Magnetic resonance imaging in the complications of kidney transplantation

Kidney transplantation is currently the treatment of choice in most patients with end-stage chronic renal failure owing to the excellent results in terms of both graft and patient survival. However, surgical complications are still very frequent. Although urological (stricture, urinary fistulas, vesico-ureteral reflux) and lymphatic complications (lymphocoele) have a high incidence, they only rarely lead to graft loss. By contrast, vascular complications (stenosis, arterial and venous thrombosis, arterio-venous fistulas, pseudoaneurysms) are relatively rare, but potentially serious and may affect graft survival. Finally, medical complications such as acute tubular necrosis (ATN), rejection and de novo neoplasms may also arise in kidney transplantation. The purpose of this pictorial review is to illustrate the increasingly significant contribution of magnetic resonance angiography (MRA) in the management of complications of kidney transplantation, and emphasise how this method should now be considered a mandatory step in the diagnostic workup of selected cases. Moreover, the application and role in this setting of new magnetic resonance imaging (MRI) techniques, such as diffusion-weighted and blood oxygen level-dependent (BOLD) MRI, are also discussed.

Interobserver reliability of the chest radiograph in pulmonary embolism

This study was sought to evaluate the interobserver agreement for interpreting the chest radiograph of patients with suspected acute pulmonary embolism (PE). The chest radiographs of 300 patients with clinically suspected acute PE were reviewed by 4 radiologists. Observers assessed the chest radiographic abnormalities and classified the chest radiograph as normal or abnormal. We found that the overall interobserver agreement was good for the exclusion of any pleural or parenchymal abnormality (k = 0.6; 95% CI: 0.56-0.64) but fair (k = 0.28; 95% CI: 0.17-0.40) between junior radiologists when evaluating supine chest radiographs. The level of interobserver agreement for the interpretation of the chest radiograph as consistent or not with PE was fair (k = 0.24; 95% CI: 0.19-0.29), regardless of the observer experience. In conclusion, chest radiography may be reliably used for targeting patients with suspected acute PE for different subsequent diagnostic investigations.

E-learning in radiology: an Italian multicentre experience

OBJECTIVE

The aim of this study was to design, deliver and evaluate an e-learning teaching programme for post-graduate radiodiagnostics training that would involve various post-graduate schools throughout Italy.

MATERIALS AND METHODS

All of the Directors of Italian post-graduate schools of radiodiagnostics were sent an e-mail on 27 September 2010 informing them of our willingness to set up an e-learning project for the academic year 2010-2011 in the form of single-subject teaching seminars. The proposed subjects were the semeiotics of the various organs and apparatuses in the context of "Urgent/Emergency Pathology". After having received registrations, a calendar of lessons was planned to be held between 10 November 2010 and 12 October 2011. The validity of the project was tested by means of a multiple-choice questionnaire covering the technical and didactic quality of the entire project, to be completed by the students.

RESULTS

Fifty-one percent of the universities in Italy participated in the project: Trieste, Udine, Verona, Milan-Bicocca, Novara, Varese, Genoa, Sassari, Rome Campus, the Catholic University of Rome, Chieti, Foggia, Catania, Modena, Florence, Palermo, Bologna, Pavia, Parma and Ferrara. The lessons were attended by a total of 10,261 post-graduate medical students, for an average of 513.1 students per lesson. Seventy percent of the students judged the didactic content "excellent", 25% "good", and 5% "satisfactory"; none said it was unsatisfactory. In terms of visual quality (particularly the details of the radiological images proposed in the form of slides and/or video clips), 73% judged it "excellent", 20% "good", 6% "satisfactory", and 1% "poor". The audio quality was judged "excellent" by 71%, "good" by 22%, "satisfactory" by 6% and "poor" by 1%. In relation to judgement of audio and video quality, it has to be underlined that this was greatly affected by the hardware/software configuration and the band speed and technology of the Internet connection.

