Pancreatic carcinoma: MR assessment of tumor invasion of the peripancreatic vessels.

OBJECTIVE: Our goal was to determine the value of MRI in the assessment of vascular invasion in the preoperative staging of pancreatic carcinoma. MATERIALS AND METHODS: In 53 consecutive patients with an established diagnosis of pancreatic ductal adenocarcinoma, SE T1-weighted and breath-hold gradient echo images at 0.5 T were obtained before and after bolus injection of Gd-DTPA. Major peripancreatic vessels were evaluated for the presence of (a) no tumor invasion, (b) contiguity with tumor, and (c) tumor encasement. All patients subsequently underwent surgery. Results of unenhanced and contrast-enhanced MRI studies were compared with the histologic findings in the resected specimens in 34 cases and with the surgical findings in 19 nonresected cases. RESULTS: In six patients, pathologic examination showed the presence of tumor confined to the pancreas with no vascular invasion. With MRI, five of these cases were correctly evaluated; in the remaining case, tumor-vessel contiguity was erroneously diagnosed. In 21 patients, tumor contiguity with adjacent vessels was found at pathologic examination. At MRI, 16 of these cases were correctly assessed, and 5 were understaged as tumors confined to the pancreas. Of the remaining 26 patients, 7 had vascular encasement by tumor at pathologic examination of the resected specimen; the other 19 patients had unresectable tumors encasing the adjacent vessels at surgical evaluation. MRI detected vascular encasement in 21 of these 26 cases; in the other 5, tumor contiguity was incorrectly diagnosed. The overall accuracy of MRI for determining vascular invasion was 79%. CONCLUSION: MRI is a helpful method for preoperative assessment of vascular involvement due to pancreatic carcinoma.

Small hepatocellular carcinoma treated with percutaneous ethanol injection: unenhanced and gadolinium-enhanced MR imaging follow-up.

PURPOSE: To determine the value of magnetic resonance (MR) imaging in follow-up of small (< 3 cm) hepatocellular carcinoma treated with percutaneous ethanol injection (PEI). MATERIALS AND METHODS: Fifty-seven patients underwent MR imaging before and after PEI. At follow-up every 6 months, MR images were correlated with results of fine-needle aspiration biopsy (FNAB). In 12 patients, correlation with histologic findings in surgical specimens was possible. RESULTS: In 39 patients followed up for 24 months, the treated lesions showed hypointensity on unenhanced (T2-weighted) images and loss of enhancement on enhanced (T1-weighted) images. At 6-month follow-up in six patients, the lesions showed areas of hyperintensity on unenhanced images and enhancement on enhanced images. These lesions contained residual viable tumor at FNAB. Twelve patients underwent surgical resection after 6-month follow-up. Correct diagnosis of complete or partial tumor necrosis was made in nine of these 12 patients with enhanced images and in three with unenhanced images. CONCLUSION: Gadolinium-enhanced T1-weighted MR imaging is more accurate than unenhanced T2-weighted MR imaging in evaluation of PEI therapy.

Carcinoma of the cervix: value of plain and gadolinium-enhanced MR imaging in assessing degree of invasiveness.

The accuracy of nonenhanced spin-echo (SE) T2-weighted and contrast material-enhanced SE T1-weighted magnetic resonance (MR) imaging in assessing the degree of local tumor invasion was determined prospectively in 53 consecutive patients with clinically established early-stage carcinoma of the cervix. With a 0.5-T superconducting unit, pulse sequences of 2,000/90 (repetition time msec/echo time msec) for T2-weighted images and 500/20 for T1-weighted images were used. In all cases, findings of the two MR imaging techniques were compared with results of histologic examination of surgical specimens. Tumor infiltration into the surrounding structures was classified as partial stromal, complete stromal, or parametrial. Tumor-cervical stroma and tumor-parametrium contrast-to-noise ratios (C/Ns) were higher (P < .05) at nonenhanced T2-weighted than at enhanced T1-weighted than at enhanced T1-weighted imaging. In determining the depth of invasion, the overall accuracy was 85% for nonenhanced T2-weighted and 57% (P < .05) for enhanced T1-weighted imaging. With conventional SE sequences, nonenhanced T2-weighted MR imaging is superior to contrast-enhanced T1-weighted MR imaging in determining the degree of invasiveness in clinical early-stage cervical tumors.

