Clinical significance of periportal tracking as an extrarenal manifestation of acute pyelonephritis.

PURPOSE: The purpose of this study was to evaluate whether hepatic periportal tracking (PPT) in patients with acute pyelonephritis correlates with the severity of pyelonephritis. MATERIAL AND METHODS: A database search was conducted of patients with clinically suspected acute pyelonephritis who underwent abdominal computed tomography (CT) between January 2004 and June 2009 for disease evaluation. The final study group consisted of 274 patients (221 women, 53 men) with a mean age of 43 ± 20 years. The abdominal CT studies were retrospectively reviewed by two radiologists by consensus to assess PPT, renal wedge-shaped hypoperfusion areas, and renal abscesses. The laboratory reports obtained on the day of the CT examinations were reviewed for C-reactive protein (CRP), white blood cell count (WBCC), and leukocytes in urine. Presence of PPT was correlated with the presence of renal abscess, extension of renal hypoperfusion areas as well with levels of CRP, leukocytosis, and urine leukocytes using the Fisher's exact Test and the Wilcoxon Test. RESULTS: All patients showed renal hypoperfusion areas consistent with the clinical diagnosis of acute pyelonephritis. Twenty-nine patients (11%) showed PPT which was significantly associated with the extension of the wedge-shaped renal hypoperfusion areas (P < 0.001), the presence of a renal abscess (P < 0.01), as well as the level of CRP (P < 0.001) and urine leukocytes (P < 0.01). A renal abscess was observed in 36% of patients with PPT compared with 14% of patients without PPT. CONCLUSION: The PPT should be kept in mind as an extrarenal finding in acute pyelonephritis and may indicate a more serious clinical course of the disease.

CT-guided biopsy of lesions of the lung, liver, pancreas or of enlarged lymph nodes: value of additional fine needle aspiration (FNA) to core needle biopsy (CNB) in an offsite pathologist setting.

RATIONALE AND OBJECTIVES: To assess the value of additional fine needle aspiration (FNA) to core needle biopsy (CNB) in computed tomography-guided biopsy of lesions of the lung, liver, pancreas, or of enlarged lymph nodes in an offsite cytopathologist setting. MATERIALS AND METHODS: This retrospective Health Insurance Portability and Accountability Act-compliant study was approved by the Institutional Review Board (IRB); informed consent (IC) was waived. Data of 377 patients who underwent computed tomography-guided FNA and CNB of lesions of the lung, liver, pancreas, or enlarged lymph nodes were enrolled. An onsite cytopathologist was not available. Sensitivity and specificity were calculated for FNA, CNB, and combined FNA/CNB. For the purpose of our study, positive diagnoses from CNB specimens or subsequent biopsy or surgical resection specimens or clinical follow-up data were considered as the standard of reference. RESULTS: CNB yielded a significantly higher sensitivity than FNA in all sites, except the pancreas, where the difference did not reach statistical significance. Additional FNA to CNB did not significantly increase the sensitivity. Specificity did not significantly differ between FNA, CNB, and combined FNA/CNB in all sites. Malignancies of 1.7% were detected only with FNA, without evidence of malignancy in CNB; for the remaining malignancies, CNB was positive or indeterminate. CONCLUSION: Additional FNA to CNB without an onsite cytopathologist does not yield higher sensitivity or specificity compared to CNB alone.

MDCT angiography of the pulmonary arteries: influence of body weight, body mass index, and scan length on arterial enhancement at different iodine flow rates.

