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H Hricak

Publications and source records attributed to H Hricak.

At least 19 recordsLinked to original sources
PubMed1996

Invasive cervical carcinoma: role of MR imaging in pretreatment work-up--cost minimization and diagnostic efficacy analysis.

PURPOSE: To examine the cost and efficacy of diagnostic work-up in patients with invasive cervical cancer. MATERIALS AND METHODS: In 246 patients with invasive cervical cancer, all diagnostic tests performed before treatment were recorded. Patients were divided into two groups: those who underwent magnetic resonance (MR) imaging as the initial study (n = 105) and those who did not (n = 141). A list of 1995 Medicare global payments was used to measure cost. Bayesian analysis (likelihood ratios derived from a literature search) was performed for bladder, rectal, parameterial, and nodal involvement in stage Ib disease. RESULTS: Significantly fewer procedures and fewer invasive studies were performed in the MR imaging group. Net cost savings for the MR imaging group was $401 for all patients and $449 for patients with stage Ib disease. For stage Ib disease, the 0% pretest probability of bladder or rectal invasion does not justify the routine use of barium enema examination, cystoscopy, or proctoscopy. The increase in predictive values for parameterial and nodal disease was highest for MR imaging when tumor size was at least 2 cm. CONCLUSION: Guidelines for the pretreatment work-up of clinical stage Ib cervical cancer need revision. MR imaging should be used as an adjunct to clinical evaluation.

Adenocarcinoma↗
PubMed1996

Three-dimensional H-1 MR spectroscopic imaging of the in situ human prostate with high (0.24-0.7-cm3) spatial resolution.

PURPOSE: To evaluate if three-dimensional hydrogen-1 magnetic resonance spectroscopic imaging (3D MRSI) when combined with a clinical MR imaging examination could discriminate prostatic adenocarcinoma from normal prostatic zonal anatomy and benign prostatic hyperplasia (BPH) on the basis of observable metabolite levels. MATERIALS AND METHODS: Combined phased-array, endorectal MR imaging and 3D MRSI was performed in nine young healthy volunteers, five patients with BPH, and 85 patients with prostate cancer and BPH. Volume MR imaging and 3D MRSI data were analytically corrected for the reception profile of the endorectal and pelvic phased-array coils, aligned with the MR imaging data, and compared with postoperative pathologic histology findings. RESULTS: Statistically significant variations in metabolite levels with prostatic zonal anatomy, age, and pathologic condition were detected with a 3D MRSI examination added to a clinical MR imaging examination. Significantly higher choline levels and significantly lower citrate levels were observed in regions of cancer compared with BPH and normal peripheral zone tissues. The ratio (choline + creatine/citrate) in regions of cancer (2.1 +/- 1.3 [standard deviation]) had no overlap with normal peripheral zone values and minimal overlap with BPH values (0.61 +/- 0.21). An estimate of the spatial extent of prostate cancer was determined by generating metabolite images in which this metabolite ratio significantly exceeded normal peripheral zone values in multiple contiguous sections. CONCLUSION: These results suggest that a 3D MRSI examination added to a clinical MR imaging examination may help define the presence and spatial extent of prostate cancer.

Adenocarcinoma↗
PubMed1996

Prostate carcinoma: MR imaging findings after cryosurgery.

PURPOSE: To determine the morphologic changes in the prostate gland after cryosurgery and to assess the value of magnetic resonance (MR) imaging in detecting residual tumor. MATERIALS AND METHODS: Twenty-seven patients with prostate carcinoma underwent endorectal MR imaging after cryosurgery. Eighteen patients also underwent MR imaging before cryosurgery. MR findings were correlated with posttreatment clinical data, prostate-specific antigen level, and biopsy results. RESULTS: Mean prostate volume had decreased by 52% in patients examined 8 weeks or more after cryosurgery. Zonal differentiation was lost in 22 of 27 patients (81%). Areas of intraprostatic necrosis were identified in 14 of 27 patients (52%). A thick capsule enveloped the gland and neurovascular bundles in 24 of 27 patients (89%). Osteonecrosis of the symphysis pubis was seen in six of 27 patients (22%). Positive and negative predictive values for MR assessment of recurrent tumor were 44% and 73%, respectively. CONCLUSION: Cryosurgery-induced changes in the prostate gland preclude reliable detection of residual prostate carcinoma at MR imaging.

Aged↗
PubMed1996

Prostate cancer: metabolic response to cryosurgery as detected with 3D H-1 MR spectroscopic imaging.

