CT-Guided Percutaneous Drainage and Fluid Aspiration in Intensive Care Patients

Fifty-two intensive care unit (ICU) patients with clinical signs of sepsis who were considered to be at extremely high risk for operation were subjected to CT-guided interventions. Bedside ultrasound (US) had been performed prior to CT in all patients but diagnoses were equivocal or US-guided interventions had failed. Nineteen patients solely underwent CT-guided diagnostic aspiration of fluid collections to rule out infection. Eighteen patients (72%) with abscess formations after surgery or trauma were cured by catheter drainage alone; 4 patients required additional surgery. Out of 8 patients suffering from acute pancreatitis (after several necrosectomies), abscesses could be cured in 5 (62.5%). Three patients with acute necrotizing pancreatitis (no surgery) were not cured by the interventional procedure and all required surgical debridement. Even patients who required additional surgery after drainage improved clinically after the interventional radiologic procedure. Our overall success rate was 64%, emphasizing the need for CT in the case of equivocal US results or if US-guided procedures have failed in ICU patients with signs of sepsis.

[Health economics evaluation of magnetic resonance imaging for the staging of prostate cancer for Austria and Germany]

PURPOSE

The aim of this study was the health economics analysis of MR imaging in the preoperative staging of patients with prostate carcinoma (PCa).

MATERIALS AND METHODS

The health economics analysis consisted of the following steps: modeling, determination of probabilities and parameters based on a detailed literature search, evaluation using the averages of the parameters, and sensitivity analyses of the results over the ranges of values. We performed a cost-utility analysis from health insurance's perspective for Austria and Germany. The population under investigation included patients with confirmed PCa. The alternative was a decision for therapy with or without staging using MR imaging. A localized PCa was treated by prostatectomy and locally advanced PCa by radiation/hormone therapy. The result parameters were quality adjusted life years (QALYs) and costs per patient.

RESULTS

The evaluation showed that MR imaging is useful regarding costs and utilities prior to radical prostatectomy which is expensive and may be associated with serious clinical consequences. The costs per patient were lower by € 2635 and the utilities were higher by 0.099 QALYs. The strategy without MR imaging for staging was dominated by the strategy using MR imaging for staging in the evaluation using the base values and in almost all sensitivity analyses.

CONCLUSION

For the parameters used and almost all scenarios of the sensitivity analysis, our decision-analytic model revealed a higher cost-utility ratio for the strategy using MR imaging for the staging of PCa.

[Health-economic evaluation of magnetic resonance imaging before biopsy for diagnosis of prostate cancer]

PURPOSE

The aim of this study was the health-economic analysis of MR imaging in the diagnostics of suspicious prostate carcinoma (PCa) before execution of a first biopsy.

MATERIALS AND METHODS

The health-economic analysis included four steps: modeling, determination of probabilities, evaluation, and sensitivity analyses. We performed an effectiveness analysis from the patient perspective as well as a cost-effectiveness and a cost-utility analysis from the health insurance perspective for Austria and Germany. The effectiveness and cost-effectiveness analysis used a hypothetical cohort of 100,000 patients. The result parameters were number of biopsies, number of detected PCa, and monetary costs. For the cost-efficiency analysis, the result parameters, quality-adjusted life years (QALYs) and costs, were calculated for an individual patient.

RESULTS

The efficiency analysis showed that MRI before a first biopsy can prevent ca. 64,000 unnecessary biopsies/ 100,000 patients. The diagnostic efficiency was higher by a factor of 1.7. Due to MRI, eight PCas were additionally detected. From a health insurance perspective, MRI was not cost-effective. Extra costs of ca. 42 m. € per 100,000 patients and of 650 € per prevented biopsy were calculated. The costs per detected PCa were increased by 1395 €. The attainable QALYs were a little higher for the MRI alternative, which was therefore not dominated.

CONCLUSION

Our results do not permit a clear recommendation for or against the application of MRI in the diagnostics of PCa. From the patient perspective, it is to be endorsed due to the higher medical efficiency. However, it is connected with higher health insurance costs.