Small hepatocellular carcinoma: MR follow-up of treatment with percutaneous ethanol injection.

To assess the potential role of magnetic resonance (MR) imaging in the follow-up evaluation of small hepatocellular carcinoma (HCC) treated with percutaneous ethanol injection (PEI), 31 patients with a single HCC lesion less than 3.0 cm in diameter underwent MR imaging at 0.5 T before and after treatment. Posttreatment follow-up included contrast material-enhanced computed tomography (CT) and fine-needle biopsy in all cases. The most important characteristic of the treated HCC lesions was hypointensity on T2-weighted MR images in cases (27 of 31) in which complete tumor necrosis was achieved with PEI. This feature corresponded to a nonenhanced, low-attenuation area on follow-up contrast-enhanced CT scans. Four HCCs were positive for malignant cells at 6-month fine-needle biopsy; in these lesions, residual tumor tissue was of high signal intensity on T2-weighted MR images and of high attenuation on contrast-enhanced CT scans. In each case, incomplete tumor necrosis was confirmed at pathologic examination of the surgical specimen.

Estimating the depth of myometrial involvement by endometrial carcinoma: efficacy of transvaginal sonography vs MR imaging.

OBJECTIVE: In this study we compare transvaginal sonography with MR imaging for use in detecting the depth of myometrial involvement by endometrial carcinoma. SUBJECTS AND METHODS: Forty-two consecutive patients with stage I endometrial carcinoma had transvaginal sonography and MR imaging at 0.5 T. All the patients had a hysterectomy within 1-10 days after the imaging studies. The results of histologic examination of the surgical specimen were considered the gold standard of the study. We compared transvaginal sonography and MR imaging for use in assessing myometrial invasion by endometrial carcinoma by means of the staging classification of the International Federation of Gynecology and Obstetrics: stage Ia (tumor limited to endometrium), stage Ib (invasion of less than half the myometrium), stage Ic (invasion of more than half the myometrium). The overdiagnoses and the underdiagnoses for both techniques were calculated. We also evaluated the sensitivity and specificity of the two techniques for assessing the presence of myometrial invasion (stage Ib + stage Ic) and the presence of deep myometrial invasion (stage Ic). The diagnostic indexes evaluated and the differences between them were analyzed by using McNemar's test and 95% confidence intervals. The staging diagnoses based on MR imaging and sonographic findings were compared with staging diagnoses based on histologic examination, and a score was assigned to each diagnosis: these scores were then evaluated with Wilcoxon's signed rank test for paired data. RESULTS: Histologic examination showed that six of the 42 patients had tumor confined to the endometrium (stage Ia), 14 had involvement of the inner half of the myometrium (stage Ib), and 22 had involvement of the outer half of the myometrium (stage Ic). The staging was concordant between the two imaging techniques in 32 cases (concordance, 76%). Among the 10 discordant cases, diagnosis was correct in six cases for MR and four cases for sonography. Overall staging based on sonography was correct with respect to histologic staging in 29 cases (69%; 95% confidence interval, 52-81%). Five tumors (12%) were underdiagnosed and eight (19%) were overdiagnosed. Staging based on MR findings was correct with respect to histologic staging in 31 cases (74%; 95% confidence interval, 58-85%). Five tumors (12%) were underdiagnosed, and six (14%) were overdiagnosed. CONCLUSION: In our experience, there is no difference in the staging diagnoses of transvaginal sonography and MR imaging. Also, concordance with histologic staging diagnoses and sensitivity and specificity indexes did not show statistical differences between the two techniques, although these last results have to be considered with caution because of the low power of the statistical tests.

Myometrial invasion by endometrial carcinoma: assessment with plain and gadolinium-enhanced MR imaging.