PURPOSE: To determine, in patients with prostate cancer treated with cryosurgery, whether levels of choline and citrate measured at magnetic resonance (MR) spectroscopy can help discriminate regions of residual tumor from other prostatic tissues and necrosis. MATERIALS AND METHODS: Combined MR imaging and three-dimensional proton spectroscopic imaging were performed in 25 patients (mean age, 69 years) with prostate cancer who underwent cryosurgery. Volume imaging and spectroscopic data were analytically corrected for the reception profile of the endorectal and pelvic phased-array coils. Spectral data were aligned with the MR imaging data and compared with serum prostate-specific antigen levels and biopsy results. RESULTS: Histologically confirmed necrotic tissue (432 voxels) did not demonstrate any observable choline or citrate. The (choline + creatine)/ citrate values in regions of histologically confirmed benign prostatic hyperplasia (0.61 +/- 0.21 [standard deviation], 52 voxels) and cancer (2.4 +/- 1.0, 65 voxels) after cryosurgery were not statistically significantly different from those before therapy but were statistically significantly different from the ratio in necrotic tissue and from each other. The (choline + creatine)/citrate images threshold and overlaid in color on T2-weighted images yielded an estimate of the spatial extent of prostate cancer and benign prostatic hyperplasia. CONCLUSION: Volume MR imaging with MR spectroscopic imaging provided a noninvasive assessment of the presence and location of residual cancer after unsuccessful therapy and helped identify successful cryosurgery in patients who still had an elevated prostate-specific antigen level.

Aged↗
PubMed1996

Local staging of prostatic carcinoma: comparison of transrectal sonography and endorectal MR imaging.

OBJECTIVE: We compared the results of transrectal sonography and endorectal MR imaging in the local staging of prostatic carcinoma. SUBJECTS AND METHODS: 56 patients (mean age, 61.1 +/- 7.3 years) with the diagnosis of prostate cancer who by transrectal sonography had no evidence of gross extracapsular extension underwent endorectal coil MR imaging prior to radical prostatectomy. Imaging findings prospectively evaluated in each patient were cancer laterality, extracapsular extension, and seminal vesicle invasion. Twenty-one of 56 (38%) patients had extracapsular extension on final pathology. A total of 100 sides and five seminal vesicles were involved with cancer, and 27 sides (21 patients, six with bilateral extracapsular extension) demonstrated extracapsular extension. Imaging results were correlated with step-sectioned, radical prostatectomy pathologic data, and statistical analysis was expressed at a p = .05 level of significance. Retrospective readings of the images were used to construct receiver operating characteristic curves for the detection of extracapsular extension. RESULTS: For tumor laterality, transrectal sonography was compared with endorectal coil MR imaging for sensitivity (70% versus 97%; p < .001), specificity (58% versus 58%), positive predictive value (93% versus 95%) and negative predictive value (18% versus 70%). For extracapsular extension, transrectal sonography was compared with endorectal coil MR imaging for the entire prostate and individually for each side of the prostate. The respective results for sensitivity (48% versus 91%, p < .01 and 37% versus 78%, p < .005), specificity (71% versus 49% and 87% versus 73%), positive predictive value (50% versus 51% and 48% versus 48%), and negative predictive value (69% versus 90% and 81% versus 91%). The receiver operating characteristic analysis of retrospective data demonstrated endorectal coil MR imaging to be superior to transrectal sonography in the detection of extracapsular extension. The small number of seminal vesicles involved by cancer (n = 5) precluded meaningful comparisons between the imaging techniques. CONCLUSIONS: Endorectal coil MR imaging is more sensitive but less specific than transrectal sonography for detecting extracapsular extension of carcinoma of the prostate. Both procedures have low positive predictive values yet similarly high negative predictive values when each side of the prostate is assessed independently for extracapsular extension.

Humans↗
PubMed1996

Abdominopelvic MR imaging in the nonobstetric evaluation of pregnant patients.

Managing a pregnant patient with a suspected nonobstetric abdominopelvic disorder is challenging. Information from imaging affects the treatment options, which range from operating emergently and risking miscarriage to terminating the pregnancy or delaying treatment until after delivery. The most common indications for MR imaging during pregnancy are disorders of the central nervous and cardiovascular systems. In the evaluation of the abdomen and pelvis, sonography plays the pivotal role; however, sonography may be inconclusive because of its limited specificity in tissue characterization and technical difficulties caused by the enlarged uterus. For these reasons MR imaging has emerged as a valuable adjunct to sonography. In this pictorial essay we describe a variety of nonobstetric abdominopelvic disorders during pregnancy in which MR imaging contributed to patient management.