MR imaging-guided biopsy and therapeutic intervention in a closed-configuration magnet: single-center series of 361 punctures

OBJECTIVE

The purpose of the study was to evaluate practical experience with interventional MR imaging in a closed-bore 1.5-T imaging system. A total of 361 MR-guided biopsies were performed in 250 patients and analyzed retrospectively. The technique comprised four steps: localization; planning; action (cutting or aspiration biopsy, or instillation of a therapeutic agent), with verification in two perpendicular planes; and obtaining control scans.

CONCLUSION

The mean duration of a biopsy was 21 min; there were no major complications. Image contrast, signal, matrix options, and visibility of needle track and tip position permitted uncomplicated orientation. The interventional MR technique could be applied in any puncture setting.

rt-PA thrombolysis in acute thromboembolic upper-extremity arterial occlusion

PURPOSE

Retrospective analysis of the results of rt-PA thrombolysis in the treatment of acute thromboembolic occlusion of the upper limb.

METHODS

Of 55 patients with demonstrated acute embolic arterial occlusion, rt-PA thrombolysis was performed on 40 occlusions in 38 patients (23 women with a mean age of 62 years, range 32-85 years; 15 men with a mean age of 65 years, range 32-92 years) according to the following design: 6 mg rt-PA/hr for 30 min, 3 mg rt-PA/hr for the next 30 min, 1 mg rt-PA/hr for 7 hr, and 0.4 mg rt-PA/hr until the end of lysis. Onset of symptoms varied from 1 to 14 days. Included were three isolated upper-arm occlusions, nine combined brachial and forearm occlusions, and 28 forearm and hand artery occlusions.

RESULTS

The overall success rate was 55%. The lysis results for isolated upper arm, combined brachial and forearm occlusions, and forearm and hand artery occlusions were 100%, 66%, and 46%, respectively. In eight patients surgical embolectomy had to be performed after failed thrombolysis. No amputation was required in the follow-up period. No lethal complications occurred.

CONCLUSIONS

Interventional rt-PA treatment of proximal upper-extremity arterial occlusions may be performed with comparable success rates to surgical embolectomy and without severe complications. For distal occlusions the results are inferior to the success rates obtained with surgery.

Anatomy of the orbital apex and cavernous sinus on high-resolution magnetic resonance images

Diseases of the orbital apex and cavernous sinus usually present with involvement of multiple cranial nerves, corresponding to the complex anatomy of the region. In nontraumatic disorders, magnetic resonance imaging is the diagnostic modality of choice. However, its capabilities can be fully used only with thorough knowledge of the complicated topographic relationships in this region. This article describes the imaging anatomy of the cranio-orbital junction and adjacent subarachnoid spaces. High-resolution magnetic resonance images of normal subjects are presented, and the results are compared with findings reported in the literature. The following anatomic structures can be visualized on high-resolution magnetic resonance images: extraocular muscles and corresponding connective tissue, major orbital and cerebral arteries, ophthalmic veins, cavernous sinus, and all sensory and motor cranial nerves of the eye along their intraorbital and intracranial course.

High-resolution MR imaging anatomy of the orbit. Correlation with comparative cryosectional anatomy

High resolution MR imaging of the orbit enables visualization of anatomic details in the orbit, including important blood vessels, muscles, nerves and connective tissue structures. The best resolution of anatomic details currently is obtained by using surface coils and T1-weighted spin echo sequences. Some examples of clinical applications demonstrate that a detailed knowledge of orbital imaging anatomy is a prerequisite for successful interpretation of clinical MR images. Additionally, this noninvasive diagnostic technique may be used for anatomical in vivo studies.

[Simple and effective rt-PA thrombolysis design]

PURPOSE

Assessment of a novel, simple and practical thrombolysis scheme for the purposes of a central hospital.

