the right lower lobe. There is also intersti- tial disease that produces thickened intralobular septa cen- trally. There are multi- Fig C 49-8 ple rounded subpleural opacities, some of which Septic emboli. Alveolar proteinosis Bilateral, patchy, but usually symmetric air- Plain radiographs may be strikingly abnormal (Fig C 49-10) space disease. There may be superimposed interstitial thickening that resolves after bronchopulmonary lavage and thus probably represents edema and cellular debris rather than fibrosis. Can involve an entire segment or (Fig C 49-11) attenuation in the affected lobe is typically less lobe and even spread to the contralateral lung. Lipoid pneumonia Posterior or lower lobe opacifications that may Results from chronic aspiration or inhalation of (Fig C 49-12) have low attenuation (reflecting aspiration of petroleum-based compounds or animal or vege- lipid material). Pulmonary contusion Air-space consolidation that may be asso- Most common chest injury resulting from blunt (Fig C 49-14) ciated with rib or spine fractures, mediastinal or chest trauma. The shearing action on alveolar and chest wall hematoma, and pneumothorax or capillary walls results in focal collections of hemothorax. Pulmonary edema Ground-glass, low-grade lung opacification or Both cardiogenic and noncardiogenic edemas are re- (Fig C 49-15) frank air-space consolidation. There are accompanying hemothorax, rib fractures, subcutaneous emphysema, and pleural drain. Central “ground-glass,” low-grade lung opacification persists 3 weeks after myocardial in- farction. May occur in patients with bleeding diatheses, hemorrhage idiopathic pulmonary hemosiderosis, Good- (Fig C 49-18) pasture’s syndrome, polyarteritis nodosa, or Wege- ner’s granulomatosis. There is usually clearing 2 to 3 days after a single bleeding episode, though reticular changes may persist much longer. Widespread, patchy, and ge- ographic air-space filling in this patient with necrotizing vasculitis. Lymphoma Nodular or patchy air-space disease that some- Seeding of the lung may result in a pattern (Fig C 49-20) times contains air bronchograms. Multiple nodular opacities, some with well- defined and some with ill-defined margins. The major Fig C 49-19 differential diagnostic consideration is fungal infection in Metastases. Nodular/Reticulonodular Opacities on High-Resolution Computed Tomography Condition Imaging Findings Comments Pulmonary lymphangitic Smooth or nodular thickening of the peribron- Tumor growth in the lymphatic system of the lungs carcinomatosis chovascular interstitium and interlobular septa, occurs most commonly in patients with carcinomas (Fig C 50-1) with preservation of normal lung architecture at of the breast, lung, stomach, pancreas, prostate, the lobular level. Although some nodules (arrow) appear to be related to small vascular branches, most nodules lack a specific relationship to lobular struc- tures and appear to be random in distribution. Nodular thickening of the interlobular septa (curved arrows) and interlobar fissure (straight arrows). There may be extensive centrilobular enhanced pulmonary vessels appearing denser air-space nodules or diffuse small nodules than surrounding opacified lung). Of these, thickening, pleural effusions, and lymphad- pulmonary involvement occurs in about 20%. They may be numerous adjacent to the major fissures, in the costal and distributed throughout both lungs, or be more subpleural regions, within the interlobular localized to small areas in one or both lungs (often septa, and in the centrilobular regions. Inhalation disorders Multiple small nodules in a centrilobular and Primarily silicosis and coal-workers’ pneumoconio- (Fig C 50-6) subpleural location that are diffusely scattered sis. In mild disease, they thickened interlobular septa (as in pulmonary may be seen only in the upper lobes and have a lymphangitic carcinoma or sarcoidosis). Sub- pleural nodules (small arrows) are seen bordering the costal pleural surfaces and right major fissure. Clusters of subpleural granu- lomas (large arrows) have been termed pseudoplaques. Atypical (nontuberculous) Small or large nodules with areas of bron- The presence of small nodules in areas of lung mycobacterial infections chiectasis, or patchy unilateral or bilateral air- distant to the dominant focus of infection probably (Fig C 50-9) space consolidation. Typical appearance of numer- ous, diffuse, poorly defined nodules, some of which are perivascular and centrilobular. Numerous well-defined 1–2-mm nodules diffusely distributed through the right lower lobe.

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