Three-dimensional analysis of pulmonary nodules: variability of semiautomated volume measurements between different versions of the same software.

PURPOSE: This study was done to evaluate the variability of semiautomated volume measurements of solid pulmonary nodules between two different versions of the same volumetric software. MATERIALS AND METHODS: The volumes of 100 solid intraparenchymal nodules (mean volume 88.10 mm(3); range 7.36-595.25 mm(3)) studied with the same multidetector computed tomography (MDCT) protocol were determined using two different versions of the same volumetric software (LungCARE 2006G and LungCARE 2007S). The 2006G version is based on a single-segmentation algorithm, whereas the newer version features two algorithms: SmallSizeNodule and AllSizeNodule. The results obtained with the 2006G version were compared with those of the 2007S version with the SmallSizeNodule algorithm, as recommended by the user manual. In addition, we compared the volumetric measurements obtained by the two different algorithms of the 2007S version. RESULTS: The 2006G version and the 2007S version with the SmallSizeNodule algorithm agreed in only two of 100 cases and showed a mean variability of 1.66% (range 0%-8.78%). A more significant volumetric discrepancy was observed between the two different algorithms of the 2007S version, with the AllSizeNodule algorithm providing on average larger volumes (mean variability 71.08%; range 6.02%-218.80%) than SmallSizeNodule. Volume discrepancies were more pronounced in the subgroups of smaller nodules in all comparisons. CONCLUSIONS: There is variability also in the results provided by different versions of the same volumetric software, and this may affect the calculation of the nodule-doubling time. Computer-aided assessment of the growth of lung nodules should always be performed using the same version of volumetric software and the same segmentation algorithm.

18F-FDG PET/CT in the assessment of carcinoma of unknown primary origin.

PURPOSE: Metastatic cancers of unknown primary origin are characterised by a poor prognosis, with a survival rate from diagnosis of approximately 12 months. Conventional radiological imaging allows detection of 20%-27% of primary cancers, whereas the detection rate with positron emission tomography (PET) is 24%-40%. The aim of this study was to assess the role of 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) in the identification of occult primary cancers. MATERIALS AND METHODS: The study population consisted of 38 consecutive patients with histologically proven metastatic disease and negative or nonconclusive conventional diagnostic procedures. All patients were studied by 18F-FDG PET performed according to the standard procedure (6 h of fasting, intravenous injection of 370 MBq 18F-FDG, and image acquisition with a PET/CT scanner for 4 min per bed position). RESULTS: 18F-FDG-PET/CT detected the occult primary cancer in 20 cases (53%), showing higher sensitivity than that reported for any other imaging modality, including PET. CONCLUSIONS: The encouraging results, if validated by larger series, support the use of PET/CT in patients with carcinoma of unknown primary origin and negative conventional imaging results.

11C-choline positron emission tomography/computerized tomography for tumor localization of primary prostate cancer in comparison with 12-core biopsy.

PURPOSE: (11)C-choline positron emission tomography is an innovative imaging technique for prostate cancer. We assessed the sensitivity of positron emission tomography used together with computerized tomography for intraprostatic localization of primary prostate cancer on a nodule-by-nodule basis, and compared its performance with 12-core transrectal biopsy. MATERIALS AND METHODS: In 43 patients with known prostate cancer who had received positron emission tomography/computerized tomography before initial biopsy, we assessed sensitivity of positron emission tomography/computerized tomography for localization of nodules 5 mm or greater (those theoretically large enough for visualization) using radical prostatectomy histopathology as the reference standard. Comparison with transrectal ultrasound guided biopsy was based on sextant assessment of all cancer foci following sextant-by-sextant matching and reconstruction. Sensitivity/specificity of positron emission tomography/computerized tomography and magnetic resonance imaging for prediction of extraprostatic extension was also assessed. RESULTS: Positron emission tomography/computerized tomography showed 83% sensitivity for localization of nodules 5 mm or greater. At logistic regression analysis only nodule size appeared to influence sensitivity. At sextant assessment positron emission tomography/computerized tomography had slightly better sensitivity than transrectal ultrasound guided biopsy (66% vs 61%, p = 0.434) but was less specific (84% vs 97%, p = 0.008). For assessment of extraprostatic extension, sensitivity of PET/CT was low in comparison with magnetic resonance imaging (22% vs 63%, p <0.001). CONCLUSIONS: Positron emission tomography/computerized tomography has good sensitivity for intraprostatic localization of primary prostate cancer nodules 5 mm or greater. Positron emission tomography/computerized tomography and transrectal ultrasound guided biopsy show similar sensitivity for localization of any cancer focus. Positron emission tomography/computerized tomography does not seem to have any role in extraprostatic extension detection. Studies of diagnostic accuracy (as opposed to tumor localization) are needed in patients with suspected prostate cancer to see whether positron emission tomography/computerized tomography could have a role in not selected patients.

