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Biomedical subjects

R J Zagoria

Publications and source records attributed to R J Zagoria.

At least 19 recordsLinked to original sources

Abdominal radiography after CT reveals urinary calculi: a method to predict usefulness of abdominal radiography on the basis of size and CT attenuation of calculi.

OBJECTIVE: The purpose of this study was to determine if the radiographic visibility of urinary tract calculi could be predicted on the basis of CT features. MATERIALS AND METHODS: The images of 26 patients whose urinary tract calculi were revealed on unenhanced helical CT and who also underwent digital abdominal radiography were retrospectively reviewed. CT features studied included size and CT attenuation of the calculi. These CT findings were correlated with the ability to detect the same calculi with radiography. RESULTS: Forty-nine urinary tract calculi were detected with unenhanced helical CT in 26 patients. Twenty-six (53%) calculi were visible on radiography. Most (79%) calculi larger than 5 mm were detectable with radiography (p < 0.01). One (8%) of 13 calculi with CT attenuation below 200 H was detectable on radiographs. Ninety-five percent (21/22) of calculi with CT attenuation exceeding 300 H were visible on radiographs (p < 0.0001). The one remaining calculus was obscured by overlying anatomy. CONCLUSION: Radiographic surveillance of urinary tract calculi detected with CT may not be useful if the calculi have a CT attenuation below 200 H. Most calculi larger than 5 mm and nearly all calculi with a CT attenuation exceeding 300 H can be seen on abdominal radiographs.

Adult↗

CT diagnosis of acute flank pain from urolithiasis.

The use of noncontrast helical CT (NHCT) to assess patients with acute flank pain and hematuria for potential urinary tract stone disease was first reported in 1995. After several years of experience with the technique, sensitivity and specificity of NHCT has proven to be better than intravenous urography for evaluating ureteral stones. NHCT imaging findings for urinary calculi and the differential diagnosis are discussed in this article. Various extraurinary diseases found while using NHCT in searching for stone disease are addressed and illustrated. As experience with the use of NHCT has increased, clinicians have broadened the indications for this technique, which has a lower charge than standard CT, beyond the specific evaluation of urinary colic. This indication creep has increased the number of NHCT examinations ordered. It has also reduced the rate of stone positivity and increased the diagnostic yield for extraurinary disease.

Abdominal Pain↗

Do's and don't's of percutaneous nephrostomy.

Percutaneous nephrostomy procedures generally are safe. The associated mortality rate is approximately 0.04%, and the incidence of important complications is 5% (2-4). To minimize complications, certain precautions always should be followed. First, radiologists should perform a preprocedural evaluation of the patient, with correction of marked coagulopathy or thrombocytopenia before all but the most emergent procedures. Second, antibiotics should be administered routinely before nephrostomy drainage; the choice of antibiotics can be based on the specific patient's risk factors for bacteriuria. To minimize the risk of clinically important renal vascular damage, radiologists should do the following: 1. Always achieve adequate visualization of the calices. 2. Identify a posterior calix for puncture that will give access to the appropriate segment of the kidney for anticipated procedures and allow safe creation of a tract. 3. Puncture below the 11th rib (and preferably below the 12th rib when feasible). 4. Puncture the tip of a posterior calix from a 20 degrees-30 degrees, posterolateral oblique approach to avoid major blood vessels. 5. Make a single-wall puncture of the calix. 6. Perform exchange transfusion for opacification of the renal pelvis and calices during percutaneous nephrostomy procedures to minimize the risk of sepsis. Overdistention can increase the likelihood of sepsis or retroperitoneal contamination. 7. Inject contrast material via a catheter placed over a wire to confirm the intracollecting system location of the entry. 8. Avoid unnecessary (complicated, prolonged) procedures in an infected, obstructed system. 9. Use only self-retaining drainage catheters to minimize the risk of inadvertent catheter dislodgment. 10. Create large-bore tracts with a balloon dilation system. By contrast, radiologists should not do the following: 1. Puncture above the 11th rib (unless all other avenues of approach have been exhausted). 2. Lose access to an obstructed kidney once the kidney has been punctured. Placement of a "safety" wire for all complex manipulations is recommended. 3. Panic if excessive bleeding or evidence of adjacent organ injury is seen. Excessive bleeding usually can be stopped with tract tamponade by using a balloon catheter advanced through the tract or with placement of an appropriate-sized nephrostomy tube to occlude the tract. If active bleeding continues or recurs, arteriography should be considered. The quantity of bleeding can be monitored with sequential hematocrit measurements. Almost all renal artery injuries can be treated with minimally invasive procedures, such as selective embolization of the branch artery involved, and this will lead to infarction of only a small segment of kidney, with preservation of functioning renal parenchyma. Injury to an adjacent organ usually can be treated nonsurgically (21,23). The most commonly injured extrarenal abdominal organ is the colon (Fig 6). On occasion, a percutaneous nephrostomy needle may traverse the retroperitoneal segment of the colon, and this type of injury generally can be treated nonsurgically, as well (23). If the colon has been traversed, adequate urinary drainage should be ensured before the transcolonic nephrostomy catheter is removed (so that a nephrocolonic fistula is not maintained). This can be done by placing a ureteral stent and a bladder catheter (18). Once adequate urinary drainage is provided, the nephrostomy catheter can be withdrawn into the colon and used as a percutaneous colostomy drain. The percutaneous colostomy tract should be allowed to mature for several days before this catheter is removed. In addition, appropriate antibiotics should be administered from the time a transcolonic tract is identified until the percutaneous tract has healed completely. Transthoracic entry can cause pneumothorax and pleural effusions. These should be treated only if they are large or cause symptoms (21). (ABSTRACT TRUNCATED)