MATERIALS AND METHODS

314 thromboembolic lower extremity occlusions in 260 consecutive patients were treated by thrombolysis as follows: 6 ml rt-PA/h for 30 min; 3 ml rt-PA/h for another 30 min; 1 ml rt-PA/h for 7 hours, and 0.4 ml rt-PA until vessel patency. Antegrade introduction of a 5 F straight end-hole catheter through a 6 F, constantly heparin-flushed sheath, to the level of occlusion was followed by subsequent advancement of the catheter tip according to progress of lysis at time intervals of 2, 4, and 8 hours. The regimen was continued overnight.

RESULTS

82% of arterial occlusions were completely recanalized at the end of thrombolysis. Then, angioplasty was performed if appropriate. Best results (100% recanalization rate) were achieved by treating occlusions of the superficial femoral artery, even in cases of involvement of the entire length of the vessel, and isolated popliteal occlusions. A recanalization rate of 70% was achieved by treating distal crural vessel occlusion. Bypass grafts were recanalized in 50%.

COMPLICATIONS

3 x major hematoma, 2 x transluminal perforation; 16 x minor hematoma from the puncture site at the sheath, 4 x erythema, obviously reaction to rt-PA (together n = 25; 8%).

CONCLUSIONS

We empirically found and solidly evaluated an effective thrombolysis scheme. Our results demonstrate that major advances are possible even in this well-grounded field.

Placement of venous stents: clinical experience with a self-expanding prosthesis

A self-expanding vascular prosthesis was used to treat 20 venous stenoses or occlusions in 13 patients. The lesions were caused by tumor (n = 5), postoperative fibrous scars (n = 2), and chronic hemodialysis fistulas (n = 13). Follow-up ranged between 6 weeks and 53 months (mean follow-up, 14.9 months). Acute occlusion occurred in two stents, one within a tumor stenosis and one in a dialysis shunt after 3 days and 2 days, respectively. Balloon angioplasty, thrombolysis, and aspiration in the first case and balloon angioplasty and thrombolysis in the second case successfully restored patency. Definite occlusion occurred in these two patients after 8 weeks and 5 months, respectively. Ten secondary interventions were performed in three patients with 10 restenoses who had stenotic arm veins in chronic hemodialysis at presentation. Five of seven patients who received treatment for stenoses associated with hemodialysis underwent successful kidney transplantation 5-27 months after placement of vascular stents. Both patients who received treatment for benign strictures had patent stents at follow-up examinations performed at 45 and 53 months, respectively. Four of five stents placed for malignant stenoses were patent at venography (n = 3) or autopsy (n = 1).

Hemodialysis related venous stenoses: treatment with self-expanding endovascular prostheses

Seven patients undergoing chronic hemodialysis presented a total of ten venous stenoses which were treated with self-expanding metallic vascular endoprostheses. Four lesions were central (brachiocephalic and subclavian vein). One acute occlusion could be successfully recanalized by PTA. Restenosis prompted seven secondary interventions. Four patients underwent a kidney transplantation between 5 and 8 months after vascular stenting. Definite occlusion occurred in one patient. According to our experience, stenting of large central veins in hemodialysis patients seems less prone to restenosis due to intimal hyperplasia. Despite a high restenosis rate in the peripheral lesions we believe that stenting is a useful tool in the treatment of hemodialysis-related venous stenosis, permitting a significant prolongation of shunt function.

CT-guided percutaneous drainage and fluid aspiration in intensive care patients

Fifty-two intensive care unit (ICU) patients with clinical signs of sepsis who were considered to be at extremely high risk for operation were subjected to CT-guided interventions. Bedside ultrasound (US) had been performed prior to CT in all patients but diagnoses were equivocal or US-guided interventions had failed. Nineteen patients solely underwent CT-guided diagnostic aspiration of fluid collections to rule out infection. Eighteen patients (72%) with abscess formations after surgery or trauma were cured by catheter drainage alone; 4 patients required additional surgery. Out of 8 patients suffering from acute pancreatitis (after several necrosectomies), abscesses could be cured in 5 (62.5%). Three patients with acute necrotizing pancreatitis (no surgery) were not cured by the interventional procedure and all required surgical debridement. Even patients who required additional surgery after drainage improved clinically after the interventional radiologic procedure. Our overall success rate was 64%, emphasizing the need for CT in the case of equivocal US results or if US-guided procedures have failed in ICU patients with signs of sepsis.