Predictive role of positron emission tomography (PET) in the outcome of lymphoma patients.

An extensive analysis of the reliability of positron emission tomography (PET) after induction treatment in patients with Hodgkin's disease (HD) or aggressive non-Hodgkin's lymphoma (NHL). In all, 75 untreated patients with HD (n=41) or aggressive NHL (n=34) were studied with both PET and CT scans following standard chemotherapy induction therapy (ABVD or MACOP-B) with/without radiotherapy. Histopathological analysis was performed when considered necessary. After treatment, four out of five (80%) patients who were PET(+)/CT(-) relapsed, as compared with zero out of 29 patients in the PET(-)/CT(-) subset. Among the 41 CT(+) patients, 10 out of 11 (91%) who were PET(+) relapsed, as compared with 0 out of 30 who were PET(-). The actuarial relapse-free survival (RFS) rates were 9 and 100% in the PET(+) and PET(-) subsets, respectively (P=0.00001). All five patients who were PET(+)/CT(-) underwent a lymph node biopsy: in four (80%) cases, persistent lymphoma and was confirmed at histopathological examination. Two HD patients who were PET(-)/CT(+) (with large residual masses in the mediastinum or lung) were submitted to biopsy, which in both cases revealed only fibrosis. In HD and aggressive NHL patients, PET positivity after induction treatment is highly predictive for the presence of residual disease, with significant differences being observable in terms of RFS. PET negativity at restaging strongly suggests the absence of active disease; histopathological verification is important in patients who show PET positivity.

Traumatic injuries: imaging of thoracic injuries.

Chest trauma is one of the most important causes of death, in particular in individuals under the age of 40 years. The mortality rate for chest trauma, often related to motor vehicle accidents, is approximately 15.5%; it increases dramatically to 77% with associated shock and head injury (Glasgow scores of 3-4). The accurate diagnosis of pathologies consequent to blunt chest trauma depends on a complete knowledge of the different clinical and radiological manifestations. The first diagnostic approach is classically based on chest X-ray often carried out on supine position at the hospital admission. A CT study must then be performed in all chest trauma patients in whom there is even the smallest diagnostic doubt on plain film. In particular, spiral CT (SCT) assumes a fundamental role in the demonstration of mediastinal hemorrhage and direct signs of aortic lesions. At present, SCT is routinely part of a diagnostic evaluation which also includes scans of the brain and the abdomen in polytraumatized patients. Magnetic resonance is the ideal method for visualizing diaphragmatic lesions. Furthermore, recent reports have demonstrated the high diagnostic value of MR in evaluating aortic injuries. The purpose of this article is to review the most common radiological patterns related to chest trauma.

Role of HRCT in the identification of atypical pulmonary mycobacteriosis.

