Hyperfractionated Cyclophosphamide and Dexamethasone Alone or in Combination with Daratumumab and/or Carfilzomib for the Treatment of Relapsed or Refractory Multiple Myeloma: A Single-Center Retrospective Analysis

BACKGROUND

Hyperfractionated cyclophosphamide and dexamethasone (HyperCd) alone, or with carfilzomib(K) and/or daratumumab(D), represents a potential treatment option when rapid disease control is needed for patients with aggressive presentations of relapsed/refractory multiple myeloma (RRMM).

PATIENTS AND METHODS

This is a single-center, retrospective analysis of adult patients with RRMM who received HyperCd with or without K and/or D between May 1, 2016 and August 1, 2019 at the University of Texas MD Anderson Cancer Center. We here report treatment response and safety outcomes.

RESULTS

Data from 97 patients, 12 with plasma cell leukemia (PCL), were reviewed in this analysis. Patients had had a median of 5 prior lines of therapy and received a median of 1 consecutive cycle of hyperCd-based therapy. The overall response rate (ORR) of all patients was 71.8% (HyperCd 75%, HyperCdK 64.3%, D-HyperCd 73.3%, and D-HyperCdK 76.9%). Median progression-free survival and overall survival among all patients was 4.3 months (HyperCd 3.1 months, HyperCdK 4.5 months, D-HyperCd 3.3 months, and D-HyperCdK 6 months) and 9.0 months (HyperCd 7.4 months, HyperCdK 9.0 months, D-HyperCd 7.5 months, and D-HyperCdK 15.2 months), respectively. Grade 3/4 hematologic toxicities were common, thrombocytopenia being the most frequent at 76%. Notably, 29-41% of patients per treatment group had existing grade 3/4 cytopenias at initiation of hyperCd-based therapy.

CONCLUSION

HyperCd-based regimens provided rapid disease control among MM patients, even when heavily pre-treated and with few remaining treatment options. Grade 3/4 hematologic toxicities were frequent, but manageable with aggressive supportive care.

Abstract P5-12-09: A novel commercial LC-MS/MS assay for tamoxifen (TAM) and its major metabolites

The standard of care for women presenting with early stage- ER-positive breast cancer (BC) following "curative" surgery has been 5 years of TAM. Adjuvant treatment with TAM has changed the natural history of BC, producing a significant reduction in 5- and 10-year recurrence rates; however, because of its adverse effects, many women (approx. 40%) do not complete the recommended 5 years of treatment. Furthermore, since TAM is a pro-drug that needs to be converted to endoxifen to be effective, inter-individual variability in endogenous enzymatic activity (i.e., CYP2D6) can affect endoxifen exposure. Certain drugs (e.g., SSRIs) can also reduce endoxifen exposure by inhibiting CYP2D6.

It is thought that a reduction in endoxifen exposure reduces the efficacy of TAM treatment and increases recurrence risk. However, several recent studies contradict this hypothesis and suggest that a) there is more than one pathway to get to endoxifen, even in the presence of variant CYP2D6; and b) TAM may act through its other metabolites as well, not just endoxifen.

Thus, a CYP2D6 genetic test may overly simplify our understanding of TAM metabolism and prompt clinicians to draw the wrong conclusions. As such, it would seem useful to develop an assay to directly measure each patient's unique serum metabolite levels. The ability to quantitate all the major TAM metabolites would also allow researchers to assess which metabolite level(s) most closely correlates with both recurrence and toxicity, allowing individualized patient dosing. In this regard, results from the BIG1-98 study suggest that some metabolites may be more closely associated with adverse effects than others. This finding could be clinically useful when combined with outcomes data, as poor adherence to TAM may be an unrecognized reason for a number of recurrences that could potentially be avoided by therapeutic drug monitoring (TDM) using a sensitive and specific assay.

With this in mind we developed an HPLC-MS/MS method that quantitatively measures TAM and 6 of its major metabolites in a single assay. This high-throughput assay has been validated to CLIA '88 standards and is run in a high-volume commercial CLIA certified laboratory. Although some of the metabolites had been measured previously by HPLC or LC-MS/MS, this is the first assay that measures all of the major metabolites, including the newly identified norendoxifen.

Results

Serum from 100 women taking TAM at 20 mg/d for > 6 months was tested using this assay, and observed ranges were calculated for this patient cohort. The observed ranges from the analysis are shown in Table 1, along with the lower limit of quantitation (LLOQ) for each analyte.

Table 1. Observed ranges and LLOQs for Tamoxifen and MetaboliteAnalyteLLOQ (ng/mL)Observed Range (ng/mL)Endoxifen0.40.93-43.19Tamoxifen1.512.5-233.1N-Desmethyl Tamoxifen1.53.0-374.04-Hydroxy Tamoxifen0.20.24-5.05N-Desmethyl 4'- Tamoxifen0.41.17-19.954'-Hydroxy Tamoxifen0.40.4-6.33Norendoxifen1.2<7.3

Conclusions

A novel commercial assay has been developed for TAM and its metabolites, which for the first time allows physicians to use a TDM approach for their TAM-treated patients.

Citation Format: Clarke NJ, Weber DM, Goldman SM, Morton JW, Lagier RJ, Birse CE, Bender RA, Waldman FM. A novel commercial LC-MS/MS assay for tamoxifen (TAM) and its major metabolites. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-12-09.

Siltuximab (CNTO 328) with lenalidomide, bortezomib and dexamethasone in newly-diagnosed, previously untreated multiple myeloma: an open-label phase I trial

The safety and efficacy of siltuximab (CNTO 328) was tested in combination with lenalidomide, bortezomib and dexamethasone (RVD) in patients with newly-diagnosed, previously untreated symptomatic multiple myeloma. Fourteen patients were enrolled in the study, eleven of whom qualified to receive therapy. A majority of patients (81.8%) completed the minimal number or more of the four required cycles, while two patients completed only three cycles. The maximum tolerated dose (MTD) of siltuximab with RVD was dose level −1 (siltuximab: 8.3 mg/kg; bortezomib: 1.3 mg/m²; lenalidomide: 25 mg; dexamethasone: 20 mg). Serious adverse events were grade 3 pneumonia and grade 4 thrombocytopenia, and no deaths occurred during the study or with follow-up (median follow-up 28.1 months). An overall response rate, after 3–4 cycles of therapy, of 90.9% (95% confidence interval (CI): 58.7%, 99.8%) (9.1% complete response (95% CI: 0.2%, 41.3%), 45.5% very good partial response (95% CI: 16.7%, 76.6%) and 36.4% partial response (95% CI: 10.9%, 69.2%)) was seen. Two patients withdrew consent, and nine patients (81.8%) opted for autologous stem cell transplantation.