CONCLUSIONS

Technological evolution is overcoming all barriers, and technology is also having a positive impact on the approach to teaching. Our multicentre teaching experience merits the following considerations: the quality of the teaching product was certified by the students' judgements of its didactic content and the quality of reception; the economic cost of the teaching had a minimal impact on the post-graduate schools (€ 18 per lesson). In terms of breaking down national barriers, it is to be hoped that the coordination and integration of diagnostic imaging e-learning projects, with the participation of post-graduate schools in different European countries, can be developed not only in a spirit of "cultural sharing" and the exchange of teaching experiences.

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.

Low agreement of visual rating for detailed quantification of pulmonary emphysema in whole-lung CT

BACKGROUND

Multidetector spiral computed tomography (CT) has opened the possibility of quantitative evaluation of emphysema extent in the whole lung. Visual assessment can be used for such a purpose, but its reproducibility has not been established.

PURPOSE

To assess agreement of detailed assessment of pulmonary emphysema on whole-lung CT using a visual scale.

MATERIAL AND METHODS

Thirty patients with chronic obstructive pulmonary disease underwent whole-lung inspiratory CT. Four chest radiologists rated the same 22 ± 2 thin sections using a visual scale which defines a range of emphysema extent between 0 and 100. Two of them repeated the rating two months later. Inter- and intra-operator agreement was evaluated with the Bland and Altman method. In addition, the percentage of emphysema at -950 Hounsfield units in the whole lung was determined using fully automated commercially available software for 3D densitometry.

RESULTS

In three of six operator pairs and in one of two intra-operator pairs the Kendall τ test showed a significant correlation between the difference and the average magnitude of visual scores. Among different operators the half-width of 95% limits of agreement (95% LoA) was wide ranging between a score of 14.2-27.7 for an average visual score of 20 and between 18.5-36.8 for an average visual score of 80. Within the same operator the half-width of 95% LoA ranged between a score of 10.9-21.0 for an average visual score of 20 and between 25.1-30.1 for an average visual score of 80. The visual scores of the four radiologists were correlated with the results of densitometry (P < 0.001; r = 0.65-0.81).

CONCLUSION

The inter- and intra-operator agreement of detailed assessment of emphysema in the whole lung using a visual scale is low and decreases with increasing emphysema extent.

Predicting survival in newly diagnosed idiopathic pulmonary fibrosis: a 3-year prospective study

The natural history of idiopathic pulmonary fibrosis (IPF) is not well defined and its clinical course is variable. We sought to investigate the survival and incidence of acute exacerbations (AEs) and their significant predictors in newly diagnosed patients. 70 patients newly diagnosed with IPF were prospectively followed for at least 3 yrs. Baseline evaluation included Medical Research Council dyspnoea score (MRCDS), 6-min walk test, pulmonary function tests, all of which were repeated at 6 months, and high-resolution computed tomography. A retrospective cohort of 68 patients was used for confirmation. Mean survival from the time of diagnosis was 30 months, with a 3-yr mortality of 46%. A Risk stratificatiOn ScorE (ROSE) based on MRCDS > 3, 6-min walking distance ≤ 72% predicted and composite physiologic index > 41 predicted 3-yr mortality with high specificity. 6-month progression of ROSE predicted rapid progression. 3-yr incidence of AE was 18.6%, mostly occurring in the first 18 months; risk factors for AE were concomitant emphysema and low diffusing coefficient of the lung for carbon monoxide. Results were confirmed in an independent cohort of patients. In newly diagnosed IPF, advanced disease at presentation, rapid progression and AEs are the determinants of 3-yr survival. The purpose of the multifactorial ROSE is to risk-stratify patients in order to predict survival and detect rapid disease progression.

Subclinical interstitial lung abnormalities in stable renal allograft recipients in the era of modern immunosuppression

BACKGROUND

Interstitial lung abnormalities have been detected in up to 24% of kidney transplant patients receiving traditional immunosuppressive therapies (eg, cyclosporine, azathioprine); they usually occur early after transplantation and tend to resolve over time. Newer immunosuppressants such as mycophenolic acid and, particularly, mammalian target of rapamycin (mTOR) inhibitors (eg, sirolimus) may cause significant lung toxicity. However, the prevalence and severity of interstitial lung lesions in long-term, stable kidney transplant patients receiving either traditional or newer immunosuppressants is not known.

