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Biomedical subjects

Mark A Rosen

Publications and source records attributed to Mark A Rosen.

13 recordsLinked to original sources
PubMed2007

High frame-rate simultaneous bilateral breast DCE-MRI.

A simultaneous bilateral back-projection method for 3D dynamic contrast-enhanced (DCE)-MRI of the breasts was developed and evaluated. Using a double-side band modulation of the RF slab excitation pulse, discontinuous volumes that included both breasts were simultaneously selected. The number of slice phase-encoding steps was undersampled by a factor of 2, and the resulting signal aliasing from one volume to the other was removed using SENSE processing. In-plane encoding was performed with an interleaved radial acquisition reconstructed using dynamic k-space-weighted image contrast (KWIC) temporal filtering. Image resolution was 0.5 x 0.5 x 3.0 mm(3) with an effective temporal resolution of 15 s for both breast volumes. Combined with the 2x acceleration from SENSE encoding, this is a 16x acceleration factor over a conventional MR bilateral breast scan. An initial evaluation of these methods was performed on a cohort of women who presented with palpable or mammographically visible breast abnormalities. A total of 73 abnormalities were found in 45 of the 54 bilateral examinations that were performed. In 11 of these cases there was a significant finding in the contralateral breast. DCE images of both breasts can be acquired simultaneously, resulting in high-resolution images as well as rapid sampling of the contrast kinetics.

Breast↗
PubMed2006

Maternal morbidity after maternal-fetal surgery.

OBJECTIVE: There is a paucity of published data on the maternal risks of fetal surgical interventions. We analyzed maternal morbidity and mortality that were associated with different types of fetal intervention (open hysterotomy, various endoscopic procedures and percutaneous techniques) to quantify this risk. STUDY DESIGN: We performed a retrospective evaluation of a continuous series of 187 cases that had been performed between July 1989 and May 2003 at the Fetal Treatment Center, a highly specialized interdisciplinary center for fetal surgery at the University of California, San Francisco. The primary outcome was the frequency of maternal morbidity for open, endoscopic, and percutaneous procedures to access the fetus. RESULTS: There were 187 pregnant women with confirmed major fetal malformations who were candidates for intrauterine fetal intervention. Maternal-fetal surgery was performed in 87 cases by open hysterotomy, in 69 cases by endoscopic procedures, and in 31 cases by percutaneous techniques. There were no maternal deaths, but significant short-term morbidity was observed. There were no significant differences in the incidence of premature rupture of membranes, pulmonary edema, placental abruption, postoperative vaginal bleeding, preterm delivery, or interval from maternal-fetal surgery to delivery between endoscopic procedures and open surgery. Complications were significantly less in the percutaneous ultrasound-guided procedures. Endoscopic procedures, even with a laparotomy, showed statistically significantly less morbidity compared with the open hysterotomy group regarding cesarean delivery as delivery mode (94.8% vs 58.8%; P < .001), requirement for intensive care unit stay (1.4% vs 26.4%; P < .001), length of hospital stay (7.9 vs 11.9 days; P = .001), and requirement for blood transfusions (2.9% vs 12.6%; P = .022). Chorion-amnion membrane separation (64.7% vs 20.3%; P < .001) was seen more often in the endoscopy group. CONCLUSION: Short-term morbidities include increased rates of cesarean birth, treatment in intensive care, prolonged hospitalization, and blood transfusion, all of which were more common with hysterotomy compared with other techniques. Maternal-fetal surgery can be performed without maternal death. Results from this study provide helpful data for counseling prospective patients.

Female↗
PubMed2005

Fetal pain: a systematic multidisciplinary review of the evidence.