Conservative treatment of scaphoid nonunion in children and adolescents

This is a retrospective study of six children with ununited scaphoid fractures treated conservatively. Their mean age was 12.8 years (9.7 to 16.3). Five had no early treatment. Radiological signs of nonunion were found at a mean of 4.6 months (3 to 7) after injury. Treatment consisted of cast immobilisation until clinical and radiological union. The mean clinical and radiological follow-up was for 67 months (17 to 90). We assessed the symptoms, the range of movement of the wrist and the grip strength to calculate the Modified Mayo Wrist score.

The fracture united in all patients after a mean period of immobilisation of 5.3 months (3 to 7). Five patients were pain free; one had mild pain. All returned to regular activities, and had a range of movement and grip strength within 25% of normal, resulting in an excellent Modified Mayo Wrist score.

Prolonged treatment with cast immobilisation resulted in union of the fracture and an excellent Modified Wrist Score in all patients.

Long-term follow-up on overall survival from the MM-009 and MM-010 phase III trials of lenalidomide plus dexamethasone in patients with relapsed or refractory multiple myeloma

We present a pooled update of two large, multicenter MM-009 and MM-010 placebo-controlled randomized phase III trials that included 704 patients and assessed lenalidomide plus dexamethasone versus dexamethasone plus placebo in patients with relapsed/refractory multiple myeloma (MM). Patients in both studies were randomized to receive 25 mg daily oral lenalidomide or identical placebo, plus 40 mg oral dexamethasone. In this pooled analysis, using data up to unblinding (June 2005 for MM-009 and August 2005 for MM-010), treatment with lenalidomide plus dexamethasone significantly improved overall response (60.6 vs 21.9%, P<0.001), complete response rate (15.0 vs 2.0%, P<0.001), time to progression (median of 13.4 vs 4.6 months, P<0.001) and duration of response (median of 15.8 months vs 7 months, P<0.001) compared with dexamethasone-placebo. At a median follow-up of 48 months for surviving patients, using data up to July 2008, a significant benefit in overall survival (median of 38.0 vs 31.6 months, P=0.045) was retained despite 47.6% of patients who were randomized to dexamethasone-placebo receiving lenalidomide-based treatment after disease progression or study unblinding. Low beta(2)-microglobulin and low bone marrow plasmacytosis were associated with longer survival. In conclusion, these data confirm the significant response and survival benefit with lenalidomide and dexamethasone.

Vorinostat in combination with lenalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma: A phase I study

8586

Background: Novel drug combinations may improve patient outcome in relapsed/refractory multiple myeloma (MM), which remains especially challenging to treat. Preclinical studies suggest that the histone deacetylase inhibitor vorinostat may have synergistic potential when combined with lenalidomide and dexamethasone. This phase I, multicenter, open-label study evaluated vorinostat plus lenalidomide and dexamethasone in patients (pts) with relapsed or refractory MM. The primary objective was to determine the maximum tolerated dose (MTD); other endpoints included overall safety and tolerability, as well as activity of the combination. Methods: Pts aged ≥18 years with relapsed or refractory MM were enrolled sequentially into 1 of 5 dosing levels ( Table ) using a standard 3+3 design for ≤8 cycles. Barring dose-limiting toxicities (DLTs) in the first cycle, dose escalation continued until the MTD was established. Response was assessed, and adverse events (AEs) were recorded. Results: Of 12 pts accrued to date, 11 (92%) have experienced ≥1 AE, with drug-related AEs reported by 6 pts (96% ≤Grade 2). The most common drug-related AEs (each in 4 pts) were fatigue and thrombocytopenia. Serious AEs in 2 pts (17%) were not considered drug-related. No pts discontinued due to AEs, and no DLT has been observed to date. Dose escalation to dose level (DL) 4 was achieved as no DLTs were observed in DLs 1–3. The MTD has not yet been reached. Of 11 pts evaluable for efficacy, best responses include: complete response in 1 pt, partial response in 2 pts, minimal response in 2 pts, and stable disease in 3 pts; 3 pts had progressive disease (PD). Currently, 9 pts remain on treatment, with 3 pts discontinuing treatment due to PD. Conclusions: These preliminary data suggest that vorinostat with lenalidomide and dexamethasone represents a well tolerated and active novel oral combination therapy for the treatment of relapsed/refractory MM.

[Table: see text]

[Table: see text]

Comparison of lenalidomide plus dexamethasone therapy used at first relapse versus later salvage therapy in relapsed or refractory multiple myeloma patients

8594

Background: The benefit of initiating lenalidomide plus dexamethasone at first relapsed was evaluated in this subset analysis from phase III studies in patients with relapsed or refractory multiple myeloma (MM). Methods: Patients from the randomized, multicenter clinical trials MM-009 and MM-010 who had received at least 1 prior treatment and were not resistant to dexamethasone were treated with lenalidomide (25 mg daily for 21 days of every 28 day cycle) plus dexamethasone (40 mg on days 1–4, 9–12, and 17–20 every 28 days for 4 months, then 40 mg on days 1–4 every cycle thereafter until disease progression or intolerance), or dexamethasone (same dose and schedule) plus placebo. Baseline characteristics such as age, sex, ECOG score, and baseline β2-microglobulin levels between the 2 patient groups were similar, however, median time from diagnosis and prior therapy were statistically different. Results: Multivariate analysis showed that more prior therapies is associated with shorter time-to-progression (TTP). Patients who received 1 prior therapy demonstrated a significant improvement in outcomes such as TTP, progression-free survival (PFS), overall response rate (ORR), complete response/very good partial response rate (CR/VGPR), median duration of treatment and overall survival (OS) after first relapse compared with those who received ≥ 2 prior therapies ( Table ). Toxicity, rate of dose reduction, or treatment discontinuation in the cohort with 1 prior therapy did not increase, despite longer treatment. Conclusions: When used at first relapse compared with salvage therapy, lenalidomide plus dexamethasone treatment resulted in significantly prolonged TTP, PFS, and OS, and an improved quality of response. Lenalidomide plus dexamethasone should be considered at an early stage of therapy for patients with MM.