OBJECTIVE: The purpose of this study was to assess whether body weight, body mass index, and scan length influence arterial enhancement during CT angiography (CTA) of the pulmonary arteries at different iodine flow rates. MATERIALS AND METHODS: CTA examinations of the pulmonary arteries performed for routine clinical care of 120 patients between March and December 2003 were retrospectively evaluated. Patients had received either 120 mL of contrast medium with an iodine concentration of 300 mg I/mL (group A) or 90 mL of contrast medium with an iodine concentration of 400 mg I/mL (group B). The iodine dose was 36 g, and the injection rate was 4 mL/s in all examinations. The iodine flow rate was 1.2 g I/s in group A and 1.6 g I/s in group B. Arterial attenuation along the z-axis was measured per patient, and the influence of body weight, body mass index, and scan length on enhancement of the pulmonary arteries in the two groups was assessed. RESULTS: In group A and in group B, body weight and body mass index correlated significantly with mean enhancement along the z-axis (r = -0.35 and -0.26 for group A and -0.48 and -0.40 for group B). Scan length showed no correlation with pulmonary attenuation. Mean pulmonary artery enhancement was significantly higher in group B with a difference of 51 H compared with group A. CONCLUSION: Pulmonary artery attenuation in CTA of the pulmonary arteries shows a small but significant correlation with body weight and body mass index independently of the iodine flow rate used. A higher iodine flow rate improves pulmonary artery enhancement.

Psoriatic arthritis and rheumatoid arthritis: findings in contrast-enhanced MRI.

OBJECTIVE: Our objective was to define typical MRI findings of the wrist and the hand in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA). MATERIALS AND METHODS: Eighteen PsA and 21 RA patients with arthralgia of the wrist or hand joints underwent gadolinium-enhanced MRI of the wrist and hand. Two experienced radiologists interpreted abnormalities in consensus with respect to periarticular soft-tissue swelling, synovitis with or without effusion, periostitis, bone edema, bone erosions, bone cysts, and tenosynovitis. The distribution of the abnormalities also was evaluated. RESULTS: Erosions were statistically more frequent in patients with RA (p < 0.05). Periostitis was statistically seen more frequently in patients with PsA (p < 0.05). No statistically significant difference was found in the frequency of synovitis, bone marrow edema, bone cysts, and tenosynovitis between the two groups (p > 0.05). The radiocarpal joint, the midcarpal joints, the carpometacarpal joints, and the metacarpophalangeal joints were significantly affected more frequently in patients with RA than in patients with PsA (p < 0.05), whereas the proximal interphalangeal joints were significantly more frequently affected in patients with PsA (p < 0.05). CONCLUSION: Periostitis and synovitis of the proximal interphalangeal joints are typical MRI findings in patients with PsA, whereas synovitis with erosions of the wrist, the midcarpal joints, the carpometacarpal joints, and the metacarpophalangeal joints are typical findings in patients with RA.

MDCT angiography of the pulmonary arteries: influence of iodine flow concentration on vessel attenuation and visualization.

OBJECTIVE: Our objective was to assess the influence of iodine flow concentration on attenuation and visualization of the pulmonary arteries in thoracic MDCT angiography. MATERIALS AND METHODS: One hundred consecutive patients who were referred to our department with suspected acute pulmonary embolism underwent MDCT angiography of the pulmonary arteries either with 120 mL of standard contrast medium (300 mg I/mL) (group A) or with 90 mL of high-concentration contrast medium (400 mg I/mL) (group B). The contrast medium was injected at a flow rate of 4 mL/sec. The scan delay was determined using a semiautomatic bolus-tracking system in all examinations conducted with the same scanning parameters. Quantitative analysis was performed by region-of-interest measurements along the z-axis to compare the attenuation profiles of the two groups. Attenuation of the fourth-, fifth-, and sixth-order arteries was assessed visually for differences between the two groups. RESULTS: The mean enhancement along the z-axis was 268 +/- 56 H in group A and 344 +/- 108 in group B. The difference of 76 H was statistically significant (p < 0.001). The attenuation profile was similar in both groups. The detection rate of fifth- and sixth-order arteries was significantly higher in group B than in group A (94% compared with 91% and 72% compared with 60%, respectively, p < 0.01). CONCLUSION: Use of a high flow concentration of iodine in MDCT angiography of the pulmonary arteries significantly increases attenuation of the pulmonary arteries, thereby improving visualization of subsegmental pulmonary arteries.

Non-small cell lung cancer: evaluation of pleural abnormalities on CT scans with 18F FDG PET.