AIM: 1) To identify the principal radiological signs of atypical pulmonary mycobacteriosis by means of X-rays and CT/HRCT; 2) to compare the two methods in order to evaluate their reliability with particular interest for the diagnostic role of HRCT in the identification of the disease; 3) to establish any significant differences in the pathology between AIDS and immunocompetent patients. MATERIAL AND METHODS: The chest X-rays and CT/HRCT of 28 atypical pulmonary mycobacteriosis patients (16 with AIDS and 12 immunocompetent) have been studied. The subjects were examined during the period of October 1993 to May 2000 and were found to be positive for atypical mycobacterium and consequently underwent a standard chest X-ray. Twenty cases were followed-up with a chest CT/HRCT; of these only 17 were performed within 30 days of the traditional chest X-ray which was considered to be the time limit in order to validate the comparison between the two methods. RESULTS: The significant semeiotical findings were the parenchymal consolidations observed in 25 patients (89%) by standard chest X-rays; the CT/HRCT confirmed the findings in 4 cases while in 13 it enhanced the evaluation of their extensions. In 9 cases the standard chest X-ray established the presence of cavitations which were confirmed by the CT/HRCT in only 7 cases. Lymphadenopathy was observed in 3/28 patients (10.7%) through standard X-rays and in 15/17 cases (82%) through CT/HRCT. The latter method revealed to be extremely useful in the identification of this pathology. Nodules and micronodules were seen in 5 patients with traditional X-rays and in 9 cases with CT/HRCT. Bronchogenic spread signs of disease became visible only with CT and in particular with HRCT (11/17 patients = 65%). Comparing the two groups (AIDS and immunocompetent) taken into consideration, the most frequent lesion present in both was parenchymal consolidation resulting more bilateral in the AIDS subjects. Cavitation and pleural edema were seen more often in the AIDS group while bronchiectasia, bronchogenic spread and signs of previous pleuro-parenchymal suffering were more frequent in the immunocompetent patients. Lymphadenopathy was frequently found in the total study population but appeared slightly prevalent for the group not afflicted with AIDS. CONCLUSION: Radiological study of the chest permitted the identification of signs useful in the diagnosis of mycobacteriosis in all the patients studied. The application of CT/HRCT added helpful elements in almost all of the cases examined demonstrating to be more effective than the standard chest X-ray not only in terms of improved evaluation of known lesions but also in the identification of lesions which are difficult to determine by means of traditional radiology.

Role of color Doppler ultrasonography in the preoperative staging of pancreatic cancer.

We describe our experience with color Doppler ultrasonography (CDU) in the preoperative staging of pancreatic cancer and, particularly, in detecting the involvement of the portal-mesenteric trunk (PMT). Of the 54 patients studied, 43 (79.6%) underwent surgery and 11 (20.4%) did not because of evident infiltration of the PMT. Of the 43 patients operated on, the CDU study was normal in 8 cases (18.6%), abnormal in 33 (76.7%), and not possible in the remaining 2 cases (4.7%). Results of the CDU were confirmed intraoperatively in 39 cases (diagnostic accuracy, 95.1%). In only two cases (4.9%) did the CDU not show involvement of the PMT, which was, instead, demonstrated by intraoperative ultrasonography (false negatives). Of the 11 nonoperated patients, all showed morphological alterations at CDU, while only 7 showed hematic flow changes. The sensitivity of CDU was 94.2% and the specificity 100%. The positive predictive value was 100%; the negative predictive value, 75%. The results indicate that CDU may be the first imaging technique for preoperative assessment of PMT involvement in pancreatic cancer.

[Dynamic computed tomography in the study of bronchiolitis obliterans]. / La Tomografia Computerizzata dinamica nello studio delle bronchioliti obliteranti.

Obliterative or constrictive bronchiolitis is characterized by narrowing of the small airways, due to submucosal and peribronchiolar fibrosis, with chronic obstruction. The vast majority of cases of bronchiolitis obliterans are associated with other diseases and only few cases are idiopathic. We report on the main computed tomography (CT) methods used study obliterative bronchiolitis, the CT findings and the differential diagnosis with other diseases. The dynamic study of alveolar ventilation with CT uses inspiratory and expiratory CT or high-resolution CT (HRCT), spiral dynamic CT or HRCT with advanced image display, ultrafast CT. In abnormal cases HRCT shows direct and indirect signs of small airways disease. The most common (> 80%) sign of obliterative bronchiolitis is the so-called mosaic oligohemia, with low attenuating lobules, caused by air trapping and best seen on expiratory CT, associated with blood flow redistribution to more normal lobules; this finding simulates the ground-glass pattern from infiltrative lung disease. Differential diagnosis is more difficult in the presence of true ground-glass patterns associated with diffuse bronchiolar obstruction and also with mosaic oligohemia due to pulmonary vascular disease and pulmonary emphysema. HRCT can distinguish these diseases and dynamic CT is more sensitive than functional tests in detecting regional abnormalities and air trapping. The combination of HRCT, rapid volumetric scanning and advanced image display is a powerful tool study the normal and abnormal features of bronchiolar function and alveolar ventilation.