[The value of mammography in patients up to the age of 35]

The use of mammography in young women is under debate. In this prospective study of 220 women aged up to 35 years, the indications for mammography were compared with the final diagnosis. In this way, an attempt was made to define the signs and symptoms that justify mammography in this age group. The results show that mammography is indicated only in the presence of palpable lumps. All other signs or symptoms should not be investigated by means of ionising radiation in this particular age bracket.

Arterial stent placement with use of the Wallstent: midterm results of clinical experience

Self-expandable stents of the Wallstent type were used in 26 iliac and 15 femoropopliteal artery lesions of 31 patients to treat stenoses or occlusions. The indications were confined to complex lesions, including residual stenoses and dissections after percutaneous procedures or previous surgery in the iliac artery lesions, and long-segment (mean, 13.5 cm) occlusions with inadequate response to percutaneous recanalization in the femoropopliteal artery lesions. In the iliac artery group, after stent placement, 96% of the lesions were patent at a mean follow-up of 16 months (range, 6-30 months). In the femoropopliteal artery group, of 11 patients available for follow-up, only six had patent stents at 7-26 months (mean, 20 months). Four of these six patients required one to three secondary interventions. Self-expanding endoprostheses are of great value in complex iliac artery lesions where simple balloon dilation is insufficient. Stent placement for long femoral artery lesions should be performed with utmost reserve, and the extent of stent placement should be as short as possible.

Injury of the Achilles tendon: diagnosis with sonography

We determined the diagnostic accuracy of sonography for the assessment of injury to the Achilles tendon. After anatomic investigations in three human cadavers, we performed a clinical study in 24 healthy volunteers and 73 symptomatic patients referred for achillodynia or signs of heel thickening or both in whom a clinical diagnosis of acute total rupture was excluded. High-resolution real-time sonography was performed and the results were compared with final clinical diagnoses (55 patients) and surgical findings (18 patients). Fifty-two of the patients had been involved in various sporting activities (long-distance runners, jumpers, and basketball players), three patients had familial hypercholesterolemia, five patients had systemic inflammatory disease, and 13 patients had no known underlying cause. Anatomic investigation demonstrated accurate assessment of tendon structure and thickness. Sonograms were abnormal in 53 patients (sensitivity, 0.72; specificity, 0.83), and the extent of structural disorders of the tendon could be assessed properly. Abnormalities occurred in the form of tendon swelling (45%), abnormal tendon structure (42%), rupture (15%), and peritendinous lesions (47%). No changes were detected in low-grade disease of short duration, which suggests symptoms caused by functional disorders. Sonography is valuable in the diagnosis of various lesions of the Achilles tendon and its surrounding tissue. Furthermore, it can be used to estimate the degree of tendon abnormality and to differentiate between functional and morphologic conditions.

[Better evaluability of post-therapeutic mammograms using a double-exposure technic. A prospective perception study]

The authors have found the results of a dual-exposure technique for the breast which proved very useful for evaluations following surgery and irradiation. The technique consists of double exposure of the treated breast on two films, one with the exposure data of the normal breast and one with two additional mAs steps. The two films demonstrate anatomical details better than conventional techniques. The over-exposed film shows 18% more reticular patterns than the standard exposure. The authors believe that the dual-exposure technique is a valuable adjunct in the management of the postoperative breast-cancer patient.

Breast calcifications in renal hyperparathyroidism

A prospective mammographic study was performed on 151 women to determine the prevalence of breast calcifications in patients with chronic renal failure. Frequency, size, structure, and location of calcific lesions were assessed in 15 patients with compensated renal insufficiency, 22 on hemodialysis, 14 who had renal transplants, and 100 who had normal kidney function. Serum levels of calcium, phosphorus, alkaline phosphatase, and parathyroid hormone were determined for all 151 women. The calcific lesions occurred preponderantly in dialysis patients (arteries, 55%; parenchyma, 68%; and ducts, 36%). Next in order were those with renal transplants (43%, 64%, and 29%, respectively) and those with renal insufficiency (33%, 53%, and 20%, respectively). Patients with renal disease had significantly more calcifications (p less than .001) than the patients with normal kidney function: arteries, 45% vs 8%; parenchyma, 61% vs 27%; and ducts, 29% vs 9%. Frequencies of calcifications correlated with serum levels of parathyroid hormone. None of the calcifications induced by renal disease simulated those seen in carcinoma of the breast.