[Table: see text]

[Table: see text]

Early mobilization after flexor tendon repair in children

PURPOSE

Aim of the study was to provide an age-adapted rehabilitation protocol for flexor tendon repairs of children and to evaluate a patient series accordingly.

METHODS

A modified Kessler's technique was used to repair 49 flexor tendon injuries in 39 children. All children had immediate postoperative mobilization according to the protocol that provides specific guidelines for preschoolers, children and teenagers. Range of motion was monitored and the final results were evaluated retrospectively.

RESULTS

All children could be treated successfully according to the protocol with no occurrence of secondary tendon ruptures. Forty finger injuries were evaluated according to the Strickland classification, resulting in a median total active motion of 92.6 % with 29 (72.5 %) excellent results, 8 (20 %) good results, 3 (7.5 %) fair results and no poor result. All 7 thumbs had an excellent result according to the Buck-Gramcko score. There was no significant difference in outcomes between the three age groups.

CONCLUSIONS

The rehabilitation protocol provided in this study allows an age-adapted early mobilization of children's hands after flexor tendon injuries. It respects age-specific limitations in rehabilitation and takes a child's superior healing capacity compared to adults into account. The good results and the very low complication rate observed in the present series suggest that the extra effort of early mobilization may be justified.

[The psychosocial/-sexual development of boys with hypospadias]

Boys with hypospadias can suffer from specific psychological stress as a result of genital surgery and a cosmetically and/or functionally impaired penis. During recent decades intensive efforts have been made to improve the surgical techniques; yet the psychosocial and psychosexual development of children and adolescents after hypospadias surgery has only rarely been investigated. While the results of the few studies are altogether very contradictory, they also indicate that hypospadias patients suffer from specific problems like a negative perception of genital appearance. Therefore, they should be offered long-term follow-ups and psychosocial support until they reach young adulthood. For future research, it is necessary to systematically investigate the boys' quality of life and development in methodologically sound studies.

Autologous stem cell transplantation is safe and feasible in elderly patients with multiple myeloma

Several clinical trials have shown the superiority of autologous stem cell transplantation over conventional dose therapy for patients with multiple myeloma. This treatment, however, is limited to younger patients (<65 years) owing to concerns about toxicity and treatment-related mortality (TRM) in older patients. We treated 26 elderly myeloma patients (>70 years), who received a preparative regimen of melphalan 200 mg/m2 (19 patients), melphalan 180 mg/m2 (six patients) or melphalan 140 mg/m2 (one patient). Twenty-two of the 26 patients were alive after a median follow-up of 25 months (range=8-74). Responses (complete+partial response) were seen in 20 patients (77%), five (19%) of which were complete responses. Median PFS was 24 months, whereas median OS has not been reached. Cumulative incidence of 100-day TRM was 0%. Three-year PFS and OS were 39% (range=16-61) and 65% (range=35-83), respectively. A low serum albumin (<3.5 g/dl) was associated with a shorter PFS (P=0.02). Patients with relapsed disease at transplant, and an interval of >12 months between diagnosis and autotransplant, had a shorter OS (P=0.0004 and 0.04). HDT and autologous transplant is safe and feasible in elderly myeloma patients.

Percutaneous vertebroplasty and/or kyphoplasty is an effective and safe treatment for painful vertebral compression fractures in multiple myeloma (MM)

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Background: Painful vertebral compression fractures are a major source of morbidity in MM. Vertebroplasty involves percutaneous injection of polymethylmethacrylate (PMMA) into a vertebral body, while kyphoplasty involves inflation of a balloon for painful kyphotic deformity prior to stabilization with PMMA. Methods: We assessed safety and efficacy of 100 vertebroplasties and/or kyphoplasties in 81 consecutive myeloma patients between 12/2000 and 2/2005. Results: Median age was 63 (range 32–84), with 29% having prior radiotherapy to the vertebra treated. Contraindications included epidural compression of neural elements and failure to localize a symptomatic level. Kyphoplasty was preferred if kyphosis of > 20 degrees contributed to pain, or if the posterior vertebral cortex was disrupted so that controlled delivery of bone cement was difficult. Vertebroplasty was performed when vertebral collapse was either slight or so severe that insertion of balloon device was not possible, or if patient could not tolerate the general anesthesia required for kyphoplasty. The median preoperative visual analog pain score (0–10) was 8(range 2–10); the median postoperative pain score was 3 (range 0–10) (p < 0.01). There were no significant complications . Conclusions: Percutaneous vertebroplasty and kyphoplasty provided rapid and marked pain relief. These procedures are safe and feasible and represent the treatment of choice in selected MM patients with severe refractory pain due to pathologic compression fractures.

No significant financial relationships to disclose.

Lenalidomide plus high-dose dexamethasone provides improved overall survival compared to high-dose dexamethasone alone for relapsed or refractory multiple myeloma (MM): Results of a North American phase III study (MM-009)

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Background: Lenalidomide is a novel, orally administered, immunomodulatory drug (IMiD) that has single-agent activity against MM and additive effects when combined with dexamethasone (Dex). Methods: In this phase 3, multicenter, double-blind trial, 354 patients (pts)with relapsed or refractory MM were treated with Dex 40 mg daily on days 1–4, 9–12, 17–20 every 28 days and were randomized to receive either lenalidomide (Len) 25 mg daily orally on days 1–21 every 28 days or placebo. Beginning with cycle 5, Dex was reduced to 40 mg daily on days 1–4 only, every 28 days. Patients were stratified with respect to B2M (≤ 2.5 vs. > 2.5 mg/mL), prior stem cell transplant (none vs. ≥ 1), and number of prior regimens (1 vs > 1). The treatment arms were well balanced for prognostic features. Results: The overall response rate was greater with Len-Dex than with Dex-placebo (59.4% vs. 21.1%; p < 0.001). Complete responses were achieved in 12.9% of pts treated with Len-Dex and 0.6% of pts treated with Dex-placebo. The median time to progression (TTP) for pts treated with Len-Dex was 11.1 months compared to 4.7 months for pts treated with Dex-placebo (p < 0.000001). Median overall survival was higher with Len-Dex (not reached) compared to Dex-placebo (24 months) (hazard ratio 1.76, p = .0125). Grade 3–4 neutropenia was more frequent with combination therapy than with Dex-placebo (24% vs. 3.5%), however ≥ grade 3 infections were similar in both groups. Thromboembolic events occurred in 15% of pts treated with Len-Dex and in 3.5% of pts treated with Dex-placebo. Atrial fibrillation occurred in 8 pts and CHF developed in 4 pts treated with Len-Dex. Conclusions: Considering the ease of oral administration, higher response rate, longer time to progression and overall survival benefit, the combination of lenalidomide-dexamethasone may very well represent the treatment of choice for early refractory or relapsing multiple myeloma. The relatively infrequent side effects should not detract from these improvements, but the use of prophylactic antithrombotic therapy should be considered for patients treated with the combination of lenalidomide and dexamethasone.