Abdomen↗
PubMed1996

Hormonal ablation of prostatic cancer: effects on prostate morphology, tumor detection, and staging by endorectal coil MR imaging.

OBJECTIVE: The purpose of our study was to evaluate the effect of androgen deprivation therapy on the MR imaging findings of prostate gland anatomy and cancer pathology in men with prostatic cancer treated with hormonal ablation before radical prostatectomy. MATERIALS AND METHODS: Twenty-two patients (mean age, 66 years old) were divided into two groups: in group I (n=10), MR imaging studies were done before and after hormonal treatment; in group II (n=12), MR imaging studies were done only after hormonal treatment. MR imaging was performed on a 1.5 T-scanner (Signa; General Electric Medical Systems, Milwaukee, WI) and included transverse plane phased-array coil T1-weighted images (TR/TE, 600/12), combined endorectal phased-array coil transverse plane T1-weighted images, fast spin-echo T2-weighted (4000/102), and coronal plane fast spin-echo T2-weighted images. Image evaluation was by consensus and included assessment of the gland size, signal intensity, tumor depiction, extracapsular extension, seminal vesicle invasion, and overall staging accuracy (Jewett and Whitmore classification). MR imaging findings were correlated with pathologic findings of step section radical prostatectomy. RESULTS: After hormonal therapy, the volume of the prostate gland showed a mean decrease of 33.5% +/- 19.6% SD (range, 0-64%). Volume reduction in the transition zone (mean 29.2% +/- 22% SD) was less than in the peripheral zone (mean, 55.8% +/- 25.8% SD) (p < .05). On T2-weighted images, the peripheral zone showed homogeneous decreases in signal intensity in 13 of 22 (58%) patients. Compared with pathologic findings, the accuracy of tumor detection by MR imaging was 74% (98 of 132 sites). Tumor presence was overestimated in 32 of 132 (24%) sites. Overall staging accuracy after hormonal ablation was 68% (15 of 22). The positive predictive value and negative predictive value for extracapsular extension were 57% (13 of 23 sites) and 90% (19 of 21 sites), respectively, and for seminal vesicle invasion were 80% (8 of 10 sites) and 97% (33 of 34 sites), respectively. CONCLUSION: As detected by MR imaging, hormonal ablation caused a decrease in size and signal intensity of the prostate gland and seminal vesicles and overestimation of tumor presence and extracapsular extension.

Aged↗
PubMed1995

Cervical carcinoma: computed tomography and magnetic resonance imaging for preoperative staging.

OBJECTIVE: To assess the accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of invasive cervical cancer. METHODS: Seventy-nine women with untreated cervical cancer underwent pre-treatment MRI (n = 71) and/or CT (n = 37) within 4 weeks of surgical evaluation. Twenty-nine women had both MRI and CT. Images were evaluated for tumor detection, size, stromal invasion, local extension, and nodal metastases. RESULTS: Tumor size was evaluated accurately by MRI, with a correlation coefficient of 0.93. Magnetic resonance estimates of tumor size were within 0.5 cm of the surgical sample in 64 of 69 women (93%). Magnetic resonance was 88% accurate evaluating the presence of stromal invasion and 78% accurate for depth of stromal invasion. Computed tomography could not evaluate tumor size or stromal invasion because it could not distinguish cancer from the surrounding normal cervical tissue. In evaluating stage of disease, MRI had an accuracy of 90%, compared with 65% for CT (P < .005). Magnetic resonance imaging was more accurate than CT (94 versus 76%, P < .005) in assessing parametrial invasion. Both modalities were comparable in evaluating lymph node metastases (86% each). In determining operative candidates (stage I and minimal IIA), MRI was 94% accurate, compared with 76% for CT (P < .005). CONCLUSION: Compared with CT, MRI offered significantly improved evaluation of tumor size, stromal invasion, and local and regional extent of disease in pre-treatment imaging for cervical cancer.

Adult↗
PubMed1995

Citrate as an in vivo marker to discriminate prostate cancer from benign prostatic hyperplasia and normal prostate peripheral zone: detection via localized proton spectroscopy.