[Malformation of the inner ear. Cerebrospinal otorrhea in stapedectomy]

Otoliquorrhoea occurred during stapedectomy (gusher) and signified a case of inner ear malformation which was not apparent on preoperative tomograms but could be demonstrated on postoperative CT scans. There was no bony separation between the irregularly dilated inner auditory canal and the vestibulum. The cochlea was not fully rotated. Intraoperative problems in such malformations may lead to further postoperative hearing impairment. Hence, we report on the clinical, operative and CT findings in order to avoid an operation in patients with similar signs and symptoms.

[Tuberculosis of the female breast: diagnostic clarification]

Modern therapeutic possibilities made tuberculosis of the breast a rare entity which, however, still exists and usually mimicks a malignancy. It represents a secondary organ manifestation and should be considered in differential diagnosis in all cases of primary lung tuberculosis and when fine needle biopsy fails to yield the expected tumour cells. We demonstrate such a case of breast tuberculosis and stress the cytologist's option to restain any cytological slide according to Ziehl-Neelsen. In our case, this renewed staining established the correct diagnosis.

The intravertebral vacuum phenomenon

An intravertebral vacuum phenomenon was observed within 19 vertebrae of 17 patients. It represents a non-healing vertebral fracture. Three possible pathologic mechanisms are discussed: ischemic bone necrosis, trauma with ensuing ischemic necrosis, and intraosseous disc prolapse. The intravertebral vacuum phenomenon was found in two patients with multiple myeloma and thus does not exclude the presence of malignancy in the affected bone. Radiographs obtained during traction or extension may be of diagnostic value.

Dynamic 123I-HDA myocardial scintigraphy after aortocoronary bypass grafting

In an attempt to evaluate the dynamics of fatty acid metabolism after aortocoronary bypass grafting (ACBG), ten patients were investigated after ACBG by 123I-HDA myocardial scintigraphy. Tracer kinetics were followed for 90 min and compared to those of 36 nongrafted patients with different underlying heart diseases, including healthy volunteers. Regional analysis and monoexponential curve fitting were used to evaluate t1/2 (half-life of the early period of tracer elimination); biexponential curve analysis was used to calculate Ca/Cb, the ratio of a fast and a slow component of tracer elimination. Rest and stress MUGA-RNV served as discriminating parameters to discern between patient groups with normal and abnormal ventricular function. Group I (normal controls) encompassed ten patients with normal ventricular function, including three after ACBG, and group II seven patients after ACBG and with abnormal ventricular function. Group III had coronary artery disease (CAD) documented by angiography, and group IV by prior myocardial infarction (MI). Group V included patients with cardiomyopathy (CMP). Regional analysis of group II revealed no significant differences to control regions (Gr I) for t1/2 or Ca/Cb, but showed for Ca/Cb a nonsignificant shift toward group III values. However, group II differed significantly from group III and V. Three patients with normal ventricular function after ACBG showed elimination values that were all well within the range of completely normal individuals. Thus our data support the assumption that a normal function is indicative of a normal metabolism. Following myocardial fatty acid metabolism during rest might be a helpful noninvasive tool for etiologic differentiation of disturbed ventricular function.

[Sonographic localization of a bullet in the pericardium]

We report a case of pericardial localisation of a bullet by sonography. The metallic foreign body could be demonstrated by its typical sonographic appearance of a strongly echogenic lesion with acoustic reverberation artefacts. Sonography proved superior to the other diagnostic modalities including computed tomography.

