MR Brain Screening in ADPKD Patients : To Screen or not to Screen?

BACKGROUND: Adult polycystic kidney disease (ADPKD) still represents a major cause of renal failure and intracranial aneurisms (IA) have a higher prevalence in ADPKD than in the general population. Current guidelines suggest performing brain MRI only in the subjects with a positive familiar history of IAs or subarachnoid hemorrhage (SAH). This is a retrospective case-control analysis to evaluate the usefulness of a MR screening program in ADPKD patients. METHODS: We retrospectively analyzed all ADPKD patients followed in our outpatient clinic between 2016 and 2019 who underwent a brain MRI screening. We evaluated the presence of IAs and others brain abnormalities and compared our results with a non-ADPKD population (n = 300). We performed univariate and multivariate regression analysis to evaluate if general and demographic features, laboratory findings, clinical parameters and genetic test results correlated with IAs or other brain abnormalities presence. RESULTS: Among the patients evaluated 17 out of 156 (13.6%) ADPKD patients had IAs, compared to 16 out of 300 (5.3%) non-ADPKD controls (p < 0.005). Considering ADPKD patients presenting IAs, 12 (70.6%) had no family history for IAs or SAH. Genetic analysis was available for 97 patients: in the sub-population with IAs, 13 (76.5%) presented a PKD1 mutation and none a PKD2 mutation. We found that arachnoid cysts (AC) (p < 0.001) and arterial anatomical variants (p < 0.04) were significantly more frequent in ADPKD patients. CONCLUSION: In our population ADPKD patients showed a higher prevalence of IAs, AC and arterial variants compared to non-ADPKD. Most of the IAs were found in patients presenting a PKD1 mutation. We found a significant number of alterations even in those patients without a family history of IAs or SAH. The practice of submitting only patients with familial IAs or kidney transplantation candidates to MRI scan should be re-evaluated.

Natural history of honeycombing: follow-up of patients with idiopathic pulmonary fibrosis treated with single-lung transplantation.

PURPOSE: Although honeycombing is one of the key features for the diagnosis of idiopathic pulmonary fibrosis (IPF), its origin and evolution are still poorly understood. The aim of our study was to analyse the natural history of honeycombing in patients treated with single-lung transplantation. MATERIALS AND METHODS: We considered seven patients who underwent single-lung transplantation; two of them (28.6%) were excluded from our analysis because they died in the posttransplantation period, whereas the remaining five (71.4%) were evaluated with computed tomography (CT) over 67.6±38.56 months. Each CT scan was assessed for disease extension and cyst size (visual score and size of target cysts); CT scans acquired after 2006 were also assessed for native lung volume. RESULTS: All patients showed disease progression (with a concurrent reduction in lung volume in two, 40%) and a progression of honeycombing, with increased number and size of cysts in four (80%). We observed dimensional changes in all target cysts (enlargement or reduction); three patients (60%) also had radiological evidence of complications, such as spontaneous rupture with pneumothorax and development of mycetomas within the cysts. CONCLUSIONS: Honeycombing is a dynamic process in which the overall trend is represented by a dimensional increase in cystic pattern; however, single cysts may have a different evolution (enlargement, reduction or complications). This behaviour could be explained by the variety of the pathogenetic processes underlying honeycombing, with cysts that may present abnormal communication with the airway, including the development of a check-valve mechanism.

Spiral CT evaluation of pulmonary emphysema using a low-dose technique.

