Raymond B. Dyer

Spontaneous Perinephric Hemorrhage: Imaging and Management

We report on 10 patients with spontaneous perinephric hemorrhage associated with underlying disease, including renal cell carcinoma (5), angiomyolipoma (2), malignant melanoma (1), periarteritis nodosa (1) and severe portal hypertension (1). The etiology could not be identified with computerized tomography (CT) in 5 cases (50%), including 2 renal cell carcinomas, 1 angiomyolipoma, 1 periarteritis nodosa and 1 portal hypertension. Arteriography demonstrated underlying lesions in 4 of these 5 cases (80%) including the case of vasculitis. CT combined with magnetic resonance imaging is accurate for the diagnosis of spontaneous perinephric hemorrhage but the underlying pathological condition is often undetectable in the acute phase due to the perinephric blood. CT should be the first study performed if this diagnosis is suspected. Arteriography is recommended if a renal mass is not detected. If a mass is not identified with these 2 imaging studies and the patient is clinically stable, followup thin slice CT should be performed.

A Comparison of Anatrophic Nephrolithotomy and Percutaneous Nephrolithotomy with and without Extracorporeal Shock Wave Lithotripsy for Management of Patients with Staghorn Calculi

A retrospective study was conducted comparing anatrophic nephrolithotomy (10 cases), percutaneous nephrolithotomy alone (4 cases) or percutaneous nephrolithotomy combined with extracorporeal shock wave lithotripsy (23 cases) for the treatment of large staghorn calculi. A comparison based on collecting system anatomy demonstrated that anatrophic nephrolithotomy resulted in a greater stone-free rate, shorter hospitalization and lower costs while complication rates were similar. Anatrophic nephrolithotomy should still be considered a viable treatment option, especially for patients with large branched calculi in complex collecting systems.

The small renal mass: detection, characterization, and management

With the widespread availability and use of cross-sectional imaging (computed tomography [CT], ultrasonography [US], and magnetic resonance ([MR] imaging), the detection of small renal masses has become commonplace [1–5]. Unfortunately, this improved ability to detect these previously unrecognized renal masses has caused some consternation for radiologists and referring physicians, because difficulty in classifying these masses may complicate management decisions. Once a small renal mass is detected, characterizing the lesion with a specific diagnosis is most important, because some of these masses are malignancies diagnosed at an early stage, and the single most important determinant in the prognosis of primary renal malignancy is the stage of the tumor at the time of treatment initiation [6]. Renal cell carcinoma (RCC) is resistant to both radiotherapy and chemotherapy [6]. Therefore, diagnosis at an early stage, when the tumor is surgically resectable, offers a patient the best chance for long-term survival. Alternatively, because nephrectomy is associated with a 5% perioperative mortality and a higher rate of morbidity [7], accurate characterization of benign renal masses may prevent unnecessary surgery. In this article, radiologic techniques for detection, characterization, and management of small renal masses are discussed.

Role of angiography in the detection of aortic branch vessel injury after blunt thoracic trauma.

PURPOSE The occurrence of aortic arch branch vessel injury as an isolated occurrence or in association with aortic injury after blunt chest trauma has not been emphasized in the literature. The imaging evaluation is also controversial. METHODS We reviewed thoracic aortograms of 166 patients examined at our institution from May 1995 to May 1999 performed after blunt thoracic trauma. We evaluated the aortograms for aortic and arch branch vessel injuries. Twenty-four injuries were detected and all patients had either a wide mediastinum demonstrated on plain radiographs (22 patients) or mechanism of injury conducive to aortic injury. RESULTS Of the 166 patients, 24 (14%; 16 men, 8 women; mean age, 50 years) had aortic or arch branch vessel injuries. Isolated aortic injury occurred in 15 (9%) of 166 patients. Branch vessel injury occurred in 9 (5%) of 166 patients; seven patients (10 branch vessels) had isolated branch vessel injury and two patients (three branch vessels) had branch vessel injury associated with aortic injury. The injured branch vessels were brachiocephalic artery (four), left common carotid artery (four), left subclavian artery (three), right internal mammary artery (one), and left vertebral artery (one). The types of branch vessel injuries included intimal tears (nine vessels; 69%), and transection causing a pseudoaneurysm (four vessels; 31%). Revised Trauma Scores in patients with branch vessel injuries were 12 in seven patients and 11 and 4 in one each. CONCLUSION We emphasize the angiographic findings in these patients that can at times be quite subtle. Awareness of the incidence of such injuries either in isolation or associated with aortic injury has implications regarding evaluation of this patient population with less invasive techniques such as CT or transesophageal echocardiography.

Comparison of penile duplex ultrasonography to pudendal arteriography. Variant penile arterial anatomy affects interpretation of duplex ultrasonography.

