Early MR demonstration of spinal metastases in patients with normal radiographs and CT and radionuclide bone scans

Forty patients with known primary tumor and progressive back pain, suspected of having spinal metastatic disease, underwent magnetic resonance (MR) examinations of the thoracic and lumbosacral spine. Conventional radiographs and CT scans of the spine were all normal. The radionuclide bone scans were equivocal. In 21 patients focal or diffuse vertebral MR abnormalities were detected. In nine patients the lesions were hypointense on T1 sequence, and the same lesions were demonstrated poorly or not at all on T2 and proton density sequences. In eight other patients the bone marrow metastases presented with strong signal intensity on T2 and were poorly or not at all demonstrated on T1 and proton density sequences. In three patients with multiple myeloma, the signal intensity pattern of the vertebrae was diffusely heterogeneous, with alternating small foci of strong and weak signals (a mosaic-like pattern). Following the MR studies, needle biopsy confirmed the malignancy in the 21 patients who had shown abnormalities. No correlation between the type of primary tumor and the signal intensity of the vertebral metastases was shown. Possibly the mosaic pattern shown in three of the multiple myeloma patients represents a special case.     

The role of computed tomography in the detection of bone metastases in breast cancer patients

Computed tomography (CT) of bone was carried out in 20 patients with breast cancer, all of whom had abnormal radionuclide uptake on skeletal scintigrams but normal conventional radiographs. Twenty-eight sites were examined and 13 showed metastases in 11 patients. Five of these patients had no evidence of extra-skeletal recurrent disease. Follow-up at eight of these sites showed healing, sclerosis or progression, all of which correlated well with clinical findings. CT showed benign causes of radionuclide accumulation in three patients (7 sites) but no abnormality in six patients (8 sites). None of these patients has subsequently developed bone metastases. CT is superior to conventional radiographs in the diagnosis of skeletal metastases and should be carried out when skeletal scintigraphy is positive and conventional examinations are normal.     

Comparative accuracy of high resolution computed tomography and chest radiography in the diagnosis of chronic diffuse infiltrative lung disease

One hundred individuals who had undergone both high resolution computed tomography (HRCT) and chest radiography were studied to determine the accuracy of each technique in establishing the diagnosis of diffuse lung disease. The group consisted of 86 patients with a diagnosis of a chronic diffuse infiltrative lung disease and 14 normal subjects. Two independent observers assessed the HRCT examinations and chest radiographs and recorded the three most likely diagnoses. Overall a confident diagnosis was reached more often with HRCT (49%) than with chest radiography (41%). The diagnoses were correct in 82% of HRCT examinations and 69% of chest radiographs. Diagnoses made on HRCT, irrespective of the degree of certainty, were accurate more often than diagnoses made on chest radiography (56% and 47% respectively). Of the patients thought to have a normal chest radiograph, 42% had diffuse infiltrative lung disease (DILD). Of the patients thought to be normal on HRCT, 18% had DILD. Conversely, normal subjects were correctly identified as such in 82% of chest radiographs and in 96% of HRCT examinations. This study emphasizes the important role of CT in helping to confirm or refute the presence of abnormality when the chest radiograph is normal or questionably abnormal, and underlines the superior diagnostic accuracy of HRCT compared with conventional chest radiography in DILD.     

Role of chest CT in non-Hodgkin lymphoma

A retrospective study of 48 patients with non-Hodgkin lymphoma (NHL) who underwent 54 computed tomographic (CT) examinations of the chest evaluated the role of chest CT in the management of this disease. Of 18 cases in which chest radiographs were not indicative of NHL, CT scans showed abnormalities consistent with NHL in five (28%). Of 11 cases where radiographs were questionable, CT confirmed NHL in five (45%) and excluded it in six (55%). Of 25 cases where radiographs were consistent with NHL, CT confirmed the findings in 23 (92%) and added information in all 25. Chest CT affected management in eight of 25 treated and five of 19 untreated patients. It appears to be useful in untreated patients with stage I or II NHL but no definite radiographic abnormalities, or with abnormal radiographs but no extrathoracic spread, and in treated patients with questionable radiographs. CT is not helpful in untreated patients with stage III or IV NHL or treated patients with normal radiographs.     

