BACKGROUND AND PURPOSE: To minimize diagnostic confusion, a CSF specimen should be free from traumatically introduced red blood cells (RBCs). The purpose of this research is to determine if patient age, sex, gauge of the lumbar puncture (LP) needle, or the level of LP is associated with an increased risk for traumatic fluoroscopy-guided LP.MATERIALS AND METHODS: Data were collected retrospectively for consecutive male and female patients of all ages (n = 756) who underwent a fluoroscopy-guided LP for a 2-year period, We defined traumatic LP as a CSF sample with an RBC count more than 500 cells/mm(3) without xanthochromia.RESULTS: Rate of traumatic LP was 13.3%. The rate of traumatic LP at the L4-L5 level (19%) was significantly higher than at the L2-L3 (9%) or L3-L4 level (10%). Patients older than 80 years had higher traumatic LP rates (25.9%) compared with patients between ages 11 and 80 years (12.4%). Sex and gauge of the spinal needle were not associated with increased rate of traumatic LP. Patients younger than 1 year had failed LP rate of 58.8% compared with 3.2% failure rate in older patients.CONCLUSIONS: Fluoroscopy-guided LP at the L4-L5 level is associated with nearly twice the risk for traumatic puncture compared with the L2-L3 or L3-L4 level. Rates of traumatic result are twice as high in adults older than 80 years compared with younger patients. Failure rates for fluoroscopy-guided LP are low except in children younger than 1 year, in whom failure occurs in most cases.

OBJECTIVE. The objective of our study was to evaluate the success rate for radiofrequency ablation of renal tumors and to determine the risk of serious complications.CONCLUSION. No serious complications occurred after 27 CT-guided radiofrequency ablation sessions in 22 patients. In total, no residual tumor was detected on follow-up contrast-enhanced CT or MRI 1-35 months (mean, 7 months) after final tumor ablation in 20 (91%) of 22 patients. Two patients with residual viable tumor deferred further treatment. Complete tumor ablation was achieved after a single treatment session in 83% of patients, and in 8% of patients after subsequent ablation sessions. Size was the major determinant for achieving tumor eradication with a single session of ablation, with all 11 tumors 3 cm or smaller being completely ablated after one session. Tumor location, histology, and the presence of renal disease did not correlate with treatment success. Contrast-enhanced CT performed immediately after ablation is reliable to exclude residual viable tumor. CT-guided radiofrequency ablation of renal tumors is safe and has a high rate of success in the treatment of small renal tumors, with no evidence of recurrence at midterm follow-up of treated patients.

The language of radiology is rich with descriptions of imaging findings, often metaphorical, which have found common usage in the day-to-day practice of genitourinary radiology. These "classic signs" give us confidence in our diagnosis. Some of the signs have become so familiar to us that they are referred to as an "Aunt Minnie." When the sign is invoked, or an Aunt Minnie is recognized, it often brings an impression of the image to mind, and it may have specific diagnostic and pathologic implications. The article uses classic signs accumulated from the literature to review a variety of pathologic conditions in the urinary tract.

Radiofrequency Ablation of Isolated Local Recurrence of Renal Cell Carcinoma After Radical NephrectomyCharles A. McLaughlin1, Michael Y. Chen1, Frank M. Torti2, M. Craig Hall3 and Ronald J. Zagoria1Audio Available | Share

Minimally invasive therapy in the urinary tract begins with renal access by means of percutaneous nephrostomy. Indications for percutaneous nephrostomy include urinary diversion, treatment of nephrolithiasis and complex urinary tract infections, ureteral intervention, and nephroscopy and ureteroscopy. Bleeding complications can be minimized by entering the kidney in a relatively avascular zone created by branching of the renal artery. The specific site of renal entry is dictated by the indication for access with consideration of the anatomic constraints. Successful percutaneous nephrostomy requires visualization of the collecting system for selection of an appropriate entry site. The definitive entry site is then selected; ideally, the entry site should be subcostal and lateral to the paraspinous musculature. Small-bore nephrostomy tracks can be created over a guide wire coiled in the renal pelvis. A large-diameter track may be necessary for percutaneous stone therapy, nephroscopy, or antegrade ureteroscopy. The most common extension of percutaneous nephrostomy is placement of a ureteral stent for treatment of obstruction. Transient hematuria occurs in virtually every patient after percutaneous nephrostomy, but severe bleeding that requires transfusion or intervention is uncommon. In patients with an obstructed urinary tract complicated by infection, extensive manipulations pose a risk of septic complications.

