Mass-like peripheral zone enhancement on CT is predictive of higher-grade (Gleason 4 + 3 and higher) prostate cancer

PURPOSE

To determine whether focal peripheral zone enhancement on routine venous-phase CT is predictive of higher-grade (Gleason 4 + 3 and higher) prostate cancer.

MATERIALS AND METHODS

IRB approval was obtained and informed consent waived for this HIPAA-compliant retrospective study. Forty-three patients with higher-grade prostate cancer (≥Gleason 4 + 3) and 96 with histology-confirmed lower-grade (≤Gleason 3 + 4 [n = 47]) or absent (n = 49) prostate cancer imaged with venous-phase CT comprised the study population. CT images were reviewed by ten blinded radiologists (5 attendings, 5 residents) who scored peripheral zone enhancement on a scale of 1 (benign) to 5 (malignant). Mass-like peripheral zone enhancement was considered malignant. Likelihood ratios (LR) and specificities were calculated. Multivariate conditional logistic regression analyses were conducted.

RESULTS

Scores of "5" were strongly predictive of higher-grade prostate cancer (pooled LR+ 9.6 [95% CI 5.8-15.8]) with rare false positives (pooled specificity: 0.98 [942/960, 95% CI 0.98-0.99]; all 10 readers had specificity ≥95%). Attending scores of "5" were more predictive than resident scores of "5" (LR+: 14.7 [95% CI 5.8-37.2] vs. 7.6 [95% CI 4.2-13.7]) with similar specificity (0.99 [475/480, 95% CI 0.98-1.00] vs. 0.97 [467/480, 95% CI 0.96-0.99]). Significant predictors of an assigned score of "5" included presence of a peripheral zone mass (p < 0.0001), larger size (p < 0.0001), and less reader experience (p = 0.0008). Significant predictors of higher-grade prostate cancer included presence of a peripheral zone mass (p = 0.0002) and larger size (p < 0.0001).

CONCLUSION

Focal mass-like peripheral zone enhancement on routine venous-phase CT is specific and predictive of higher-grade (Gleason 4 + 3 and higher) prostate cancer.

Multislice CT urography: state of the art

Recent improvements in helical CT hardware and software have provided imagers with the tools to obtain an increasingly large number of very thin axial images. As a result, a number of new applications for multislice CT have recently been developed, one of which is CT urography. The motivation for performing CT urography is the desire to create a single imaging test that can completely assess the kidneys and urinary tract for urolithiasis, renal masses and mucosal abnormalities of the renal collecting system, ureters and bladder. Although the preferred technique for performing multislice CT urography has not yet been determined and results are preliminary, early indications suggest that this examination can detect even subtle benign and malignant urothelial abnormalities and that it has the potential to completely replace excretory urography within the next several years. An important limitation of multislice CT urography is increased patient radiation exposure encountered when some of the more thorough recommended techniques are utilized.

Effectiveness of abdominal compression during helical renal CT

RATIONALE AND OBJECTIVES

The authors performed this study to assess the effect of abdominal compression on opacification and distention of the proximal renal collecting system during helical computed tomography (CT).

MATERIALS AND METHODS

Abdominal compression was applied during helical CT in 31 patients who were scanned 150 and 300 seconds after initiating a dynamic bolus injection of contrast material. Two reviewers assessed renal collecting system opacification and measured the maximal short-axis diameter of the collecting system at three locations: the upper pole, the lower pole, and the proximal ureter. A similar evaluation was performed in a control group of 29 patients who underwent CT without compression at 300 seconds after initiating the injection of contrast material.

RESULTS

Both reviewers noted collecting system opacification at all locations in 52 of 56 noncompressed collecting systems scanned at 300 seconds, 57 of 59 compressed collecting systems scanned at 300 seconds, but only 26 of 59 compressed collecting systems scanned at 150 seconds. Measured collecting system distention was statistically significantly greater at 300 seconds in patents who received compression than in patients who did not (P = .0013). For patients who received compression, measured collecting system distention was statistically significantly greater on scans obtained at 300 seconds than on scans obtained at 150 seconds (P = .0001).

CONCLUSION

Abdominal compression during renal helical CT produces a detectable increase in renal collecting system distention. In patients who receive compression, scanning at 300 seconds rather than at 150 seconds results in greater collecting system distention and more consistent opacification.

Delayed enhanced CT of lipid-poor adrenal adenomas

OBJECTIVE

Although representing a minority of adrenal adenomas, the lipid-poor variety cannot be accurately identified on unenhanced CT or chemical shift MR imaging. We compared the delayed contrast-enhanced CT features of lipid-poor adenomas with those of lipid-rich adenomas and of adrenal nonadenomas to determine whether there were differences in the washout features between these groups of lesions.

SUBJECTS AND METHODS

Eighteen proven lipid-poor adenomas, 56 lipid-rich adenomas, and 40 adrenal nonadenomas underwent CT before, immediately after, and 15 min delay after IV contrast injection. Region-of-interest measurements were made of all adrenal lesions at the three time points. The degree of enhancement, enhancement washout, percentage enhancement washout, and relative percentage enhancement washout were calculated for each adrenal mass. Pooled data were analyzed statistically. Optimal threshold values for diagnosing adrenal adenomas were also determined.

RESULTS

The mean CT attenuation of lipid-poor adenomas was significantly higher than that of lipid-rich adenomas at all three phases but not significantly different from that of nonadenomas. The mean percentage enhancement washout on images obtained 15 min after administration of contrast material was similar for lipid-rich and lipid-poor adenomas but was significantly higher than that of nonadenomas. The mean relative percentage enhancement washout was significantly different among all three groups.