Initial results in the assessment of multiple myeloma using 18F-FDG PET

This prospective study was undertaken to investigate the appearance of multiple myeloma on fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET). Furthermore, the accuracy of FDG-PET in detecting myeloma lesions and its influence on patient management were evaluated. Forty-three patients with known multiple myeloma (n=28) or solitary plasmacytoma (n=15) underwent FDG-PET. The results of routinely performed radiographs and of scans obtained using all available imaging modalities (MRI, CT), as well as the clinical course, were used for verification of detected lesions. Focally increased tracer uptake was observed in 38 of 41 known osteolytic bone lesions (sensitivity 92.7%) in 23 patients. In addition, 71 further bone lesions which were negative on radiographs were detected in 14 patients. Twenty-six (36.6%) of these lesions could be confirmed in ten patients. As a result of FDG-PET imaging, clinical management was influenced in five (14.0%) patients. The positive predictive value for active disease was 100% in patients with focal or mixed focal/diffuse skeletal FDG uptake and 75% in patients with diffuse bone marrow uptake. Depending on the interpretation of the PET scans in patients with diffuse bone marrow uptake, the sensitivity ranged from 83.8% to 91.9% and the specificity from 83.3% to 100%. FDG-PET thus proved highly accurate in detecting multiple myeloma, and revealed a greater extent of disease than routine radiographs in 14 of 23 (60.9%) patients who had osteolytic bone lesions. FDG-PET might contribute to the initial staging of solitary plasmacytoma.     

显微镜下多血管炎肺损害的临床与CT表现

目的 分析显微镜下多血管炎(MPA)肺损害的临床与CT表现特征.方法 对2005年8月至2008年11月期间的16例MPA肺损害患者的临床表现、抗中性粒细胞胞浆抗体实验室检查结果及CT表现进行回顾性分析.结果 (1)临床表现:11例MPA肺损害者有咯血或血痰,8例以肺部症状为首发症状者均被误诊为其他肺部疾病;所有患者均合并有肾脏、心血管及内分泌等其他多器官受损表现.(2)实验室检查结果:16例核周型抗中性粒细胞胞浆抗体均为阳性,14例髓过氧化物酶-抗中性粒细胞胞浆抗体阳性.(3)CT检查结果:16例患者均有肺间质性改变,其中15例以间质性病变为主,1例以实质性病变为主;8例有肺间质纤维化征象,11例有实变影,6例间质纤维化征象与实变影合并存在;6例出现纵隔淋巴结肿大.结论 多数MPA肺损害患者临床上有咯血和血痰表现,CT表现以间质性病变为主,对于有上述表现的中老年患者,无论是否合并肾等其他器官受损表现,都要警惕MPA,并及时进行相关检查.     

显微镜下多血管炎肺损害的临床与CT表现

目的 分析显微镜下多血管炎(MPA)肺损害的临床与CT表现特征.方法 对2005年8月至2008年11月期间的16例MPA肺损害患者的临床表现、抗中性粒细胞胞浆抗体实验室检查结果及CT表现进行回顾性分析.结果 (1)临床表现:11例MPA肺损害者有咯血或血痰,8例以肺部症状为首发症状者均被误诊为其他肺部疾病;所有患者均合并有肾脏、心血管及内分泌等其他多器官受损表现.(2)实验室检查结果:16例核周型抗中性粒细胞胞浆抗体均为阳性,14例髓过氧化物酶-抗中性粒细胞胞浆抗体阳性.(3)CT检查结果:16例患者均有肺间质性改变,其中15例以间质性病变为主,1例以实质性病变为主;8例有肺间质纤维化征象,11例有实变影,6例间质纤维化征象与实变影合并存在;6例出现纵隔淋巴结肿大.结论 多数MPA肺损害患者临床上有咯血和血痰表现,CT表现以间质性病变为主,对于有上述表现的中老年患者,无论是否合并肾等其他器官受损表现,都要警惕MPA,并及时进行相关检查.     

Role and limitations of plain radiography in chest radiology]

Despite the recent development of diagnostic modalities such as CT and MRI, plain radiography continues to play an important role in chest radiology. Chest radiography remains the imaging modality of choice for initial examinations because it offers simplicity, low cost, and a large amount of information. It is important for radiologists to understand normal anatomy and variants simulating disease to avoid false-positive interpretations of chest radiographs and unnecessary CT examinations. It should be noted that many cases can be diagnosed correctly by chest radiographs alone. Only after careful evaluation of an abnormality on chest radiograph should CT examination be performed. We should also be aware that some serious chest diseases, including miliary tuberculosis, can present normal chest radiographs in the early stage. In such patients with respiratory symptoms, even when the chest radiograph is negative, CT examination should be performed promptly to avoid disease progression.     