Lymph nodes of the neck: evaluation with US

Ultrasound (US) proved highly effective for detection, localization, and delineation of enlarged lymph nodes of the neck. Infiltration of adjacent structures, specifically the common, internal, and external carotid arteries, and the neck muscles was reliably demonstrated. Benign and malignant lymph node enlargement could not be differentiated. US examinations changed the operative course of 56% of patients studied. In 41%, a more radical operative procedure was performed than was previously planned; in 14%, US demonstrated inoperability. Small-parts US is a very useful adjunct to current imaging techniques of cervical lymph node disease.

[Expansion, deformation and bursting characteristics of frequently used balloon dilatation catheters. In vivo studies on canine vessels (2)]

In an experimental angioplasty study in dogs, we evaluated the characteristics of dilatation and deformation, as well as the pressure requirements, bursting points, and types of bursting of four different balloon dilatation catheters. The balloons, which were selected 0%, 30%, and 80-100% larger than the arterial lumen, measured 4, 6, and 8 mm in diameter and were inflated with an automated pump which simultaneously recorded balloon pressure and volume. Changes to the vessel wall were assessed radiographically and by histology. In vivo, balloon dilatation catheters demonstrated a markedly different behaviour than in vitro. Significantly higher pressures were tolerated due to the support of the arterial sleeve. Non-compliant oversized balloons caused more damage to the arterial wall than compliant ones. Oversized balloons attained their required diameters only with high inflation pressures of 10 to 12 atm or after rupture of the artery.

Hydrophilic-lipophilic balance as predictor of mucus coating with barium sulfate

In order to improve barium coating of the mucus layer covering the alimentary tract, various surface active substances are added to commercially available contrast media. The action of additives can be expressed in part by their hydrophilic-lipophilic balance (HLB). In an experimental study using human colonic mucus and barium sulfate USP, surfactants of varying HLB (range, 3-11) were used to study the range of HLB resulting in optimal coating. The best coating occurred with an HLB of 7. Quality of coating may be predicted based on knowledge of the HLB of various surface active additives.

[Expansion, deformation and bursting characteristics of commonly used balloon dilatation catheters. In vitro studies (1)]

We evaluated the characteristics of dilatation and deformation, as well as pressure requirements, bursting point, and type of bursting of the five most common balloon dilatation catheters. Polyvinyl chloride, polyethylene, and polyurethane-nylon balloons from 4 different manufacturers were examined in water-baths and an arrangement of tightly fitting teflon tubes. Defined balloon inflations were monitored and documented until balloon rupture occurred. Significant differences were found according to the different constructions and materials of the balloon catheters. Modern PVC showed a quality equal to PE material. Marked and clinically relevant differences of balloon compliance and behaviour in the water baths and within teflon tubes were demonstrated.

The disease-free wall in coronary atherosclerosis: its relation to degree of obstruction

Coronary atherosclerotic lesions are more often located eccentrically (70%) than concentrically (30%). In this study, the configuration of eccentric coronary artery atherosclerotic lesions was assessed by means of computerized planimetry in 100 specimens of eccentric arterial lesions. Special attention was given to the relation between the disease-free wall and the severity of obstruction. The mean disease-free wall are length measured between 17 and 23% of the total vessel circumference in eccentric coronary artery lesions that obstructed 50 to 90% of the cross-sectional area. This ratio persisted irrespective of the location of the lesion within the vessel and was not significantly different with vessels of different sizes. The presence of disease-free arcs of coronary artery wall as observed in this pathologic study may relate to three factors in clinical coronary artery disease: The published observations of spasm in segments of arteries harboring structural obstructive lesions may be explained by the frequent presence of uninvolved arcs of coronary artery walls. Multiple views during coronary arteriography are necessary to accurately reflect the degree of obstruction. The results of percutaneous transluminal coronary angioplasty may be influenced by both the disease-free arc and the atheromatous obstruction.