[Table: see text]

Comparison of lenalidomide in combination with dexamethasone to dexamethasone alone in patients who have received prior thalidomide in relapsed or refractory multiple myeloma

7522

Background: Lenalidomide (len), an analog of thalidomide (thal) is a novel, oral immunomodulatory agent that is effective against multiple myeloma (MM). Two randomized, Phase III trials (MM009 and MM010) have recently demonstrated superior responses and overall survival (OS) for patients (pts) treated with len and dexamethasone (dex) in comparison with dex-placebo. This is a prospective subgroup analysis to assess the impact of prior therapy with thal on the sensitivity of MM to subsequent lenalidomide. Methods: We evaluated 692 pts from both trials (MM009 and MM010). The pts had relapsed/refractory MM, were not refractory to dex and were randomized to receive either len (25 mg daily for 3 weeks (wks) every 4 wks) plus dex (40 mg on days 1–4, 9–12, 17–20 every 4 wks for 4 cycles, then 40 mg on days 1–4 every subsequent cycle) or placebo plus dex. Standard criteria were used to evaluate response and TTP. Results: Pooled data from 692 pts showed superior median TTP (48.1 vs 20.1 wks) and OR (59.2% vs 22.5%) in pts treated with len/dex compared to dex-placebo (p <0.001). Although subgroup analysis of pts with prior thal therapy revealed that pts who received len/dex had significantly improved OR, PR CR and median TTP than pts who received dex-placebo, OR, CR and TTP were highest in len/dex pts not previously treated with thal. Multivariate analysis indicates that after controlling for the treatment factor and baseline disease characteristics, whether or not pt had prior exposure to thal is a marginally significant variable to predict TTP. The risk of deep venous thrombosis and pulmonary embolism in these subgroups will be updated on further analysis. Conclusions: Lenalidomide in combination with dexamethasone is more effective than dexamethasone-placebo regardless of prior thalidomide in relapsed/refractory multiple myeloma.

[Table: see text]

[Table: see text]

Absorbable sutures help minimise patient discomfort and reduce cost in syndactyly release

Many surgeons hesitate to use absorbable suture material to correct syndactylies because they fear that it may induce hypertrophic scarring and compromise the outcome functionally and aesthetically. In a series of 25 syndactylies all sutures were carried out using an absorbable, multifilament polyglactin suture material (Vicryl Rapid, Ethicon). A good result with no functional impairment and a natural looking commissure was achieved in 20 syndactylies. 4 syndactylies had a fair result with no functional impairment but with certain aesthetic deficits such as a slightly hypertrophic scar in 2 and a hyperpigmentation of the skin graft in 2. One patient had a poor result with hypertrophic scars that were responsible for temporary flexion contractures. No patient needed to be reoperated. This case series demonstrates that good results can be achieved using absorbable sutures for syndactyly release. Children and parents appreciated the fact that no stitches had to be removed. Secondary anaesthesia for suture removal with its inherent risks and cost was not necessary.

Laparoscopic cholecystectomy

BACKGROUND

This study was undertaken to determine if patients undergoing laparoscopic cholecystectomy may be discharged home 4 h postoperatively with similar outcomes as patients admitted overnight.

METHODS

Patients were randomized to an outpatient group (OP), consisting of patients who were discharged after a 4-h stay in the Post Anesthesia Care Unit (PACU), or to an inpatient group. Variables compared between the two groups included patient demographics; degree of postoperative pain, nausea, vomiting, and patient satisfaction; amount of pain and nausea medication taken; and number of phone calls, readmissions, or complications. Statistical analysis was performed with students t-test, Fisher's exact test, and Wilcoxon's signed rank and rank sums tests as appropriate.

RESULTS

Eighty patients were initially enrolled. Two were converted and 4 required admission after being randomized to the OP group. Patients in the OP group received more oral pain medication prior to PACU discharge. Degree of pain, number of phone calls, readmission and complication rates, and patient satisfaction were similar between both groups. Of the 4 unexpected admissions, all were identified within the 4-h PACU stay.

CONCLUSIONS

Patients undergoing laparoscopic cholecystectomy who are discharged home 4 h postoperatively will experience the same satisfaction with no increase in complications as patients admitted overnight.

Cytogenetic findings in lymphoplasmacytic lymphoma/Waldenström macroglobulinemia. Chromosomal abnormalities are associated with the polymorphous subtype and an aggressive clinical course

We correlated bone marrow cytogenetic findings with morphologic and immunophenotypic data in 37 patients with lymphoplasmacytic lymphoma (LPL)/Waldenström macroglobulinemia (WM). Each LPL/WM case was classified as lymphoplasmacytoid (n = 18), lymphoplasmacytic (n = 10), or polymorphous (n = 9) using the Kiel criteria. Of 12 cases with chromosomal abnormalities, a single numeric abnormality was present in 4 and a complex karyotype in 8. The most common numeric abnormalities were and -8 in 3 cases each; the most common structural abnormality was del(6q) in 6 cases. Cytogenetic abnormalities were significantly less common in the lymphoplasmacytic and lymphoplasmacytoid groups (5/28 [18%]) compared with the polymorphous group (7/9 [78%]). Clinical follow-up was available for 28 patients for a median of 36 months. Six (67%) of 9 patients with aneuploid tumors, including 4 with polymorphous subtype, subsequently had clinical progression or developed high-grade lymphoma. In contrast, 4 (21%) of 19 patients with diploid tumors, including 1 of polymorphous type, developed clinical progression or high-grade lymphoma. We conclude that abnormal cytogenetic findings in LPL/WM correlate with the polymorphous subtype and poor prognosis.