METHODS

We conducted a prospective, cross-sectional study examining high-resolution lung computed tomography (CT) scans in 63 stable kidney transplant recipients whose immunosuppressive therapy had remained unchanged for over 24 months. We compared CT findings of patients taking newer (mycophenolic acid and mTOR inhibitors) and traditional (calcineurin inhibitors and azathioprine) immunosuppressive drugs.

RESULTS

Interstitial lung alterations were observed in only 3/63 patients (4.8%); the prevalence was 11.5% (3/26) versus 0% (0/37) among the newer versus traditional immunosuppressive therapy groups, respectively (P = .065). The CT patterns were usual interstitial pneumonia and nonspecific interstitial pneumonia-like. The median time between transplant and CT was 49 months in the three patients with CT alterations and 95 months in the remaining 23 patients on newer immunosuppressants. It was 75 months for all patients on newer immunosuppressive drugs and 133 months for those on traditional therapies (P = .0015). A follow-up CT, performed in 2/3 patients with interstitial abnormalities, showed that the lesions were stable in one, while they had disappeared in the other.

CONCLUSIONS

Interstitial lung abnormalities are infrequent and mild in stable kidney transplant patients treated with newer as well as traditional immunosuppressive drugs. As such abnormalities were detected in patients screened earlier after transplantation, the time since transplantation rather than the drug type is probably the major determinant.

Three cases of bone metastases in patients with gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are rare, but represent the most common mesenchymal neoplasms of the gastrointestinal tract. Tumor resection is the treatment of choice for localized disease. Tyrosine kinase inhibitors (imatinib, sunitinib) are the standard therapy for metastatic or unresectable GISTs. GISTs usually metastasize to the liver and peritoneum. Bone metastases are uncommon. We describe three cases of bone metastases in patients with advanced GISTs: two women (82 and 54 years of age), and one man (62 years of age). Bones metastases involved the spine, pelvis and ribs in one patient, multiple vertebral bodies and pelvis in one, and the spine and iliac wings in the third case. The lesions presented a lytic pattern in all cases. Two patients presented with multiple bone metastases at the time of initial diagnosis and one patient after seven years during the follow-up period. This report describes the diagnosis and treatment of the lesions and may help clinicians to manage bones metastases in GIST patients.

Defining the intra-subject variability of whole-lung CT densitometry in two lung cancer screening trials

RATIONALE AND OBJECTIVES

To define a statistically based variation of individual whole-lung densitometry above which a real increase of pulmonary extent can be suspected in lung cancer screening trials.

MATERIALS AND METHODS

Baseline and 3-month follow-up low-dose computed tomography (LDCT) examinations of 131 smokers or former smokers recruited in the ITALUNG (32 subjects) and MILD (99 subjects) trials were compared using for each data set two different image processing tools for whole-lung densitometry. Both trials were approved by institutional review boards, and written informed consent was obtained from all participants. Assuming that no change of emphysema extent can occur in a 3-month interval, the Bland and Altman method was used to assess the agreement between baseline and follow-up LDCT examinations for lung volume, 15th percentile (Perc15) of lung density and Perc15 corrected for lung volume by application of a linear detrend on log-transformed data.

RESULTS

Similar results were obtained in each data set using two different image processing tools. In the ITALUNG cohort the 95% limits of agreement (LoA) interval of volume corrected Perc15 was -9.7 to 10.7% using image processing method 1 and -10.3 to 11.5% using image processing method 2. In the MILD cohort, the 95% LoA interval of volume corrected Perc15 was -14.7 to 17.3% with both image processing methods.

CONCLUSION

In the two considered lung cancer screening settings a range of 9.7-14.7% decrease of volume corrected Perc15 represents a statistically defined threshold to suspect a real increase of emphysema extent in serial LDCT examinations.

