CT venography for the diagnosis of postpartum venous thromboembolism: a prospective multi-center cohort study.

OBJECTIVES: To assess the role of CT venography (CTV) in the diagnosis of venous thromboembolism (VTE) during the postpartum period. MATERIALS AND METHODS: This multicenter prospective cohort study was conducted between April 2016 and April 2020 in 14 university hospitals. All women referred for CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE) within the first 6 weeks postpartum were eligible. All CTPAs were performed on multidetector CT machines with the usual parameters and followed by CTV of the abdomen, pelvis, and proximal lower limbs. On-site reports were compared to expert consensus reading, and the added value of CTV was assessed for both. RESULTS: The final study population consisted of 123 women. On-site CTPA reports mentioned PE in seven women (7/123, 5.7%), all confirmed following expert consensus reading, three involving proximal pulmonary arteries and four limited to distal arteries. Positive CTV was reported on-site in nine women, five of whom had negative and two indeterminate CTPAs, bringing the VTE detection rate to 11.4% (14/123) (95%CI: 6.4-18.4, p = 0.03). Expert consensus reading confirmed all positive on-site CTV results, but detected a periuterine vein thrombosis in an additional woman who had a negative CTPA, increasing the VTE detection rate to 12.2% (15/123) (95%CI: 7.0-19.3, p = 0.008). Follow-up at 3 months revealed no adverse events in this woman, who was left untreated. Median Dose-Length-Product was 117 mGy.cm for CTPA and 675 mGy.cm for CTPA + CTV. CONCLUSION: Performing CTV in women suspected of postpartum PE doubles the detection of venous thromboembolism, at the cost of increased radiation exposure. CLINICAL RELEVANCE STATEMENT: CTV can help in the decision-making process concerning curative anticoagulation in women with suspected postpartum PE, particularly those whose CTPA results are indeterminate or whose PE is limited to the subsegmental level. KEY POINTS: Postpartum women are at risk of pulmonary embolism, and CT pulmonary angiography can give equivocal results. CT venography (CTV) positivity increased the venous thromboembolism detection rate from 5.7 to 11.4%. CTV may help clinical decision-making, especially in women with indeterminate CTPA results or subsegmental emboli.

Temporal Deployment of Attention by Mental Training: an fMRI Study.

In this study, we employed a visuo-motor imagery task of alertness as a mental training to examine temporal processing of motor responses within healthy young adults. Participants were divided into two groups (group 1; n = 20 who performed the mental training before the real physical task and a control group who performed the physical task without mental training). We vary the time interval between the imperative stimulus and the preceding one (fore-period) in which temporal preparation and arousal increase briefly. Our behavioural results provide clear evidence that mental training reinforces both temporal preparation and arousal, by shortening reaction time (RT), especially for the shortest fore-periods (FP) within exogenous "FP 250 ms" (p = 0.008) and endogenous alertness "FP 650 ms" (p = 0.001). We investigated how the brain controls such small temporal changes. We focus our neural hypothesis on three brain regions: anterior insula, dorsolateral prefrontal cortex, and anterior cingulate cortex and three putative circuits: one top-down (from dorsolateral prefrontal cortex to anterior cingulate cortex) and two bottom-up (from anterior insula to dorsolateral prefrontal cortex and anterior cingulate cortex). In fMRI, effective connectivity is strengthened during exogenous alertness between anterior insula and dorsolateral prefrontal cortex (p = 0.001), between anterior insula and cingulate cortex (p = 0.01), and during endogenous alertness between dorsolateral prefrontal cortex and anterior cingulate cortex (p = 0.05). We suggest that attentional reinforcement induced by an intensive and short session of mental training induces a temporal deployment of attention and allow optimizing the time pressure by maintaining a high state of arousal and ameliorating temporal preparation.

PPARγ Agonists: Emergent Therapy in Endometriosis.

Endometriosis is one of the major gynecological diseases of reproductive-age women. This disease is characterized by the presence of glands and stroma outside the uterine cavity. Several studies have shown the major role of inflammation, angiogenesis, adhesion and invasion, and apoptosis in endometriotic lesions. Nevertheless, the mechanisms underlying endometriotic mechanisms still remain unclear and therapies are not currently efficient. The introduction of new agents can be effective by improving the condition of patients. PPARγ ligands can directly modulate these pathways in endometriosis. However, data in humans remain low. Thus, the purpose of this review is to summarize the potential actions of PPARγ agonists in endometriosis by acting on inflammation, angiogenesis, invasion, adhesion, and apoptosis.