PURPOSE: To evaluate the diagnostic accuracy and clinical acceptability of low-dose spiral CT for determining pulmonary volumes and emphysema extension in patients with pulmonary emphysema, in comparison with studies based on spiral CT at conventional dose. MATERIALS AND METHODS: We prospectively evaluated eighteen patients, current or former smokers, with a clinical diagnosis of chronic obstructive pulmonary disease. All the patients underwent: HRCT with three scans at predetermined levels; quantitative spiral CT, with two inspiratory scans, one conventional scan at 240 mA, and the second one a low-dose scan at 80 mA. We used the following parameters: 120 kV, rotation time 0.8", scan time less than 20" (single inspiratory breath-hold), layer thickness 7.5 mm, pitch 6 (high speed), interpolation algorithm at 180 degrees. A 3D reconstruction was performed, with segmentation of the lungs and automatic quantification of pulmonary volumes. We compared the volumes of absolute and percent emphysema and the ratings of the dose delivered to the patient (CTDIw and DLP) obtained with the two spiral CT scans with each other and with the respiratory function tests. RESULTS: The average total lung capacity (TLC) obtained by conventional-dose spiral CT (CTs1) was 6889.4 cc (SD +/-1813.2), and the capacity with low-dose spiral CT (CTs2) was 6929.4 cc (SD +/-1811.6). The percentage of emphysema was 39.7% (range: 2.2-63.5%; SD: +/-19.9) for the CTs1 and 41.1% (range: 2.1-66.4%; SD: +/-20). The CTDIw corresponding to CTs1 was 12.2 mGy (range: 11.9-16.4; SD: +/-1), the one corresponding to CTs2, 3.6 mGy (range: 3.6-4.9; SD: +/-0.3). The DLP corresponding to CTs1 was 391.7 mGy x cm (range: 333.3-518.9; SD: +/-46.7), the one corresponding to CTs2 was 117.8 mGy x cm (range: 100.3-156; SD: +/-14). As for the respiratory function tests, the total lung capacity (TLC) obtained by body plethysmography was 7061 cc (SD: +/-2029.7); the percent TLC was 115.9 (range: 66-165; SD: +/-27.6), the forced expiratory volume at one second (FEV1%, percentage of predicted value) was 46.7% (range: 17-123; SD: +/-27.3), residual volume (RV%) as a percentage of predicted value was 186.3 (range: 84-359; SD: +/-80.7), the Tiffeneau index (TI) was 46% (range: 25-71; SD: +/-15.7). We observed a very significant correlation between radiological and functional TLC for both CT methods. The percentage scores for emphysema obtained with the two methods correlated significantly with the functional indexes. The pixel index of CTs1 correlated with TLC% (r=0.87; p<0.0001), FEV1% (r=-0.53; p<0.02), RV% (r=0.76; p=0.004), TI (r=-0.79; p=0.0001). The pixel index of CTs2 correlated with TLC% (r=0.87; p<0.0001), FEV1% (r=-0.56; p=0.01), RV% (r=0.78; p=0.003), TI (r=-0.8; p=0.0001). The adoption of the method with low tube current entailed a highly significant reduction in the estimated dose delivered to patients (CTDIw and DLP) with r=0.9 and p < 0.0001. DISCUSSION AND CONCLUSIONS: Quantitative low-dose spiral CT is a very good method to quantify pulmonary volumes and calculate the extension of the anatomic emphysema. The reduction of mA from 240 to 80 lowers the estimated dose by 30%, without compromising the accuracy of the results. Our study achieved a highly significant correlation between the results obtained with the two spiral CT techniques and between these results and the respiratory function tests. In clinical practice, the easiest way to reduce the dose in spiral CT of the lung is to reduce the tube current. The low-dose method allows a significant reduction in radiation exposure. Further studies are required to establish to what extent the dose can be reduced without increasing in quantum noise and thereby compromising the quality of the study.

Multidetector CT-urography in the study of urological complications in renal transplant.

PURPOSE: To evaluate the value of CT-urography in the diagnosis and follow-up of the urological complications of renal transplantation. MATERIALS AND METHODS: We performed 19 CT-urography examinations (3 of which were follow-up) on 15 patients by using a spiral multislice CT scanner and multiplanar reconstructions. The examinations were carried out directly after administration of 100 ml of iodinated contrast medium by slow iv infusion, with acquisitions starting 5 minutes after the end of the infusion. Surgery was regarded as the gold standard for the diagnosis of urological complications in the operated patients, whereas in patients who had undergone medical therapy or stent placement the gold standard was 1 month ultrasound and clinical follow-up with evaluation of diuresis and renal function. RESULTS: Between January 1999 and December 2001 a total of 210 kidney transplantations were performed at our hospital. There were 34 urological complications in 28 patients with a 16.1% prevalence, consistent with the major international studies. The complications detected were 14 urine leaks and 19 ureteral obstructions secondary to stones, oedema, blood clots and stricture. We observed one case of reflux in the allograft ureter. Fourteen out of 16 CT-urography examinations yielded important clues for the diagnosis of urological complications in kidney allografts, completely replacing standard urography. In particular, CT-urography correctly detected 5 urinary fistulas by demonstrating iodinated contrast material leaks along the ureteral tract, and 8 cases of obstructive uropathy due to different causes (1 submucosal tunnel edema, 1 blood clot, 1 stone and 5 cases of ureteral stricture). One case of urinary fistula and one of obstructive uropathy were not detected. DISCUSSION AND CONCLUSIONS: CT-urography proved to be an important diagnostic tool in the evaluation of urological complications of kidney allografts, showing a diagnostic accuracy over 90%; it is useful for confirming the type and site of urological lesions, and therefore to provide guidance for a targeted surgical approach. Compared with excretory urography, which is no longer used in this diagnostic field, CT-urography is more complete and precise as it provides information not only about the urinary tract, but also about the kidney parenchyma and pararenal fluid collections. The only disadvantage, which limits its use to selected cases, is the risk associated with the use of iodinated contrast agents in patients with impaired renal function.

Evaluation of the resistive index (RI) for the diagnosis of acute renal rejection in renal allografts from the same donor.