CONTEXT: Proposed federal legislation would require physicians to inform women seeking abortions at 20 or more weeks after fertilization that the fetus feels pain and to offer anesthesia administered directly to the fetus. This article examines whether a fetus feels pain and if so, whether safe and effective techniques exist for providing direct fetal anesthesia or analgesia in the context of therapeutic procedures or abortion. EVIDENCE ACQUISITION: Systematic search of PubMed for English-language articles focusing on human studies related to fetal pain, anesthesia, and analgesia. Included articles studied fetuses of less than 30 weeks' gestational age or specifically addressed fetal pain perception or nociception. Articles were reviewed for additional references. The search was performed without date limitations and was current as of June 6, 2005. EVIDENCE SYNTHESIS: Pain perception requires conscious recognition or awareness of a noxious stimulus. Neither withdrawal reflexes nor hormonal stress responses to invasive procedures prove the existence of fetal pain, because they can be elicited by nonpainful stimuli and occur without conscious cortical processing. Fetal awareness of noxious stimuli requires functional thalamocortical connections. Thalamocortical fibers begin appearing between 23 to 30 weeks' gestational age, while electroencephalography suggests the capacity for functional pain perception in preterm neonates probably does not exist before 29 or 30 weeks. For fetal surgery, women may receive general anesthesia and/or analgesics intended for placental transfer, and parenteral opioids may be administered to the fetus under direct or sonographic visualization. In these circumstances, administration of anesthesia and analgesia serves purposes unrelated to reduction of fetal pain, including inhibition of fetal movement, prevention of fetal hormonal stress responses, and induction of uterine atony. CONCLUSIONS: Evidence regarding the capacity for fetal pain is limited but indicates that fetal perception of pain is unlikely before the third trimester. Little or no evidence addresses the effectiveness of direct fetal anesthetic or analgesic techniques. Similarly, limited or no data exist on the safety of such techniques for pregnant women in the context of abortion. Anesthetic techniques currently used during fetal surgery are not directly applicable to abortion procedures.

Abortion, Induced↗
PubMed2005

Diffuse optical tomography of breast cancer during neoadjuvant chemotherapy: a case study with comparison to MRI.

We employ diffuse optical tomography (DOT) to track treatment progress in a female subject presenting with locally advanced invasive carcinoma of the breast during neoadjuvant chemotherapy. Three-dimensional images of total hemoglobin concentration and scattering identified the tumor. Our measurements reveal tumor shrinkage during the course of chemotherapy, in reasonable agreement with magnetic resonance images of the same subject. A decrease in total hemoglobin concentration contrast between tumor and normal tissue was also observed over time. The results demonstrate the potential of DOT for measuring physiological parameters of breast lesions during chemotherapy.

Adult↗
PubMed2003

Gadolinium susceptibility artifact causing false positive stenosis isolated to the proximal common carotid artery in 3D dynamic contrast medium enhanced MR angiography of the thorax--a brief review of causes and prevention.

Due to the close proximity of arteries and veins in the superior mediastinum and upper extremities, T2* shortening effects of the gadolinium within the central veins may cause artifactual vascular stenosis (susceptibility artifact) on arterial-phase MR angiographic images of the major branches of the aortic arch. We report a case of artifactual stenosis isolated to the origin of the left common carotid artery on arterial-phase MR angiography, secondary to susceptibility artifact from non-diluted gadolinium in the adjacent brachiocephalic vein. The cause of the artifact, its identification and prevention is reviewed.

Adult↗
PubMed2002

Ejaculatory function in stage T1 nonseminomatous germ cell tumors: retroperitoneal lymph node dissection versus surveillance--a decision analysis.