Neural mechanisms associated with treatment decision making: An fMRI study.

Great progress has been made in understanding how people make financial decisions. However, there is little research on how people make health and treatment choices. Our study aimed to examine how participants weigh benefits (reduction in disease progression) and probability of risk (medications' side effects) when making hypothetical treatment decisions, and to identify the neural networks implicated in this process. Fourteen healthy participants were recruited to perform a treatment decision probability discounting task using MRI. Behavioral responses and skin conductance responses (SCRs) were measured. A whole brain analysis were performed to compare activity changes between "mild" and "severe" medications' side effects conditions. Then, orbitofrontal cortex (OFC), ventral striatum (VS), amygdala and insula were chosen for effective connectivity analysis. Behavioral data showed that participants are more likely to refuse medication when side effects are high and efficacy is low. SCRs values were significantly higher when people made medication decisions in the severe compared to mild condition. Functionally, OFC and VS were activated in the mild condition and were associated with increased likehood of choosing to take medication (higher area under the curve "AUC" side effects/efficacy). These regions also demonstrated an increased effective connectivity when participants valued treatment benefits. By contrast, the OFC, insula and amygdala were activated in the severe condition and were associated with and increased likelihood to refuse treatment. These regions showed enhanced effective connectivity when participants were confronted with increased side effects severity. This is the first study to examine the behavioral and neural bases of medical decision making.

Low molecular weight fucoidan prevents neointimal hyperplasia in rabbit iliac artery in-stent restenosis model.

OBJECTIVE: Smooth muscle cell (SMC) proliferation within the intima is regulated by heparan sulfates. We studied a low molecular weight (LMW) fucoidan (sulfated polysaccharide from brown seaweed) on SMC proliferation in vitro and intimal hyperplasia in vivo. METHODS AND RESULTS: In vitro study revealed that LMW fucoidan reduces rabbit SMC proliferation and is internalized in SMC perinuclear vesicles. On rabbit iliac arteries perfused in vivo with fluorolabeled LMW fucoidan after angioplasty, the labeling was mainly located on sites of injury. Pharmacokinetic studies showed that LMW fucoidan exhibited in rats an elimination half-life of 56+/-25 minutes (n=8) after intravenous administration and a constant plasma rate for > or =6 hours after intramuscular administration. After stent implantation in their iliac arteries, rabbits were also treated with LMW fucoidan (5 mg/kg IM twice a day). Histomorphometric analysis at day 14 indicated that LMW fucoidan reduced intimal hyperplasia by 59% (1.79+/-0.4 versus 0.73+/-0.2 mm2, P<0.0001) and luminal cross-sectional area narrowing by 58% (0.38+/-0.08 versus 0.16+/-0.04, P<0.0001). Blood samples showed no anticoagulant activity due to LMW fucoidan. CONCLUSIONS: This natural polysaccharide with high affinity for SMCs and sustained plasma concentration markedly reduced intimal hyperplasia, suggesting its use for the prevention of human in-stent restenosis.

CT density distribution analysis in patients with cystic fibrosis: correlation with pulmonary function and radiologic scores.