The recent increase in usage of ureteral stents in the management of a variety of urinary tract disease processes mandates familiarity with these devices, their consequences, and their potential complications, which at times can be devastating. Radiology plays an important role in the routine monitoring of stents and in the evaluation of these consequences and complications. It may also offer solutions for their correction. Stents should be monitored while in place, promptly removed when no longer needed, and changed periodically if chronically indwelling. Risk factors for complications should be minimized with high fluid intake, timely evaluation of clinical complaints, and aggressive treatment of documented infection. Certain patients may not be best served by indwelling stent placement, and urinary diversion by means of other mechanisms may be indicated. The implanting physician is responsible for informing the patient of the requirements, consequences, and complications associated with stent placement. Failure to do so has obvious management and potential medicolegal implications.

Mesenteric venous thrombosis is an uncommon but potentially lethal cause of bowel ischemia. Several imaging methods are available for diagnosis, each of which has advantages and disadvantages. Doppler ultrasonography allows direct evaluation of the mesenteric and portal veins, provides semiquantitative flow information, and allows Doppler waveform analysis of the visceral vessels; however, it is operator dependent and is often limited by overlying bowel gas. Conventional contrast material-enhanced computed tomography (CT) allows sensitive detection of venous thrombosis within the central large vessels of the portomesenteric circulation and any associated secondary findings; however, it is limited by respiratory misregistration, motion artifact, and substantially decreased longitudinal spatial resolution. Helical CT and CT angiography, especially when performed with multi-detector row scanners, and magnetic resonance (MR) imaging, particularly gadolinium-enhanced MR angiography, enable volumetric acquisitions in a single breath hold, eliminating motion artifact and suppressing respiratory misregistration. Helical CT angiography and three-dimensional gadolinium-enhanced MR angiography should be considered the primary diagnostic modalities for patients with a high clinical suspicion of mesenteric ischemia. Conventional angiography is reserved for equivocal cases at noninvasive imaging and is also used in conjunction with transcatheter therapeutic techniques in management of symptomatic portal and mesenteric venous thrombosis.

The aim of this study was to detrmine wheth er TR AIL is express ed in colorectal carcinomas (Ca).Section s of formal in-fixed and paraffin -embedded tissu e from 48 Ca were immunohistochemically stained for TRAIL using a commercially available monoclonal antibody, and standard imm unoperoxidase method.The percent of positive cell s was determined on a semi-quantitative sca le.TRAIL immunoreactivity was completely negat ive in 17 (35%), and detected in l -IO% of the cancer ce lls in 8 (17 %), 11-25% in 7 (15%), 26-50 % in 9 (19 %), 5 1-75% in 6 (12 %), and in > 75% of the cancer cells in I (2%) tumors.Fifteen (54%) of the 28 TR AIL-positive Ca and 2 (12%) of the 16 TRAIL-negative Ca were assoc iated with lymph node metastasis ( p =O.OI, Fisher ' s exact test) .Strong TRAIL immun oreactivity was always present in the surfac e epithel ial cells and cell s of the upper one third of the crypt in non-d ysplast ic colonic epithel ium , even in sections away from the tum or.In conclusio n, our data suggest that I) TRAIL may play a role in immun e evasion in co lorectal carcinoma, similar to that of Fas ligand, and 2) in the normal colon , TRAIL may play a role in physiol ogic apoptosis and turn over of epithel ial cells.

Radiologic evaluation of gastritis and duodenitis.D W Gelfand, D J Ott and M Y ChenAudio Available | Share

Tomography of the kidneys is a routine procedure performed during intravenous urography. Precisely locating the kidneys, however, can be difficult. This article describes a study performed to determine a simple and accurate measurement for kidney location as a guide to obtaining initial nephrotomographic sections. The authors measured the distance from the midplane of the kidney to the posterior skin line on abdominal CT images in 26 patients. This distance averaged one-third the thickness of the abdominal region. The best depth for the nephrotomographic cut was found to be one-third the thickness of the abdomen plus the thickness of any table pad.

Radiologic detection of colonic neoplasms: benefits of a systems-analysis approach.D W Gelfand, Y M Chen and D J OttAudio Available | Share

The oropharyngeal function study is a videotaped radiographic examination of the oropharynx and cervical esophagus used in patients who are at major risk for aspiration because of swallowing difficulty. Preceding the radiographic evaluation, the patient is assessed clinically by a swallowing therapist who attends the examination with the radiologist. Close cooperation between the therapist and radiologist better defines the specific swallowing problems, avoids inadvertent aspiration of large amounts of contrast material, and best directs proper management of the patient. We describe our cooperative approach to evaluating oropharyngeal dysphagia.

