Dialysis is not indicated immediately after administration of nonionic contrast agents in patients with end-stage renal disease treated by maintenance dialysis.

OBJECTIVE: This study was undertaken to determine the necessity of immediate dialysis after intravascular injection of contrast material in patients with end-stage renal disease who are being maintained on hemodialysis. Although many physicians support this practice, we could find no reports of studies to confirm or refute its necessity. SUBJECTS AND METHODS: We studied 10 patients being treated with hemodialysis who were undergoing 11 diagnostic procedures that required intravascular contrast material. The patients received 40-225 ml of nonionic contrast material and were followed up with clinical examination and laboratory analysis to determine any adverse effects from contrast administration or the need for dialysis or both. RESULTS: No significant changes in blood pressure, ECG, total serum protein level of osmolality, extracellular fluid volume, or body weight occurred after injection of contrast material. None of the patients had clinical features that necessitated emergent dialysis. CONCLUSION: We conclude that nonionic contrast material can be given safely to patients with end-stage renal disease who are being maintained on hemodialysis. Immediate postprocedural dialysis is unwarranted as a routine practice.

Radiologic anatomy--a credit course for first-year medical students.

Diagnostic radiology should assume a more prominent role in medical student education. We have developed a 4-year plan for radiologic education at the University of Florida. The initial step in this plan is a required credit course in radiologic anatomy given in the first semester. Designed to introduce students to various imaging modalities while teaching anatomic recognition, the course combines a lecture series with systematized self-study film packets and self-test packets. These are reinforced by a videotape series and other written materials. Examinations are in practical format utilizing radiographs on viewbox stations. The course provides a foundation for subsequent coursework in diagnostic radiology, including radiologic pathology and clinical radiology. These courses stress how to workup patients and how to use the radiologist as a consultant in patient care. The response to the radiologic anatomy course has been highly favorable.

Correlation of lymphangiography, computed tomography, and laparotomy in the staging of Hodgkin's disease.

PURPOSE: To determine the predictive value of lymphangiography and computed tomography of the abdomen and pelvis for infradiaphragmatic involvement of Hodgkin's disease. METHODS AND METHODS: We retrospectively reviewed the findings on 125 patients with Hodgkin's disease treated at the University of Florida who underwent lymphangiography and staging laparotomy; 33 patients also underwent computed tomography of the abdomen and pelvis. The positive predictive value and negative predictive value were calculated for both studies. RESULTS: The positive predictive value of lymphangiography for paraaortic or pelvic disease was 35%, while the negative predictive value was 95%. The positive predictive value of computed tomography of the abdomen and pelvis for paraaortic or pelvic disease was 20%; the negative predictive value was 93%. There was no advantage in predicting paraaortic or pelvic disease when both studies were obtained as compared to either study alone. For splenic disease, the positive predictive value of computed tomography was 43%; the negative predictive value was 77%. Of the patients with a positive lymphangiography, 57% were found at laparotomy to have either no abdominal disease or upper abdominal disease only, with or without minimal splenic disease, making them reasonable candidates for radiotherapy alone. Of the patients with a negative lymphangiogram, 14% were found at laparotomy to have either lower abdominal disease or extensive splenic disease, and so were not good candidates for radiotherapy alone. CONCLUSION: We recommend laparotomy for patients who may be candidates for radiotherapy alone or combined modality therapy with limited chemotherapy.

Multiple criteria in sonographic diagnosis of prostatic carcinoma allows identification of all glands harboring clinically significant tumor: an in vitro study with histopathologic correlation.

Fresh whole prostate glands were examined systematically in a water bath to look for four sonographic criteria for prostatic carcinoma: well-circumscribed hypoechoic regions, external asymmetry of the gland, increase in anterior-posterior diameter ratio, and irregularity of the prostatic capsule. Whole mount sections were examined to correlate the histopathologic and sonographic findings. Using hypoechogenicity alone, 26 of 43 glands harboring tumor were identified correctly. Using all four criteria, 40 of 43 glands harboring tumor were identified, a statistically significant improvement in sensitivity (P less than 0.05). Specificity of both methods was similar (P greater than 0.1). The three tumors that were missed measured 0.5 x 0.5 x 0.5 cm, 0.5 x 0.5 x 0.5 cm, and 0.3 x 0.4 x 0.9 cm, and were found at autopsy in patients who died of causes unrelated to the prostate. The authors conclude that systematic examination of the gland with attention to multiple criteria for abnormality can improve case finding in prostatic adenocarcinoma.

Screening test for detection of metallic foreign objects in the orbit before magnetic resonance imaging.

RATIONALE AND OBJECTIVES: A study was designed to determine whether plain films, used as a screening modality for magnetic resonance imaging (MRI), could reliably detect intraorbital metallic foreign objects. METHODS: In the first experiment, 20 metal particles were placed in five human cadaver orbits. Routine orbital plain film series and computed tomography (CT) were obtained, randomized, and interpreted blinded by three experienced radiologists. RESULTS: The threshold size of particle detection for CT (0.07 mm3) was lower than for plain films (0.12 mm3). Placing metal particles in artificial and true vitreous demonstrated that all particles moved under a magnetic field at 1.5 T. When human globes were exposed to industrial tools (grinder, bandsaw, air hose, etc.), no metal objects penetrated the sclera. CONCLUSIONS: Plain films can be used as a low-cost, low-radiation screening procedure for high-risk patients with occupations involving metal work. CT should be used for patients with a history of eye trauma from other causes.