PURPOSE: Ejaculatory function remains a major concern for patients with low stage nonseminomatous germ cell tumors of the testis. Whereas, it has been extensively studied in patients undergoing retroperitoneal lymph node dissection, preservation of ejaculatory function on surveillance protocols has not been studied. To compare ejaculatory function for surveillance protocols to primary retroperitoneal lymph node dissection appropriately, we constructed a decision analysis model mimicking the standard treatment algorithm for stage 1 nonseminomatous germ cell tumor of the testis. MATERIALS AND METHODS: The primary clinical payoff for this study is ejaculatory function. Based on this model, we established that a primary nerve sparing retroperitoneal dissection must be performed with a 96.8% ejaculatory function rate to be recommended as the appropriate therapy. However, if a highly skilled surgeon routinely performs post-chemotherapy dissection with an ejaculatory function rate of 69.2% or greater, surveillance should be offered as the primary treatment modality. This result simply demonstrates a high skill level to allow the surgeon to salvage ejaculatory function in post-chemotherapy retroperitoneal lymph node dissection settings. If this level cannot be achieved, primary retroperitoneal lymph node dissection is the best choice. If we account for a 10% loss of ejaculatory function from primary chemotherapy, the minimum ejaculatory function rate for primary retroperitoneal dissection decreases to 95.7%. RESULTS: In the post-chemotherapy setting an 85.7% ejaculatory function rate must be achieved for surveillance to be considered the optimal choice. Clearly, less surgical rigor is needed with a primary retroperitoneal lymph node dissection when correcting for the effects of chemotherapy on ejaculatory function. Despite this fact, 1-way sensitivity analysis revealed that our model is insensitive to the ejaculatory function effects of chemotherapy. Furthermore, if the likelihood of recurrence on surveillance is greater than 16%, primary nerve sparing retroperitoneal lymph node dissection should again be recommended. CONCLUSIONS: Thus, to maximize ejaculatory function for patients with stage 1 nonseminomatous germ cell tumor a nerve sparing primary retroperitoneal lymph node dissection should always be performed, unless the likelihood of recurrence on surveillance is low or the surgical skill level allows for a highly successful post chemotherapy nerve sparing dissection.

Adult↗
PubMed2002

Nitrous oxide for relief of labor pain: a systematic review.

A systematic review was conducted to determine the efficacy and safety of nitrous oxide for labor analgesia. Eleven randomized controlled trials with adequate control groups and outcome assessment by parturients during or shortly after the intervention were used to determine efficacy. To determine adverse outcome, descriptions found in 8 controlled trials and in 8 observational studies were included. A nonsystematic review of studies on occupational exposure was also conducted. Nitrous oxide is not a potent labor analgesic, but it is safe for parturient women, their newborns, and health care workers in attendance during its administration. It appears to provide adequately effective analgesia for many women.

Administration, Inhalation↗
PubMed2002

Paracervical block for labor analgesia: a brief historic review.

This historic review was written to clarify the known efficacy and side effects of paracervical blockade for labor analgesia. Although the popularity of the technique has diminished considerably, it continues to be used by some clinicians with ostensibly good results. The Cochrane Controlled Trials Register (CCTR;SR-PREG) and the electronic database MEDLINE were searched for studies reported in English to determine efficacy and side effects of paracervical block. Four randomized controlled studies specifically addressed paracervical block efficacy as assessed by parturients during labor with results of excellent or good analgesia among approximately 75%. Postparacervical block fetal bradycardia is the most significant side effect with a reported incidence ranging from 0% to approximately 40%. Overall, it appears that the incidence of postparacervical block fetal bradycardia is approximately 15%. However, the etiology of the observed fetal bradycardia remains unclear, and the incidence of adverse impact on fetal or neonatal outcome remains uncertain because there are too few trials with too few patients.

Analgesia, Obstetrical↗
PubMedDate not supplied

Breast reconstruction with a transverse rectus abdominis myocutaneous flap: spectrum of normal and abnormal MR imaging findings.

The authors retrospectively reviewed their clinical database for cases of breast magnetic resonance (MR) imaging performed in women who had undergone breast reconstruction with a transverse rectus abdominis myocutaneous (TRAM) flap. Patient histories, MR imaging results, and, when available, biopsy results were reviewed. During a 4-year period, 24 neobreasts were imaged in 22 women who had undergone TRAM flap reconstruction after mastectomy. In most of the cases (64%), the indication for MR imaging was a palpable abnormality or pain. In four of 24 cases (17%), recurrent breast cancer was detected. These cases consisted of a local chest wall tumor (n = 2), an infiltrating chest wall tumor (n = 1), and axillary nodal recurrence (n = 1). In all four cases, MR imaging demonstrated a suspicious lesion or abnormality. In 11 of 24 cases (46%), benign findings only were demonstrated. These consisted of localized or diffuse skin thickening, fibrosis, fat necrosis, and seroma. In nine of 24 cases (38%), no pathologic abnormality was identified. MR imaging is useful in detection of locally recurrent tumor in patients who have undergone breast reconstruction with a TRAM flap. MR imaging allows differentiation between benign and malignant findings in patients with palpable abnormalities or pain after TRAM flap reconstruction.

Adult↗