OBJECTIVES: This study was designed to determine whether citrate levels detected by localized 1H spectroscopy could reliably discriminate regions of prostate adenocarcinoma from surrounding regions of normal peripheral zone and benign prostatic hyperplasia (BPH). METHODS: In 28 patients and 5 volunteers stimulated echo proton spectroscopy was used in conjunction with endorectal surface coils to obtain water-suppressed 1H spectra from regions of normal prostate peripheral zone, BPH, and prostate cancer. 1H spectra from prostate cancer patients were correlated with pathologic areas identified on T2-weighted endorectal coil magnetic resonance (MR) images and histologic study of the step-sectioned gland after surgery. RESULTS: The major finding of in vivo studies was consistently lower citrate levels in prostate cancer compared with BPH and normal prostate peripheral zone. This was reflected by significantly (P < 0.05) lower mean citrate/(creatine plus choline) peak area ratio observed for regions of cancer (0.67 +/- 0.17) compared with BPH (1.21 +/- 0.29) and normal peripheral zone (1.46 +/- 0.28). Moreover, there was no overlap of individual cancer and normal peripheral zone citrate ratios and no significant difference between citrate ratios in regions of normal peripheral zone in young volunteers (1.28 +/- 0.14) and age-matched patients (1.46 +/- 0.28). The observed alterations in vivo citrate levels were supported by citrate concentration data obtained from extracts of histologically proven samples of normal, benign, and malignant prostatic tissues removed at surgery. In vitro citrate levels in the normal peripheral zone (30.9 +/- 8.5 mumol/g wet weight) and BPH (46.3 +/- 5.4 mumol/g wet weight) were significantly higher than those for prostate cancer (3.74 +/- 0.54 mumol/g wet weight). CONCLUSIONS: These studies further demonstrate the potential of citrate as an in vivo marker for discriminating prostate cancer from surrounding regions of normal peripheral zone and BPH.

Adenocarcinoma↗
PubMed1995

Magnetic resonance imaging of vascular lesions of the scrotum and penis.

We report 2 rare cases of vascular lesions in the scrotum and penis: an arteriovenous malformation in a young man and a lymphohemangioma in a boy. Both patients had undergone previous treatment and had recurrent lesions. Magnetic resonance imaging was performed preoperatively for detailed information regarding lesion extent and involvement of adjacent structures.

Adolescent↗
PubMed1995

Radiation-induced decrease in nitric oxide synthase--containing nerves in the rat penis.

PURPOSE: Evaluate effect of prostatic irradiation on erectile function. MATERIALS AND METHODS: Forty-seven male adult rats were divided into three groups according to a single radiation dose to the prostate: control (no irradiation) (n = 15), 1,000 cGy (n = 15), and 2,000 cGy (n = 17). Five months after irradiation, rats underwent evaluation of penile vascularity and of erectile response to central and peripheral stimulation. After the study a proximal-shaft penile segment was obtained for staining. RESULTS: Histologic evaluation demonstrated that, with increasing radiation, the number of nitric oxide synthase-containing nerve fibers per penile segment decreased significantly: control, 225.6 +/- 9.7; 1,000 cGy, 156.3 +/- 12.0; 2,000 cGy, 85.8 +/- 10.1 (standard error of the mean). Maximal intracavernous pressure induced with electrostimulation decreased significantly with increasing radiation dose. After injection of papaverine, maximal intracavernous pressure was significantly decreased in only the 2,000-cGy group. CONCLUSION: A dose of 2,000 cGy over the prostatic bed induces erectile dysfunction by causing defects in the vascular supply of the erectile tissue and in the nerves and smooth muscle.

Amino Acid Oxidoreductases↗
PubMed1995

Prostate cancer: effect of postbiopsy hemorrhage on interpretation of MR images.

PURPOSE: To assess the frequency of changes in signal intensity after prostatic biopsy and the effect of these changes on the magnetic resonance (MR) imaging staging of prostate cancer. MATERIALS AND METHODS: Seventy-three patients with biopsy-proved prostate cancer were divided into two groups according to time between biopsy and imaging (less than and more than 21 days). The findings at MR imaging were compared with those at pathologic examination. RESULTS: Postbiopsy hemorrhage was detected in 21 of 26 (81%) patients who underwent imaging less than 21 days after biopsy and in 23 of 47 (49%) patients who underwent imaging more than 21 days after biopsy (P < .01). Postbiopsy changes persisted for as long as 4 1/2 months. Less than 21 days after biopsy, there was a tendency to overestimate tumor presence and extracapsular extension. After 21 days, tumor presence was underestimated but the positive predictive value for extracapsular extension was improved. Staging accuracy less than 21 days after biopsy was 46%; this improved to 83% after 21 days (P < .01). CONCLUSION: Staging accuracy is significantly improved when imaging is deferred for 21 days after biopsy.

