Blue rubber bleb nevus syndrome: CT diagnosis of intussusception.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
B R Baumgartner
Publications and source records attributed to B R Baumgartner.
Gallstone extracorporeal shock-wave lithotripsy: time and treatment considerations.
We evaluated 30 gallstone lithotripsy procedures performed on 27 patients with the Dornier MPL-9000 Lithotripter to determine how time was spent in the lithotripsy suite and to evaluate the various technical reasons for interrupting the administration of shock waves during the treatment. The procedure averaged 98 +/- 32 min total time in the lithotripsy suite. This included an average of 22 +/- 6 min before the treatment, 70 +/- 28 min for administration of shock waves, and 6 +/- 2 min after the treatment. The time required to deliver the shock waves did not correlate with patient age, sex, or weight; the number of gallstones; or the number or date of the treatment. However, a trend was seen toward an association between shorter treatment times and larger stone volumes. On the average, the administration of shock waves was interrupted every 48 shock waves for various reasons. Electronically changing the imaging plane of the in-line sonographic transducer to retarget the stone in the focal zone was by far the most frequent reason for interrupting shock-wave delivery, averaging 56 shock waves between changes. We conclude that extracorporeal shock-wave lithotripsy of gallstones is a time consuming and technically demanding procedure that requires continuous monitoring and frequent interruption in order to optimize targeting and fragmentation of the stone(s) while maintaining the patient's comfort.
Adult↗
Technical aspects of biliary extracorporeal shock wave lithotripsy.
Radiologic imaging procedures play a major role in the evaluation of the potential patient for biliary extracorporeal shock wave lithotripsy, both during the procedure and in follow-up evaluation. The treating physician must have a thorough knowledge of ultrasonography techniques. Lithotripsy requires continual monitoring and frequent reassessment to optimize targeting and fragmentation of the gallstones while maintaining patient comfort.
Cholecystography↗
MR imaging of the cervix: off-axis scan to improve visualization of zonal anatomy.
Explore the source record for details and available documents.
Cervix Uteri↗
Magnetic resonance imaging of the kidneys and adrenal glands.
A simple renal cyst will have low signal intensity on T1-weighted SE images with short TE and short TR because of the long T1 values of the cyst fluid. With increasing TE and TR, cysts demonstrate increased signal intensity due to the long T2 values of the cyst fluid. On T1-weighted images a complicated cyst will have higher signal intensity than a simple cyst; it may not be possible to differentiate these complicated cysts from solid masses. MRI seems to be useful in identifying simple cyst fluid and, therefore, has potential in characterization of cystic lesions considered complex by CT or ultrasound. Unfortunately, imaging techniques have not yet been optimized, diagnostic criteria are somewhat vague, and accuracy has not been established in a representative patient population. Solid masses often can be identified and differentiated from simple, uncomplicated cysts on MR images. The inability to differentiate among various types of solid tumors or to separate these from complicated cysts or inflammatory masses remains a limitation. Most lesions are more readily seen on contrast-enhanced CT than on MR images and therefore the role of MRI in the detection and diagnosis of renal cell carcinoma remains limited. Although the high detection rate of renal cell carcinoma is encouraging, CT is still more sensitive than MR in demonstrating solid lesions less than 3 cm in diameter. MRI cannot be used as a screening modality for renal tumors. MRI seems quite helpful in the staging of renal cell carcinoma. Macroscopic extension into the perinephric fat, tumor extension into the renal vein and the inferior vena cava, and macroscopic metastases to other organs are readily seen. Furthermore, differentiation between enlarged nodes and vessels is possible with MRI. Some authors recommended the use of MRI to stage renal cell carcinoma in patients with known contraindication to contrast, prior suboptimal bolus contrast enhanced CT scan, and equivocal CT findings. MRI can replace the inferior vena cavagram in the staging work-up and MR may be superior to CT for planning the surgical approach in Stage IIIA lesions by determining the upper extent of tumor thrombus within the inferior vena cava or the right atrium.(ABSTRACT TRUNCATED AT 400 WORDS)
Adrenal Gland Diseases↗
Renal corticomedullary junction. Performance of T1-weighted MR pulse sequences.