A prospective study was designed to determine the sensitivity and specificity of nonenhanced T2-weighted and contrast material-enhanced T1-weighted magnetic resonance (MR) imaging in assessing the depth of myometrial invasion in patients with proved endometrial cancer. In 56 consecutive patients with clinically determined early-stage disease, findings of the two MR imaging techniques were compared with results of histologic examination of surgical specimens. Myometrial invasion was classified as absent (stage IA), superficial (stage IB), or deep (stage IC). In the assessment of each tumor stage, the sensitivity and specificity of contrast-enhanced T1-weighted MR imaging were higher than those of non-enhanced T2-weighted MR imaging. In determining the degree of myometrial tumor invasion, the overall sensitivity of enhanced T1-weighted MR imaging was 87.5%, whereas that of nonenhanced T2-weighted MR imaging was 71.4% (P less than .05). The use of contrast material may improve the ability to assess, with MR imaging, the depth of myometrial invasion by endometrial cancer.

Testicular masses in association with adrenogenital syndrome: US findings.

Adrenogenital syndrome (AGS) is the result of inborn enzymatic defects in the synthesis of steroid hormones. The production of cortisol is deficient and that of adrenocorticotropic hormone is increased. Sometimes male patients have clinically detectable testicular lesions, known as testicular tumors of AGS (TTAGS). From 1985 to 1991, scrotal ultrasonography (US) was performed in 30 consecutive pubertal and postpubertal patients with AGS to investigate the prevalence and US characteristics of TTAGS. Eight of 30 patients had a testicular lesion (27%); six of the eight lesions were clinically undetected. The mean diameter of the lesions was 16.44 mm (range, 2-28 mm). The lesions were hypoechoic in all cases, with well-defined margins in six cases. The nodules were multifocal in all patients and bilateral in six (75%). If testicular lesions are present in a patient with AGS, TTAGS are likely, and frequent US monitoring is adequate for diagnostic evaluation.

Myometrial invasion by endometrial carcinoma: assessment by MR imaging.

In patients with early-stage endometrial cancer, preoperative knowledge of myometrial tumor extension has important prognostic and therapeutic implications. The purpose of this prospective study was to determine the sensitivity and specificity of MR imaging for assessing the depth of myometrial invasion in patients with endometrial cancer that clinically was thought to be confined to the uterine corpus. Sixty-five consecutive patients were included in the study. All patients had MR imaging before radical surgery. MR imaging findings were compared with microscopic pathologic findings in all cases. On MR images and at histologic analysis, myometrial invasion was classified as absent (tumor confined to the endometrium), superficial (less than 50% of myometrial thickness), or deep (50% or more of myometrial thickness). At histologic examination, tumor limited to the endometrium was proved in 14 cases, superficial myometrial invasion by tumor was present in 34 cases, and deep tumor invasion was demonstrated in 17 cases. In determining the presence of tumor confined to the endometrium, MR imaging had a sensitivity of 57% and a specificity of 96%. In the assessment of tumor with superficial myometrial invasion, MR imaging had a sensitivity and a specificity of 74%, whereas in assessing deep myometrial penetration, the sensitivity and specificity of MR were 88% and 85%, respectively. Errors in MR interpretation when determining myometrial tumor spread were more frequently overestimations rather than underestimations. Our results indicate that MR imaging is useful for the preoperative assessment of myometrial invasion in patients with proved endometrial cancer.

Invasive cervical carcinoma: MR imaging after preoperative chemotherapy.