RATIONALE AND OBJECTIVES: The progressive changes in lung morphology observed in cystic fibrosis (CF) can potentially affect the statistical distribution of computed tomography (CT) density values. This study aimed to characterize the lung CT density distributions by quantifying indices of the kurtosis and skewness of the lung density distribution and to compare these indices to radiologic scores and lung function parameters in children and young adults with CF. MATERIALS AND METHODS: CT scans and lung function of 26 patients with CF were retrospectively examined. The Bhalla radiologic scoring was performed separately, in random order, by two expert radiologists, blinded to the patient's identity, age, clinical status, results of lung function tests, and the other paired observer's score. RESULTS: Positive relations were evidenced between the log indices of lung density distribution kurtosis (iKurtosis) and the overall radiologic scores (RS) of both observers (R = 0.58; P < .001 vs RS1 and R = 0.71; P < .001 vs RS2). A similar relationship was evidenced with the log index of the degree of distribution asymmetry (iSkewness; R = 0.62; P < .001 vs RS1 and R = 0.62; P < .001 vs RS2). Log-iKurtosis and log-iSkewness were related to FEV1 (R = -0.56; P < 10(-5) and R = -0.55; P < 10(-5)) and to residual volume (R = 0.40; P < .001 and R = 0.45; P < .001, respectively). Both radiologic scores showed significant relation with lung function. The correlation between RS1 and RS2 was excellent (R = 0.93), with a Cohen weighted kappa of 0.43. CONCLUSIONS: Characteristic indices of lung CT density distribution are correlated to lung function and radiologic scores in patients with CF and merit further evaluation as part of more comprehensive automated methods for quantifying CF lung CT data.

Evaluation of a new hands-up ergonomics for chest radiography in geriatric patients.

RATIONALE AND OBJECTIVES: Pneumonia is the leading cause of death after the age of 85 years. Chest radiography (CXR) requires forced inspiration for accurate assessment, but kyphosis, denutrition, muscular weakness, and neurologic disorders limit active inspiration. The aim of this study was to evaluate a new passive expansion technique, by raising the patient's arms above the head, in the radiographic diagnosis of pneumonia. METHODS: During a 10-month period, CXR were performed in 1452 geriatric patients for pulmonary acute disorders in our geriatric university hospital. When fewer than five anterior rib segments were visible on the conventional front view, a second CXR was performed with the patient's arms being raised above the head by a radiologist. The diagnostic questions were: Are more than five anterior rib segments present? Is pneumonia visible? The chest radiographs were independently analyzed (3-step confidence scale) by two radiologists and compared by interobserver kappa-coefficients calculation. RESULTS: One hundred three patients (97 female, 6 male), representing 7% of the examined population, with an average age of 86.5 years (range, 70-104 years) were included. An additional anterior rib segment was visible on the front CXR when the arms were raised above the head (P < 0.001). Pneumonia was diagnosed in 59 patients with high agreement (kappa = 0.84) by the passive expansion technique, whereas the pneumonia infiltrate was visible in only 44 patients with considerably lower agreement (kappa = 0.36) when the arms were positioned along the trunk (P < 0.03). CONCLUSIONS: Raising the arms above the head optimizes the quality of CXR and increases the detection of pneumonia in the geriatric patient. New ergonomics and adequate contention are required.

Risk factors for nosocomial pneumonia in a geriatric hospital: a control-case one-center study.

OBJECTIVES: To determine the risk factors (RFs) and the incidence of nosocomial pneumonia (NP). DESIGN: Control/case study conducted from January 1 to April 15, 1999. Prospective enrollment. SETTING: Geriatric university hospital with long-, intermediate-, and short-term care facilities. PARTICIPANTS: Inpatients aged 65 and older with NP. MEASUREMENTS: NP diagnosis relied on at least two clinical signs of respiratory infection and on chest radiography. Each NP case was randomly paired with two controls and followed up for 30 days to determine complication and mortality rates. RFs between cases and controls were compared (chi-square test, odds ratio (OR), 95% confidence interval, significance level P =.05). RFs that were significant in univariate analysis were tested using multivariate analysis and logistic regression. RESULTS: Seventy-five cases of NP were diagnosed in 2,142 patients. The average incidence rate was 3.5% (short-term facilities = 0.5%; intermediate-term facilities = 8.3%; long-term care facilities = 5.3%). The complication rate was 58.1%. The most frequent complications were recurrent NP, heart and respiratory failure, phlebitis, and pressure ulcers. The NP mortality rate was 12.2%. The independent RFs of NP were a history of NP during the previous 6 months (OR = 4.50) and oxygen therapy (OR = 16.15), P <.001. Additional RFs were severe malnutrition, heart failure, prescription of antibiotics during the month preceding the emerging NP, eating dependency, and feeding by nasogastric tube. CONCLUSION: The main RF for NP is a history of pneumonia. NP prevention in geriatrics should rely on early management of respiratory infections and malnutrition, surveillance of oxygen therapy and enteral feeding, rational use of antibiotics, and adaptation to the patient's dependency.

