An MRI method is described for demonstrating improved oxygenation of human tumors and normal tissues during carbogen inhalation (95% O 2 , 5% CO 2 ). T* 2 -weighted gradient-echo imaging was performed before, during, and after carbogen breathing in 47 tumor patients and 13 male volunteers. Analysis of artifacts and signal intensity was performed. Thirty-six successful tumor examinations were obtained. Twenty showed significant whole-tumor signal increases (mean 21.0%, range 6.5-82.4%), and one decreased (؊26.5 ؎ 8.0%). Patterns of signal change were heterogeneous in responding tumors. Five of 13 normal prostate glands (four volunteers and nine patients with nonprostatic tumors) showed significant enhancement (mean 11.4%, range 8.4 -14.0%). An increase in brain signal was seen in 11 of 13 assessable patients (mean 8.0 ؎ 3.7%, range 5.0 -11.7%). T* 2 -weighted tumor MRI during carbogen breathing is possible in humans. High failure rates occurred due to respiratory distress. Significant enhancement was seen in 56%, suggesting improved tissue oxygenation and blood flow, which could identify these patients as more likely to benefit from carbogen radiosensitization.

Functional imaging is becoming increasingly important in the evaluation of cancer patients because of the limitations of morphologic imaging, particularly in the assessment of response to therapy. Diffusion-weighted magnetic resonance (MR) imaging has been established as a useful functional imaging tool in neurologic applications for a number of years, but recent technical advances now allow its use in abdominal and pelvic applications. Diffusion-weighted MR imaging studies of female pelvic tumors have shown reduced apparent diffusion coefficient (ADC) values within cervical and endometrial tumors. In addition, this unique noninvasive modality has demonstrated the capacity to help discriminate between benign and malignant uterine lesions and to help assess the extent of peritoneal spread from gynecologic malignancies. Potential pitfalls can be avoided by reviewing diffusion-weighted MR imaging findings in conjunction with anatomic imaging findings. Increasing familiarity with ADC calculation and manipulation software will allow radiologists to provide new information for the care of patients with known or suspected gynecologic malignancies.

Introduction: Detection of lymph node (LN) metastasis is important for the optimal management of rectal cancer patients. Ultrasmall-particle superparamagnetic iron oxide (USPIO) contrast enhanced magnetic resonance imaging (MRI) has emerged as an effective method of assessing nodal involvement in various malignancies. We have investigated the correlation between nodes seen on specimen MRI and those found at histopathology and the optimum time interval between contrast injection and surgery in USPIO mesorectal lymphography.Method: Thirteen rectal cancer patients underwent MRI before and 24 h after intravenous infusion of USPIO contrast (SineremÒ, Advanced Magnetics Inc, Cambridge, MA, USA). Total Mesorectal Excision (TME) surgery was followed by fixed specimen MRI. Lymph nodes seen on specimen MRI and those found at pathology were compared for studies performed <5 days and ‡5 days prior to surgery.Results: Histopathological LNs found correlated well with those seen on specimen MRI (all patients, r = 0.73; P = 0.005, figure). Correlation was better for the <5 day group (r = 0.84; P = 0.01) than for the ‡5 day group (r = 0.54; P = 0.35).Discussion: USPIO specimen MRI is useful in mesorectal LN assessment. We demonstrate good correlation between specimen MRI and histopathology and show that fewer errors occur in assessment when the time interval between contrast injection and surgery is <5 days.Factors influencing lymph node retrieval in colorectal cancer and its effect on survival Introduction: NICE has set standards for lymph node (LN) harvest in surgery for colorectal cancer (CRC). We report the effect of the operating surgeon and reporting pathologist on lymph node yield and the role of LN yield on survival.