To evaluate assessment of tumor regression with magnetic resonance (MR) imaging, the authors studied 21 consecutive patients with cervical carcinoma tumors that were more than 3 cm in diameter. Thirteen of the 21 also demonstrated parametrial invasion. In all cases, MR imaging was performed both before and after chemotherapy. Pathologic specimens were obtained at hysterectomy in all patients. Comparison of pathologic and MR imaging findings after chemotherapy showed that all tumors decreased in size. Size of tumor was correctly determined at MR in 17 cases and was slightly overestimated in four cases. Five patients had residual parametrial invasion that was histologically confirmed. In detecting parametrial spread after treatment, MR imaging had an accuracy of 90.4%. Tumors had high signal intensity on T2-weighted images, whereas intratumoral necrosis was characterized by low signal intensity on the same images. Peritumoral inflammatory tissue found at pathologic examination in four of 21 cases was not specifically identified on MR images. In patients with invasive cervical carcinoma, MR imaging may be useful in evaluating tumor response to preoperative chemotherapy.

Small hepatocellular carcinoma treated with percutaneous ethanol injection: MR imaging findings.

Fifty-seven magnetic resonance (MR) imaging examinations were obtained at 0.5 T in 19 patients before and after percutaneous ethanol injection (PEI) for 23 hepatocellular carcinoma (HCC) lesions less than 3.5 cm in diameter. Seventeen patients also underwent MR imaging 6 months after completion of therapy. In 11 patients, computed tomography was performed before and after treatment. After PEI, fine-needle biopsy specimens were obtained in all cases. Before treatment, HCC lesions had low signal intensity on T1-weighted images in 13 cases, had the same signal intensity as normal liver parenchyma in six, and had high signal intensity in four; all 23 tumors had high signal intensity on T2-weighted images. After treatment and at 6-month follow-up, all 21 lesions that contained no malignant cells at fine-needle biopsy had high signal intensity on T1-weighted images and had low signal intensity on T2-weighted images. The remaining two HCC lesions in which tumor necrosis was not achieved with PEI displayed a different MR pattern, since the residual neoplastic tissue showed no change in signal intensity on either T1- or T2-weighted images. The authors conclude that MR imaging may be useful for evaluating the effectiveness of PEI in achieving tumor regression.

Carcinoma of the cervix: value of MR imaging in detecting parametrial involvement.

In patients with cervical carcinoma, precise knowledge of parametrial tumor extension affects the therapeutic decision between surgery and radiation therapy. The purpose of this prospective study was to determine the efficacy of MR imaging in detecting the presence or absence of parametrial invasion in patients with cervical cancer thought clinically to be confined to the cervix. Twenty-five consecutive patients were included in the study. All patients underwent radical hysterectomy or total abdominal hysterectomy and had detailed histologic evaluation of the parametrium. Ten had pathologic evidence of parametrial invasion; in the remaining 15, no parametrial invasion was identified pathologically. MR findings were compared with pathologic findings in all cases. For determining parametrial involvement, MR imaging had an accuracy of 88%, a sensitivity of 100%, and a specificity of 80%. Our results suggest that MR imaging is a reliable means of assessing parametrial invasion by cervical cancer.

Pancreatic cancer versus chronic pancreatitis: diagnosis with CA 19-9 assessment, US, CT, and CT-guided fine-needle biopsy.

The authors prospectively performed serum CA 19-9 assessment, ultrasound (US), computed tomography (CT), and CT-guided fine-needle aspiration biopsy (FNAB) of the pancreas in 81 consecutive patients with suspected chronic pancreatitis or pancreatic neoplasm. The final diagnosis was pancreatic cancer in 54 patients and chronic pancreatitis in 27 patients. CA 19-9 assessment, US, CT, and FNAB were considered nondiagnostic, respectively, in 0%, 25%, 19%, and 6% of cases. When a definite diagnosis was rendered, the positive predictive value was 90% for CA 19-9 assessment, 95% for US, 98% for CT, and 100% for FNAB; the negative predictive value was, respectively, 69%, 95%, 86%, and 100%. The accuracy of all diagnostic and nondiagnostic studies was 81% for CA 19-9 assessment, 72% for US, 77% for CT, and 94% for FNAB. It is concluded that CT-guided pancreatic FNAB is the most reliable examination for enabling differential diagnosis of pancreatic cancer and chronic pancreatitis. When the pancreas is well visualized at US, the negative predictive value for pancreatic cancer is more accurate than that of CA 19-9 assessment and CT.