[Bronchial involvement in sarcoidosis. Study with high resolution computerized tomography]. / II coinvolgimento bronchiale nella sarcoidosi. Studio con Tomografia Computerizzata con alta risoluzione.

We investigated the HRCT findings of bronchial abnormalities in thoracic sarcoidosis, the post-treatment reversibility of such patterns and their specificity for sarcoidosis. Sixty-one sarcoidosis patients were submitted to chest radiography and HRCT at onset. The diagnosis had transbronchial biopsy confirmation in all patients. HRCT was repeated in 21 patients after a cycle of steroid therapy. Sarcoidosis patients were randomized with 29 patients with diffuse infiltrative lung diseases of different nature. The HRCT findings of bronchial abnormalities follow: extrinsic bronchial compression or displacement by lymphadenopathies (regular/irregular), bronchial wall thickening (regular/irregular), bronchial lumen abnormalities, traction bronchiectasis and bronchiolectasis. Bronchial abnormalities were found in the first HRCT study in 44/61 sarcoidosis patients (72.1%), in 18 patients with extrinsic bronchial compression or displacement by lymphadenopathies (40.9%), in 2 with bronchiectasis or bronchiolectasis (4.5%) and in 24 with one or more other abnormalities (54.5%). Bronchial signs were found in 16/21 patients examined with HRCT after steroid therapy (76.1%). Bronchial abnormalities remained unchanged in 11 patients (68.7%), they improved or disappeared in 5 patients (31%) and appeared ex novo in 2 patients. HRCT patterns of bronchial abnormalities were found in 17/29 patients with other diseases (58.6%), with high rates of bronchial wall thickening and bronchiectasis or bronchiolectasis. The most common HRCT bronchial finding in sarcoidosis was extrinsic bronchial compression of displacement by lymphadenopathies. This was the only sign which could actually differentiate sarcoidosis from other patients (p < 0.01). Other signs (bronchial lumen abnormalities and bronchial wall thickening) were frequently found in both sarcoidosis and non-sarcoidosis patients and did not permit to distinguish the former from the latter. In our experience, HRCT findings of bronchial abnormalities were frequently observed in sarcoidosis patients, but they are not specific enough to diagnose sarcoidosis and their usefulness is limited in predicting posttreatment reversibility (activity evaluation) of this condition.

Monitoring bulky mediastinal disease with gallium-67, CT-scan and magnetic resonance imaging in Hodgkin's disease and high-grade non-Hodgkin's lymphoma.

Treatment of both Hodgkin's disease (HD) and high-grade non-Hodgkin's lymphoma (HG-NHL) with bulky presentation at diagnosis frequently results in residual masses detected radiologically. Conventional diagnostic radiology and computed tomography (CT) are generally unable to detect the differences between tumor tissue and fibrosis. Gallium-67-citrate (67Ga) SPECT and magnetic resonance imaging (MRI) can potentially differentiate residual active tumor tissue and fibrosis. Thirty-three patients with HD or HG-NHL presenting with bulky mediastinal disease were studied with CT, 67Ga SPECT, and MRI (only for 16 patients) at diagnosis, after two-thirds of their chemotherapy, at the end of chemotherapy, and after radiotherapy in order to evaluate the mediastinal region on the basis of persistence of residual masses and activity of pathological tissue. After treatment, all patients with 67Ga-negative (30/33) disease are still in continuous complete response. Among the three 67Ga-positive patients, 2 relapsed within one year and another one is still alive without evidence of disease. Regarding MRI, two patients were found to be positive, one of them concomitant with 67Ga-positivity; both patients survive in complete response. In lymphoma patients with bulky mediastinal presentation, the 67Ga SPECT remains the preferable imaging technique for monitoring and differentiating the eventual active residual tumor. In combination, CT and 67Ga SPECT represent a suitable complete imaging approach to the radiological diagnosis which may be useful in these particular patients. MRI could probably be considered as a second-line method and from our data would be used only in selected cases because of the high cost, accessibility, and lower specificity as opposed to 67Ga SPECT in evaluating potentially active residual disease.