PURPOSE: To evaluate the accuracy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in differentiation of pleural malignancy and cancer-unrelated pleural disease in patients with non-small cell lung cancer (NSCLC) and pleural abnormalities at computed tomography (CT). MATERIALS AND METHODS: In 92 patients, pleural abnormalities were detected at contrast material-enhanced thoracic CT, which was performed for newly diagnosed NSCLC (n = 41) or restaging (n = 51). CT findings were negative for pleural malignancy when pleural effusion with attenuation of 10 HU or less and/or rib fractures with no evidence of pathologic fracture were present; findings were indeterminate when pleural effusion with attenuation greater than 10 HU and/or solid pleural abnormalities without osseous destruction of the chest wall were present; and findings were positive if any osseous destruction of the chest wall adjacent to a pleural mass was present. All patients underwent FDG PET. Findings were negative for pleural malignancy if pleural activity was absent, equal to, or less than mediastinal background activity; findings were positive if pleural activity was higher than mediastinal background activity. Reading of CT and FDG PET scans was first performed separately and then was combined. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPP), and accuracy were calculated for CT and FDG PET separately and for CT and FDG PET combined, with cytologic and/or histologic analysis as standard of reference. RESULTS: In detection of pleural malignancies, CT findings were indeterminate in 65 (71%) patients and true-negative in 27 (29%). Respective sensitivity, specificity, PPV, NPV, and accuracy of FDG PET in detection of pleural malignancies were 100%, 71%, 63%, 100%, and 80%; and those of CT and FDG PET combined, 100%, 76%, 67%, 100%, and 84%. CONCLUSION: Findings suggest that a negative FDG PET scan for indeterminate pleural abnormalities at CT indicates a benign character, while positive findings on an FDG PET scan are sensitive for malignancy.

Aortoiliac enhancement during computed tomography angiography with reduced contrast material dose and saline solution flush: influence on magnitude and uniformity of the contrast column.

RATIONALE AND OBJECTIVES: To compare the magnitude and uniformity of aortoiliac contrast enhancement obtained from uniphasic contrast material injections versus contrast material injections with reduced iodine dose followed by a saline flush in aortoiliac multislice CT angiography (CTA). METHODS: Twenty-nine patients with abdominal aortic aneurysms underwent aortoiliac CTA using protocols A and B. With protocol A, 120 mL contrast material (300 mgI/mL), and with protocol B, 100 mL contrast material followed by a 40-mL saline solution flush were administered at a flow rate of 4 mL/s. Quantitative analysis was performed by calculating mean aortoiliac attenuation, mean plateau deviation, and mean difference between maximum and minimum attenuation value for both groups. Qualitative analysis was performed by visual assessment of vascular enhancement using 2-dimensional and 3-dimensional postprocessing techniques. RESULTS: The mean aortoiliac attenuation with protocol A was 291 +/- 62 HU, and with protocol B it was 285 +/- 61 HU. The difference of 6 HU was not statistically significant (P = 0.27). Mean plateau deviation was significantly smaller using protocol A than protocol B (16 +/- 9 HU vs. 20 +/- 10 HU, P = 0.03). In addition, the mean difference between maximum and minimum attenuation value was significantly smaller with protocol A than with protocol B (59 +/- 29 HU vs. 72 +/- 32 HU, P = 0.01). Visual analysis showed no difference in contrast material magnitude and homogeneity between the protocols. CONCLUSIONS: In aortoiliac CTA, a saline solution flush after contrast material bolus allows an iodine dose reduction of approximately 20 mL without impairing the magnitude of contrast enhancement but degrades the uniformity of the contrast column. However, the degradation does not affect visual analysis.

Improvement of parenchymal and vascular enhancement using saline flush and power injection for multiple-detector-row abdominal CT.