Inability to demonstrate the renal corticomedullary junction (CMJ) on magnetic resonance (MR) images has been reported in connection with several medical renal diseases. T1-weighted spin echo pulse sequences have been advocated to demonstrate a signal intensity difference between cortex and medulla. This study was undertaken to determine which of several T1-weighted spin echo (SE) and gradient echo (GE) sequences are better for delineation of the CMJ. The MR studies were performed at 0.5 Tesla on 27 normal volunteers. Multi-slice axial images of both kidneys were obtained in all subjects at each of the following five pulse sequences: SE 250/20, SE 500/30, SE 900/30, and GE 300/15 with 80 degrees and 64 degrees flip angles. Contrast/noise ratios were calculated for the signal intensity differences between cortex and medulla; the average standardized contrast/noise ratios ranked as follows: GE 300/15/80 degrees = 3.01 +/- 0.74, GE 300/15/64 degrees = 2.72 +/- 0.74, SE 250/20 = 2.02 +/- 0.33, SE 500/30 = 1.96 +/- 0.51, and SE 900/30 = 1.71 +/- 0.39. In addition, the five sequences for each patient were randomized and the images were independently ranked for delineation of CMJ by three MR radiologists. The cumulative subjective ranking for all observers from best to worst is as follows: SE 500/30, GE 300/15/80 degrees, GE 300/15/64 degrees, SE 900/30, SE 250/20. Although better contrast/noise ratios are achieved with the GE sequences and the more T1-weighted SE sequences, as a practical matter this does not seem to be the only significant factor when compared with the visual image evaluation by independent observers.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Focal hepatic lesions: detection by dynamic and delayed computed tomography versus short TE/TR spin echo and fast field echo magnetic resonance imaging.
Eighteen patients with focal hepatic lesions were evaluated with two computed tomographic (CT) techniques including dynamic sequential bolus contrast CT and delayed contrast CT, and 3 magnetic resonance (MR) techniques including a spin echo pulse sequence with TE/TR of 21/310 msec and 2 fast field echo sequences using a TE/TR of 15/300 msec and 80 degrees flip angle (T1-weighted) and TE/TR of 15/500 msec and 10-20 degrees flip angle (T2-weighted). We concluded that CT, using delayed contrast and dynamic sequential bolus contrast techniques, was consistently superior to the 3 MR pulse sequences used on our imagers in terms of number of lesions detected, lesion-to-liver contrast, and quality of scan.
Adult↗
Renal allograft rejection: evaluation by Doppler US and MR imaging.
A prospective study compared the efficacy of Doppler ultrasonography (US) and magnetic resonance (MR) imaging in evaluating 38 renal allografts, with specific attention to transplant rejection. Forty-three Doppler US and 42 MR examinations were performed and interpreted. Histologic correlation was obtained from 22 biopsy or nephrectomy specimens. Clinical correlation or a response to instituted therapy was used as confirmation in the remaining allografts. Accuracy in identifying cyclosporine toxicity or acute tubular necrosis could not be evaluated because there were few such cases, with concomitant rejection in most. The ability to predict and identify presence or absence of rejection was not affected by different serum creatinine values. Doppler US was significantly superior to MR imaging in identifying allograft rejection, demonstrating a higher sensitivity (95% vs. 70%), specificity (95% vs. 73%), and accuracy (95% vs. 71%). Because of its low cost and accessibility, Doppler US should become the primary modality for renal transplant screening.
Adult↗
Kidney changes after extracorporeal shock wave lithotripsy: appearance on MR imaging.
The occurrence of changes in the kidneys after extracorporeal shock wave lithotripsy (ESWL) was evaluated with magnetic resonance (MR) imaging in 34 patients, utilizing T1-weighted spin-echo pulse sequences. Five of the 34 patients underwent bilateral ESWL therapy before MR imaging. Of the 39 kidneys studied, 29 (74%) showed one or more changes on MR imaging: subcapsular or perinephric fluid (n = 10), focal (n = 16) or diffuse (n = 8) loss of the corticomedullary junction (CMJ), and focal areas of increased (n = 7) or decreased (n = 3) signal intensity. The CMJ changes were more prominent with increasing numbers of shock waves administered during the procedure. These relatively subtle changes detected on MR imaging may not be apparent with other imaging techniques. The long-term clinical significance of these findings is not yet known, although no apparent serious renal pathologic condition was detected.
