Can FDG-PET be used to predict growth of stage I lung cancer?

AIM: To determine the relationship between the metabolic activity measured by 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) and computed tomography (CT)-derived tumour growth rates for stage 1 lung cancer. METHODS: Stage I lung cancer patients at our institution who underwent FDG PET, and who had at least two pre-treatment chest CT examinations (n=51), were retrospectively identified. Metabolic activity was defined by maximum lesion standardized uptake value (SUV) and maximum lesion-to-mean background activity (LBR). Growth rates were determined from serial CT volume measurements and the doubling time (DT) was calculated. Tumour growth rates were divided into rapid (DT<180 days), intermediate (DT=180-270 days), and slow (DT>270 days) groups. RESULTS: Rapid, moderate, and slow DT were seen in 22, 19, and 10 patients, respectively. Means (standard deviations) of SUV in the three groups (from rapid to slow growth rate) were 8.2 (4.8), 5.5 (4.5), and 2.2 (1.1), respectively and of LBR were 22.7 (10.1), 15.1 (12.6), and 6 (2.6), respectively. There was a significant relationship between SUV and DT (p<0.05), as well as between LBR and DT (p<0.05). CONCLUSIONS: For stage I lung tumours, there is a significant relationship between growth rates, as measured by serial CT examinations, and the initial pre-treatment metabolic activities, as measured by FDG uptake. This suggests that in patients in whom it is difficult to decide on the aggressiveness on treatment, FDG-PET may be used as additional prognostic tool for determining management.

Intrathoracic splenosis: superiority of technetium Tc 99m heat-damaged RBC imaging.

Intrathoracic splenosis is a rare diagnosis that is usually made following an invasive procedure. Although radiographic and CT findings are nonspecific, these findings combined with a history of splenic injury should suggest the possibility of this diagnosis. We present a patient with intrathoracic splenosis diagnosed on the basis of a technetium Tc 99m heat-damaged RBC scan following false-negative technetium Tc 99m sulfur colloid scan results.

Bronchostenosis due to childhood tuberculosis and manifested as an asymptomatic mass.

We report a case of bronchostenosis manifested as an asymptomatic mass on preoperative chest roentgenogram. Bronchoscopic biopsy inadvertently led to drainage of the obstructed bronchus. The various pathogenic origins of bronchostenosis are discussed, with the most likely cause in this case being previous tuberculosis.

Ventilator-associated pneumonia in patients with adult respiratory distress syndrome: CT evaluation.

PURPOSE: To determine the diagnostic accuracy of computed tomography (CT) for pneumonia in patients with adult respiratory distress syndrome (ARDS). MATERIALS AND METHODS: CT scans were obtained within 1 week of bronchoscopic sampling in 31 patients receiving mechanical ventilation for ARDS for more than 48 hours. Of 11 patients with pneumonia, five developed symptoms less than 11 days after the onset of ARDS (early ARDS). CT scans were rated for pneumonia independently by four radiologists who were unaware of the clinical diagnosis. Diagnostic accuracy was defined by means of the area under the receiver operating characteristic curve, or A2. RESULTS: Diagnostic accuracy for pneumonia was fair (A2 = 0.69 +/- 0.04 [standard error]) owing to 70% true-negative ratings (vs 59% true-positive ratings). The generalizability coefficient was good (0.79). No single CT finding was significantly different for the presence of pneumonia. Nondependent opacities predominated in 10 (91%) of 11 patients with pneumonia and 12 (60%) of 20 without pneumonia. Nondependent opacities predominated in nine (56%) of 16 patients with early ARDS and 13 (87%) of 15 with late ARDS. CONCLUSION: CT has fair diagnostic accuracy for ventilator-associated pneumonia in patients with ARDS owing primarily to identification of patients without pneumonia. No single CT sign was significantly different for pneumonia, but dependent atelectasis was more common in patients with early ARDS without pneumonia.

Pulmonary complications in children with hematologic malignancies: accuracy of diagnosis with chest radiography and CT.