Effects of helium pneumoperitoneum in pregnant ewes

BACKGROUND

Previous animal studies have demonstrated that a carbon dioxide (CO(2)) pneumoperitoneum in pregnant ewes causes maternal and fetal acidosis, decreased uterine blood flow (UtBF), and fetal hypertension. This study was undertaken to determine whether helium (He) produces these same effects when used as an insufflating gas.

METHODS

Six gravid ewes, at 116 to 120 days gestation, underwent catheterization of the maternal femoral artery and vein and the fetal hindlimb artery and vein, as well as insertion of a uterine artery flow probe. After a 6-day recovery period, the animals were anesthetized; a Hasson trocar was placed; and an He pneumoperitoneum was established (10 mmHg for 30 min followed by 15 mmHg for 30 min). The following parameters were recorded at baseline and at preset time points: maternal and fetal heart rate (HR), blood pressure (BP), arterial blood gasses, maternal end-tidal CO(2) (EtCO2), and UtBF. The percentage of change over time was determined for each variable. The results were compared with results previously obtained in control animals and in animals undergoing CO(2) pneumoperitoneum. Statistical significance was determined by repeated measures analysis of variance (ANOVA).

RESULTS

The following statistically significant changes were found.

CONCLUSIONS

Like CO(2), He used for pneumoperitoneum resulted in decreased UtBF and fetal hypertension because of increased intra-abdominal pressure. Unlike a CO(2), He used for pneumoperitoneum does not cause maternal or fetal acidosis, indicating that the metabolic effects seen with CO(2) are the result of the specific gas used. Therefore, He may be a safer gas than CO(2) to use for laparoscopic procedures in pregnant patients.

Periumbilical necrotizing fasciitis in the newborn

Periumbilical necrotizing fasciitis (PNF) in the newborn is an invasive bacterial infection of the abdominal wall with a fulminant course and a high mortality rate. Little is known about the etiology, risk factors and microbiology of the disease. 18 patients with periumbilical necrotizing fasciitis were included in this retrospective study and were compared with 50 patients with omphalitis over a 6-year period, between 1992 and 1998. This represents the largest reported study. The children with periumbilical necrotizing fasciitis presented at a younger age compared to the omphalitis group (8.4 days vs. 9.1 days) and had a shorter clinical history (1.9 days vs. 2.8 days), suggesting that PNF is not a mere sequela of omphalitis but has distinctive underlying causes. None of our patients in the omphalitis group had a progression of the disease towards necrotizing fasciitis. The microbial spectrum of cultures obtained in patients with PNF consisted of mixed anaerobes and aerobes in 55%, and mixed aerobes in 36% of cases. Early aggressive therapy, including elective endotracheal intubation, immediate surgical debridement of the abdominal wall, antibiotics and supportive measurements resulted in a survival rate of 56%. Far from being satisfactory, this is nevertheless higher than the 12.5% to 45% survival rate quoted in previous publications.

Quantitative nuclear morphometry by image analysis for prediction of recurrence of ductal carcinoma in situ of the breast

Clinical management of ductal carcinoma in situ (DCIS) remains a challenge because significant proportions of patients experience recurrence after conservative surgical treatment. Unfortunately, it is difficult to prospectively identify, using objective criteria, patients who are at high risk of recurrence and might benefit from additional treatment. We conducted a multi-institutional, collaborative case-control study to identify nuclear morphometric features that would be useful for identifying women with DCIS at the highest risk of recurrence. Tissue sections of archival breast tissue of 29 women with recurrent and 73 matched women with nonrecurrent DCIS were stained for DNA, and nuclei in the DCIS lesions were evaluated by image analysis. A clear correlation between mean fractal2_area (FA2) and nuclear grade was observed (P < 0.001), allowing an objective determination of nuclear grade. Several nuclear morphometric features, including mean and variance of variation of radius, mean area, mean and variance of frequency of high boundary harmonics (FQH), and variance in sphericity, were found to be useful in discriminating recurrent from nonrecurrent DCIS subjects. However, the nuclear features associated with recurrence differed between high- and low-grade lesions. For lesions with high FA2 (nuclear grade 3), mean variation of radius, mean FQH, and mean area alone yielded recurrence odds ratios of 4.55 [95% confidence interval (CI) 0.45-45.96], 3.86 (95% CI, 0.88-16.98), 2.90 (95% CI, 0.31-27.2), respectively. Using a summed feature model, high-FA2 lesions showing three poor prognostic features had an odds ratio of 15.63 (95% CI, 1.22-200), compared with those with zero or one poor prognostic feature. Lesions with low mean FA2 (nuclear grade 1 or 2) showing high variances in sphericity and FQH had an odds ratio of 7.71 (95% CI, 1.77-33.60). Addition of other features did not enhance the odds ratio or its significance. These results suggest that nuclear image analysis of DCIS lesions may provide an adjunctive tool to conventional pathological analysis, both for the objective assessment of nuclear grade and for the identification of features that predict patient outcome.

Quadratic Gabor filters for object detection

We present a new class of quadratic filters that are capable of creating spherical, elliptical, hyperbolic and linear decision surfaces which result in better detection and classification capabilities than the linear decision surfaces obtained from correlation filters. Each filter comprises of a number of separately designed linear basis filters. These filters are linearly combined into several macro filters; the output from these macro filters are passed through a magnitude square operation and are then linearly combined using real weights to achieve the quadratic decision surface. For detection, the creation of macro filters (linear combinations of multiple single filters) allows for a substantial computational saving by reducing the number of correlation operations required. In this work, we consider the use of Gabor basis filters; the Gabor filter parameters are separately optimized. The fusion parameters to combine the Gabor filter outputs are optimized using an extended piecewise quadratic neural network (E-PQNN). We demonstrate methods for selecting the number of macro Gabor filters, the filter parameters and the linear and nonlinear combination coefficients. We present preliminary results obtained for an infrared (IR) vehicle detection problem.