Risk factors for deep vein thrombosis in inpatients aged 65 and older: a case-control multicenter study.

OBJECTIVES: To identify independent risk factors of symptomatic deep vein thrombosis (DVT) in geriatric inpatients and to define high-risk patients likely to benefit from preventive treatment. DESIGN: Hospital-based case-control multicenter study with prospective data collection. SETTINGS: Geriatric university hospitals with long-, intermediate-, and short-term care facilities. PARTICIPANTS: All patients aged 65 and older in 19 geriatric departments were submitted to clinical surveillance over a 16-month period. MEASUREMENTS: Twenty-three potential risk factors of phlebitis were screened for. Comparison using logistic regression of 310 consecutive patients with symptomatic DVT versus 310 randomly selected controls was performed. The risk for symptomatic DVT in geriatrics was then scored from the clinical risk factors identified using multivariate analysis. This score is defined by the sum of the odds ratio (OR) of each risk factor present. RESULTS: Six factors were identified as independently related to the development of DVT: restriction of mobility (from OR=1.73, limited mobility without immobilization, to OR=5.64, bedridden during <15 days), aged 75 and older (OR=1.5/10 years), history of DVT or pulmonary embolism (OR=3.38), acute heart failure (OR=2.52), chronic edema of the lower limbs (OR=2.51), and paresis or paralysis of a lower limb (OR=2.06). The defined score of 8 or higher corresponded to an 88.7% probability of having symptomatic DVT. CONCLUSION: Treatments to prevent symptomatic DVT in hospitalized elderly should be evaluated on patients with these factors.

The optional VenaTech(™) Convertible (™) vena cava filter: experimental study in sheep.

PURPOSE: Retrieval of optional caval filters may be impaired by filter tilting, migration, fracture, or embedding in the IVC wall. The goal of this experimental study was to evaluate a new optional filter, convertible by unlocking and removing the filter head. METHODS: Forty-nine Pre-Alp sheep (average weight, 55 kg) were anesthetized. IVC was catheterized via the right femoral vein (n = 46) or via the internal jugular vein (n = 3) with a 12.9-F sheath. VenaTech(™) Convertible(™) IVC filters were inserted as either permanent filters (n = 14) or as filters to be converted. Conversion was immediately after deployment (n = 19) or delayed after 1, 3, or 6 months (n = 20). Filter delivery, deployment, and conversion with measurement of migration and tilting were evaluated by cavography. Incorporation of the filter's stabilizers and arms in the IVC wall was assessed by gross anatomy. RESULTS: Delivery system insertion, filter release, and immediate conversion were successful in all cases. Delayed conversion was completed in all but one sheep, due to insufficient snare tension. Complimentary balloon-catheter inflation was required in 12 of 20 delayed conversions to achieve filter opening. In all 49 sheep, no thrombosis, migration, or significant tilting occurred. Within 4 weeks of conversion, the filter's stabilizers and arms were incorporated into the IVC wall. Upon removal, the filter head was free of intimal growth. CONCLUSIONS: The VenaTech(™) Convertible(™) optional IVC filter was successfully implanted in all sheep with no migration or tilting. Conversion at various dates by filter head removal was feasible in all but one case.

The VenaTech LP permanent caval filter: effectiveness and safety in the prevention of pulmonary embolism--a European multicenter study.