Humans↗

Trends in the use of unenhanced helical CT for acute urinary colic.

OBJECTIVE: Unenhanced helical CT for urolithiasis detection is a limited CT examination that was designed specifically for the detection of urolithiasis. The purpose of this study was to repeat a prior study to assess whether clinicians had broadened the indications and changed the yield and findings of unenhanced helical CT. MATERIALS AND METHODS: One hundred consecutive patients with suspected renal colic or flank pain referred for unenhanced helical CT were selected for this study. We reviewed the original radiographic reports for each patient and recorded the presence of ureteral calculi. Other urinary abnormalities and extraurinary lesions were also recorded and compared with the results of the previous study. RESULTS: In this study, 56% of the patients who underwent unenhanced helical CT had symptoms of urinary colic, and 44% of patients had unspecified flank pain, compared with 100% of patients with symptoms of urinary colic 1 year earlier. The sensitivity and specificity of unenhanced helical CT in detecting ureteral calculi were 96% and 99%, respectively. Ureteral calculi were identified in only 28% of the patients versus 49% of patients (p < .01) 1 year earlier. Extraurinary lesions were identified in 45% of the patients versus 16% (p < .01) 1 year before. CONCLUSION: As clinicians developed familiarity with this technique, the indications for performance of unenhanced helical CT were expanded with a consequent reduction in the rate of detection of stone disease and identification of an increased number of extraurinary lesions, which suggests a demand for emergency abdominal CT studies.

Acute Disease↗

Abnormal calcification on plain radiographs of the abdomen.

The purpose of this pictorial review is to facilitate recognition and understanding of calcifications seen on conventional radiographs of the abdomen. Calcifications can be categorized by organ system and location in the abdomen. Both common and rare calcifications in the urinary tract, liver, gallbladder, spleen, pancreas, adrenal glands, digestive tract, genital tract, peritoneal cavity, and retroperitoneum are illustrated. Abnormal calcifications in the urinary tract are subcategorized by kidneys, ureters, bladder, and urethra. The density, shape, size, margins, pattern, position, and mobility of calcifications are emphasized for differential diagnoses.

Adrenal Glands↗

Assessment of rectal tumor infiltration utilizing endorectal MR imaging and comparison with endoscopic rectal sonography.