Adult↗
Sonographic evaluation of renal stones treated by extracorporeal shock-wave lithotripsy.
Real-time sonography was performed on 94 patients the day before and at 24 and 48 hr after extracorporeal shock-wave lithotripsy (ESWL) therapy. The ability of sonography to detect renal stones before ESWL, changes in the calculi after ESWL, and the occurrence of pre- and post-ESWL hydronephrosis was evaluated. Abdominal radiographs and linear renal tomography were used as the standard of comparison. Six other patients had sonography only either before or after ESWL. One hundred patients had a total 105 kidneys treated; 18 kidneys with more than three stones were not included. The other 87 kidneys had 102 stones evaluated by sonography before having ESWL; 66 stones (65%) were identified and 36 were not. Of those calculi not seen, 10 were less than or equal to 5 mm in diameter. Nineteen of the other 26 stones were in the ureter or at the ureteropelvic junction. Comparison of sonograms of 80 kidneys obtained before and after ESWL revealed no change in 37 (46%), more stones or fragments detected in 23 (29%), fewer stones or a change in location in 12 (15%), and an apparent decrease in the size of the original stone in eight (10%). Hydronephrosis was detected by pre-ESWL sonography in 16 kidneys (20%) and was noted to develop after ESWL in 20 (31%) of the 64 other kidneys. These results indicate that the ability of sonography to detect renal calculi is related not only to stone size but also to location. The clinical significance of pre- and post-ESWL hydronephrosis found by sonography must be considered in conjunction with the patient's symptoms, laboratory data, and other radiographic studies. Therefore, the routine use of sonography in the post-ESWL patient does not seem warranted.
Humans↗
Percutaneous renal biopsies: accuracy, safety, and indications.
Fifty-one percutaneous renal needle biopsies were performed on 46 patients. Initial biopsy was adequate for diagnosis in 89% of patients. When a second biopsy was performed, this accuracy increased to 98%. Thirty-four of 51 (67%) biopsies were for renal masses and 17 (33%) for medical indications. Computed tomographic guidance was utilized in 94% of cases. Biopsies of renal masses were performed with 18-21-gauge needles, while biopsies for medical indications were performed with an 18-gauge cutting needle or 14-gauge Trucut. A rate of serious complications of 6% was noted.
Adolescent↗
Delayed hepatic CT scanning: increased confidence and improved detection of hepatic metastases.
Fifty oncologic patients with suspected hepatic metastases were prospectively evaluated by dynamic sequential hepatic computed tomography (DSHCT) and by delayed iodine hepatic computed tomography (DICT) scanning. DICT scanning was performed 4-6 hours following administration of 60 g of intravenous iodine. Both techniques were evaluated for lesion definition relative to the adjacent hepatic parenchyma and for numbers of metastases detected. Metastases were detected by both techniques in 26 patients. Fifteen patients (58%) had lesions better defined by DICT. DICT scanning detected more metastases in seven of these 15 patients. In eight patients (31%), there was no difference between the two techniques in numbers of masses detected or lesion definition. In three cases (11%), metastases were more confidently identified on the initial or DSHCT scan. DICT scanning, as described, is useful in defining and detecting hepatic metastases, especially where there is questionable hepatic involvement or better quantification of size is necessary.
Adult↗
Percutaneous aspiration and drainage of pancreatic pseudocysts.