PURPOSE: To evaluate (i) the appropriateness, safety, and patient outcomes after placement of the VenaTech LP caval filter and (ii) the success of filter insertion through various venous access routes. MATERIALS AND METHODS: An open multicenter prospective observational study was conducted in 12 European centers, including an initial part limited to four centers. Patients with common indications were eligible for inclusion after approval by an independent ethics committee. Over a 42-month period, 106 patients (46 men [43.4%], 60 women [56.6%]), 72.2 years +/- 13.3 of age (range, 37-97 y), with poor prognoses were included. Patients were examined 2-5 days after the procedure, then at 30 days +/- 5 and 90 days +/- 15 for clinical follow-up and filter assessment. Evaluation criteria were based on occurrence of pulmonary embolism (PE), adverse events, death, filter position, and caval patency. Data were available in 101 case report forms at days 2-5, in 75 at day 30 +/- 5, and in 60 at day 90 +/- 15. Two patients (1.9%) were lost to follow-up. RESULTS: The overall mortality rate was 20.8%. PE was present in 71 patients (67.0%). History of venous thromboembolic disease (VTED) was noted in 32 patients (30.2%), and recently diagnosed VTED was present in 101 patients (95.3%). Partial caval thrombosis was present before the procedure. Filter tilting of 10-45 degrees was seen in 3.9% of cases at days 2-5, 4.3% of cases at day 30 +/- 5, and 1.9% of cases at day 90 +/- 15. Follow-up evidenced neither clinical signs of PE nor significant device-related events. CONCLUSIONS: In a prospective patient cohort with a projected 3-month mortality rate of nearly 21.0% as a result of severe prognoses, the success of insertion via various venous access routes and the appropriateness and safety of the VenaTech LP caval filter were assessed. Findings at 90-day follow-up were free of symptomatic PE and device-related adverse effects.

Long-duration temporary vena cava filter: a prospective 104-case multicenter study.

BACKGROUND: Nonpermanent caval filters are placed in critical thromboembolic situations in which anticoagulation therapy is transiently contraindicated, ineffective, or the source of complications. The purpose of this study was to assess the safety and effectiveness of a second-generation long-duration temporary caval filter in these situations and compare its utility with that of other temporary filters. METHODS: This prospective study, including patients who underwent temporary caval filtration with the Tempofilter II, was conducted in nine European centers. All filters were successfully implanted. The filter was removed when the indication for caval filtration ceased. RESULTS: A total of 104 filters were inserted in 103 patients with an average age of 60 +/- 15.5 years (range, 22-92 years). Most patients (85%) had pulmonary embolism, deep venous thrombosis, or both. The main indications for caval filter placement were complications of or contraindications to anticoagulation therapy (n = 85; 82.5%) or for ineffectiveness of anticoagulation therapy (n = 12; 11.7%). The average duration of implantation was 29.5 +/- 14.0 days (range, 2-86 days). One filter migrated in the right atrium, followed by pulmonary embolism. No other case of pulmonary embolism or of infectious or mechanical complications related to the filter was observed. Thrombus was trapped within the filter in 24 cases (23.3%). All filters but one were removed, regardless of whether thrombus had been trapped. Retrieval was always successful after implantation periods up to 12 weeks. In 16 cases (15.5%), the filter was replaced by a permanent filter. CONCLUSIONS: The Tempofilter II is safe, effective, and useful in critical thromboembolic situations. It offers a valuable alternative to retrievable optional filters.

Placement of the VenaTech LP caval filter in the elderly: feasibility and clinical benefits of insertion via the arm.

PURPOSE: To evaluate routine use of access sites in the arm for percutaneous caval filter placement (PCFP) in elderly patients. Neck arthritis, patient anxiety, access site thrombosis or fecal/urinary incontinence complicating jugular or femoral access may require alternative access sites in this population. METHODS: Access via the right arm was chosen for PCFP (VenaTech LP). The indication for PCFP was deep vein thrombosis, a history of pulmonary embolism, and a contraindication to anticoagulant therapy. Ultrasound-guided puncture was performed after diameter measurement of the arm veins (ØAV). The filter was inserted with standard imaging procedures. Procedural difficulty was graded and compared with ØAV and the angle from the arm vein to the superior vena cava (alphaAV/SVC). RESULTS: Over 2 years, 16 patients (14 women, 2 men) with an average age of 90 years (range 79-97 years) were included in the study. The average ØAV value of the basilic or brachial veins was 4.2 mm (range 3.0-5.1 mm). The minimal ØAV for successful access was determined after the first 15 patients. No hematoma occurred at the puncture sites. The average alphaAV/SVC value was 62 degrees (range 29 degrees -90 degrees ). Arm access was possible in 12 of 16 patients (75%) with ØAV >or= 3.5 mm and alphaAV/SVC >or= 29 degrees . Every procedure via the arm was graded "easy" by the operator, regardless of angulation values. Femoral access was used in one case due to the impossibility of traversing the heart (patient no. 2), and jugular access was used in 3 of 16 (19%) patients due to puncture failure (patient no. 4), small ØAV (3 mm) (patient no. 6), and stenosis of the distal right subclavian vein (patient no.16), respectively. CONCLUSION: PCFP via the arm can be routinely accomplished in patients older than 75 years, provided ØAV >or= 3.5 mm, and alphaAV/SVC >or= 29 degrees .