Pulmonary lymphangitic carcinomatosis: CT and pathologic findings

The authors retrospectively reviewed the computed tomographic (CT) scans, biopsy specimens, autopsy results, and lobectomy specimens of 21 patients who had lymphangitic carcinomatosis. Ten-millimeter collimation CT scans were obtained from all patients, and selected 1.5-mm CT scans were obtained from ten patients. In five patients, the diagnosis was established with open lung biopsy, lobectomy, or autopsy; in nine, with bronchial biopsy or transbronchial biopsy; and in seven, with clinical and radiologic criteria. Certain characteristic findings on CT scans were evident: uneven thickening of bronchovascular bundles, thickening of isolated interstitial lines, and the presence of polygonal lines. These findings may be seen on CT scans even if the findings on chest radiographs are normal or nonspecific. The pathologic basis for these characteristic CT findings may relate to tumor thrombi in lymphatic vessels rather than edema and fibrosis, at least in the early stages of disease.     

Hodgkin disease: clinical utility of CT in initial staging and treatment

One hundred seven consecutive new cases of Hodgkin disease were evaluated with chest radiography and computed tomography (CT) for initial staging. The data were evaluated with regard to five popular treatment protocols for Hodgkin disease. Thoracic CT scans were normal in 30 of 31 patients who had normal radiographs. In the remaining 76 patients, CT demonstrated 194 new sites of disease and disproved 25 suspected sites of disease. The use of CT scans changed the staging of disease in 20 patients, 16 of whom had extranodal extension. The effect of using CT findings on treatment depended on whether radiation therapy was used, and, if so, which treatment protocol was followed. The use of CT findings would have changed the treatment in 6.5%-62.7% of new cases of Hodgkin disease. The authors recommend that CT scans be obtained in all patients with Hodgkin disease, especially those with abnormal chest radiographs.     

Comparison of plain radiographs and coronal CT scans in infants and children with recurrent sinusitis

We performed a prospective study of 70 infants and children with recurrent sinusitis. We compared plain radiographs with coronal CT scans of the sinuses to determine if plain radiographs can be used to accurately diagnose and localize residual sinus disease amenable to endoscopic surgery. This residual disease is thought to be important in the pathogenesis of recurrences of sinusitis. The patients were taking antibiotics and were clinically well at the time of the two examinations (performed on the same day). Findings on slightly over 80% of the CT scans were abnormal. In about 75% of the patients, the findings on plain radiographs did not correlate with those on CT scans. About 45% of the patients had normal findings on plain radiographs of at least one sinus with an abnormality of that sinus shown on CT scans. Almost 35% of the patients had what was interpreted as an abnormality of at least one sinus on plain radiographs, but that sinus was normal on CT scans. Sinusitis in infants and children is often underdiagnosed or overdiagnosed on the basis of findings on plain radiographs of the sinuses. Plain radiographs cannot be used to determine the need for, or to guide, endoscopic surgery on the sinuses.     

Intervertebral disk-space infection: CT changes. Work in progress

Seven patients who had spinal interspace infections underwent clinical, laboratory, and radiographic examinations, and findings are reported. Lytic fragmentation of adjacent vertebral bodies is a characteristic appearance on CT scans. Sagittal-coronal reformations confirm the end-plate irregularity and establish the diagnosis. Since the changes of diskitis are delayed and often obscured by accompanying degenerative disease on plain radiographs, CT appears to offer a diagnostic modality that shortens the usual delay from onset of symptoms to diagnosis.     

Summer-type hypersensitivity pneumonitis: comparison of high-resolution CT and plain radiographic findings.