[The assessment of the activity of idiopathic pulmonary fibrosis by high-resolution computed tomography]. / Valutazione di attività della fibrosi idiopatica polmonare mediante Tomografia Computerizzata ad alta risoluzione.

The authors report the results of the study performed with high resolution CT (HRCT) in a group of 29 patients affected with idiopathic pulmonary fibrosis (IPF). Each patient underwent HRCT at the beginning of the study and after one year. A complete clinico-functional assessment was available in 20 cases and functional CT correlation was made in these patients; 15/20 subjects underwent immunosuppressive therapy with corticosteroids and cyclophosphamide. Disease severity was assessed with chest radiography and HRCT. On the basis of CT findings the patients were classified into three groups, according to Wells classification: predominant ground-glass pattern, mixed pattern and predominant reticular disease with honeycombing. Furthermore, a visual score was assigned to total disease extent and a different score to ground-glass and reticular opacities. Our data confirm the poor accuracy of chest radiography in assessing disease type and overall severity, versus the outstanding diagnostic accuracy of HRCT. We also found a high incidence of mediastinal adenopathies (37.9% of the patients) and signs of pulmonary arterial hypertension (62%), together with low extent of pulmonary emphysema (65.5% of the patients; mean extent: 5.4%). Ground-glass attenuation is an early sign of IPF and might suggest alveolitis activity. In our series, however, the patients with grade I disease were rare (6.8%), but likely to benefit from therapy. Different from Wells, we found no significant difference in the evolution of the patients with grade II versus grade III disease. Wells grading was useful in early disease assessment, but the visual score of total disease extent and the score of ground-glass and reticular opacities were much more useful in the follow-up because they can assess disease progression. Furthermore, in the few patients with predominant alveolitis, who improve after therapy, the relative prevalence of the reticular pattern might allocate the patient in a higher Wells group with a "paradoxical" worsening, if the visual score of the extent of the primary lesion is not used.

[Bulky mediastinal lymphomas: role of magnetic resonance and SPECT-Ga-67 in the evaluation of residual masses]. / I linfomi "bulky" con localizzazione mediastinica: ruolo della risonanza magnetica e della SPET-Ga67 nella valutazione delle masse residue.

A residual mediastinal mass is a common finding during and/or after treatment for bulky mediastinal lymphoma and represents a difficult diagnostic problem. For correct therapy modulation, fibrosis must be distinguished from active disease. To assess diagnostic imaging potentials in the characterization of residual masses, 41 patients with bulky mediastinal lymphoma were examined with CT, MRI and Ga67-SPET; 92 examinations were performed for each technique: 14 before treatment, 42 during and after chemotherapy, 13 after radiotherapy and 23 six months after the end of treatment. CT provides useful pieces of information on tumor size but fails to depict tissue changes: therefore, only MR and SPET results were considered and compared with clinico-biological and follow-up findings. MRI and SPET were often in agreement with each other (78/92 cases) and with clinical data (98.7%); each examination yielded only one false positive. In case of disagreement (14/92 patients), MRI yielded more false-positive findings because it failed to differentiate neoplastic tissue from treatment-related conditions, i.e., granulation tissue, inflammation, necrosis, early fibrosis. In contrast, negative MR results were more reliable, MR negative predictive value being 100%. Ga67-SPET exhibited high sensitivity (97.1%) and specificity (91.2%), with fewer false positives than MRI (5 vs. 10). In conclusion, both examinations were accurate in the characterization of residual mediastinal masses during and after therapy, but MRI had higher sensitivity and Ga67-SPET higher specificity. Therefore, the authors acknowledge the complementary role of these two techniques and the necessity of an integrated approach, i.e., combined MRI and Ga67-SPET or CT and Ga67-SPET.

[Transrectal ultrasonography in the study of recurrences in patients surgically treated for rectal neoplasms]. / Studio mediante ecografia transrettale delle recidive nei pazienti operati per neoplasia rettale.