Gadolinium-enhanced digital subtraction angiography of hemodialysis fistulas: a diagnostic and therapeutic approach.

OBJECTIVE: The aim of our study was to evaluate the feasibility, safety, and potential role of the contrast agent gadoterate meglumine for digital subtraction angiography as a single diagnostic procedure or before percutaneous transluminal angioplasty of malfunctioning native dialysis fistulas. MATERIALS AND METHODS: Over a 20-month period, 23 patients (15 women, eight men) with an age range of 42-87 years (mean, 63 years) having end-stage renal insufficiency and with recent hemodialysis fistula surgical placement underwent gadoterate-enhanced digital subtraction angiography with a digital 1024 x 1024 matrix. Opacification was performed on the forearm, arm, and chest with the patient in the supine position using an injection (retrograde, n = 14; anterograde, n = 8; arterial, n = 1) of gadoterate meglumine into the perianastomotic fistula segment at a rate of 3 mL/sec for a total volume ranging from 24 to 32 mL. Percutaneous transluminal angioplasty was performed in three patients and required an additional 8 mL per procedure. Examinations were compared using a 3-step confidence scale and a two-radiologist agreement (Cohen's kappa statistic) for diagnostic and opacification quality. Tolerability was evaluated on the basis of serum creatinine levels and the development of complications. RESULTS: No impairment of renal function was found in the 15 patients who were not treated with hemodialysis. Serum creatinine level change varied from -11.9% to 11.6%. All studies were of diagnostic quality. The presence of stenosis (n = 14) or thrombosis (n = 3) in arteriovenous fistulas was shown with good interobserver agreement (kappa = 0.71-0.80) in relation to opacification quality (kappa = 0.59-0.84). No pain, neurologic complications, or allergiclike reactions occurred. Three percutaneous transluminal angioplasty procedures (brachiocephalic, n = 2; radiocephalic, n = 1) were successfully performed. CONCLUSION: Gadoterate-enhanced digital subtraction angiography is an effective and safe method to assess causes of malfunction of hemodialysis fistulas. It can also be used to plan and perform percutaneous transluminal angioplasty.

Fast breath-hold T2-weighted MR imaging reduces interobserver variability in the diagnosis of adenomyosis.

OBJECTIVE: We compared two rapid MR imaging T2-weighted pulse sequences with high-resolution turbo spin-echo for the diagnosis of adenomyosis, and we evaluated interobserver variability. SUBJECTS AND METHODS: Fifty-six consecutive patients referred for hysterectomy prospectively underwent MR imaging. Two fast pulse sequences using a breath-hold technique-true fast imaging with steady-state free precession (FISP) and turbo inversion recovery-and turbo spin-echo T2-weighted images of the pelvis were obtained in each patient. The images were analyzed in a blinded manner and independently by three reviewers with different levels of experience for the accuracy of adenomyosis diagnosis, image quality, anatomic visualization, and image artifacts. The accuracy for the diagnosis of adenomyosis on turbo spin-echo T2-weighted imaging combined with one or two fast pulse sequences was evaluated for each reviewer. RESULTS: Twenty-four patients (42.9%) had a histologic diagnosis of adenomyosis. The accuracy for the diagnosis of adenomyosis for reviewers 1, 2, and 3 using turbo spin-echo T2-weighted, true FISP, and turbo inversion recovery sequences was 83.9%, 67.8%, 75%; 83.9%, 67.8, 78.5%; and 87.5%, 73.2%, and 75%, respectively. A difference in the accuracy rate was found among the observers for the three sequences (p < 0.001). Whatever the pulse sequence, the accuracy rate was higher for the reviewer with more experience in gynecologic imaging. The combination of turbo spin-echo T2-weighted imaging with at least one rapid sequence increased the accuracy of observers with little experience in gynecology. With turbo inversion recovery sequences, the image quality score was low for the three reviewers compared with turbo spin-echo T2-weighted and true FISP sequences. The combination of turbo spin-echo T2-weighted and true FISP sequences gave the highest image quality scores. CONCLUSION: Breath-hold T2-weighted sequences optimize the accuracy of MR imaging for the diagnosis of adenomyosis and reduce interobserver variability.