The aim of this study was to determine if a saline solution flush following low dose contrast material bolus improves parenchymal and vascular enhancement during abdominal multiple detector-row computed tomography (MDCT). Forty-one patients (24 men and 17 women; mean age 49 years, age range 27-86 years) underwent abdominal MDCT (collimation 4x5 mm, 15-mm table increment, reconstruction interval 5 mm, gantry rotation period 0.8 s) with a single- as well as with a double syringe power injector. Indication for examination were benign and malignant tumors and inflammatory diseases. Patients received 100 ml nonionic contrast material (300 mgI/ml) alone or pushed with 20 ml saline solution. Mean enhancement values for both protocols were measured in the liver, the spleen, the pancreas, the renal cortex, the portal vein, the inferior vena cava and the abdominal aorta. Double syringe power-injector protocol led to significantly higher parenchymal and vascular enhancement than single syringe power-injector protocol (p<0.05). The improvement in mean enhancement of the liver was 9 +/- 9 HU, of the spleen 8 +/- 10 HU, of the pancreas 7 +/- 9 HU, and of the renal cortex 8 +/- 20 HU. The improvement in mean enhancement of the portal vein was 10 +/- 17 HU of the inferior vena cava 8 +/- 13 HU and of the abdominal aorta 10 +/- 17 HU. The use of a double syringe power injector with saline flush following contrast material bolus significantly improves parenchymal and vascular enhancement during contrast-enhanced abdominal MDCT with low iodine doses.

Abdominal multidetector row computed tomography: reduction of cost and contrast material dose using saline flush.

OBJECTIVE: To evaluate the potential of a saline solution flush after the contrast material bolus in abdominal multidetector row CT (MDCT) in contrast material dose and cost reduction. METHODS: Abdominal MDCT was performed in 78 patients who were assigned randomly to 2 groups receiving 120 mL nonionic contrast material (300 mgI/mL) alone or 100 mL of the same contrast material pushed with 40 mL of saline solution. Mean attenuation values for both groups were measured in the liver, the spleen, the pancreas, the portal vein, the inferior vena cava, and the abdominal aorta. Cost analyses were performed for both groups. RESULTS: There was no significant difference in parenchymal and vascular enhancement between both groups. The difference of the enhancement was 2 HU for the liver (P = 0.11), 2 HU for the spleen (P = 0.44), 3 HU for the pancreas (P = 0.38), 9 HU for the portal vein (P = 0.11), 3 HU for the inferior vena cava (P = 0.55), and 10 HU for the aorta (P = 0.06). Taking the costs of contrast material, saline solution, and disposal material into account, 7.30 dollars was saved by the patient using a saline solution flush. CONCLUSIONS: Using a saline flush after the contrast material bolus in abdominal MDCT allows an iodine dose reduction of approximately 6 g, or 17%, without impairing mean parenchymal and vascular enhancement and a cost reduction of 7.30 dollars per patient.

Impingement syndrome of the ankle following supination external rotation trauma: MR imaging findings with arthroscopic correlation.

Our objective was to identify MR imaging findings in patients with syndesmotic soft tissue impingement of the ankle and to investigate the reliability of these imaging characteristics to predict syndesmotic soft tissue impingement syndromes of the ankle. Twenty-one ankles with chronic pain ultimately proven to have anterior soft tissue impingement syndrome were examined by MR imaging during January 1996 to June 2001. The MR imaging protocol included sagittal and coronal short tau inversion recovery (STIR), sagittal T1-weighted spin echo, axial and coronal proton-density, and T2-weighted spin-echo sequences. Nineteen ankles that underwent MR imaging during the same period of time and that had arthroscopically proven diagnosis different than impingement syndrome served as a control group. Fibrovascular scar formations distinct from the syndesmotic ligaments possibly related to syndesmotic soft tissue impingement were recorded. Arthroscopy was performed subsequently in all patients and was considered the gold standard. The statistical analysis revealed an overall frequency of scarred syndesmotic ligaments of 70% in the group with ankle impingement. Fibrovascular scar formations distinct from the syndesmotic ligaments presented with low signal intensity on T1-weighted images and remained low to intermediate in signal intensity on T2-weighted MR imaging. Compared with arthroscopy, MR imaging revealed a sensitivity of 89%, a specificity of 100%, and a diagnostic accuracy of 93% for scarred syndesmotic ligaments. The frequency of scar formation distinct from the syndesmotic ligaments in patients with impingement syndrome of the ankle was not statistically significantly higher than in the control group. In contrast to that, anterior tibial osteophytes and talar osteophytes were statistically significantly higher in the group with anterior impingement than in the control group. Conventional MR imaging was found to be insensitive for the diagnosis of syndesmotic soft tissue impingement of the ankle. Fibrovascular scar tissue distinct from syndesmotic ligaments is suggestive for the diagnosis of soft tissue impingement, but the reliability of these findings is still questionable.