Summer-type hypersensitivity pneumonitis is an immunologic disease that occurs only in Japan. It is a form of hypersensitivity pneumonitis in which the clinical symptoms appear in the summer and subside spontaneously in mid autumn. The purpose of our study was to determine the CT findings in this condition, to compare the CT findings with those on chest radiographs, and to assess the variations in the CT findings over time. Accordingly, high-resolution CT scans and chest radiographs of 15 patients with summer-type hypersensitivity pneumonitis were retrospectively studied. Seven patients had sequential CT examinations 18-37 days apart. The CT scans and chest radiographs were reviewed by two observers independently. CT findings included diffuse micronodules (n = 15), slightly elevated lung density (n = 13), and patchy air-space consolidation (n = 13). In one patient, the findings on a chest radiograph were normal, while CT showed parenchymal abnormalities. In two cases, follow-up CT showed micronodular abnormalities after findings on the chest radiograph had returned to normal. Our results show that high-resolution CT findings of summer-type hypersensitivity pneumonitis include pulmonary micronodules, increased lung density, and air-space consolidation. High-resolution CT appears to be more useful than plain chest radiographs in the evaluation of pulmonary parenchymal abnormalities in this condition.     

Value of FDG PET in the assessment of patients with multiple myeloma

OBJECTIVE: Our objective was to evaluate if whole-body PET with FDG is able to detect bone marrow involvement in patients with multiple myeloma and to assess its appearance and distribution pattern. MATERIALS AND METHODS: Seventeen whole-body FDG PET scans were performed in 13 patients with multiple myeloma. Four patients were referred for evaluation of extent of disease pretherapy and nine patients were referred for assessment of therapy response (chemotherapy, radiation therapy, bone marrow transplant). FDG PET images were evaluated for distribution and uptake pattern. Standardized uptake values were obtained to quantify FDG uptake. Results of other imaging examinations (MRI, CT, radiography), laboratory data, biopsies, and the clinical course were used for verification of detected lesions. RESULTS: FDG PET was able to detect medullary involvement of multiple myeloma. There were two false-negative results. In one patient, the radiographic skeletal survey showed subcentimeter lytic lesions within the ribs that were not detected on FDG PET and in the other patient, a lytic lesion detected on radiographs showed only mildly increased FDG uptake that was not identified prospectively. There was one false-positive FDG PET result in a patient who had undergone radiation therapy 3 weeks before PET. FDG PET was helpful in differentiating between posttherapeutic changes and residual/recurrent tumor and in assessing response to therapy. FDG PET resulted in upstaging of disease in four patients, which influenced subsequent management and prognosis. Sensitivity of FDG PET in detecting myelomatous involvement was 85% and specificity was 92%. CONCLUSION: FDG PET is able to detect bone marrow involvement in patients with multiple myeloma. FDG PET is useful in assessing extent of disease at time of initial diagnosis, contributing to staging that is more accurate. FDG PET is also useful for evaluating therapy response.     

CT of recurrent retroperitoneal sarcomas

OBJECTIVE: We reviewed the medical records and CT scans of 33 patients with recurrent retroperitoneal sarcomas to determine the patterns of recurrent disease. MATERIALS AND METHODS: We reviewed the medical records and CT examinations obtained at the time the recurrence was diagnosed and tabulated data for all patients. Data for patients with high-grade malignancies were compared with those of patients with low-grade malignancies to determine whether there were differences in the interval between initial tumor resection and recurrence. We also compared CT appearances to determine patterns of recurrent disease. RESULTS: Twenty-five of 33 recurrences were detected within 2 years of initial surgery. Only 16 patients had symptoms, and when present, most symptoms were nonspecific. In 28 (85%) patients, recurrent tumor was in the abdomen at the time of diagnosis. In nine patients, the largest detectable abdominal tumor was less than 5 cm in diameter. Interval to recurrence was similar for patients with low- and high-grade tumors. Although the CT appearance was similar for both grades, distant metastases were identified only in patients with high-grade malignancies. CONCLUSION: Primary retroperitoneal malignancies frequently recur within 2 years of initial surgical resection. For asymptomatic patients, diagnosis is typically made during routine follow-up CT. Most patients have abdominal recurrences that may be small when first detected.     