Chronic lithium nephropathy: MR imaging for diagnosis.

PURPOSE: To evaluate the appearance of lithium nephropathy at magnetic resonance (MR) imaging. MATERIALS AND METHODS: Sixteen patients with renal insufficiency and clinical and laboratory evidence of nephropathy secondary to therapy with lithium salts were examined with a 1.5-T MR imaging unit with T1-weighted, T2-weighted fast imaging with steady-state precession (true FISP), rapid acquisition with relaxation enhancement, half-Fourier turbo spin-echo, and gadolinium-enhanced (FISP three-dimensional MR angiographic) sequences. Renal size and the presence, number, location and size of parenchymal cysts were analyzed. The cysts in each kidney were defined as rare (fewer than 10 cysts), sparse (between 10 and 30 cysts), abundant (30-60 cysts), or very abundant (more than 60 cysts). RESULTS: The mean length of both kidneys was 104 mm +/- 9 in seven cases, and one or both kidneys were less than 90 mm in length in nine cases. Renal microcysts measuring from 1 to 2 mm were detected in all patients. They were either very abundant (n = 12), abundant (n = 2), or sparse (n = 2). The cysts were located with equal abundance in both the cortex and the medulla in 11 cases and were predominantly located in the renal cortex in five cases. No renal artery stenosis was present. CONCLUSION: Microcysts secondary to long-term lithium therapy can be detected with MR imaging.

Histomorphometric evaluation of (198)Au endovascular brachytherapy in a renal artery restenosis model in rabbits.

OBJECTIVE: The main mid-term complication of percutaneous transluminal angioplasty of the renal artery is restenosis, which occurs in up to 50% of patients. Although no pharmacologic agent to date has been effective in preventing restenosis, both beta-ray emitters and gamma-ray emitters used in endovascular brachytherapy have been shown to reduce coronary restenosis. The objectives of this study were to evaluate the efficacy of (198)Au endovascular brachytherapy in preventing restenosis after percutaneous transluminal renal angioplasty and to determine the radiation dose to the operator. MATERIALS AND METHODS: Twenty-one New Zealand white rabbits (10 females and 11 males) weighing an average of 3.5 kg (range, 3.2-3.8 kg) who had been fed a normal diet underwent bilateral 33% overdilatation with deendothelialization of the renal arteries. After 7 weeks, the induced renal artery stenoses were treated by percutaneous transluminal renal angioplasty. The rabbits were randomly assigned to one of three groups before receiving endovascular 25-Gy irradiation at a radial 2.0-mm depth with a 0.5 x 15 mm (198)Au wire (106 MBq). The right renal artery was irradiated in group A; the left, in group B. The rabbits in group C randomly received a right- or left-sided dummy wire. Operator exposure to radiation was measured using thermoluminescent dosimeters and ionization chambers. The rabbits were sacrificed after 3 weeks. The aorta and renal arteries were perfusion-fixed. The renal arteries were removed for histologic and histomorphometric study. RESULTS: Forty-two renal arteries were cut into a series of 4- micro m-thick slices. Five arteries were thrombosed (two in the irradiated group and three in the control group, p > 0.05). In the patent arteries (n = 37), the average neointimal area was 0.068 mm(2) (range, 0.009-0.234 mm(2)) in 15 irradiated segments (315 slices total), whereas the average neointimal area was 0.135 mm(2) (range, 0.016-0.324 mm(2)) in 22 control segments (462 slices total) (analysis of variance, p < 0.009), showing a percentage area of restenosis of 10.4% in irradiated arteries and 43.4% in non-irradiated arteries (p < 0.0003). Radiation dose per procedure to the operator was 0.034 mSv in the index finger, 0.024 mSv in the wrist, and undectable in the body. CONCLUSION: Endovascular brachytherapy with (198)Au appears to inhibit early renal artery restenosis and exposes the operator to a safe level of radiation.