[Nonvisualization of the gallbladder lumen by sonography]

Out of 12 000 sonographic examinations of the abdomen in 211 cases the gallbladder was not visualized. The retrospective analysis of 41 patients revealed in 75% gallstones, in 15% space occupying lesions (4 carcinomas, 1 abscess, 1 sludge). In 10% the sonography gave a false positive result. The reasons are discussed.

Technical developments and instrumentation: percutaneous transhepatic feeding jejunostomy

A new access route for insertion of a feeding jejunostomy using a percutaneous transhepatic approach is described in a case with advanced antral cancer. Standard PTC techniques and angiographic catheters were used.

Significance of balloon pressure recording during angioplasty. An experimental study

During angioplasty of artificial stenoses, atherosclerotic human cadaver arteries, and normal canine arteries, pressure and volume of the dilatation balloons were continuously recorded. We found that a sudden yield of a lesion corresponded to a sudden drop in the pressure curve and an increase of the balloon volume. Volume monitoring was insensitive, but pressure recording was very precise. Continuous pressure recording, using a non-compliant inflation system, correctly demonstrated small breaks and ruptures of atherosclerotic vessels, changes not seen on fluoroscopy.

The relation between arterial and balloon rupture in experimental angioplasty

Canine carotid, iliac, and femoral arteries underwent transluminal angioplasty with increasing balloon pressure from 4.5 to 12.5 atm. Balloons were selected according to vessel diameter: equal to (zero), 50% larger, and 100% larger than the vessel. The aim of this study was to assess possible disruption of the artery by a bursting balloon. With zero or 50% overdilation, arterial rupture did not occur despite balloon rupture. With 100% overdilation, arterial rupture always preceded balloon rupture. Rupture of all layers of the vessel was caused by severe overdistension, followed by secondary rupture of the balloon because it had lost its external support.

[Bedside chest x-rays and extravascular lung water determination in intensive care patients]

Radiological staging of pulmonary oedema was compared with the determination of extra-vascular lung water by means of a double indicator dilution technique. One hundred and forty-six ward chest radiographs were evaluated and compared with the results of simultaneous measurements of lung water. Seventy-seven cases could be evaluated statistically. Chest x-rays regarded as normal corresponded to extra-vascular lung water of 5 to 9 ml./kg. body weight. Interstitial oedema (radiological stage I and II) corresponded to extravascular lung water levels of 8 to 12 ml./kg. Differentiation of stages I and II was not possible. During stage III, extra-vascular lung water was 15 to 21 ml./kg. A comparative analyses of these findings revealed a discrepancy of 34%. The reasons for this are discussed.

[Mirizzi syndrome: a sonographic diagnosis?]

The ultrasound appearances of 11 patients with operatively confirmed Mirizzi syndrome have been analysed. The trio 'dilated intrahepatic bile ducts, concretions in the neighbourhood of the dilated common hepatic duct with a normal distal duct' permit the diagnosis of the Mirizzi syndrome with considerable certainty. In five patients these features were found by sonography and no other diagnostic procedure was necessary. In six patients, ERC was carried out in order to evaluate the distal common bile duct. In one case PTC was carried out, since the liver hilum could not be seen on sonography.

Radiologic diagnosis of wandering spleen complicated by splenic volvulus and infarction

Wandering spleen is a rare condition caused by malattachment of the dorsal mesogastrium. This condition is prone to torsion of the splenic pedicle leading to splenomegaly, hypersplenism, and infarction. Preoperative diagnosis can be suggested radiologically. A case of wandering spleen is reported and its embryologic, clinical, and radiographic features are discussed.

Transluminal angioplasty evaluated by electron microscopy

To gain more understanding about the changes that follow balloon angioplasty, an electron and light microscopic study was carried out in normal canine arteries. Thirty-five arterial segments were dilated with balloon catheters. Early changes consisted of denudation of the intima with widespread necrosis of myocytes and dehiscence of collagen fibers. After three days, myocytes had disappeared leaving empty spaces and edematous ground substance. After two weeks, reendothelization occurred and there was evidence of intimal hyperplasia persisting up to two months. Repair of the dilated arterial segments occurred by proliferation of myocytes, formation of intima, and proliferation of collagen. In two to three months, repair of the intima and media was completed. After six months, dilated segments were characterized by persistent intimal hyperplasia and increased collagen content in the media.