Benefits of 3D technique in guiding percutaneous retroperitoneal biopsies

PURPOSE

This study aimed to assess the usefulness and advantages of multiplanar reformations (MPR) during multidetector-row computed tomography (MDCT)-guided percutaneous fine-needle aspiration biopsy (FNAB) and core biopsy of retroperitoneal lesions that are difficult to access with the guidance of ultrasound and axial CT alone owing to overlying bony structures, large vessels or abdominal organs.

MATERIALS AND METHODS

MDCT-guided retroperitoneal FNAB and core biopsy was performed on 14 patients with suspected retroperitoneal neoplasm. We used MPR images (sagittal and coronal) obtained with a six-detector-row MDCT scanner and 20-22 gauge Chiba needles.

RESULTS

Using MDCT with 3D MPR allowed biological samples to be obtained in all cases (ten cytological and four histological) and diagnostic samples in 11/14 cases (78.5%). Histological samples were deemed adequate for diagnostic assessment in all cases and cytological samples in 7/10 cases (70%).

CONCLUSIONS

MPR images allowed sampling of retroperitoneal lesions until now considered unreachable with the guidance of axial MDCT alone. Compared with the conventional procedure, the use of MPR images does not increase the procedure time.

Late recurrences of gastrointestinal stromal tumours (GISTs) after 5 years of follow-up

In practice, relapses of gastrointestinal stromal tumours after long time of surgical resection occur. However, few published data are available for duration, intensity and imaging sources of follow-up in radically excised patients with localized disease. Therefore, every single institution chooses the surveillance schedule according to its experience. The aim of this study was to describe the late recurrences of disease 5 years after the primary tumour's excision in a series of patients with recurrent GIST from our institution. We retrospectively reviewed 42 patients with "recurrent" GIST, collected since 2001. Ten patients were always followed at our institution, and 32 patients came to our attention at the time of recurrence. The analysed series were divided into two groups: patients who developed recurrence before 5 years and patients who developed recurrence 5 years after the primary tumour's excision. Among 42 patients, 36 patients developed the recurrence within 5 years of the primary tumour excision, whereas 6 patients developed the recurrence 5 years after primary tumour excision diagnosed during follow-up or casually for other reasons. All patients had distant recurrence, involving liver and peritoneum, whereas no local relapse was observed. These patients were heterogeneous in primary tumour site, risk classification and molecular analysis. Duration of the follow-up for radically excised patients with GIST remains still unsettled; however, the integration of every clinical, pathological and molecular parameter is essential to optimize the duration and intensity of the follow-up for each single patient.

Interstitial lung diseases in a lung cancer screening trial

We assessed the prevalence of interstitial lung disease (ILD) in a cohort of smokers included in a lung cancer screening trial. Two observers independently reviewed, for the presence of findings consistent with ILD, the computed tomography (CT) examinations of 692 heavy smokers recruited by the Multicentric Italian Lung Detection (MILD) trial. Four CT patterns were considered: usual interstitial pneumonia (UIP), other chronic interstitial pneumonia (OCIP), respiratory bronchiolitis (RB) and indeterminate. Subsequently, the evolution of ILD in those subjects who had undergone a repeat CT examination after 3 yrs was assessed. The UIP pattern and the OCIP pattern were identified in two (0.3%) out of 692 and 26 (3.8%) out of 692 patients, respectively; 109 (15.7%) out of 692 patients showed CT abnormalities consistent with RB, while an indeterminate CT pattern was reported in 21 out of 692 (3%) patients. Age, male sex and current smoking status were factors associated with the presence of OCIP and UIP (combined) pattern, although the relationship did not attain statistical significance. A progression of the disease was observed in three (25%) out of 12 subjects with OCIP who underwent repeat CT after 3 yrs. Thin-section CT features of ILD, probably representing smoking-related ILD, are not uncommon in a lung cancer screening population and should not be overlooked.