PURPOSE: To investigate the importance of the resistive index (RI) in the diagnosis of acute renal rejection, compared with the RI of the twin kidney from the same donor, transplanted in two different patients. MATERIAL AND METHODS: From January to December 2000, we studied retrospectively 25 pairs (50 patients) of renal allografts from the same donor considering the RI obtained with by eco color-Doppler ultrasound, daily diuresis and renal function (serum creatinine level) in the first six days following surgery. Improvement of diuresis and renal function after corticosteroid therapy was considered the gold standard for the diagnosis of acute rejection. RESULTS: Medical complications (acute renal rejection) in the first six days were occurred in three cases, two in the first transplanted kidney as first and one in the second; all three cases showed disappearance of the diastolic waveform component. Considering a RI variation >0.15 with respect to the initial value, the sensitivity, specificity and diagnostic accuracy in the Doppler diagnosis of acute rejection were 100%, 97.1% and 97.3% respectively, with a prevalence of 7.8%. There were no statistically significant correlations between the RI variation of the renal transplant and the twin kidney from the same donor. DISCUSSION AND CONCLUSIONS: Doppler ultrasound is an important diagnostic tool in the detection of medical complications in the immediate postoperative period and during renal transplant follow-up. RI analysis, when studied serially and in the right clinical settings, allows an early diagnosis of renal rejection with high sensibility and specificity.

[Idiopathic interstitial pneumonitis presenting with Wells grade III. Can imaging methods help predict further progression of disease?]. / Fibrosi polmonare idiopatica con grado III di Wells all'esordio. Possono le metodiche di diagnostica per immagini aiutare a predire la progressione ulteriore della malattia?

PURPOSE: Three different grades of idiopathic pulmonary fibrosis can be identified by HRCT pattern. Patients with predominant ground-glass opacity (grade I) usually improve after treatment and may have a better prognosis. The subjects with a predominant reticular pattern and honeycombing (grade III) have irreversible fibrosis and usually do not improve after immunosuppressive therapy. Nevertheless, these patients may worsen even in the absence of HRCT features of the so-called alveolitis. We investigated the predictive role of some noninvasive imaging methods (HRCT with visual score of disease extent; Gallium scintigraphy; DTPA scintigraphy) in patients with idiopathic fibrosis and a prevalent macroscopic fibrosis at HRCT study. MATERIAL AND METHODS: Fourteen former smokers with grade III idiopathic fibrosis were examined. None of the patients had been treated. They were all submitted to HRCT, lung function studies, Gallium and DTPA scintigraphy, both at presentation (T0) and follow-up sessions (T1: mean one year post-diagnosis). The HRCT extent of disease was evaluated by means of the visual score as the fraction of the total lung volume. The patients were divided into two groups, using a cut-off value of 50%. All the patients underwent a Gallium scintiscan (using a fixation index of 160 as cut-off) and a ventilatory scintigraphy with DTPA-aerosol, with radionuclide clearance assessment. The lung function tests considered were vital capacity (VC), arterial blood oxygen partial pressure (PaO2) and the diffusing lung capacity for carbon monoxide (DLCO). RESULTS: After one year of follow-up, the HRCT extent score increased (from 46.6% to 50%) and lung function worsened (VC from 66.8% to 63.4% of predicted; DLCO from 37.6% to 27.1%; PaO2 from 77 to 71 mmHg). The patients presenting with HRCT extension score > 50% had a worse lung function at T0 and showed a significant deterioration of PaO2 and HRCT at T1. On the other hand, VC and DLCO significantly worsened in the subjects with HRCT score < 50% at presentation. The patients with a Gallium fixation index > 160 significantly deteriorated in HRCT score, VC and DLCO. Those with Gallium index < 160 had major worsening only for diffusing lung capacity for carbon monoxide. Thirteen of 14 patients had an abnormal value of DTPA clearance at presentation. No variation was observed at T1. DISCUSSION AND CONCLUSIONS: The majority of patients with idiopathic fibrosis are grade III at presentation. They can further deteriorate both in HRCT extent of disease and lung function impairment. After one year of follow-up HRCT extent score increased in 64% of the patients, with a mean increase of 5%. HRCT worsening was more apparent in the patients with a HRCT score > 50% at presentation. In the remaining patients, the worsening of lung function tests was more apparent than the anatomoradiological changes. DTPA clearance had no predictive value in this series. Gallium scintigraphy was a useful prognostic index. The patients with Gallium fixation index > 160 had better lung function and lower HRCT extent score at T0 but significantly deteriorated at T1. A positive Gallium scan at presentation could be considered a useful index of persisting active "alveolitis" in patients with grade III disease, not visible at HRCT study, due to overwhelming fibrosis. These patients, who were untreated, exhibit quicker radiological and functional worsening.