PURPOSE: To determine the diagnostic accuracy of chest radiography and computed tomography (CT) in patients with complications during treatment for hematologic malignancies. MATERIALS AND METHODS: CT scans were obtained 1 week or less before bronchoscopic sampling or biopsy in 48 pediatric patients (age range, 8 months to 18 years at diagnosis) undergoing treatment for leukemia, lymphoma, or myeloproliferative disease. Radiographs were obtained less than 1 week before CT. Pulmonary complications comprised fungal (n = 11), viral (n = 4), and bacterial (n = 5) pneumonias; cryptogenic organizing pneumonia ([COP] n = 4); and pulmonary tumor (n = 4). Chest radiographs and CT scans were rated independently by three radiologists who were unaware of these diagnoses. RESULTS: Satisfactory diagnostic accuracy, defined by the area under the receiver operating characteristic (ROC) curve, was noted for fungal pneumonia (radiography, ROC area = 0.82; CT, ROC area = 0.78), COP (radiography, ROC area = 0.75; CT, ROC area = 0.75), and pulmonary tumor (radiography, ROC area = 0.73; CT, ROC area = 0.83). Generalizability was good for fungal pneumonia (radiography, generalizability coefficient [GC] = 0.84; CT, GC = 0.84) and COP (radiography, GC = 0.75; CT, GC = 0.99). There was no statistically significant difference in diagnostic accuracy between radiography and CT for any of the diagnoses. CONCLUSION: Radiography and CT have satisfactory accuracies for fungal pneumonia and COP. For these conditions, CT identified more true-positive cases than did radiography.

Lemierre syndrome.

We report a case of Lemierre syndrome. Although it is seen infrequently, it must be considered in patients with sore throat or dental pain, lateral neck pain, sepsis, and pulmonary symptoms. Diagnosis is based on clinical presentation, occurrence of anaerobic septicemia, radiologic evidence of internal jugular venous thrombosis, and pulmonary septic emboli.

Pulmonary complications after bone marrow transplantation.

Many of the pulmonary complications that we have described have a nonspecific radiographic appearance. The most crucial information for proper interpretation of the chest radiographs is the chronologic onset of radiographic abnormalities after transplantation. Before and immediately after engraftment, local peripheral opacities accompanied by a surrounding rim of edema are regarded as fungal infections, and therapy with granulocyte transfusions and amphotericin B is initiated. Diffuse interstitial thickening is likely to represent edema, pulmonary hemorrhage, bacterial infection, or ARDS rather than CMV or P. carinii pneumonia in the neutropenic host. After engraftment, diffuse interstitial processes become the predominant lung abnormalities. In allogeneic transplant patients who are serologically positive for CMV or who receive serologically positive donor marrow for CMV, pneumonitis caused by this virus is perhaps the most common treatable lung infection. Idiopathic interstitial pneumonias present in a similar fashion to CMV pneumonia; however, the response to corticosteroid therapy is only occasionally gratifying. The onset of nodular opacities in this period may be due to a number of disorders, such as opportunistic infection, BOOP, PTLPD or recurrent tumor. Open lung biopsy usually is required for definitive diagnosis.

Childhood lymphoma: diagnostic accuracy of chest radiography for severe pulmonary complications.

INTRODUCTION: We sought to determine whether chest radiography can be reliably used to distinguish persistent or relapsing pulmonary lymphoma from a variety of infectious and noninfectious pulmonary conditions that can occur in children receiving treatment for lymphoma. METHODS: We studied chest radiographs of 37 patients (30 with non-Hodgkin's lymphoma, and seven with Hodgkin's disease) who died of paediatric lymphoma or of treatment complications. Pulmonary findings at autopsy comprised lung tumour (n = 14), pleural tumour (n = 12), pneumonia (n = 22), adult respiratory distress syndrome (ARDS; n = 16), haemorrhage (n = 27), and infarction (n = 13). Using a 4-point scale and without knowledge of autopsy findings, three radiologists independently rated antemortem radiographs for the presence of pulmonary tumour, pleural tumour, pneumonia in general, pneumonia caused by viral, bacterial, fungal, and protozoan pathogens, ARDS, pulmonary haemorrhage, and pulmonary infarction. Diagnostic accuracy was defined by the area under the receiver-operating-characteristic curve (AZ). RESULTS: Diagnostic accuracy was good for pulmonary tumour (AZ, 0.71 +/- 0.6), protozoan pneumonia (AZ, 0.77 +/- 0.06), and ARDS (AZ, 0.86 +/- 0.07) but poor for all other conditions. The absence of both pleural effusions and mediastinal/right hilar lymphadenopathy was significantly associated (P < or = 0.04) with the absence of lung tumour. DISCUSSION: The pulmonary processes in these patients can all demonstrate diffuse airspace opacification, and many patients had multiple lung abnormalities at autopsy. The radiologist-readers were unable to identify which pulmonary conditions were responsible for radiographic findings in most patients. The readers were able to identify patients who did not have pulmonary lymphoma. If pulmonary involvement with lymphoma is unlikely, bronchoscopy with bronchoalveolar lavage may be sufficient to establish a diagnosis. When pulmonary lymphoma is a clinical consideration, open lung biopsy is usually required for diagnosis.