CONCLUSION

Lipid-poor adenomas cannot be differentiated from adrenal nonadenomas on the basis of a single mean attenuation value. However, lipid-poor adrenal adenomas show enhancement and enhancement washout features nearly identical to lipid-rich adenomas and can be distinguished from nonadenomas on the basis of a percentage washout threshold value of 60% and a relative percentage washout of 40%.

Helical CT cholangiography with three-dimensional volume rendering using an oral biliary contrast agent: feasibility of a novel technique

OBJECTIVE

We evaluated the feasibility and image quality of a new noninvasive biliary imaging technique: helical CT cholangiography with three-dimensional volume rendering using an oral biliary contrast agent.

SUBJECTS AND METHODS

Nineteen subjects including five healthy volunteers and 14 patients underwent helical CT cholangiography. Subjects ingested 6.0 g of iopanoic acid 6-10 hr before undergoing imaging. Axial data were used to construct three-dimensional volume-rendered cholangiograms. Two radiologists, an endoscopist, and a laparoscopic surgeon reviewed the images and evaluated overall image quality. In the 14 patients, findings from CT cholangiography were compared with those from ERCP, surgery, and intraoperative cholangiography.

RESULTS

All segments of the biliary tree were opacified in all volunteers except one, in whom the intrahepatic ducts were not opacified. Image quality was good to excellent in all volunteers. Anomalous cystic duct insertions were seen in two volunteers. Opacification of the biliary tree was rated as acceptable to excellent in nine patients and suboptimal in five. In five patients with good or excellent opacification, the biliary anatomy correlated with findings on intraoperative cholangiography or ERCP. CT cholangiography revealed additional conditions (gallbladder varices and acute pancreatitis) and variant anatomy in three patients.

CONCLUSION

Results of this pilot project suggest that obtaining CT cholangiograms using an oral biliary contrast agent is a feasible, noninvasive method for revealing biliary anatomy. However, visualization of the biliary tree was suboptimal in 36% of the patients, which represents a limitation of this technique.

Refractory shadowing from pelvic masses on sonography: a useful diagnostic sign for uterine leiomyomas

OBJECTIVE

Our objective was to determine the diagnostic usefulness of sonography for revealing a recurrent acoustic shadowing pattern when imaging for possible uterine leiomyoma.

SUBJECTS AND METHODS

During an 18-month period, all pelvic masses discovered on sonography were prospectively examined for recurrent refractory shadows. Sonograms of 222 masses with a definitive final diagnosis were reviewed by two radiologists unaware of the follow-up results. Each mass was analyzed for the presence of three or more recurrent refractory shadows, each of which did not arise from an echogenic lead point. After all masses were rated independently, a consensus rating was reached for any discrepancy between observers.

RESULTS

Of the 222 masses, 152 (68%) were leiomyomas. The remainder resulted from a wide variety of other uterine and adnexal disorders. Agreement between the two observers regarding refractory shadows was excellent. Kappa coefficients were 0.86 at transabdominal and 0.96 at transvaginal approaches. Sensitivity of the refractory shadow pattern for leiomyomas was higher for transvaginal (87%) than for transabdominal (52%) sonography. Specificity of the refractory shadow pattern was 89% for transvaginal and 92% for transabdominal sonography. Using logistic regression analysis, we found a statistically significant association between a refractory shadowing pattern and leiomyoma for both transabdominal and transvaginal sonography (p < 0.001).

CONCLUSION

Recurrent refractory shadowing in a pelvic mass on sonography is highly suggestive of leiomyoma and can be a useful diagnostic clue for distinguishing leiomyomas from other pelvic masses.

Radiography of thoracic intravascular stents in children with congenital heart disease

Seventeen balloon expandable stents were placed in thoracic vessels in eleven children with vascular stenoses related to congenital heart lesions. We describe the normal radiographic appearance of three types of balloon expandable stents implanted in pulmonary arteries, pulmonary veins, and the superior vena cava of these children as well as the appearance of the complications we encountered. Knowledge of the radiographic appearance of these devices is important as chest radiography is a primary method of follow-up in children with balloon expandable stents placed to treat stenoses of intrathoracic vessels related to congenital heart disease.

Guanazole (NSC-1895)--a phase I clinical study

Two dose schedules of guanazole were used in this phase I clinical study: intermittent prolonged 5-day infusion and intermittent iv bolus twice weekly. Ninety-seven treatment observations were analyzed for toxic effects resulting from the prolonged infusion and 42 from the twice-weekly bolus schedule. The main toxic effect was bone marrow suppressions, the frequency and severity of which were intensified by prior chemotherapy or radiotherapy and repetition of guanazole therapy. The leukocyte count was affected more than the platelet count. Partial responses were observed in four patients: two with lung carcinoma, one with prostate carcinoma, and one with melanoma. Further phase II clinical studies of guanazole are indicated.

Pleural effusion in cancer patients. A prospective randomized study of pleural drainage with the addition of radioactive phsophorous to the pleural space vs. pleural drainage alone

Sixty-seven patients with disseminated cancer were randomly allocated to treatment with continuous closed chest drainage removing all fluid for 72 hours (PD) or pleural drainage for 72 hours with the instillation into the pleural space of radioactive colloidal chromic phosphate (PD + 32P). Forty-nine patients had breast carcinoma, and the remaining 18 patients had other cancers. Four of 49 patients with breast cancer and 13 of 18 with other cancer were dead in 8 weeks from the onset of effusion. In the group of patients with breast cancer PD + 32P controlled the effusion in 12 of 22 (54%) and PD alone in 15 of 30 episodes (50%). In the nonbreast group of patients PD + 32P controlled the effusion in five of six evaluable episodes (83%), and PD alone was successful in two of nine (22%). In 33% of breast cancer patients and 25% of the nonbreast-cancer patients, systemic chemotherapy produced objective remissions. Pleural effusion did not recur in any of these patients.