Color Doppler sonography in the diagnosis of acute scrotum in boys

Evaluation of acute painful scrotum is difficult and imaging studies have been reported to be unreliable in detecting testicular torsion. In order to assess the value of color Doppler sonography in acute scrotal disease, the authors reviewed 65 consecutive boys, ranging in age from 1 to 16 years. The study demonstrated absent or diminished flow signals in 11 patients. All of them had a surgical intervention, and in 8 of them, a testicular torsion was confirmed. 54 boys had a symmetrical or increased flow signal on the affected side. Just 5 boys among this group underwent surgical exploration. On follow up, none of the 54 patients with good flow signals proved to have a testicular torsion. Sonography and color Doppler sonography helped to differentiate epididymitis and torsion of a testicular appendage as a basis for further investigations and correct conservative therapy. In detecting a testicular torsion, color Doppler sonography yielded a positive predictive value of 73%, a sensitivity of 100% and a negative predictive value of 100%. We therefore conclude, that Doppler sonography can reliably rule out testicular torsion so that routine scrotal exploration in cases of acute scrotum is no longer necessary. By reducing the number of emergency operations and hospitalization days, color Doppler sonography can cut down the total cost of managing acute painful scrotum in boys.

Duodenojejunal atresia with apple peel configuration of the ileum and absent superior mesenteric artery: observations on pathogenesis

A child with loss of the third and fourth part of the duodenum and of the proximal jejunum was found to have an apple peel configuration of the remaining small bowel. The complete absence of branches from the superior mesenteric artery impaired the blood supply of the distal duodenum. An annular pancreas was found in this patient with Down's syndrome. This anomaly may have impaired the flow through the pancreaticoduodenal arcade, which would normally compensate for the distal vascular occlusion. According to current understanding, duodenal atresia is a primary malformation. The current case suggests, however, that in rare circumstances vascular accidents may be the underlying cause for duodenal atresia.

Brain: gadolinium-enhanced fast fluid-attenuated inversion-recovery MR imaging

PURPOSE

To determine the clinical utility of gadolinium-enhanced fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging of the brain by comparing results with those at gadolinium-enhanced T1-weighted MR imaging with magnetization transfer (MT) saturation.

MATERIALS AND METHODS

In 105 consecutive patients referred for gadolinium-enhanced brain imaging, FLAIR and T1-weighted MR imaging with MT saturation were performed before and after administration of gadopentetate dimeglumine (0.1 mmol per kilogram of body weight). Pre- and postcontrast images were evaluated to determine the presence of abnormal contrast enhancement and whether enhancement was more conspicuous with the FLAIR or T1-weighted sequences.

RESULTS

Thirty-nine studies showed intracranial contrast enhancement. Postcontrast T1-weighted images with MT saturation showed superior enhancement in 14 studies, whereas postcontrast fast FLAIR images showed superior enhancement in 15 studies. Four cases demonstrated approximately equal contrast enhancement with both sequences. Six cases showed some areas of enhancement better with T1-weighted imaging with MT saturation and other areas better with postcontrast fast FLAIR imaging. Superficial enhancement was typically better seen with postcontrast fast FLAIR imaging.

CONCLUSION

Fast FLAIR images have noticeable T1 contrast making gadolinium-induced enhancement visible. Gadolinium enhancement in lesions that are hyperintense on precontrast FLAIR images, such as intraparenchymal tumors, may be better seen on T1-weighted images than on postcontrast fast FLAIR images. However, postcontrast fast FLAIR images may be useful for detecting superficial abnormalities, such as meningeal disease, because they do not demonstrate contrast enhancement of vessels with slow flow as do T1-weighted images.

Intraoperative, real-time, functional MRI

Functional MRI (fMRI) methods have been demonstrated to noninvasively identify motor-sensory, visual, and other areas of eloquent cortex for guiding surgical intervention. Typically, fMRI data are acquired preoperatively during a conventional surgical planning MRI examination. Unlike direct cortical stimulation at the time of surgery, however, preoperative fMRI methods do not account for the potential movement of tissues (relative to the time of functional imaging) that may occur in the surgical suite as a direct result of the intervention. Recently, an MRI device has been demonstrated for use in the surgical suite that has the potential to reduce the extent of cortical exposure required for the intervention. However, the invasive requirements of cortical mapping may supersede the invasive requirements of the surgical intervention itself. Consequently, we demonstrate here a modification to the intraoperative MRI device that facilitates a noninvasive, real-time, functional MR examination in the surgical suite.

Prognostic features of asymptomatic multiple myeloma

Approximately 20% of patients with multiple myeloma are recognized by chance without significant symptoms. In order to prevent morbidity with timely therapy, reliable criteria are needed that distinguish those likely to show early or late disease progression. Multiple clinical features were assessed in 101 consecutive, asymptomatic and previously untreated patients. Patients with one or more lytic bone lesions were excluded because this feature had been found previously to be associated with early progression. Multivariate analysis indicated that only serum myeloma globulin > 30 g/l, IgA protein type, and Bence Jones protein excretion > 50 mg/d remained as significant independent variables. The presence of two or more of these features signified high-risk disease with early progression (median 17 months) whereas the absence of any adverse variable was associated with prolonged stability (median 95 months) (P < 0.01). Magnetic resonance (MR) imaging of the spine was useful only in patients with one adverse feature and an intermediate time to progression (median 39 months). An abnormal pattern (40% of patients) helped to distinguish patients with an imminent complication from those with more stable disease. Because a serious complication (fracture, hypercalcaemia) occurred in 35% of patients with early disease progression, chemotherapy seems justified for selected patients with asymptomatic disease at diagnosis. The remaining patients were at such low risk for progression (median 6 years) that they may be followed safely at long intervals without treatment.

Factors related to enrollment in the breast cancer prevention trial at a comprehensive cancer center during the first year of recruitment

BACKGROUND

Using an a priori theoretic model of behavior change, factors predicting enrollment in a randomized chemoprevention trial during the first year of recruitment were assessed prospectively.

METHODS

Eligible participants were asked to complete a 90-item semistructured questionnaire after attendance at an informational meeting. Components of the Health Belief Model (including perceived susceptibility, perceived severity, perceived benefits and barriers, cues to action, and health motivation), health status, preventive health behaviors, and social influence were assessed in relation to enrollment.

RESULTS

Overall, 331 women attended one of the meetings, and 73% completed a questionnaire; 45% enrolled on the trial and 55% did not. In bivariate analyses, all but one of the perceived barriers were associated negatively with enrollment; however, items assessing perceived susceptibility, perceived severity, and perceived benefits were not. Nonparticipants also were more likely to be over 49 years of age, to be currently or to have been on estrogen replacement therapy, and to have had hot flashes. In logistic regression analysis, not being able to take estrogen replacement therapy was the strongest predictor of nonparticipation (odds ratio [OR], 12.13, 95% confidence interval [CI], 3.63, 40.60). Other factors associated with nonparticipation were concern about side effects of tamoxifen (OR, 5.06; CI, 2.37, 10.80); the possibility of getting a placebo (OR, 7.75; CI, 1.51, 39.67); the costs associated with the trial (OR, 3.21; CI, 1.12, 9.24); and absence of concern that significant others would be reassured if the respondent was taking tamoxifen (OR, 2.58; CI, 1.04, 6.41).