Magnetic resonance imaging for evaluation of childhood aplastic anemia.

PURPOSE: We prospectively evaluated the ability of magnetic resonance imaging (MRI) of the thoraco-lumbar vertebrae to determine the relative amount of red and fatty marrow in children with aplastic anemia. PATIENTS AND METHODS: Twenty pediatric patients (ages 1-19 years) with aplastic anemia underwent T1-weighted (T1W, n = 31) and short T1 inversion recovery (STIR, n = 30) MRI of the midline sagittal thoraco-lumbar spine. Bone marrow (BM) biopsies from the posterior iliac crest (n = 29) were also performed. All studies were evaluated by blinded observers; MR grading was based on visual inspection of signal intensity. Biopsy-estimated cellularity was compared with T1W and STIR grading when these were performed within 14 days of each other (n = 16). All studies were compared to a simultaneous absolute neutrophil count (ANC), absolute reticulocyte count (ARC), and platelet count. RESULTS: BM cellularity estimated by BM biopsy was significantly associated with STIR grading (p = 0.032, Jonckheere-Terpstra test), as were peripheral ANC (p = 0.044), ARC (p = 0.007), and platelet count (p = 0.003). T1W grade was significantly associated with ANC (P = 0.011) but not ARC (p = 0.053) or platelet count (p = 0.377). Biopsy-estimated cellularity was associated with ANC (p = 0.032) and ARC (p = 0.036), but not platelet count (p = 0.282). CONCLUSION: In childhood aplastic anemia patients, STIR (and, to a lesser extent, T1W) MRI of the thoraco-lumbar spine reflects BM activity, as measured by peripheral blood ANC, ARC, and platelet count, and BM cellularity, as measured by BM biopsy. MRI may thus provide a noninvasive measure of hematopoietic status.

The fibroproliferative phase of late adult respiratory distress syndrome.

Tissue response to insults is similar regardless of the tissue involved, and occurs in two sequential and interconnected steps, inflammation and fibroproliferation. Adult respiratory distress syndrome (ARDS) is a disease characterized by acute onset of diffuse and severe inflammatory reaction of the lung parenchyma with loss of compartmentalization, resulting in protein rich exudative edema. Following tissue injury, a complex pattern of responses begins to repair the lung. Ineffective repair is evident histologically with extensive pulmonary fibroproliferation and clinically with fever (without a source of infection) and inability to improve lung function. We will review recent observations indicating that an exaggerated pulmonary inflammatory response plays a key role in the progression of ARDS. We will provide a unifying pathogenetic model of ARDS, showing how the evolution from acute to chronic inflammation explains the progression of histological, laboratory, clinical, and physiological findings seen during the course of unresolving ARDS.

Use of Tl-201 to detect untreated pediatric Hodgkin disease.

PURPOSE: To evaluate the usefulness of thallium-201 scintigrams in depiction of supradiaphragmatic lymphadenopathy associated with newly diagnosed Hodgkin disease in pediatric patients. MATERIALS AND METHODS: Thallium-201 and gallium-67 scans of the chest and neck were obtained in 33 consecutive patients. Mediastinal, cervical, supraclavicular, and axillary lymph node activity was evaluated by independent raters, and results were compared in a blinded fashion with those on chest computed tomographic (CT) scans. RESULTS: Gallium and thallium scans demonstrated similar accuracy in depiction of CT-defined mediastinal masses. The kappa statistic indicated moderate to strong agreement with CT results. Similarly, there was no statistically significant difference between the accuracy of thallium and gallium scans in depiction of extramediastinal lymphadenopathy. CONCLUSION: Thallium scintigraphy is effective for depiction of lymphadenopathy in pediatric patients with untreated Hodgkin disease. Serial thallium studies may provide an alternative to gallium scans in monitoring response to treatment.