The relationship between radiological and manometric findings in esophageal motility disorders is poorly understood. Therefore, 20 subjects (4 normal; 13 diffuse spasm; 3 other motility disorders) were studied using synchronous manometry and videofluoroscopy with alternate 5-ml and 10-ml barium swallows. A total of 181 swallows were analyzed. Concordance between manometry and fluoroscopy was excellent for individual swallows (98%), groups of 5 swallows (97%), and final diagnoses (90%). Contraction onset intervals less than 0.8 s apart over 5 cm (velocity greater than 6.25 cm/s) were critical in determining abnormal bolus transit (98% sensitivity and positive predictive value). Radiologically, segmental tertiary activity (complete luminal obliteration) was always associated with disrupted primary peristalsis, but nonsegmental tertiary activity was often seen with normal bolus transit and did not have a specific manometric correlate. Four patterns of interrupted peristalsis radiologically were found--segmental tertiary contractions, a generalized esophageal contraction, absence of motor activity, or discoordinated "to-and-fro" movement. Surprisingly, nearly complete barium clearance occurred by the first two mechanisms in two thirds of swallows. Thus, the authors believe radiology and manometry are both excellent studies for identifying abnormal esophageal peristalsis. In difficult cases, these tests give complementary information because radiology assesses bolus movement while manometry provides quantitative pressure data.

Diffuse esophageal spasm (DES) is characterized by substernal chest pain, dysphagia, and a manometric pattern of frequent simultaneous contractions with intermittently normal peristalsis. The authors correlated the radiographic and manometric findings in 17 patients with DES to better clarify the role of radiography in the evaluation of this uncommon motility disorder. Incomplete or absent primary peristalsis was observed on radiographs in 13 patients (76%), and mild to severe tertiary activity was seen in 12 patients (71%). The mean estimated thickness of the esophageal wall in patients with DES was 2.6 mm compared with 2.5 mm in an age-matched control group of 17 patients with normal esophageal manometric findings (P greater than .05). The authors conclude that most patients with DES show abnormal esophageal motility on radiographs, although the findings were nonspecific and required clinical and manometric correlation. Esophageal wall thickness was normal in patients with DES and appears to be an overemphasized sign in differentiating DES from other esophageal motility disorders.

We analyzed the sensitivity of the barium enema examination in 128 patients with 191 endoscopically proven colonic polyps and 12 carcinomas, relative to patient age, indications, and the type of examination used. Seventy-seven patients (60%) had rectal bleeding, and 51 (40%) patients with 87 lesions, including six carcinomas, did not. Overall roentgenographic sensitivity was 88%, with a 93% detection rate in patients less than 70 years old as compared to 76% for older patients. Sensitivity of single- and double-contrast barium enema examination was 82% and 91%, respectively. There were similar detection rates for lesions 1 cm or more in size (91% vs 95% for single- and double-contrast examinations, respectively), but double-contrast examination was slightly better at detecting smaller polyps (88%, vs 70% for single-contrast examination). Compared to colonoscopy, which has an average reported false-negative rate of 12% in detecting neoplasms, the barium enema is similarly reliable, less costly, and safer.

The positive predictive value for a radiographic diagnosis of colonic polyp, the prevalence of polypoid disease, and posttest probability relative to patient age were studied. The positive predictive value for colonic polyp on single- and double-contrast barium enema was determined for 191 polyps found radiographically in 136 patients who also underwent colonoscopy for confirmation. Of 72 polyps seen in 54 patients on single-contrast examination, 59 were confirmed endoscopically; 110 of 119 polyps seen in 82 patients on double-contrast examination were confirmed similarly, giving positive predictive values of 82% and 92%, respectively. Positive predictive values per patient, disregarding the number of polyps present, were 87% (47/54) and 90% (74/82) for the single- and double-contrast examinations, respectively. False-positive errors were due to stool, air bubbles, haustration, and misinterpretation of an appendiceal stump. By using specificities derived from our prevalence of polypoid disease and previously reported sensitivities, we drew posttest probability curves showing that predictive values depend both on the chance of disease before the test is done and on the efficacy of the test used.