CONCLUSIONS

These findings support the view that recruitment efforts for chemoprevention trials should address barriers specific to their circumstances. In addition, increasing the support available from personal social networks may enhance recruitment to chemoprevention trials for breast cancer.

Prognostic significance of magnetic resonance imaging in patients with asymptomatic multiple myeloma

PURPOSE

To assess the prognostic significance of magnetic resonance (MR) imaging in patients with newly diagnosed asymptomatic multiple myeloma.

PATIENTS AND METHODS

Thirty-eight consecutive patients with asymptomatic myeloma of low tumor mass and negative skeletal surveys underwent MR imaging of the thoracic and lumbosacral spine. The presence and patterns of marrow involvement were correlated with standard laboratory parameters and time to disease progression.

RESULTS

Nineteen patients (50%) had evidence of marrow involvement at spinal MR imaging. MR patterns of marrow involvement were classified as diffuse (five patients), variegated (nine), and focal (five). Patients with abnormal MR imaging studies required therapy after a median of 16 months, versus 43 months for those with normal MR studies (P < .01).

CONCLUSION

Abnormal marrow patterns were present in half of patients with asymptomatic myeloma. An abnormal MR study of the spine identified asymptomatic patients who were likely to require treatment earlier than those with a normal MR study. A normal MR pattern provided additional justification to defer institution of chemotherapy. However, MR imaging remains an investigational tool to stage patients with multiple myeloma until more data are accumulated.

Regression of gastric lymphoma of mucosa-associated lymphoid tissue with antibiotic therapy for Helicobacter pylori

Regression of low-grade B cell gastric lymphoma of mucosa-associated lymphoid tissue after eradication of Helicobacter pylori with antibiotic therapy was recently shown in a small number of patients with low-volume tumors. A patient with a > 10 cm nodular gastric mucosa-associated lymphoid tissue lymphoma that caused hematemesis and weight loss is described. Antibiotic therapy of H. pylori resulted in full clinical recovery and resolution of the mass lesion and morphological features of lymphoma on routine histological examination. However, monotypic immunostaining of plasma cells persisted in a separate and grossly normal-appearing region of the stomach. Antibiotic therapy may be of benefit in patients with mucosa-associated lymphoid tissue lymphoma with mass lesions and significant signs and symptoms, but periodic search for residual lymphoma is needed.

Intensive sequential therapy for VAD-resistant multiple myeloma

Few effective regimens are available for patients with advanced multiple myeloma resistant to alkylating agents and VAD. We treated 65 patients with advanced and refractory multiple myeloma with the combination of cyclophosphamide (3.0 gm/m2) and etoposide (900 mg/m2) followed by GM-CSF at a daily dose of 0.125 mg/m2. Thirty-five percent of patients responded with a 6% mortality rate. After a median of 2 months, 16 patients received myeloablative treatment supported by autologous bone marrow or blood stem cells. Four of ten previously resistant patients responded so that the overall response rate was 42%. The median survival for all patients was 10 months and the median remission was 8 months. The median survival for patients with both low serum lactate dehydrogenase and B2 microglobulin, or for those who received myeloablative treatment, was projected at 18 months. Our combination of cyclophosphamide and etoposide provided an effective rescue treatment for many patients with advanced multiple myeloma resistant to conventional therapies. This program allowed early blood stem cell collection in support of subsequent myeloablative therapy for selected patients.

2Chlorodeoxyadenosine therapy of patients with Waldenström macroglobulinemia previously treated with fludarabine

BACKGROUND

Fludarabine monophosphate and 2Chlorodeoxyadenosine are nucleoside analogues with activity against Waldenström macroglobulinemia. However, it is not clear whether prior exposure to one analogue precludes response to the other compound.

PATIENTS AND METHODS

Fourteen patients with Waldenström's macroglobulinemia and prior exposure to fludarabine were treated with two courses of 2chlorodeoxyadenosine.

RESULTS

Three out of four patients that had previously responded to fludarabine and were relapsing from unmaintained remission, achieved a partial response with 2chlorodeoxyadenosine therapy. However, only one out of 10 patients with disease resistant to fludarabine responded to 2chlorodeoxyadenosine.

CONCLUSIONS

2chlorodeoxyadenosine may be effective in patients with Waldenström macroglobulinemia sensitive to fludarabine. However, this compound has limited activity for patients with disease resistant to fludarabine.

MR angiography of the pelvis with variable velocity encoding and a phased-array coil

PURPOSE

To evaluate the feasibility of an automated variable velocity-encoding sequence and improve the signal-to-noise ratio (S/N) on magnetic resonance angiograms with use of phase contrast and a pelvic phased-array coil.

MATERIALS AND METHODS

Three cardiac-gated, two-dimensional (2D), phase-contrast (PC) sequences were evaluated in 10 healthy subjects. A 2D gated PC sequence with variable velocity encoding (velocity-optimized phase contrast [VOPC]) was compared with gated 2D PC sequences performed with high or low constant velocity encoding. S/Ns in VOPC images obtained with a pelvic phased-array coil were compared with those in VOPC images obtained with a body coil.

RESULTS

Two blinded readers preferred VOPC for simultaneous display of large and small blood vessels in one acquisition compared with constant low (P = .0105) and high (P = .0067) velocity encoding and for overall image interpretation. VOPC images obtained with the pelvic coil had a 68%-100% better S/N compared with those obtained with the body coil.

CONCLUSION

Use of a phased-array coil and variable velocity encoding improves depiction of segmental vascular anatomic structures of the pelvis.