The value of transrectal US is known in the preoperative staging of rectal cancer but remains debated in the follow-up of the patients submitted to anterior resection or local therapy. The authors report their experience with the postoperative follow-up of 80 patients submitted to 125 transrectal US exams to study method reliability. The results were 9 true positive, 2 false positive, 113 true negative and 1 false negative cases, with 90% sensitivity, 98.3% specificity and 97.6% accuracy rates. Positive predictive value was 81.8% and negative predictive values was 99.1%. Twelve patients were submitted also to MRI which correctly diagnosed one false negative result of transrectal US. Twenty-one patients were examined also with transrectal Doppler and color-Doppler US: in rectal cancer recurrences the peak velocity of hemorrhoid vascular flow was higher than in non-recurrent patients. On the basis of our results, transrectal US deserves to be included in the postoperative follow-up of the patients submitted to anterior resection or to local therapy for rectal cancer. Moreover, according to our preliminary findings, Doppler and color-Doppler US can improve transrectal US reliability in detecting local recurrences.

[High-resolution computed tomography in the study of congenital cystic adenomatoid malformation of the lung]. / La tomografia computerizzata ad alta risoluzione nello studio della malformazione congenita adenomatoide cistica del polmone.

Congenital cystic adenomatoid malformation of the lung is a rare condition requiring an early diagnosis and the accurate assessment of its site and extent since it can be surgically treated with excellent prognosis. This study enrolled 12 patients with suspected congenital cystic adenomatoid malformation examined with high-resolution CT (HRCT) under general anesthesia and after pulmonary hyperinsufflation, to investigate HRCT capabilities in the pathological and topographic characterization of the lesion. In 11 patients HRCT showed features suggestive of cystic adenomatoid malformation and histology confirmed the diagnosis (type I in 9 cases and type II in 2 cases). In contrast, in 1 case of extralobar pulmonary sequestration, only pathology could exclude an associated cystic adenomatoid malformation type III. In all patients HRCT assessed lesion site and extent accurately: the lesions involved only one lobe in 7 patients, whereas in the other 5 more lobes were involved, unilaterally (3/5) or bilaterally (2/5). Associated lesions were found in 6 patients (2 intralobar pulmonary sequestrations, 1 rhabdomyosarcoma, 3 pulmonary inflammations). HRCT allowed the finest anatomic structures to be identified and made it possible to acquire images without movement or reflected dysventilation, which meant better disease assessment and more correct treatment planning. In conclusion, the authors suggest HRCT in the study of cystic adenomatoid malformations and for all lung conditions in the pediatric age.

[Use of computerized tomography in asthmatic patients]. / Impiego della Tomografia Computerizzata nel paziente asmatico.

This study was aimed at assessing the role of high resolution Computed Tomography (HRCT) in the asthmatic patient, during disease worsening. Chest radiography plays a major role in the assessment of the most common complications of asthma, such as pneumothorax, pneumomediastinum, or lobar collapse. Conventional CT and HRCT are sometimes used when a complication is suspected, particularly chronic eosinophilic pneumonia and allergic bronchopulmonary aspergillosis. We prospectively examined 31 asthmatic patients with clinical and functional worsening submitting them to chest radiographs and HRCT scans. In 5 of them, radiographic findings were suggestive of a complication: 3 patients presented allergic bronchopulmonary aspergillosis and 2 chronic eosinophilic pneumonia; in these cases HRCT confirmed the diagnosis and yielded other useful pieces of information, but did not change the prognosis or the therapeutic approach. In the remaining 26 patients, HRCT findings were abnormal in 61% of cases, while chest films were abnormal in 26% of cases only. An outstanding diagnostic contribution came from HRCT which demonstrated a high incidence of small airway disease and, above all, cylindrical bronchiectasis (53.8%), especially in the upper lobes. HRCT also demonstrated that asthma does not usually cause emphysematous destruction in the patients that never smoked. Even though our study enrolled only a small number of patients, the results suggest that asthma is a more destructive disease than previously believed and that HRCT could be a useful examination to perform even when chest film findings are normal.