Renal peripelvic lymphatic cysts (lymphangiomas) associated with generalized lymphangiomatosis.

Renal peripelvic lymphatic cysts (lymphangiomas) are usually seen as an isolated finding. They appear as multiple mass lesions with low attenuation on computed tomography (CT), and show no contrast enhancement. We present a case of renal peripelvic lymphatic cysts associated with generalized lymphangiomatosis, and examined with magnetic resonance imaging (MRI), CT, and lymphangiography. Multiplanar MRI demonstrated the extent of disease, including retroperitoneal lesions. The lesions had low-signal intensity on T1-weighted and high-signal intensity on T2-weighted images. The diagnosis of generalized lymphangiomatosis was verified by renal sinus cyst puncture, lymphangiography, and tissue biopsy.

Peritoneal mesothelioma. Radiologic appearances correlated with histology.

Previous imaging reports of peritoneal mesothelioma have described a variety of radiologic appearances, but have not included its pathologic classification. We retrospectively reviewed 10 cases of peritoneal mesothelioma representing the following histologic categories: 7 epithelial, 2 sarcomatoid, and one biphasic. By imaging, epithelial mesotheliomas demonstrated diffuse thickening of the peritoneum and mesentery and/or multiple small nodules. The sarcomatoid-type appeared as a mass and the biphasic-type had radiologic and gross pathologic features of both sarcomatoid and epithelial types. We conclude that peritoneal mesothelioma presents with a wide spectrum of radiographic appearances and should therefore be included in the differential diagnoses of diffuse as well as localized peritoneal processes.

Antiperistaltic and isoperistaltic intussusception associated with abnormal motility after Roux-en-Y gastric bypass: a case report.

Antiperistaltic and recurrent intussusceptions are extremely rare in the adult. We report a patient with both. The patient developed an antiperistaltic intussusception distal to her Roux enteroenterostomy years after a Roux-en-Y gastric bypass for morbid obesity. The diagnosis was made preoperatively with gastrointestinal contrast radiography and ultrasonography. At surgery, the intussusception was reduced, and 12 inches of nonviable bowel was resected, with a functional end-to-end anastomosis. An isoperistaltic intussusception occurred in the early postoperative period just distal to the anastomosis. Manometric evaluation of the Roux limb after the second operation showed altered gastrointestinal motility, consisting of orad-propagated and aboard-propagated migrating motor complexes, minimal phase 2 activity, and lack of conversion to the fed pattern with a liquid meal. Although manometry was not performed before the development of the intussusception, our findings are consistent with the hypothesis that altered intestinal motility may contribute to the development of intussusception.

[The pulsatile flow index (PFI) in the diagnosis of dysfunctional kidney transplants]. / Der Pulsationsflussindex (PFI) in der Diagnostik dysfunktioneller Nierentransplantate.

In 61 patients (167 examinations) the pulsatile flow index (PFI) was used to diagnose the cause of renal transplant dysfunction. The results were correlated with histology and clinical course and outcome, angiography or quantitative radionuclide renography. Renal transplant rejection was diagnosed by PFI with a sensitivity of 85%. The specificity was 81% and the diagnostic accuracy 83%. The positive predictive value was found to be 76%, whereas the negative predictive value was 89%. In presence of acute tubular necrosis (ATN) the PFI was normal in 89% of examinations and therefore distinguishable from acute rejection.

Pulsatile flow index for qualitative measurements of blood flow with duplex ultrasound. An experimental study.

We determined the accuracy of Doppler blood flow measurements in an experimental investigation using a tissue-simulating phantom, pulsatile flow pumps and heparinized blood. A new index for qualitative assessment of blood flow, the pulsed flow index (PFI) is described. The PFI takes advantage of the area under the flow velocity curve between the true zero line and the diastolic baseline. Under conditions of continuous flow, the PFI ranged from 0.82 to 0.94 (mean value 0.90). The PFI was found to be relatively independent of the transducer/vessel angle (+/- 8%) and the inter/intra-operator variation was small (+/- 7.5%, or +/- 7%, respectively).

Loss of corticomedullary demarcation on magnetic resonance imaging: an index of biopsy-proven acute renal transplant dysfunction.

A prospective study of 19 cadaveric renal allograft recipients with suspected graft rejection was undertaken to compare the histological findings of the renal transplant biopsy with the results of magnetic resonance imaging (MRI). All 19 patients underwent a biopsy of the transplant allograft. Biopsy results included acute cellular rejection, acute vascular rejection, chronic vascular rejection (CVR), and acute tubular necrosis (ATN). Recipients of cadaveric renal allografts with normal function served as controls. The control showed distinct corticomedullary demarcation (CMD) on T1-weighted imaging. In contrast, CMD was absent or diminished in all the patients with suspected allograft rejection. Unfortunately, the loss of CMD did not correlate with a specific biopsy diagnosis. Patients with biopsy evidence of acute and chronic rejection or ATN demonstrated loss of CMD with similar image patterns. In conclusion, MRI is capable of detecting renal allograft dysfunction, but does not permit the determination of a specific cause.

Diagnosis of perirenal fibrosis by MR imaging.

A case of retroperitoneal perirenal fibrosis resulting in bilateral proximal ureteral obstruction is reported. Magnetic resonance imaging provided tissue specific diagnosis of the disease.