MR angiography using velocity-selective preparation pulses and segmented gradient-echo acquisition

We describe a cardiac-gated MR angiographic imaging method that employs velocity-selective preparation (VSP) pulses in conjunction with segmented gradient-echo acquisition and subtraction to produce images that, ideally, contain no signal from stationary tissues and display vessels with a signal intensity that is dependent on the velocity of the blood in the vessels. The novel features of this method are a) it acquires several phase-encoding values/application of a single VSP pulse, b) it uses subtraction to eliminate signal that is not sufficiently suppressed by the VSP pulses, and c) it uses VSP pulses that are synchronized with the cardiac cycle so it can be used to produce ghost-free images of pulsatile blood. An advantage of this sequence is that it detects a signal that, after preparation, is relatively unaffected by changes in blood velocity. This leads to a large signal-to-noise ratio for all the phase-encoding values, a reduction of ghosting artifacts, and the ability to visualize blood that is in motion for only a short time during the cardiac cycle. Because the signal is prepared during peak flow, venous signal can be suppressed by making the sequence sensitive to high velocities. An additional advantage of this sequence is that it permits sampling with a short TE because the velocity-encoding gradient can be applied in a preparatory interval. Signal loss that results from dephasing during the longer TE preparation interval can be reduced or eliminated by allowing the dephased spins to flow out of the region of complex flow, and perhaps out of the field-of-view, by introducing a delay between the finish of the VSP pulse and the beginning of data acquisition.

Generalized matched filtering for time-resolved MR angiography of pulsatile flow

Generating flow-specific images (arteriograms, venograms) with optimal signal-to-noise ratios for time-resolved MR angiography is a conditional maximum problem, and its solutions are generalized matched filters. We have investigated six matched filters, corresponding to all possible combinations of three flow suppression conditions and two signal-to-noise ratio maximization procedures. Four of these matched filters correspond to previously described methods: the subtractive matched filter, the standard deviation, the global venous eigenimage and the global arterial eigenimage. The two others are referred to here as the local venous eigenimage and the local arterial eigenimage. These six matched filters have been applied to 2D time-resolved phase contrast angiographic data. The local arterial eigenimage is found to be the most effective in suppressing undesired venous flow and preserving desired arterial flow.

Preoperative evaluation of giant cell tumors of the radius with magnetic resonance angiography

We report three clinical cases of giant cell tumor of the distal radius in which reconstructions were performed with vascularized fibular grafts. Magnetic resonance angiography, a newer and noninvasive technique, was used in addition to preoperative magnetic resonance imaging. All patients had routine digital subtraction arteriography, with which magnetic resonance angiography compared favorably, demonstrating the carpal arch anatomy and other major vessels at the tumor site. In two patients the trifurcation vessels of both legs were also studied with magnetic resonance angiography before fibular harvest. In one case, the fibula graft was successfully harvested on the basis of the magnetic resonance angiographic findings. In the other case, digital subtraction arteriography had been done to evaluate suspected peripheral vascular disease. In that case magnetic resonance angiography correlated well with the digital subtraction arteriographic study, showing bilateral anterior tibial artery occlusions and patent posterior tibial and peroneal arteries. Magnetic resonance angiography has the potential to replace conventional angiography in preoperative evaluation of upper-extremity tumors.

Combined MRI and MRA for limb salvage planning

Magnetic resonance angiography (MRA) was performed in two patients with primary bone neoplasms being staged for differing types of limb-salvage procedures. A gated two-dimensional (2D) phase contrast MRA sequence that is capable of variable velocity encoding throughout the cardiac cycle was used to acquire the MRA images. The resulting cardiac phase images were added with a matched filter algorithm to create a single high signal-to-noise ratio image. An SE MR image in the same plane and field of view was then added to the MRA image. This displayed the relationship of vascular and stationary tissues within a composite picture: a "2D combined angiographic-stationary tissue" image. The anatomy represented gave information equivalent to conventional angiography. While this technique is not an ideal 3D rendering, it is easier to use. Along with other SE sequences acquired as needed for staging, it provides a complete preoperative evaluation of a tumor bed or donor site for a vascularized graft harvest.

Quantitative velocity images from thick slab 2D phase contrast

Thick slab two-dimensional phase contrast (2D PC) angiography provides a large amount of anatomical information in a short acquisition time. Quantitative velocity information is, however, destroyed by the necessary projection dephasing gradient. We present a 2D PC acquisition scheme which retains quantitative velocity information in a thick slab acquisition. A thick slab acquisition produces an image which is a projection through an entire vessel. Accurate velocity measurements must take into account the intravoxel phase cancellation caused by a distribution of velocities within the vessel. In addition to the description of the data acquisition scheme, we outline a method for determining the mean velocity within a vessel having a laminar flow distribution. It is shown that without the consideration for intravoxel phase cancellation, the mean velocity measurement from thick slab images overestimates the true mean velocity by 10%.

Peripheral MR angiography with variable velocity encoding. Work in progress

An electrocardiographically triggered two-dimensional phase-contrast (PC) magnetic resonance angiographic pulse sequence was developed in which velocity encoding (VENC) was varied throughout an acquisition in response to changes in blood velocity during the cardiac cycle. This was done to better capture signal in the peripheral vasculature, where pulsatile flow degrades images. After reconstruction, a matched filter addition technique was applied to the cardiac phase images to obtain a single high-quality static image. Images were obtained of six healthy volunteers--with and without varying VENC--and contrast-to-noise ratio (C/N) calculations were performed for the added images. Varying VENC significantly improved vascular signal from small and large vessels (P less than .02), but it was most helpful for small vessels, for which the C/N increased by as much as 260% (average increase, 149%). These preliminary findings suggest that variable VENC can enhance the signal from the small and large peripheral blood vessels in cardiac-gated PC acquisitions.

A data adaptive reprojection technique for MR angiography

Inability to detect vessel overlap and vascular loops can compromise the interpretation of magnetic resonance angiograms. A data-adaptive ray tracing (DART) technique was developed to produce the appropriate variations in signal intensity at points of vessel overlap in order to simulate the standard angiographic representation of vessels. In this technique a threshold is utilized to identify vessels in the image slices composing a 3D angiographic data set. A mask, which defines regions slightly larger than the vessel boundaries, is obtained by blurring the vessel information surviving the initial threshold. This mask is converted to binary form prior to multiplication by the original angiographic data set. Following application of an additional threshold to the masked data, line integrals through the regions defined by the mask are performed to obtain an angiographic signal proportional to the integrated vessel signal as in conventional angiography. This integrated reprojection is then uniquely combined with a maximum intensity pixel (MIP) reprojection to produce the final DART image. The application of the DART technique to 2D time-of-flight and 3D phase-contrast angiograms successfully enabled the identification of over-lapping vessels and vascular loops. DART was also found to produce less vessel narrowing than the MIP technique.