BACKGROUND: The preoperative assessment of depth of invasion of rectal carcinoma is increasingly important as new treatment methodologies are developed. Accuracy of preoperative endorectal MR imaging was therefore compared with that of the endoscopic rectal sonography in determining depth of invasion of rectal carcinomas. METHOD: From March 1993 to April 1994, 10 consecutive patients with biopsy-proven rectal carcinomas were imaged with both endorectal MR imaging and endoscopic rectal sonography. These two studies were performed an average of 2.7 days apart in each patient. All 10 patients had surgical resection of the rectal carcinoma within days of imaging studies. TNM staging of each malignant lesion was correlated with the imaging reports. RESULT: Staging accuracy was 80% for endorectal MR imaging and 70% for endoscopic rectal sonography. With MR imaging, one T2 lesion was overstaged and one T3 lesion was understaged. With sonography, two T2 lesions were overstaged and one T3 lesion was understaged. One MR error resulted from misinterpretation. All other staging errors occurred in patients with tumor spread into, but not through, the muscularis propria or with microscopic spread through this layer. CONCLUSIONS: Endorectal MR imaging and endoscopic rectal sonography have similar accuracy for assessing depth of invasion of rectal carcinoma.

Endosonography↗

Imaging approach to staging of renal cell carcinoma.

Current imaging techniques, especially CT and MR imaging, make accurate preoperative staging of renal cell carcinoma possible. Because surgery provides the only effective therapy and because survival depends on local and distant extent, precise staging is critical for preoperative planning and prognosis. This article reviews the advantages, limitations, accuracy, and pitfalls of each of the imaging approaches to staging renal cell carcinoma, concentrating on CT and MR imaging. This information then is summarized in a suggested overall approach to staging renal cell carcinoma.

Carcinoma, Renal Cell↗

The role of imaging in staging renal adenocarcinoma.

Numerous surgical options are available to physicians treating patients with renal adenocarcinoma. In the current clinical setting, imaging plays a key role in determining which options are selected. Newer imaging techniques such as helical CT with CT angiography, MRI, and ultrasound (US) have improved staging capabilities in this patient population. However, to approach staging accuracies recently reported, attention must be paid to proper imaging parameters. This article describes the strengths, limitations, and proper techniques used for staging renal adenocarcinoma with CT, MRI, and US.

Adenocarcinoma↗

Transrectal US-guided seminal vesiculography.

Transrectal ultrasound (US)-guided seminal vesiculography is a technique that couples US with radiography to evaluate male-factor infertility. Seminal vesiculography was performed in 12 patients after needle puncture of the seminal vesicle to inject contrast material for radiography. Seminal vesiculography helped imaging of the distal male reproductive tract (vas deferens, seminal vesicles, ejaculatory ducts). This method is an improvement over standard vasography for evaluation of infertility in men with suspected ejaculatory-duct obstruction.

Humans↗

The perirenal space: relationship of pathologic processes to normal retroperitoneal anatomy.

The perirenal space may be involved by disease processes that arise within or outside the perirenal space. Key anatomic details that dictate the features of perirenal processes include the renal capsule, the perirenal septa, the renal fascia, and the conic shape and inferomedial orientation of the perirenal space. Superiorly, the perirenal space is open to the bare area of the liver. The perirenal spaces communicate with one another at the level of the lower lumbar vertebrae. The hallmark of perirenal infection is localized or diffuse gas. Chronic urinoma appears as an encapsulated cystic mass, often aligned parallel with the perirenal space. Fat within an apparent spontaneous hematoma of the perirenal space suggests angiomyolipoma. Renal cell carcinoma, lymphoma, and melanoma are the most common causes of discrete solid masses in the perirenal space; metastases occur due to the characteristic lymphatic and vascular supply of the space. Amyloidosis and fibrosis create a nonspecific rind of soft tissue around the kidneys. Diaphragmatic pseudotumor produces a linear "lesion" in the perirenal space.

Amyloidosis↗

Changing of the guard at the American Journal of Roentgenology: the Robert Berk era revisited.

As determined by the Executive council of the American Roentgen Ray Society, the editorship of the American Journal of Roentgenology (AJR) is a time-limited position. This policy allows for the perpetual influx of new ideas and ensures continued dynamism in the leadership of the Journal. The AJR now has a new editor in chief, Lee F. Rogers, M.D., as well as a new office staff and a new home for the editorial office, Winston-Salem, NC. As we look with anticipation to the future of the Journal under the guidance of Lee Rogers, the time is appropriate to reflect on the legacy of journalistic excellence and innovation that Robert N. Berk has left us.

History, 20th Century↗