Cytomegalovirus pneumonia: computed tomography findings

Cytomegalovirus (CMV) is a frequent pathogen of the respiratory tract in immunosuppressed patients. The diagnosis of CMV pneumonia frequently requires bronchopulmonary lavage or lung biopsy because the findings on chest radiographs are nonspecific. In only three cases of pure CMV pneumonia has the computed tomography (CT) appearance been described. In this study CT scans and chest radiographs of eight patients with CMV pneumonia were evaluated to determine if a characteristic CT appearance exists. The studies were evaluated for the type, severity and distribution of parenchymal abnormality. The most common CT finding was the presence of mixed alveolar and interstitial disease (seven patients); alveolar disease predominated in five of the seven patients, equal amounts of alveolar and interstitial disease were noted in one and interstitial disease predominated in the remaining patient. Air-space disease alone was present on CT examination of the eighth patient. In no case was there interstitial disease alone. Although mixed alveolar and interstitial disease was the most frequently encountered pattern, the variety of appearances suggests that the CT findings of CMV pneumonia are nonspecific.     

High-resolution CT of the lung parenchyma

High-resolution CT, a technique that optimizes the spatial resolution of lung parenchyma, uses thin collimation, reconstruction with a high-spatial frequency algorithm, image targeting, and sometimes increased kVp and mA settings. Performing a high-resolution CT study can provide information regarding lung morphology that cannot be obtained using conventional CT or plain radiographs. Alterations in anatomy can be identified at the level of the secondary pulmonary lobule, and although often nonspecific, in certain situations high-resolution CT findings can be diagnostic. High-resolution CT scanning is also helpful in identifying patients who have significant lung disease despite a normal chest radiograph, and in planning biopsy procedures.     

Computed tomography in chronic interstitial lung disease

A number of studies have demonstrated that high resolution computed tomography (CT) is superior to the radiography in the assessment of patients who have chronic interstitial lung disease. CT may demonstrate extensive parenchymal disease when the radiograph is normal and may allow for a confident diagnosis when the radiographic findings are nonspecific. Although well over 100 different diseases may involve the pulmonary interstitium, in practice, approximately 10 diseases account for 80% to 90% of all cases. This article reviews the CT manifestations of the most common chronic interstitial lung diseases.     

Neuroradiologic findings in AIDS: a review of 200 cases

The radiologic studies of 200 consecutive AIDS patients with neurologic symptoms were evaluated to determine their diagnostic specificity and prognostic value. Of 81 patients with initially normal CT scans, four (5%) later developed progressive neurologic illness. Of 75 patients with CT evidence of diffuse cerebral atrophy, 12 (16%) later developed CT abnormalities or had postmortem CNS disease. CT scans showed mass lesions initially in 44 patients and later in an additional seven patients. Although toxoplasma gondii infection was the most frequent cause of these lesions, the CT characteristics of cerebral toxoplasmosis are too nonspecific to warrant diagnosis without biopsy. Preliminary evidence suggests that MRI may be more sensitive than CT in detecting intracranial disease in patients with AIDS.     

Computed tomography for cervical spine trauma. The impact of MDCT on fracture detection and dose deposition

A multidetector computed tomography (MDCT) was installed in our department. Referral rates, examination protocols and detection rates of abnormal findings in CT examinations for cervical spine trauma 6 months before and 6 months after MDCT installation were compared to look for changes in practice. Retrospective analysis of all CT cervical spine examinations in patients with multiple trauma over two contiguous 6-month periods: from July 2003 to December 2003 (helical CT) and from January 2004 to June 2004 (MDCT). Variables recorded were number of CT examinations performed, scan plane coverage and traumatic abnormalities detected. Phantom dosimetry measurements for cervical spine examination in both helical CT and MDCT were compared. One hundred and fifty four patients underwent cervical spine CT during these periods. Helical CT period: of 91 patients undergoing CT cervical spine examination for trauma, 65 (71%) were complete cervical examinations and 26 (29%) were level-specific examinations. Eight patients (9%) had cervical spine fracture, six of which were apparent on radiographs. Dose estimations for thyroid, lens and breast were 24.76, 1.86 and 0.21 mGy, respectively, for complete cervical spine examinations. MDCT period: of 63 patients who underwent CT cervical spine examination for trauma, 61 (97%) were complete examinations and 2 (3%) were level-specific examinations. Six patients (11%) had cervical spine fracture, three of which were apparent on radiographs. Dose estimations for thyroid, lens and breast were 75.8, 9.7 and 0.7 mGy, respectively, for complete cervical spine examinations, which were notably higher than those for helical CT. After installation of MDCT, clinical requests for complete examination of the cervical spine following trauma increased. This changing trend resulted in a significantly higher radiation dose to thyroid, lens and breast.