Biopsy, Needle↗
PubMed1995

Ovarian cancer recurrence: value of MR imaging.

PURPOSE: To assess magnetic resonance (MR) imaging in depiction of ovarian tumor recurrence and for identification of patients who may not benefit from surgical reexploration. MATERIALS AND METHODS: In a prospective study, 34 patients (mean age, 57.07 years) with surgically staged ovarian cancer underwent MR imaging before reexploration. Findings at MR imaging and surgery were correlated. MR imaging tumor depiction was correlated with tumor size, presence of ascites, and CA-125 levels. RESULTS: Tumor recurrence was identified in 29 patients at surgery. MR imaging depicted tumor in 20 patients. Accuracy for lesions smaller than 2 cm was 35% and increased to 82% for lesions larger than 2 cm (P < .01). MR imaging had low sensitivity for depiction of implants in the peritoneum and mesentery. Ascites improved depiction of smaller lesions (< 2 cm). MR imaging in combination with CA-125 levels improved detection of recurrent disease (CA-125 measurement alone 53% vs CA-125 measurement and MR imaging 75%, P = .048). CONCLUSION: MR imaging is a useful adjunct to the clinical examination to identify patients with recurrent disease and those in whom reexploration may not be beneficial.

Adult↗
PubMed1995

Ovarian cancer: staging with CT and MR imaging.

PURPOSE: To evaluate ovarian cancer staging and tumor resectability with computed tomography (CT) or magnetic resonance (MR) imaging. MATERIALS AND METHODS: Eighty-two women underwent CT (n = 43) or MR imaging (n = 50); eleven of these 82 underwent both. Imaging was performed within 4 weeks of surgical staging. Radiologic, surgical, and histopathologic findings were compared. RESULTS: Overall staging accuracy was similar for CT and MR imaging (77% [33 of 43] vs 78% [39 of 50]). Evaluation of pelvic cancer extent was better with MR imaging than with CT. There was no difference in detection of abdominal disease. Most mesenteric and small-bowel implants were not detected with either CT or MR imaging. For CT, the positive predictive value for cancer nonresectability was 100% (three of three patients); the negative predictive value was 92% (37 of 40 patients). The positive and negative predictive values for MR imaging were 91% (10 of 11 patients) and 97% (38 of 39 patients). CONCLUSION: While the staging accuracy of both CT and MR imaging is only moderate, prediction of tumor resectability is excellent.

Abdominal Neoplasms↗
PubMed1995

The use and accuracy of cross-sectional imaging and fine needle aspiration cytology for detection of pelvic lymph node metastases before radical prostatectomy.

The role of cross-sectional pelvic imaging with computerized tomography or magnetic resonance imaging and fine needle aspiration in the assessment of pelvic lymph nodes in patients with prostate cancer is undefined. To address this issue we used formal decision analysis, comparing an imaging arm to a no imaging arm. Patient utility values were calculated, and test parameters and complication rates were extracted from the literature. Imaging was superior to no imaging only when the pretest probability of pelvic lymph node metastases was high. The most important parameter was the sensitivity of cross-sectional imaging for lymphadenopathy. When the sensitivity was 36%, which was the baseline figure derived from the literature, the probability of lymph node metastases required for imaging to be beneficial overall was 32%. We also performed a retrospective review of magnetic resonance imaging examinations at our institution in 174 patients with newly diagnosed prostate cancer and pathological confirmation of nodal status. The sensitivity for detecting nodal metastases was 25%. With this figure, the estimated probability of nodal metastases required to make imaging beneficial would be 45%, which is possible to achieve with highly selective clinical criteria. With a policy of imaging only in select patients the marginal cost is $794 per patient benefited (aborted radical prostatectomy because of nodal metastases detected with fine needle aspiration) compared to $50,661 per patient benefited if all patients are imaged. Thus, cross-sectional pelvic imaging before radical prostatectomy, solely for the purpose of detecting pelvic lymph node metastases, is not justified routinely. However, it is worthwhile on the basis of patient use values and cost-effectiveness in a select group of patients at high risk for nodal metastases.

Biopsy, Needle↗