Percutaneous transluminal angioplasty for treatment of renal artery stenosis in children

Angioplasty was carried out in four children with hypertension and renal artery stenosis, including one patient with neurofibromatosis and one patient with multiple arterial stenoses. Two patients did not respond. In the patient with neurofibromatosis the stenosis persisted unchanged despite multiple balloon inflations. In one patient hypertension persisted despite successful dilatation, and was probably related to longstanding contralateral kidney disease. Two patients had excellent blood pressure response to dilatation. One of these patients required redilatation of bilateral recurrent stenoses.

Effect of prostaglandin inhibition on the renal vascular response to ionic and non-ionic contrast media in the dog

In an attempt to study the role of prostaglandins in the renal vascular response to contrast media in mongrel dogs, renal arterial injections of 6 ml of either the non-ionic contrast medium Iopamidol or the ionic medium diatrizoate meglumine/Na+ were performed, before and after intravenous injection of a buffered solution of acetylsalicylic acid (10 mg/kg) (ASA). Renal blood flow was recorded using non-occluding electromagnetic flow probes. The resting renal blood flow was significantly reduced after ASA. The usual biphasic response to contrast injection was observed both before and after ASA, and using either contrast medium. Analysis of the results failed to show any difference in degree of vasodilation or vasoconstriction after ASA. We conclude that prostaglandins may affect the resting level of renal blood flow but are not mediators of the instantaneous changes in response to contrast injection.

A logical approach to renal stone removal

On the basis of experience with over 350 percutaneous stone extractions, a logical approach assuring a high success rate and minimizing complications is described. The importance of the position of the kidney in the body, the caliceal anatomy, the renal arterial anatomy, and the instrumentation used on puncture site selection are discussed. Strategies for removal of caliceal, pelvic, ureteral, and staghorn calculi, rationale, and treatment of complications are also described.

Failing arteriovenous dialysis fistulas: evaluation and treatment

A total of 31 patients with 45 episodes of failing arteriovenous dialysis fistulas was studied. Fistula failure was usually due to venous and/or anastomotic stenosis, often in conjunction with thrombosis. Abnormalities were treated by percutaneous dilation and occasionally streptokinase infusion. Most complications and failures occurred either in patients with recently created fistulas or in those with multiple or long segment stenosis associated with thrombosis. Patients with a single nonobstructing stenosis were very successfully treated with percutaneous techniques, which are the treatment of choice for this condition.

Sonography of abdominal posttransplant lymphoma

Five patients developed abdominal lymphoma an average of 89 months after successful renal transplantation. Sonographically, the lymphomas presented as bulky intraperitoneal masses or focal deposits in the liver. These lesions exhibited good sound transmission and intrinsic patterns ranging from sparse, soft echoes to coarse trabeculations. Prompt diagnosis of this serious late complication of renal transplantation is crucial.

Nephrotoxicity of contrast media assessed by occlusion arteriography

The authors describe an experimental model for the study of nephrotoxicity induced by contrast media, based on a standardized injection combined with occlusion of the renal artery so as to expose the kidney to a high concentration of contrast medium for ten minutes. Iopamidol, ioxaglate, and both isosmolar and hyperosmolar saline were well tolerated, but diatrizoate caused marked radiological and pathological changes. This model may be helpful in studies of the mechanisms underlying contrast medium nephrotoxicity and evaluating differences in toxicity between contrast agents.

A new vena caval filter for percutaneous placement and retrieval: experimental study

A new vena caval filter that can be inserted percutaneously through an angiographic catheter is described. The filter is secured by controlled penetration of the caval wall and is designed for percutaneous retrieval. The filter was easily and safely placed and removed in 11 mongrel dogs, and in an in vitro study, the filter was shown to be highly effective and less dependent than the Greenfield filter on positioning. The authors believe that the filter will be suitable for prophylactic placement in patients at high risk for pulmonary thromboembolic disease.