Ventilator-associated Pseudomonas aeruginosa pneumonia: radiographic findings.

PURPOSE: To characterize the radiographic features of ventilator-associated Pseudomonas aeruginosa pneumonia (PAP). MATERIALS AND METHODS: In 56 patients (40 men and 16 women), PAP was documented with fiberoptic bronchoscopy. All patients underwent mechanical ventilation for at least 48 hours before diagnosis. The findings on chest radiographs were recorded. In eight patients in whom computed tomography (CT) was performed, results were compared with radiographic findings. RESULTS: Twenty-six patients with adult respiratory distress syndrome (ARDS) had diffuse bilateral confluent opacities; 30 patients without ARDS had multifocal opacities. In 13 patients, cavities were detected at chest radiography, CT, or both. Seven of 29 patients with pleural abnormalities had empyema. CT provided important additional information (presence of cavities or effusions) in four cases. CONCLUSION: Findings on chest radiographs are nonspecific for PAP. The frequencies of cavities and empyema are surprisingly low, perhaps owing to prompt diagnosis and therapy.

Diagnostic imaging of pneumonia and its complications in the critically ill patient.

Chest radiography and other radiographic imaging techniques often are extremely useful in the differential diagnosis of chest diseases in ICU patients. It should be remembered, however, that the findings on these imaging studies often are nonspecific. Also, different pathologic processes may be present in a patient's lungs at the same time. Clinical parameters, medical diagnostic studies, and laboratory studies are important in the differentiation of disease processes in these patients. The radiologist should work closely with the clinician to provide optimal care for patients in the ICU setting.

Imaging features of ovarian metastases from colonic adenocarcinoma in adolescents.

This paper describes the imaging features of ovarian metastases from adenocarcinoma of the colon in adolescent females. We reviewed retrospectively abdominal and pelvic computed tomographic and pelvic ultrasound examinations, histologic slices, and clinical charts of six adolescent females with ovarian metastases secondary to adenocarcinoma of the colon. One patient had ovarian metastasis at presentation and was presumed to have a primary ovarian tumor. The ovarian metastases were either solid (n = 3), complex with both solid and cystic components (n = 2), or multilocular cysts (n = 1). The ovarian lesions were large, ranging from 6 cm to 18 cm in diameter. Colorectal carcinoma in adolescent females is frequently associated with ovarian metastases. One imaging characteristic differs in adult and adolescent ovarian metastases, although they do have features in common: in adolescents, a smaller proportion of colorectal ovarian metastases are multicystic (17%) compared with the adult series (45%). These lesions are frequently large and may be complex, multicystic, or solid. Although it is a rare disease, the differential diagnosis of adnexal masses in adolescent females should include ovarian metastases from adenocarcinoma of the colon.

Adult presentation of heterotaxic syndromes and related complexes.

(Definitions) Situs solitus indicates the normal position of the cardiac atria and viscera. Situs solitus with levocardia is the normal situation, with < 1% incidence of congenital heart disease (Table 1). Levocardia denotes a left-sided heart and a left cardiac apex; it does not give any indication of cardiac structure or body situs (Fig. 1A). Situs inversus is the mirror-image location of the atria and abdominal viscera (Fig. 1B). Heterotaxia is the abnormal arrangement of organs and major blood vessels different from the orderly arrangement of either situs solitus or situs inversus. In situs ambiguus or heterotaxia, the relationship of the atria and viscera is inconsistent. Isomerism, a form of heterotaxia, is a term used to describe symmetric morphology, i.e., both sides of the viscera, and both lungs are nearly identical to one another (Fig. 2). Right isomerism or asplenia syndrome is characterized by situs ambiguus with bilateral right-sidedness (Fig. 2A). Left isomerism or polysplenia syndrome is a second type of situs ambiguus characterized by bilateral left-sidedness (Fig. 2B). In this review, all patients having situs ambiguus with either right isomerism (asplenia syndrome) or left isomerism (polysplenia syndrome) are regarded as having cardiac malposition, an inappropriate cardiac position.