Twenty-five patients with pancreatic pseudocysts had therapeutic intervention procedures that included diagnostic aspiration, short-term drainage (aspiration until completely drained), and long-term catheter drainage. Diagnostic aspirations were used to classify the pseudocysts as infected or noninfected. Short-term drainage was performed on six pseudocysts (two infected and four noninfected) with little success. One resolved and five recurred. Fifteen pseudocysts were treated by long-term catheter drainage. Eight of these (four infected and four noninfected) resolved after initial long-term drainage; two others resolved after additional drainage. The cure rate in these 15 patients was 67%. The other five patients were treated surgically after they had been stabilized but not cured by percutaneous drainage. Complications were few and uniformly minor except for one pneumothorax. Percutaneous aspiration should be used in the diagnosis of pancreatic fluid collections. In noninfected pseudocysts, drainage can be curative. In infected pseudocysts, percutaneous drainage is useful to stabilize the patient and can be either a cure or a temporizing measure until surgery can be performed.
Drainage↗
MR imaging of renal transplants.
Fifty-six MR studies were obtained in 32 renal transplant patients, by using T1-weighted, spin-echo, and inversion-recovery pulse sequences. The findings, particularly the loss of corticomedullary differentiation, and the extent of vascular penetration into the renal parenchyma, were compared with the clinical and histologic diagnosis of transplant rejection. Thirteen MR studies on 11 patients with clinically normal renal transplants demonstrated normal corticomedullary differentiation. Renal vessels extended into the parenchyma in all 11 patients and to the cortex in 38%. In 37 MR studies on 22 patients with a clinical or histologic diagnosis of acute and/or chronic transplant rejection, the corticomedullary differentiation was normal in 8%, faint in 24%, and absent in 68%. Renal parenchymal vessels were visualized in 32%, but extended to the level of the cortex in only 8%. In 68% of the studies with transplant rejection, no parenchymal vessels were seen. When the corticomedullary differentiation was either faint or absent, the vascular pattern was normal in 6%; in 68% of cases no parenchymal vessels could be identified. We conclude the corticomedullary differentiation and the renal vascular pattern are useful parameters in the evaluation of renal transplant rejection.
Female↗
Abscess drainage in the genitourinary tract.
This article deals with the diagnosis of perirenal fluid collections as well as renal abscesses. Proper diagnostic and drainage techniques are discussed, as are patient selection, route selection, catheter selection, technique, and catheter management. In addition, the cure rates of the therapeutic procedure are reviewed.
Abdomen↗
Percutaneous biopsy of pancreatic masses.
Forty-five percutaneous needle biopsies of pancreatic masses were performed in 41 patients in whom there was clinical or radiological concern for the diagnosis of cancer. Computed tomography (CT) was the imaging technique used in 41 of the 45 biopsies. An overall sensitivity of 85%, specificity of 100%, and accuracy rate of 88% were achieved, with serious complications in three of the 45 attempts (6.7%). These figures show that percutaneous pancreatic biopsies have the potential for greater accuracy than has been previously reported and are relatively safe when compared with surgery.
Adult↗
CT densities in delayed iodine hepatic scanning.
Sixty patients underwent CT scanning of the liver prior to, immediately after, and four hours after intravenous administration of 60% meglumine diatrizoate. Twenty patients received a 50 ml bolus of contrast material (14.6 g of iodine), 20 received 100 ml (29.2 g of iodine), and 20 received 200 ml (58.4 g of iodine). In each group, delayed CT scanning safely raised the inherent density of the liver significantly (increase of 14.3% using 50 ml; 23.9% using 100 ml; and 40.7% using 200 ml). Thus, delayed scanning with doses presently used in abdominal and neurological CT examinations may be helpful in detecting hepatic lesions.
Diatrizoate↗
CT-guided adrenal biopsy: accuracy, safety, and indications.
Fifty-eight percutaneous needle biopsies of adrenal masses were performed in 53 patients. The technique was initially successful in 44 (83%) of 53 patients. Five patients had second procedures because of initial failure or the possibility of sampling error. Fourteen biopsies were performed in nononcologic patients and 39 in patients with a known malignancy. None of the adrenal masses in nononcologic patients were malignant. Only 18 (46.1%) of the 39 masses in oncologic patients were metastases; the rest represented a variety of nonneoplastic conditions. Seven minor complications occurred in six patients. Two of these patients required transfusions for hypotension or decreases in hematocrit. No correlation was noted between needle size and complications. There were no pneumothoraces. The procedure is an accurate and safe alternative to surgical biopsy.
Adrenal Gland Diseases↗