&NA; Jarow JP, Pugh VW, Routh WD, Dyer RB. Comparison of penile duplex ultrasonography to pudendal arteriography: variant penile arterial anatomy affects interpretation of duplex ultrasonography. Invest Radiol 1993;28:806‐810. rationale and objectives. Duplex ultrasonography is currently used as a noninvasive imaging modality for the functional evaluation of penile blood flow in impotent men. However, the accuracy of this test is controversial. The objective of this study was to determine the sensitivity and specificity of duplex ultrasonography, to assess the ultrasonographic parameters most predictive of arterial disease, and to evaluate the causes of misinterpretation of duplex ultrasound studies. methods. Duplex ultrasonography and pudendal arteriography were performed on 42 impotent men during a 4‐year prospective study. The predictive power of the following ultrasonographic parameters were analyzed: cavernosal arterial diameter, peak blood flow velocity, and pulsations on realtime ultrasonography. results. The results of both studies were concordant in 81% of the patients with a 77% sensitivity and 85% specificity for ultrasonography when using arteriography as the gold standard. Arterial pulsations and peak blood flow velocity were most predictive, whereas dilation was not helpful. Variant penile arterial anatomy was present in 83% of the patients and was the most frequent cause of misinterpretation of duplex ultrasonography. conclusion. Duplex ultrasonography is a fairly reliable screening test for arterial disease in impotent men. Visualization of arterial pulsations and measurement of peak blood flow velocity are the best predictors of arterial function. Awareness of the potential arterial anomalies may help reduce misinter‐pretation of ultrasonography. Arteriography is necessary in any patient being considered for penile arterial surgery because of the high frequency of anatomic variations.

Radiation Exposure to Patients During Extracorporeal Shock Wave Lithotripsy

Extracorporeal shock wave lithotripsy is rapidly becoming an accepted treatment of renal calculi. Since fluoroscopy is involved to image the stones it is important to know how much radiation the patient receives during this proCedure. Surface radiation exposure to the patient was measured in more than 300 fluoroscopic and radiographic procedures using thermoluminescent dosimeters. Initial results showed an average skin exposure of 10.1 rad per procedure for each x-ray unit, comparing favorably with exposure rates for percutaneous nephrostolithotomy and other routine radiological procedures. Factors influencing exposure levels include stone characteristics (location, size and opacity), physician experience and number of shocks required. Suggestions are given that may result in a 50 per cent reduction of radiation exposure.

Percutaneous Nephrostomy for Treatment of Intractable Hemorrhagic Cystitis

Six patients with severe hemorrhagic cystitis unresponsive to traditional localized therapy were treated with percutaneous nephrostomy for diversion of urine. Bladder hemorrhage ceased in 3 patients, decreased in 2 and was unchanged in 1. In 1 patient with profound thrombocytopenia perirenal hematoma developed as a result of the nephrostomy placement but this complication was self-limited and did not require surgery. Our experience with these 6 patients indicates that nephrostomy diversion is safe and effective in most cases of hemorrhagic cystitis refractory to traditional, nonoperative therapy. Percutaneous urine diversion may obviate the need for surgical urinary diversion in patients who have intractable hemorrhagic cystitis.

Radiologic findings in acute urinary tract obstruction.

Acute urinary tract obstruction, a common disease in daily practice, often requires performance of emergency intravenous urography (IVU). However, the spectrum of urographic abnormalities seen with acute obstruction has not been thoroughly addressed. The purpose of this study was to explore the IVU findings in patients with acute urinary tract obstruction. Records of 380 patients who underwent IVU in our hospital during a 6-mo period were reviewed for IVU evidence of acute urinary tract obstruction. Of the 380 patients, 53 (14%; 39 men, 14 women; average age = 43 yr) had acute urinary tract obstruction. All obstructions except one were located in the lower one-third of the ureter. The causes of acute urinary obstruction included ureteral stones in 34 (64%), ureteral edema or lucent stones in 16 (30%), neoplasms in 2 (4%), and inflammatory disease in 1 (2%). Abnormal radiologic findings were hydroureter in 46, nephropyelographic delay in 36, hydronephrosis in 35, interureteric ridge edema in 11, persistent dense nephrogram in 6, urine extravasation in 5, vicarious excretion in 1, striation in 1, and stricture in 1. Radiographic results were normal in one patient. The most common clinical indications of acute ureteral obstruction are flank pain and hematuria, and calculi are the major cause. In one-third of patients, radiopaque calculi are not detectable with IVU during acute urinary tract obstruction. A careful and thorough evaluation of the IVU should be performed in patients with clinical indications of acute urinary obstruction.

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.

Percutaneous Management of Localized Emphysematous Pyelonephritis

The authors report a case of emphysematous pyelonephritis that was successfully treated with radiologically guided percutaneous drainage. This case illustrates that in certain patients with focal abnormalities, functioning renal tissue can be salvaged and emphysematous pyelonephritis can be eradicated with a combination of antibiotics and radiologically guided percutaneous drainage.